Organic Wastes

A study was conducted for 21 days of pre-composting and 49 days of vermicomposting under laboratory condition by using earthworm (Lumbricus rubellus). Three different combination of treatments were prepared with eight replicates for each treatment, namely cow dung : kitchen waste in 30:70 ratio (T1), cow dung : coffee grounds in 30:70 ratio (T2), and cow dung : kitchen waste : coffee grounds in 30:35:35 ratio (T3) were used for this study. By comparing the numbers and weights of
earthworms in each treatment, only T2 indicated significant difference (p< 0.05) which it can be concluded that coffee grounds influenced the development of earthworms’ population. Nutrient elements in the vermicompost from each treatment were measured and relatively showed high percentage in C, N, P, K, Ca, and Na. Contrast for Mg and other
micronutrient elements, the result showed small percentage in Zn, Cu, Fe, Mn, B, and crude fat. The data reveals that coffee grounds can be decomposed through vermicomposting by using Lumbricus rubellus into value-added material. With the correct ratio and suitable condition of kitchen waste, coffee grounds can also be used as stabilizer in vermicomposting.

Organic matter is an important chemical parameter to check the stability and maturity of compost prepared by municipal solid waste. This study was designed to determine the percentage of organic matter that must be below 30% after 3 months of composting process. The higher value of organic matter indicates the less stable and immature compost. The organic waste was treated with inoculum and it was concluded that the windrows give stable and mature compost in terms of organic matter analysis because the results showed the organic matter content 30 and below in all windrows.

Zat pewarna baik alami maupun sintetik dari industri tekstil seperti industri batik adalah salah satu sumber pencemar air yang berbahaya. Zat pewarna ini dapat menurunkan kualitas air, sehingga konsentrasi zat pewarna dalam perairan harus sesuai dengan aturan yang berlaku. Beberapa metode yang dapat digunakan untuk menurunkan kadar zat pewarna di air limbah antara lain adsorpsi, fotodegradasi, dan ozonolisis. Naskah ini mengkaji perkembangan material berbasis MOF sebagai kandidat katalis dalam fotodegradasi zat pewarna dalam air limbah. Penggunaan material berbasis MOF untuk fotokatalis masih relatif baru namun memiliki potensi besar untuk degradasi air limbah. Material ini dapat dikembangkan dari mineral alam yang banyak tersedia di Indonesia. Kajian ini dilakukan melalui tinjauan pustaka dimana artikel-artikel yang digunakan sebagai literatur utama diperoleh dari jurnal internasional berbahasa Inggris dengan tahun terbit mulai tahun 2000. Berdasarkan hasil kajian, MOF dapat dijadikan sebagai kandidat fotokatalis dari berbagai zat pewarna seperti MB (metil biru), MO (metil orange), MV (metil violet), RhB (rhodamine biru), dll dengan hasil efisiensi degradasi yang bervariasi hingga 100%. Namun, penggunaan fotokatalis MOF dalam sampel air limbah nyata belum pernah dilaporkan. Selain itu, meskipun fotokatalis berbasis MOF dapat diperoleh dari berbagai metode seperti solvotermal (hidrotermal), larutan, dan/atau metode gel, kajian tentang produksi MOF yang ramah lingkungan skala massal tetap diperlukan.

The energy demand of the world is expected to reach 739 quadrillions BTU in 2040, which therefore demand for exploring more alternative source of renewable energy. Waste biomass though vast in reserve for generating renewable energy has its own downside. High moisture, fibrous nature, high bulk volume, hydrophilic nature and low calorific value are some of the inferior quality of waste biomass which creates bottleneck for easy renewable energy generation. Pre-treatment of biomass to overcome these challenges has created a new research interest. Among the treatment options available, the hydrothermal carbonization (HTC) method, which can process wet waste has become the most preferred choice among researchers recently. The HTC eliminates energy-intensive pre-drying process needed for other treatment methods such as pyrolysis, dry torrefaction and incineration. Through this article, we attempt to provide a detailed review of how renewable biomass can be effectively used to produce renewable energy by improving their inherent inferior characteristics. The review also highlights bottlenecks that constrain the deployment of renewable energy using HTC methods. The scope of further research direction is well identified in this review. The paper also present recent advancements which are filling the knowledge gap of HTC technology that were there earlier. Critical analysis of microwave assisted HTC and conventional heated HTC is also presented in this review. The analysis in this paper reveals that biomass is a valuable resource, and should be explored to take advantage of its renewable energy generation potential. The HTC method of biomass upgradation improves transport, storage and fuel characteristics by improving grind-ability, pellets durability, hydrophobicity, energy density, combustion behaviour and calorific value, and also helps in improving the environmental performance of solid fuel produced. Despite the fact that the technology is in the early stage of development and there still exist knowledge gap and shortcomings, the vast literature reviewed suggests that it has a potential of being future technology. Therefore, it needs further investigation which should fill existing shortcoming of the technology.

Anaerobic digestion is a technique of treatment and valorization of various organic wastes with several advantages: reduction of environmental harmful effects, production of biogas and organic fertilizer. The present work is an experimental study of the co-digestion of mixture of several organic wastes by using 6 units of metallic digesters. It follows from experimentation results that the amount of produced biogas changes with pH of the co-substrate and the digester temperature. Comparison of the amounts of produced biogas from all digesters allows us inferring that the zebu manure and rice straw mixture substrate is the best one. By means of experimental data curve fitting, a model predicting the amount of produced biogas was suggested as a function of the temperature and pH of the co-substrate. The goodness of the fit was statistically highlighted by computing the coefficient of determination.

En Colombia, según cifras del Ministerio de Ambiente, Vivienda y Desarrollo Territorial, se generan 27.300ton/día de basura de los cuales el 65% son residuos sólidos orgánicos, equivalentes a 17.745 ton/día, los cuales van a los rellenos sanitarios en la mayoría de los municipios Colombianos. Esto incrementa sustancialmente la emisión del metano como gas que provoca el efecto invernadero.
La codigestión de residuos orgánicos de diferente fuente ha resultado un proceso exitoso tanto en condiciones termofílicas como mesofílicas, y por esto, se han construido plantas de biogás centralizadas, alimentadas con diferentes residuos orgánicos para trabajar en codigestión, en diferentes países de Europa y Asia.
Se han aplicado tecnologías europeas y asiáticas en Colombia y otros países de Latinoamérica, pero no se ha investigado rigurosamente la relación de la temperatura que simule las condiciones de diferentes pisos térmicos del relieve colombiano en los que pueden aplicarse, para obtener una mayor producción de biogás en la codigestión de residuos ganaderos con residuos vegetales.
En este proyecto se pretendió resolver la pregunta de la incidencia de la temperatura en la degradación del vástago de plátano, hasta convertirla en metano y dióxido de carbono, por codigestión anaerobia con rumen como residuo bovino e inóculo anaerobio. Tales residuos se mezclaron para obtener 4 relaciones de sustrato. Se llevaron a bioreactores de 750mL, haciendo un arreglo factorial con 3 temperaturas (25, 35 y 45°C) por triplicado. Se analizaron condiciones iniciales y finales de parámetros fisicoquímicos, midiéndose el metano (gas efecto invernadero) contenido en cada uno de los bioreactores por cromatografía de gases (CG-FID) durante 40 días.
Mediante el programa Statgraphics Centurion XVI se ajustaron los valores de producción de metano a una ecuación polinomial de grado 3 en función de la temperatura y la relación de biomasa (porcentaje de vástago de plátano). La temperatura a la cual se dio la mayor producción de metano, fue a 45°C, seguida de 35°C y 25°C, con valores de 1250,1; 1018,2 y 885,7mL respectivamente. Lo cual indica que un clima templado cálido donde se tenga producción de plátano y ganado, los residuos generados de vástago de plátano pueden aprovecharse para generar energía en forma de metano mediante codigestión anaerobia con rumen bovino.
También se realizó un análisis multivariado concluyéndose estadísticamente que existe una interacción significativa entre la temperatura y la relación de biomasa con respecto a la producción de metano.  Es decir, que la producción de metano depende de la temperatura entre los rangos mesofílico y termofílico desde 25°C hasta 45°C, para cualquiera de las tres relaciones de biomasa de 0, 33 y 66% de vástago en las que se detectó presencia de metano.

Pemerintah Kota Bandung saat ini telah berupaya dalam menangani permasalahan sampah dengan membuat program-program inovasi, salah satunya adalah program waste to food. Program ini bertujuan untuk mengolah sampah organik yang ada, kemudian hasil dari pengolahan tersebut dapat diintegrasikan dengan sektor pertanian dan peternakan untuk mendapat nilai manfaat lebih. TPS Cijambe saat ini berfungsi sebagai tempat penampungan sampah sementara sebelum diangkut menuju TPA Sarimukti untuk Kelurahan Pasirendah, namun kondisinya masih perlu perbaikan agar dapat menjadi TPS yang layak. Tidak adanya alur penanganan sampah yang jelas di TPS Cijambe membuat sampah menjadi tercampur dan terjadi penumpukan sampah yang melebihi kapasitas TPS. Hal ini membuat kondisi TPS Cijambe tidak beraturan, baik dari segi tata letak sampah maupun bangunan, sehingga dibutuhkan suatu perbaikan dan pengembangan sistem pengolahan sampah yang baik agar dapat mendukung program-program yang telah direncanakan oleh pemerintah. TPS Cijambe memiliki potensi lahan yang luas dan sangat memungkinkan untuk dilakukan pengembangan daerah layanannya. Sampah yang akan diolah memiliki komposisi, 57,5 % organik, 14,8 % B3RT, 9,6% plastik 5,6 % kertas, 3,6% tekstil, 1,5 % karet, 1,4% kaca, 1,2% logam dan 4,4 % residu. Timbulan sampah yang masuk ke TPS berdasarkan hasil rencana pengembangan sebesar 0,423 kg/orang/hari pada tahun 2020 dengan densitas 0.199 ton/m3. Melalui proyeksi dengan skenario moderat, proyeksi timbulan sampah yang masuk ke TPS pada tahun 2030 sebesar 13,941 ton/hari atau sebesar 69,71 m3/hari. Pengelolaan sampah dilakukan dengan menerima sampah yang kemudian dilakukan pemilahan secara manual dengan bantuan conveyor belt. Penanganan sampah sisa makanan akan dilakukan dengan menggunakan fasilitas Black Soldier Fly (BSF) dengan tujuan untuk mendapatkan nilai lebih dari kompos dan larva BSF yang dihasilkannya. Jumlah kompos sebesar 2.501, 8 kg/hari dan larva kering sebanyak 275, 42 kg/hari. Pengelolaan sampah anorganik akan disimpan pada penampungan sampah anorganik sesuai dengan jenisnya. Sampah residu yang ada akan disimpan pada kontainer untuk diangkut. Sampah plastik, kertas, logam dan kaca akan diangkut ke Bank Sampah. Sampah residu akan diangkut ke TPA Sarimukti.

Introduction This paper reports the influence of vermi-composts prepared from cow dung and house hold waste on the growth and flowering of marigold crop. A total of seven potting media were prepared containing soil, cow dung vermicompost and cow dung ? house hold waste vermi-compost. The fertility status of soil and vermicomposts was quantified. In these media, growth and flowering of marigold plant seedlings was studied for 60 days. Results The results showed that the vermicomposting process converted the cow dung and household waste into a highly stabilized product having C:N ratio\20.0. The NPK content of vermicomposts was higher than soil. The plant grown in vermicompost-containing potting media had 2.3 times more plant height than control. Results showed that the addition of vermicompost, in appropriate quantities, to potting media has significantly positive effects on growth and flowering of marigold seedlings including plant bio-mass, plant height, number of buds and flowers. Conclusions It was concluded that addition of vermi-compost, in appropriate quantities, to potting media has synergistic effects on growth and yield of marigold.

Background King oyster mushroom (Pleurotus eryngii) contains many medicinal and nutritional values, excellent flavors, and a long shelf life. Cultivation of edible mushroom on agricultural and lignocellulosic waste like wheat straw and wood chips gives a high yield and nutritional contains. In present study, the effects of lignocellulosic organic wastes, such as wood chips, wheat and barley straw, sugar beet pulp, sawdust and maize stem residue as basal substrate and wheat and rice bran, soybean powder and their combinations were used as supplements. We analyzed mushroom production gap, mushroom fresh weight, moisture content, dry matter, and protein content of fruit body traits. A factorial experiment was conducted in a completely randomized design with four replications. Results Supplementation of wheat bran in wood chips increased the mushroom production gap and dry matter content. The highest mushroom fresh weight and moisture content were achieved on barley straw and sugar beet pulp substrate complemented with rice bran, respectively. In addition, protein content ranged from 4.64 % (barley straw ? wheat bran and wood chips ? soybean powder ? rice bran treatments) to 13.66 % (wheat straw ? wheat bran ? soybean powder treatment). Conclusions The quality of P. eryngii was significantly affected by substrate ingredients. The type of substrate as well as the type and quantity of supplement appeared to have a substantial effect on prolonging the delayed-release nutrients.

A study was carried out to determine the effects of organic, inorganic fertilizers and integrated soil fertility management and irrigation levels (1,000, 750 and 500 ml per planting station) on coffee growth. There were no significant differences (p [ 0.05) in girth, number of leaves and number of primaries due to the different soil fertility management options. Significant differences (p \ 0.05) due to soil nutrient sources were observed in coffee height where inorganic fertilizer treatment resulted in tallest coffee plants (47.4 cm) and integrated soil fertility having the shortest coffee trees (42.8 cm) after 1 year. The highest irrigation level of 1,000 ml had the tallest plants with thickest stems while the lowest level had the shortest and thinnest plants (p \ 0.05). No significant differences were observed in the number of leaves and number of primaries due to irrigation treatments. Results indicate that inorganic fertilizers are the most effective at high irrigation levels while organic manure performs better than inorganic fertilizers under low irrigation water levels.

El presente documento contiene el Estudio de Factibilidad del Proyecto Producción de Biogás a Partir de los Residuos Orgánicos del Rastro Municipal de Juigalpa, el cual es el resultado del trabajo conjunto realizado entre los especialistas de la Alcaldía de Juigalpa, Chontales, Nicaragua y del CEBiot – UPOLI, a partir de la firma en marzo del 2010 del Convenio de Colaboración entre ambas la Alcaldía Municipal de Juigalpa, y la Universidad Politécnica de Nicaragua (UPOLI), cuyo objetivo general es diseñar, construir, instalar y poner en marcha un conjunto integrado de Digestores de Presión Hidráulica de 10 m3 de volumen cada uno, que procesen los Residuales Orgánicos adecuados para la Digestión Anaerobia que genera el Rastro Municipal de Juigalpa y utilizar el biogás producido como combustible en el proceso de producción del Rastro de Juigalpa, con el fin de reducir el impacto ambiental negativo que produce el vertimiento de los residuos orgánicos que genera el Rastro Municipal de Juigalpa y a la vez brindar una solución integral energética mediante la producción de energía renovable (biogás) que permita la sustitución de combustibles fósiles como el Gas Licuado del Petróleo (GLP) que se utiliza para calentar el agua en el proceso de matanza de cerdos en el Rastro y para alimentar el horno de producción de harina de huesos. El Proyecto también contribuirá a la reducción de la emisión de Gases de CH4 y CO2  (Gases de Efecto Invernadero, GEI) tanto por la eliminación directa de las emisiones de CH4 de los residuos orgánicos que se procesan, como por la obtención de energía renovable que sustituye el uso de combustibles fósiles.

En principio se elaboró un Perfil de Proyecto que fue aprobado por la Alcaldía de Juigalpa y a continuación se procedió a elaborar el presente Estudio de Factibilidad, donde se estudiaron las condiciones actuales del Rastro Municipal y se pudo concretar la cantidad de residuales disponibles y comprobar que el Municipio tiene contemplado aplicar un conjunto de mejoras con las cuales se podrá recolectar adecuadamente todo los residuos del Rastro, facilitando su posterior procesamiento en una planta de biogás.
Después de los estudios realizados se llegó a la selección de la tecnología de Digestores de Presión Hidráulica (DPH) para Planta de Biogás del Rastro de Juigalpa, para lo cual se tuvo en cuenta la experiencia exitosa que ha tenido el CEBiot con la proyección, construcción, puesta en marcha y estabilización de la Planta DPH que opera en el Campus Central de la UPOLI desde hace casi un año, con muy buenos resultados. Se definió que la Planta para el Rastro de Juigalpa debe contar con un conjunto de 5 digestores DPH de 10 m3 cada uno, un sistema de almacenaje y distribución de biogás y un sistema de recepción y alimentación de los residuos del rastro y se hizo el primer estimado del valor de la Inversión. Finalmente se completó el Diseño Tecnológico de la Instalación y se realizó la ubicación física de la planta, a partir de un levantamiento topográfico del terreno y se elaboraron los planos de ubicación de los digestores y los sistemas de almacenaje de biogás y de distribución de residuos a procesar. Se realizó también un Estudio de Mercado que permitió comprobar la disponibilidad suficiente de residuos orgánicos a procesar, la demanda del biogás producido, la demanda de harina de huesos y la posibilidad de una futura ampliación de la Planta, lo que  resulta perfectamente factible dada la concepción modular que se ha tenido en cuenta en el Proyecto elaborado.

Se realizó además un análisis de Factibilidad Financiera, para el cual se precisó el costo del equipamiento requerido para el proceso, así como los gastos de proyecto y overhead, que ascienden a un total de US$30,916.57, así como la determinación de los ingresos anuales del proyecto por el uso del biogás como combustible sustituto y la venta de harina de huesos y se determinaron también los costos de mantenimiento y operación. Se determinó además que la evaluación financiera se haría para un plazo de 20 años y con esa base se determinó la depreciación de la inversión. Se asumió una tasa de 8% y con esa base los resultados obtenidos son muy favorables: VAN  = US$190,414; Relación Beneficio/Costo = 3.81; TIR = 61% y Tiempo de Recuperación de la Inversión = 1.78 años y en los mismos se pudo apreciar el fuerte efecto del ingreso por venta de harina de huesos, por lo cual se decidió hacer un Análisis de Sensibilidad del VAN, TIR y TR ante las variaciones en ese ingreso y se consideraron escenarios con montos reducidos de ingreso por venta de harina de huesos, llegando hasta la condición de cero ventas de harina de hueso. Los resultados del Análisis de Sensibilidad confirman la viabilidad financiera del proceso ya que aún en el caso más crítico (cero ventas de harina de huesos) los indicadores son positivos: VAN = US$59.032; TIR: 19% y TR = 6.92.

También se realizó un análisis del efecto que tendría realizar la Evaluación Económica considerando las externalidades que tanta importancia tienen en los procesos de producción de biogás, como son los efectos de la reducción de la emisión de contaminantes sólidos, la reducción de la emisión de Gases de Efecto Invernadero, la reducción en el uso de combustibles no renovables y las mejoras a la salud humana, entre otros. Considerar esos indicadores es decisivo en los proyectos de programas de biogás a escala doméstica, en los cuales los márgenes de rentabilidad son muy reducidos, pero en el caso de los proyectos a escala mediana y grande no tienen tanta importancia ya que en la mayoría de los casos la evaluación financiera es favorable.

Y este es el caso del Proyecto para el Rastro de Juigalpa ya que la evaluación financiera ha sido positiva aún en el escenario desfavorable en que  no se pueda comercializar la harina de huesos y los resultados del Análisis Económico solamente reforzarían este resultado obtenido. Por esa causa y por las dificultades para evaluar adecuadamente el efecto de los indicadores antes mencionados, se decidió no realizar la Evaluación Económica del efecto de las externalidades y tener solamente en cuenta el hecho de que con la misma se reforzaría la valoración positiva que ya se tiene.

Finalmente se hizo una evaluación del Impacto Ambiental de la Inversión y se pudo comprobar un efecto completamente positivo lo cual, unido a los resultados del Estudio Técnico, Estudio de Mercado y Evaluación Económico Financiera, demuestran la Factibilidad de este Proyecto.

Introduction Vermicomposting could increase nutrients
availability including phosphorus. During vermicomposting, a decomposition of organic substrates leads to the
production of several organic acids, such as malonic,
fumaric, succinic acids. Microorganisms both in the
intestinal organ of the worms and the organic waste have
the ability to convert insoluble P into soluble forms. Little
information exists about the effects of vermicomposting on
rock phosphate (RP) solubilization. Present study was
conducted to evaluate the solubilization of powdered RP
during vermicomposting.
Results Vermicomposting and RP application increased
NaHCO3-Pi. Rock phosphate application in vermicomposting significantly increased NaHCO3-Po. Vermicomposting significantly increased NaOH-Pi in all of the
treatments. RP application and vermicomposting increased
HCl-Pi in both organic sources. Generally, vermicomposting increased HCl-Po. Vermicomposting decreased pH
but its effect was more evident in the presence of RP.
Vermicomposting increased EC in both organic sources.
Conclusion Present study showed that vermicomposting
helps to enhance the transformation of P from RP into
various organic or inorganic P forms, which would be
readily or moderately available, thus, increase the availability of P from both RPs.

Purpose A study was conducted to assess production of Pleurotus columbinus mushroom fruiting bodies for different formulations of rice or corn straw substrates mixed at different percent portions with the corresponding com-posted straw. Methods These formulations were: (1) raw straw (RS) mixed with 5 % composted straw (CS), (2) RS mixed with 10 % CS, (3) RS mixed with 15 % CS, (4) RS mixed with 25 % CS, (5) RS mixed with 50 % CS, and (6) 100 % RS. Composted straw (CS) was made of moistened chopped RS mixed with chicken manure and soil (4:1:1, v/v). Results Data showed a magnificent impact of the substrate on oyster mushroom fruiting bodies yield and characteristics. There was a significant progressive upgrading in all parameters studied of mushroom growth and crop outcome with increasing the percentage of CS mixed with the RS substrate up to 15 %. Utilizing CS at 25 % significantly downgraded these parameters. No mushroom growth was observed at all when cultivated in medium contained 50 % CS. Instead, molds of different colors grew on that latter substrate mixture. The formulation containing 15 % CS distinctly gave the uppermost fruiting bodies yield, biological efficiency, earliness for pinheads formation, fruiting body cap diameter, thickness and weight and stem diameter, length and weight. Up to 80 % increase in fruiting bodies crop outcome relative to sole RS was detected. Conclusions This study suggests that composted straw substrates hold a great promise for the development of Pleurotus mushroom production industry.

Background: Vermicomposting is a biological process which may be a future technology for the management of animal excreta. This study was undertaken to produce vermicompost from cow dung and biogas plant slurry under field conditions. To achieve the objectives, two vermicomposting units containing cow dung (CD) and biogas plant slurry (BPS) were established, inoculated with Eisenia fetida species of earthworm and allowed to be vermicomposted for 3 months.
Results: After 3 months, the vermicompost was harvested and characterized. The results showed that the
vermicompost had lower pH, total organic carbon (TOC), organic matter (OM) and carbon/nitrogen ratio (C/N ratio)
but higher electrical conductivity (EC), nitrogen, phosphorous and potassium (NPK) content than the raw substrate.
The heavy metal content in vermicomposts was higher than raw substrates.
Conclusions: During vermicomposting, the CD and BPS were converted into a homogeneous, odourless and stabilized humus-like material. This experiment demonstrates that vermicomposting is an environmentally sustainable method for the management of animal excreta.

Background: Vermicompost (VC) made from cattle dung as raw material was used as soil supplement in the plots of size 4.5 x 4.5 m. Five treatments were given viz. Soil (control), VC@5 t/ha, VC@10 t/ha, VC@20 t/ha and NPK (recommended by PAU, Ludhiana) in triplicates in a Randomized Block Design (RBD). A total of 50 plants were selected randomly for the assessment of growth and yield of wheat Triticum aestivum L..

Purpose

Catha edulis, commonly called as khat or chat is an evergreen plant cultivated in Ethiopia for its stimulant leaves. The young leaves are chewed as a part of social recreation and the older leaves along with the twigs are discarded. This forms the major part of municipal solid waste that is dumped in large quantity in Harar region. The present study was carried in Haramaya University, Ethiopia to decompose the khat wastes along with crop residues and different animal manures (cow dung, goat manure, poultry manure and swine manure) using the earthworm Eisenia foetida.
Methods

The collected khat wastes along with crop residues and different animal manures were vermicomposted and assessed for nutrient contents using standard procedures.
Results

The result of the experiment indicated that all the parameters were improved by the decomposition using earthworms and the C/N ratio was within the limits that indicate the maturity of the compost. The organic carbon, organic matter, total nitrogen, phosphorus, copper, iron, zinc and manganese contents were analyzed and found to be improved after decomposition. The added crop residues and animal manures enhanced the decomposition process and manurial value of the khat leaf waste.
Conclusion

The nutrient content of the vermicomposts revealed khat to be a suitable substrate for vermicomposting thereby making efficient utilization of solid wastes. This can be an effective technology to reduce the solid waste and the resultant product can be used for improving soil fertility and crop production by the farmers.

Vermicomposting using Lumbricus rubellus for 49 days was conducted after 21 days of pre-composting. Three different combination of treatments were prepared with eight replicates for each treatment namely cow dung : kitchen waste in 30:70 ratio (T1), cow dung : coffee grounds in 30:70 ratio (T2), and cow dung : kitchen waste : coffee grounds in 30:35:35 ratio (T3). The multiplication of earthworms in terms of numbers and weight were measured at the end of vermicomposting. Consequently, only T2 showed significant increase (from it initial stage) compared to other treatments. The presence of coffee grounds in T2 and T3 showed higher percentage of nutrient elements in vermicompost produced. The data reveal that coffee grounds can be decomposed through vermicomposting and help to enhance the quality of vermicompost produced rather than sole use of kitchen waste in vermicomposting.

Yard waste is either dumped or is being openly burned to get rid of it, instead of using it as a valuable renewable energy source. In this study, hydrothermal carbonization of yard waste was conducted to val-orize it as a solid bio fuel, using a batch reactor. The effect of process parameter on yield, energy and physicochemical properties of the valorized solid bio fuel (hydrochar) was examined in this study by varying reaction temperature (160-200 °C for 2 h) and reaction time (2-24 h at 200 °C). The calorific value of hydrochar was within a range of 17.72-24.59 MJ/kg as compared to 15.37 MJ/kg for untreated yard waste. Hydrochar mass yield decreased from 78.6% at operating temperature-time of 160 °C-2 h to 45.6% at 200 °C-24 h. The plot of atomic ratios (H/C and O/C) demonstrates improvement in the coalification process which was mainly governed by decarboxylation and dehydration reactions. The grindability of the prepared hydrochar was comparable to that of coal. Hydrochar produced at lower reaction condition (160-200 °C at 2 h) have better flowability as compared to that produced at higher reaction condition (4-24 h at 200 °C). The reaction time longer than 12 h has a minimal effect on the yield, energy and physicochemical properties of hydrochar. Increasing reaction time and temperature improved the ignition and burnt temperature of hydrochar. All reaction condition has an energy ratio (energy output to energy input) of more than one making HTC process a net energy producer.

Recent trend of declining sustainability in agricultural production is appearing as a major threat to most of the Asian countries. To combat the situation, increasing importance is now being paid on incorporation of organic materials for rejuvenating the health condition and, hence, the productivity of these soils. Large scale availability of conventional organic manures being a big problem nowadays, major attention is being paid on recycling of different kinds of organic wastes for this purpose. Apart from abatement of environmental pollution, such reuse of organic wastes in agriculture helps in the improvement of various physical, chemical and biological properties of the soils and, thus, helps in sustaining the soil health. While recycling different organic wastes in agriculture, it is essential to process the materials through an adequate period of composting for improving their usability in the soils. However, due to some short comings of traditional composting systems, the technology of recycling of organic wastes has not been widely accepted so far. Under this situation, vermicomposting has recently emerged as a simple but efficient biotechnology for recycling wide ranges of organic wastes with the help of some specific groups of earthworms. In view of the growing popularity of this biotechnology, various aspects of waste recycling in agriculture through vermicomposting have been dealt in this communication.

Background: Chicken processing results in the production of a lot of blood which if disposed on land poses environmental hazards in terms of land pollution. The aim of the study was to develop an aerobic composting process for chicken blood to produce a nitrogen-rich soil amendment for use in agriculture. The study involved composting of blood and maize stover of different proportions (10%, 30%, 70% and 100% maize stover) in compost bins over 72 days and determining which proportions would yield compost with greater potential to support plant growth. Results: The performance of the different compost mixtures was evaluated by monitoring internal temperature, mineral N (NH 4N and NO3 −-N), C/N ratio, pH, electrical conductivity and total cations. The concentration of ammonium
N decreased by 8.75%, 50.5%, 33.5% and 18.8% for the 10%, 30%, 70% and 100% stover treatments, respectively, with
composting time. Nitrate N peaked to 1.93 and 1.06 mg/kg for the 30% and 70% treatments, respectively, on day 43,
while it peaked to 1.54 and 0.54 mg/kg for the 10% and 100% treatments, respectively, on day 50. The C/N ratios
decreased significantly (p < 0.001) for all treatments.
Conclusion: The 10% and 30% treatments had better composting performance than the 70% and 100% treatments as they reached and maintained thermophilic temperatures for at least 8 days. The 10% and 30% treatments appeared to have the greater potential of supporting crop growth.

Background Macrophytes (fresh water plants) comprise a diverse group of the flora which play important roles in the maintenance of trophic food chains and biogeochemical processes, but are deleterious when present in excess. However, due to various anthropogenic activities, there is accumulation of nutrients in aquatic ecosystems resulting in massive macrophytic growth. These weeds do not possess any economic value and remain laid on lake shores after harvesting and become a source of odor problem, thus posing a challenge to the lake management authorities regarding their proper disposal. However, vermicomposting turns these macrophytes into materials useful in horticul-ture/agriculture for restoration of soil fertility, in addition to providing a solution to the nuisance of harvested weeds. Results The study was conducted to investigate the effect of different rates (2, 4 and 6 t/ha) of macrophyte-based vermicompost on germination, growth and yield of Sola-num melongena under field conditions. The data revealed that different rates of vermicompost produced varied and significant effect (P \ 0.05) as compared to the control on germination, growth and yield parameters with maximum value recorded at 6 t/ha, followed by 4 t/ha and the least at 2 t/ha. The dose of 6 t/ha significantly (P \ 0.05) increased germination (22.56 ± 2.5 %), number of fruits per plant (3.55 ± 0.07) mean fruit weight (73 ± 5.0 g), yield per plant (1.48 ± 0.05 kg) and marketable fruits (28.66 ± 3.0 %) when compared with the control. The study suggests that macrophyte-based vermicompost as a potential source of plant nutrients for sustainable crop production. Conclusion Macrophyte-based vermicompost is an efficient quality yielder and economy enhancer for sustainable agriculture especially for the communities having vegetable gardens around lakes will benefit by using macrophyte ver-micompost, a balanced and low-cost organic fertilizer.

Purpose Field experiment was carried out in Akure in the rainforest zone of Nigeria to determine the effect of poultry manure, wood ash and rice bran on the soil fertility improvement, growth and head yield of cabbage (Brassica oleraceae L) in 2011 and 2012 cropping seasons. Methods The three organic fertilizer treatments were applied each at 6 t/ha with a reference treatment NPK 15-15-15 applied at 300 kg/ha and a control treatment arranged in a randomized complete block design with three replicates. Results The results showed significant increases (P \ 0.05) in the growth and head yield parameters of cabbage crop under the different organic fertilizers compared to the control treatment. The application of poultry manure resulted in the highest values of cabbage plant height, stem girth, leaf number, leaf area, head weight, head length and head girth followed by NPK 15-15-15, wood ash and rice bran, respectively. Cabbage head weight, head girth, head length, plant height, stem girth, leaf number and leaf area increased by 17, 18, 8,17, 19, 10 and 16 %, respectively, with application of poultry manure compared to NPK fertilizer. Also, these parameters increased by 23, 21, 13 29, 25, 17 and 45 % compared to the wood ash treatment. The highest values of soil pH, Ca and Mg were obtained under wood ash application, while the highest values of soil O.M and moderate values of soil P, K, Ca and Mg were obtained under poultry manure application. Moderate values of soil pH, K, Ca and low % N were also recorded under rice bran treatment. However, the highest K/Ca, K/Mg and P/Mg ratios of 93.1, 74.1 and 572.1, respectively, were obtained under NPK 15-15-15 fertilizer application compared to 2:1 K/Ca, 2:1 K/Mg and 16:1 P/Mg in rice bran treatment. Conclusion The poultry manure applied at 6 t/ha gave the best results in improving soil fertility, growth and head yield of cabbage, and this was because of its balanced nutrient composition and the least C/N ratio. Keywords Cabbage (Brassica oleraceae) Á Head yield and growth parameters Á Organic fertilizers and soil fertility improvement

If valorisation strategies are implemented, horse manure is a valuable resource to be used as organic soil amendment and for renewable energy generation. Huge amounts of equine residues are generated in the EU and elsewhere, most of which are currently considered as waste to be disposed of, which places an additional burden on the sector. Under a SWOT analysis perspective it becomes evident that one of the key challenges lies in the fact that horse manure varies widely with view to generated quantities and contents due to utilisation of different bedding materials and different management practices. This study further aims to evaluate the challenges related to valorisation of horse manure and to identify the most promising options. Anaerobic digestion and thermal treatment are currently the two key options that hold potential for more widespread implementation of bioenergy generation in practice.

The potential of pineapple peel as a source of cellulose nanocrystals was evaluated. Peels skin from fresh-cut fruit was used as raw material. These residues were purified to remove pigments, lipids and hemicellulose, and a bleaching process for delignification was carried out for 4-6 h. All resulting products were characterised for their lignin, hemicellulose, cellulose and ash contents using standard techniques. Dry matter at the end was low (ca. 50%) compared with the raw material (ca. 90%). The process applied resulted in ca. 20% (m/m) of purified cellulose (ca. 80% purity), with ineligible levels of lignin and hemicellulose present, especially when using 6h of bleaching. The purified cellulose was subject to acid hydrolysis for nanocrystal extraction with two testing times, 30 and 60 minutes. These cellulose nanocrystals had small sizes (< 1000 nm), with high variability and negative zeta potential values. The time of extraction did not affect the nanocrystals' chemical and physical properties. The use of 6 h of bleaching treatment during purification was shown to be more effective than 4 h. Pineapple peel was demonstrated to be a good source of cellulose for the production of cellulose nanocrystals.

Background Organic solid waste management is a major challenge in high population density areas like apartments, educational institutions, hospitals, etc., as their disposal with other wastes could not only lead to issues like vector menace, odour generation but also would lead to loss of resources that could be reused such as nutrients which will benefit soil. In places like educational institutions, the major portion of waste generated is organic waste, especially food waste and yard waste from the campus, apart from paper waste. Composting is an organic waste treatment method that is cost effective and leads to resource recovery. In this study, the characteristics of composting of yard waste and co-composting of yard waste with wastes generated in an institution (university campuses of Anna University, Chennai, India) are examined. The composts were characterized in terms of total solids, volatile solids, pH, electrical conductivity, carbon: nitrogen (C:N) ratio and total Kjeldahl nitrogen. The stability index and germination index of the compost were assessed. Results The C:N ratio of all the different composts (except the one generated from yard with canteen waste consisting of vegetable waste) produced in this study has a value less than 30:1, which satisfies the basic requirements for the compost. It was also observed that the mature compost from these feedstocks did not have heavy metals at toxic levels. Conclusion This study demonstrated that the co-com-posting of yard wastes with paper and canteen wastes (fruit, coffee grounds, tea leaf waste) could produce value-added products. In addition to that, kinetic models were developed to predict the decomposition rate constant of the process.

Purpose The disposal of solid waste is a serious environmental problem for humanity. Vermicomposting is used as one of the methods for recycling of organic waste, resulting in a humified material of great agronomic potential which promotes carbon sequestration when applied to the soil. The aim of this study was to evaluate the chemical characteristics of vermicomposts from cattle manure (CM), orange peel (OP) and filter cake (FC). Methods Three compost piles were set up, 2:1 OP ? CM, 3:1 FC ? CM and CM. The piles were initially composted for 60 days. Thereafter, earthworms were added to the piles to initiate the vermicomposting process. Results The pH and the organic carbon contents were above the minimum recommended values for organic fertilizers. The N content was below the minimum value but the C/N ratio was in the required range. The C/N values where lower in OP ? CM and FC ? CM than in CM. Further, the N contents of treatments were different with OP ? CM having the highest value. The C/N ratios of the piles were 9.52, 9.62 and 11.03 for OP ? CM, FC ? CM and CM, respectively, and were lower than the maximum recommended value by the Ministry of Agriculture, Livestock and Food (Ministry of Agriculture 2009). Conclusion Thus, co-vermicomposting of filter cake and orange peel with cattle manure has the potential for application sustainable agriculture.

By using Lumbricus rubellus, vermicomposting started after 3 weeks of pre composting. Five treatments in different ratio of cow dung : spent mushroom substrate were prepared as feed materials with four replicates for each treatment namely; 80:20
(T1), 60:40 (T2), 50:50 (T3), 40:60 (T4) and 20:80 (T5). After 7 weeks of vermicomposting, macronutrient elements of vermicompost produced were measured and the process continues with composting when all the earthworms were taken out from the treatments. Macronutrient elements of compost produced were also measured after 20 weeks of composting. The data reveals that 7 weeks for vermicomposting of cow dung and spent mushroom substrate is sufficient to produce good vermicompost rather than continuing process with 20 weeks of post composting. Therefore, it can be concluded that the duration and quality of vermicomposting is
better than composting particularly in vermicompost production.

Essa pesquisa apresenta uma análise que fizemos de  iniciativas para a reciclagem de resíduos orgânicos em duas capitais no Brasil: São Paulo e Florianópolis. Realizamos pesquisa bibliográfica sobre o tema compostagem orgânica e urbana e um levantamento de dados coletados por meio de pesquisa booleana (compostagem AND urbana AND nomes das duas cidades estudadas). Encontramos muitas iniciativas e, dentre elas, escolhemos analisar duas delas. Ambos projetos de manejo de resíduos sólidos foram realizadas a partir de ações de gestão participativa em consonância com o estabelecido pela Política Nacional de Resíduos Sólidos (PNRS), são eles: Composta SP, em São Paulo (SP), e a Revolução dos Baldinhos, em Florianópolis (SC). Nossos resultados demonstram que estas duas ações comunitárias possuem aspectos em comum: participação da população para enfrentar o problema do descarte inadequado dos resíduos orgânicos e práticas que oferecem uma efetiva solução a nível local através da compostagem urbana. Os produtos finais, chamados de húmus e bio fertilizante, são resultados e exemplos de uma economia circular reconhecida como sendo “do berço ao berço” (“cradle to cradle”) em oposição à economia linear, considerada por esses autores como sendo "do berço ao túmulo" ("cradle to grave”, no original em inglês) (McDonough & Braungart 2002). Ao final, iremos explorar como o conceito de economia circular atualmente é pensado de forma mais ampla por acadêmicos e ativistas que praticam mudanças para melhorar o tratamento de “resíduos sólidos”, para sermos "sociedades circulares". Como parte de nossas conclusões, acreditamos que ambos projetos de compostagem urbana de resíduos orgânicos são de economia circular. Concluímos que o caso “Revolução dos Baldinhos” é um exemplo de “tecnologia social” (Dagnino, Brandão & Novaes 2004; Pozzebon 2015) que possui o embrião de fomentar "sociedades circulares” (Resarch group Obsolescence 2019). É um exemplo de saber local e organização em nível comunitário da “bioeconomia circular” (Hetemäki et al. 2017) para o manejo de resíduos sólidos orgânicos em nível local nos bairros das grandes cidades.

Purpose: The review article discusses the title topic describing mostly the authors work on green chemical,  photochemical and electrochemical methods for the treatment of organic wastes present in different matrices.  Emphasis is mainly placed on the importance of the matrix, associated compounds and the method's selection. Methodology: Different green methods of treatment for organic waste available are reviewed with an outline of scientific principles. Different case studies, from the authors, work, involving the treatment of organic waste present in different matrices are discussed.  Available green chemical,  photochemical, and electrochemical methods are reviewed, and the results obtained are described and discussed. The rationale behind the choice of method was discussed in detail. Laboratory to plant adoption and the considerations therein are considered.
Main findings: The selection of treatment method depends on the nature of the organic waste and the matrix in which it is present.  This has been brought out in the study.  Advanced oxidation and electrochemical oxidation processes are practically useful methods for waste treatment and are discussed with case studies. The optimization of the advanced oxidation process is still an empirical approach. It needs a sound scientific base.
Applications of the work: The case studies described in the paper enable the proper choice of treatment method among several available options.  The study covers the essential green chemical techniques,  viz.,  photochemical and electrochemical techniques.
The novelty of the work: Many of the organic substrates subjected to treatment study were rarely reported in the open literature. Laboratory to plant scale development and the factors involved therein have been brought in many places.

Lactic acid (LA) is an organic compound used in several industries, such as food, textile, chemical, and pharmaceutical. The global interest  in  this  product  is  due  to  its  use  for  the  synthesis  of  numerous  chemical  compounds,  including  polylactic  acid,  a  biode-gradable thermoplastic and substitute for petroleum-derived plastics. An in-depth overview of the use of industrial and household wastes as inexpensive substrates in order to reduce the cost of LA production is presented. A review is carried out of the biotech-nological aspects that must be taken into account when using some wastes with high transformation potential to produce LA in a submerged  culture,  as  well  recommendations  for  their  use.  The  advantages  and  disadvantages  of  different  types  of  treatments used for the transformation of waste into suitable substrates are considered. Several methods of fermentation, as well as genetic strategies for increasing the production, are summarized and compared. It is expected that in a few years there will be many ad-vances in these areas that will allow greater large-scale production of LA using agroindustrial or household wastes, with potential positive economic and environmental impact in some regions of the planet.

This research is aimed to study comparison of the effects of applied nanozeolite and zeolite on aggrega-tion and organic carbon (OC) in each aggregate size fraction in treated soil with different levels of some plant residues and incubation for 90 days. The analysis of variance showed that the effects of applied nanozeolite, zeolite, plant residues, and their interaction and incubation times on MWDw and OC in aggregate size fractions were statistically significant. The results showed that MWDw and OC contents in each aggregate size fraction increased with the additions of nanozeolite, zeolite, and plant residues. This study also revealed that nanozeolite and alfalfa straw were more effective for increasing the MWDw and OC contents in aggregate size fractions than zeolite and wheat straw, respectively. In other words, higher percentage na-nozeolite, zeolite, and plant residues resulted in increasing the MWDw and OC in aggregate size fractions. The highest amounts of OC were observed in A and B compounds compared with the control and other treatments. However, the comparison of OC contents in all the treatments showed that proportion of nanozeolite for increasing the OC content was greater than that of zeolite. Also the highest OC contents were observed in larger aggregate size fractions. The MWDw and OC contents increased with the increasing days of incubation in treated soil. Thus, it was concluded that compound A can be more effective to improve the soil carbon sequestration.

Background: Agricultural waste has been proposed as an alternative energy resource to meet fossil fuel crisis, green house emission, and other environmental impacts worldwide. In Iran, rice husk and bagasse are main resources of biomass which can be used to produce syngas. This paper deals with a simplified model of combined gasification of coal and biomass processes considering chemical equilibrium. Results: It should be noticed that the CO 2 which is produced from agricultural waste gasification is natural because the biomass absorbs CO 2 from nature and gives it back after gasifying; however, mixing agricultural waste with coal leads to enrich syngas quality and gasifier efficiency. Conclusions: In this regard, an advanced coding was developed to simulate the thermodynamics of the co-gasifier and to find the produced syngas composition. The effects of moisture content, steam-to-biomass ratio, and gasifier temperature are then discussed on the system performance. Additionally, co-gasification of rice husk/coal was compared with co-gasification of bagasse/coal. The results indicated that adding coal to biomass increases lower heating value of syngas from 4,694 kJ/Nm 3 to 5,321 kJ/Nm 3 and gasifier efficiency from 71.29% to 77.85%.

Background The reuse of organic wastes in agriculture is an appropriate method of environment management. Most plants with ornamental leaves are cultivated in soilless media, in which peat is the basic medium; but the use of peat is questionable due to ecological damage to the environment and economic disadvantages to ornamental plant producers. Peanut shells as remained wastes of cultivating peanut has a considerable volume, compost of which can be used as available sources of ornamental plants medium. A pot experiment was conducted to investigate the possibility of using peanut shell compost in the appropriate bed in the cultivation of ornamental plants. Dracaena marginata was selected as the test plant. The control treatment consisted of a 2:1 ratio of peat to perlite, and peat was replaced by 15, 30, 45, 60 and 100 % v/v of peanut shell compost. The study was done based on a complete randomized design in three repetitions in the ornamental plants and flowers research station , Lahijan, Iran. Results The results showed that the bulk density of the planting beds decreased with the addition of peanut shell compost in comparison to the control. Peanut shell compost increased total nitrogen and available phosphorus and potassium of the media. Peanut shell compost increased plant growth indices, but the growth was reduced in 100 % in the compost treatment. The compost led to increase in nutrient uptake by plants. Conclusion In conclusion, it became known that peanut shell compost is an appropriate alternative to peat as the growth medium of ornamental plants. Because of the favorable properties and high porosity, peanut shell compost can be mixed with low-porosity substrates and applied as a substitute to peat in the cultivation media. It is not suggested to increase peanut compost level by 60 and 100 %.

The ever-increasing world energy demand drives the need for new and sustainable renewable fuel to mitigate problems associated with greenhouse gas emissions such as climate change. This helps in the development toward decarbonisation. Thus, in recent years, hydrogen has been seen as a promising candidate in global renewable energy agendas, where the production of biohydrogen gains more attention compared with fossil-based hydrogen. In this review, biohydrogen production using organic waste materials through fermentation, biophotolysis, microbial electrolysis cell and gasification are discussed and analysed from a technological perspective. The main focus herein is to summarise and criticise through bibliometric analysis and put forward the guidelines for the potential future routes of biohydrogen production from biomass and especially organic waste materials. This research review claims that substantial efforts currently and, in the future, should focus on biohydrogen production from integrated technology of processes of (i) dark and photofermentation, (ii) microbial electrolysis cell (MEC) and (iii) gasification of combined different biowastes. Furthermore, bibliometric mapping shows that hydrogen production from biomethanol and the modelling process are growing areas in the biohydrogen research that lead to zero-carbon energy soon.

Background Microorganisms have been used to decompose cellulolytic waste in agriculture for the past many years. However, much of the cellulosic waste including coffee exocarps which are wastes from raw coffee process in Vietnam is often disposed of by biomass burning and discharged into the environment in developing countries, thus causing considerable environmental pollution. Besides, these organic wastes decompose slowly when they are used to produce compost in ordinary conditions. Therefore, using microorganisms to manufacture natural compost from coffee exocarps is considered a useful and environmentally sound alternative. Results In the course of screening for cellulose-degrading bacteria and actinomycetes, 38 bacterial strains and 18 actinomycetes strains were isolated from 15 coffee exocarp samples in coffee-producing areas in Vietnam. The isolates grew with cellulose as the sole sources of carbon and energy. The results of cellulolytic activity determinations were that 13 bacteria ([34 %) and 10 actinomycetes ([56 %) showed enzymatic degradation of cellulose. The isolated strains were identified as belonging to members of the Genus Streptomyces, Actinomycetes, Clostridium and Bacillus. Cellulose-degrading ability of the isolated microorganism strains was mostly 96 % with filter paper; however, for coffee exocarps, it was considerably lower, only about 37 % of the cellulose was digested after 30 days of incubation to coffee exocarps. A medium containing rice husk powder and lactose with pH 7.0 positively affected the cellulolytic activity of A1 and A9 strains. Cellulolytic activity of B4 and B7 strains was also most appropriate when the medium contained peptone, CMC, and with a pH 7.0. Optimal temperature for actinomycetes and bacteria isolate strains was at 25–35 °C. Conclusion We concluded that the cellulolytic bacteria and actinomycete could be isolated from coffee exocarps which are normally discharged into the environment in coffee-producing areas. These microorganisms could be used to decompose cellulosic wastes, making compost from coffee exocarps, which could be applied in agriculture in Vietnam and other developing countries.