Fate and Transport of Emerging Contaminants

Emerging organic compounds EOC are substances which have been only recently determined as pollutants, and substances which have been newly developed or discovered in the environment. EOC in groundwater can cause adverse effects on the environment and human health. They enter into the natural environment as a result of various anthropogenic activities. The article provides an overview of emerging organic pollutants that occur in groundwater. These compounds are drug residues, substances originating from personal care products, pesticides, veterinary products, food additives, nanomaterials, industrial and other compounds found in wastewater. The article describes the main sources and the presence of EOC in groundwater, pathways and potential impacts (risks). An overview of EOC detection research in the world is presented. Within the review of Slovenian studies the investigations dealing with the determination of wide spectrum of EOC presence in groundwater, with drug residues in groundwater and waste water, or with the development of analytical methods for these substances were analyzed. From the entire analysis we inferred that we must be aware of the possible presence of EOC risk in groundwater even in small concentrations. To reduce the yet to some extent unknown risks, it is necessary to determine EOC threshold values in groundwater and their impact. In the future it will be necessary to identify new pollutants, to develop new analytical methods to determine their sources and routes, and in particular, to establish monitoring for these substances.

Microplastics (MPs) are ubiquitous and constitute a global hazard to the environment because of their robustness, resilience, and long-term presence in the ecosystem. For now, the majority of research has primarily focused on marine and freshwater ecosystems, with just a small amount of attention towards the terrestrial ecosystems. Although terrestrial ecosystems are recognized as the origins and routes for MPs to reach the sea, there is a paucity of knowledge about these ecological compartments, which is necessary for conducting effective ecological risk assessments. Moreover, because of their high persistence and widespread usage in agriculture, agribusiness, and allied sectors, the presence of MPs in arable soils is undoubtedly an undeniable and severe concern. Consequently, in the recent decade, the potential risk of MPs in food production, as well as their impact on plant growth and development, has received a great deal of interest. Thus, a thorough understanding of the fate and risks MPs, as well as prospective removal procedures for safe and viable agricultural operations in real-world circumstances, are urgently needed. Therefore, the current review is proposed to highlight the potential sources and interactions of MPs with agroecosystems and plants, along with their remediation strategies.

The present review aims to describe the recent and most impactful applications in pollutant analysis using solid-phase microextraction (SPME) technology in environmental, food, and bio-clinical analysis. The covered papers were published in the last 5 years (2014-2019) thus providing the reader with information about the current state-of-the-art and the future potential directions of the research in pollutant monitoring using SPME. To this end, we revised the studies focused on the investigation of persistent organic pollutants (POPs), pesticides, and emerging pollutants (EPs) including personal care products (PPCPs), in different environmental, food, and bio-clinical matrices. We especially emphasized the role that SPME is having in contaminant surveys following the path that goes from the environment to humans passing through the food web. Besides, this review covers the last technological developments encompassing the use of novel extraction coatings (e.g., metal-organic frameworks, covalent organic frameworks, PDMS-overcoated fiber), geometries (e.g., Arrow-SPME, multiple monolithic fiber-SPME), approaches (e.g., vacuum and cold fiber SPME), and on-site devices. The applications of SPME hyphenated with ambient mass spectrometry have also been described.

IT IS TOO OBVIOUS.

THE REASON  -  DEATH IS A KICK ASS RUSH RIDE TO PURE CONSCIOUSNESS.  WE LIKE IT.  DMT

ONENESS IS BORING, SEPARATION IS INTERESTING.  PAIN AND SUFFERING ARE THE MOST USEFUL SEPARATION TOOLS ENTAILS FOCUS AWAY FROM PURE CONSCIOUSNESS. DON'T IT?  https://www.academia.edu/34967867/HUMAN_NATURE_IS_MASOCHISTIC

ALIENS – EXTRA TERRESTRIALS  -  E.T.s

MADE IN OUR IMAGE

A large population living in suburban and rural areas in the world uses septic systems, also called onsite wastewater treatment systems, to dispose of household wastewater. In a conventional septic system, the wastewater flows from a household to a septic tank, where solids settle and a clarified effluent is produced. This effluent is dispersed into the soil for further treatment and can be a potential source of various contaminants such as nutrients, pathogens, and a new class of compounds known as trace organic chemicals (TOrCs) in shallow groundwater and surface waters. We review the current state of the science on the fate and transport of three groups of contaminants-nutrients (nitrogen, phosphorus), pathogens, and TOrCs-and water quality impacts associated with these contaminants in conventional septic systems. We also discuss alternative technologies that may be employed when site conditions or environmental needs preclude the use of conventional septic systems.

This work concentrates on the review paper published by Ahmed et al . [1]
which is dedicated to the elimination of emerging contaminants (ECs) using
biological, chemical and hybrid techniques in effluents from wastewater
treatment plants (WWTPs). Endocrine disruption chemicals (EDCs) are better
reduced by a membrane bioreactor (MBR), activated sludge, and aeration
processes between various biological processes. Surfactants, EDCs and personal
care products (PCPs) may be well reduced using activated sludge
processes. Pesticides and pharmaceuticals manifested convenient reduction
performances by biological activated carbon. Microalgae treatment techniques
may diminish nearly all sorts of ECs to a certain degree. Additional
biological methods were observed less efficient in dealing with ECs. Chemical
oxidation techniques (like ozonation/H2O2, UV photolysis/H2O2, and photo-
Fenton) may greatly eliminate up to 100% of pesticides, beta-blockers, and
pharmaceuticals; at the same time, EDCs may be better reduced via ozonation
and UV photocatalysis. Fenton method was observed less efficient in treating
any sorts of ECs. A merged setup founded on ozonation pursued by biological
activated carbon was manifested hugely efficacious in eliminating pesticides,
beta-blockers, and pharmaceuticals. An integrated ozonation-ultrasound device
may eliminate until 100% of numerous pharmaceuticals. Next research
orientations to boost the elimination of ECs have been suggested.

Pharmaceuticals and Personal Care Products (PPCPs) form a source for a diverse group of bioactive ingredients such as analgesics, antibiotics, cytostatic hormones, disinfectants, and antiseptics whose steady occurrence in urban wastewater has raised concern on their potential toxicity and ecological implication. The EU Water Framework Directive updates its database of identified emerging contaminants every 4 years that includes several PPCP originating chemicals. Increasing trends in urbanization and commercial activity are likely to facilitate increased threats from PPCP based water pollutants globally. Chronic effects on aquatic organisms, tolerance to biodegradation and conventional water treatment methods allow them to infiltrate the water cycle and food web thus reaching humans. Today, China, Brazil, USA and European countries are regularly monitoring and assessing the environmental risk of over a hundred identified PPCPs from their Wastewater treatment plants and developing treatment technologies such as bio-adsorbents, membrane separation, advanced oxidation processes, biological treatment and electrochemical processes.

There is a growing concern on heavy metals in consumer products due to their potential human health risks and environmental effects. In this study, the levels of zinc, cadmium, lead and nickel were assessed in 3 different classes of personal care products commonly used in Ibadan, Nigeria. Samples were analysed for heavy metals using Atomic Absorption Spectrophotometer (AAS) after acid digestion. Estimated daily intake (EDI) of the metals and Health Risk Index (HRI) were calculated to assess the human health risks associated with the use of these PCPs. The concentrations (mg/kg) of zinc ranged from 3.75 to 19.3, 1.88 to 112,000 and 19.8 to 217 respectively in creams, powders and eyeliners. Cadmium ranged from ND—0.50, ND—36.3 and ND—0.50 mg/kg while lead ranged from ND—6.25, ND—468 and 3.73–27.5 mg/kg and nickel ranged from ND—6.25, 0.13–107 and 2.75–22.7 mg/kg respectively. There were high concentrations of Cd, Pb and Ni in some of the samples when compared with the available permissible limits in cosmetics (Cd: 0.3 ppm, Pb: 10 ppm and Ni: 0.6 ppm while there is no permissible limit for Zn in cosmetics currently available). Prolonged use of PCPs may pose human health and environmental risks due to toxic metal loading through dermal contact and accumulation over a period of time. Hence, the need for necessary government agencies to regulate and enforce toxic metals in consumer products including cosmetics produced and imported into Nigeria to safeguard public health and the environment, which is the final sink.

The presence of 3-monochloropropanediol (3-MCPD) in edible oils has been widely reported with its potential health risks. The aim of this study was to apply optimized recent updated and validated enhanced swift analytical indirect method for determining 3-MCPD in consumed edible oils (palm, palm olein, extra virgin olive, corn, sunflower, soybean, olive pomace) and blend of 5% sunflower oil with extra virgin olive oil, using selective and sensitive gas chromatography tandem triple quadrupole mass spectrometry (GC-MS/MS) employing deuterated 3-MCPD (3-MCPD-d5) as internal standard (IS) during the entire analytical procedure to obtain precise and accurate results. The occurrence and variation of 3-MCPD contents among the studied oils were found in different levels ranged from 93.1 µg/kg to 5634.1 µg/kg oil samples, with maximum value assigned for palm oil (5634.1 µg/kg) followed by palm olein (5576.8 µg/kg), corn oil (2447 µg/kg), sunflower oil (1817.3 µg/kg), soybean oil (1486.1 µg/k...

One of the problems with most approaches in the selection of wastewater treatment systems is that the wastewater characteristics which are often estimated are assumed to remain constant through the design period of the plant. The change in standard of living, water availability and change of industrial activities are some factors that can significantly alter the wastewater characteristics and possibly affect its treatability with existing systems. This study was carried out from March to May 2009 to assess the treatability of sewage at two wastewater plants in Harare which are more than 20 years old. Characteristics studied included pH, BOD, COD, TP, TS, TSS, TDS, TVSS, Ammonia and seven selected metals linked to bacterial toxicity. Composite samples were collected at the inlet works of Crowborough and Marlborough sewage treatment works and analyzed for the selected parameters according to standard methods. Crowborough which receives a mixture of domestic and industrial wastewater incorporates biological nutrient removal (BNR) and trickling filter (TF) processes. Marlborough Sewage Treatment Works, which treats only domestic wastewater, comprises a waste stabilization pond system. The ratios of key parameters were used to assess the treatability of the sewage including the potential to remove nutrients. The level of the metals was used to infer possible inhibition of biological processes in the plant while TVSS and BOD were used to ascertain the biodegradability of the sewage. It was found that the most ratios of key wastewater quality parameters were outside the range recommended for optimum treatment by BNR process while the composition was marginally suitable for trickling filters for most samples, with the raw sewage inflow to Crowborough being in the range weak to medium strength. Toxicity was found to be a potential problem for Crowborough. Factors affecting the composition of sewage could be industrial wastewater effluent and water availability. The raw sewage inflow to Marlborough was within the range medium to strong as a result of the recurrent water shortages in the area. It is recommended that appropriate process and operational modifications be made at the treatment plants to cater for the changes in wastewater characteristics. Stringent effluent requirements should be made for industries that produce effluent with toxic elements

Despite being one of the most important oil producing provinces in the United States, information on basinal hy-drogeology and fluid flow in the Permian Basin of Texas and New Mexico is lacking. The source and geochemistry of brines from the basin were investigated (Ordovician-to Guadalupian-age reservoirs) by combining previously published data from conventional reservoirs with geochemical results for 39 new produced water samples, with a focus on those from shales. Salinity of the Ca–Cl-type brines in the basin generally increases with depth reaching a maximum in Devonian (median = 154 g/L) reservoirs, followed by decreases in salinity in the Silurian (median = 77 g/L) and Ordovician (median = 70 g/L) reservoirs. Isotopic data for B, O, H, and Sr and ion chemistry indicate three major types of water. Lower salinity fluids (b 70 g/L) of meteoric origin in the middle and upper Permian hydrocarbon reservoirs (1.2–2.5 km depth; Guadalupian and Leonardian age) likely represent meteoric waters that infiltrated through and dissolved halite and anhydrite in the overlying evaporite layer. Saline (N 100 g/L), isotopically heavy (O and H) water in Leonardian [Permian] to Pennsylvanian reservoirs (2–3.2 km depth) is evaporated, Late Permian seawater. Water from the Permian Wolfcamp and Pennsylvanian " Cline " shales, which are isotopically similar but lower in salinity and enriched in alkalis, appear to have developed their composition due to post-illitization diffusion into the shales. Samples from the " Cline " shale are further enriched with NH 4 , Br, I and isotopically light B, sourced from the breakdown of marine kerogen in the unit. Lower salinity waters (b100 g/L) in Devonian and deeper reservoirs (N3 km depth), which plot near the modern local meteoric water line, are distinct from the water in overlying reservoirs. We propose that these deep mete-oric waters are part of a newly identified hydrogeologic unit: the Deep Basin Meteoric Aquifer System. Chemical, isotopic, and pressure data suggest that despite over-pressuring in the Wolfcamp shale, there is little potential for vertical fluid migration to the surface environment via natural conduits. Published by Elsevier B.V. This is an open access article under the CC BY license

Uptake, transport and toxicity of engineered nanomaterials (ENMs) into plant cells are complex processes that are currently still not well understood. Parts of this problem are the multifaceted plant anatomy, and analytical challenges to visualize and quantify ENMs in plants. We critically reviewed the currently known ENM uptake, translocation, and accumulation processes in plants. A vast number of studies showed uptake, clogging, or translocation in the apoplast of plants, most notably of nanoparticles with diameters much larger than the commonly assumed size exclusion limit of the cell walls of ∼5-20 nm. Plants that tended to translocate less ENMs were those with low transpiration, drought-tolerance, tough cell wall architecture, and tall growth. In the absence of toxicity, accumulation was often linearly proportional to exposure concentration. Further important factors strongly affecting ENM internalization are the cell wall composition, mucilage, symbiotic microorganisms (mycorr...

Over the last few decades many attempts have been made to use biocatalysts for the biotransformation of emerging
contaminants in environmental matrices. Laccase, a multicopper oxidoreductase enzyme, has shown great potential in
oxidizing a large number of phenolic and non-phenolic emerging contaminants. However, laccases and more broadly
enzymes in their free form are biocatalysts whose applications in solution have many drawbacks rendering them
currently unsuitable for large scale use. To circumvent these limitations, the enzyme can be immobilized onto carriers
or entrapped within capsules; these two immobilization techniques have the disadvantage of generating a large
mass of non-catalytic product. Insolubilization of the free enzymes as cross-linked enzymes (CLEAs) is found to yield a
greater volume ratio of biocatalyst while improving the characteristics of the biocatalyst. Ultimately, novel techniques
of enzymes insolubilization and stabilization are feasible with the combination of cross-linked enzyme aggregates
(combi-CLEAs) and enzyme polymer engineered structures (EPESs) for the elimination of emerging micropollutants
in wastewater. In this review, fundamental features of laccases are provided in order to elucidate their catalytic
mechanism, followed by different chemical aspects of the immobilization and insolubilization techniques applicable
to laccases. Finally, kinetic and reactor design effects for enzymes in relation with the potential applications of laccases
as combi-CLEAs and EPESs for the biotransformation of micropollutants in wastewater treatment are discussed.

Desde hace unos años, estamos asistiendo a una cantidad importante de noticias que alertan de forma más bien injustificada sobre la presencia de contaminantes emergentes (recientemente descubiertos) en las masas de agua y los efectos que estos contaminates pueden tener en la salud de quienes consuman ese agua. Entre estos contaminantes emergentes se encuentran no sólo sustancias químicas sino también microorganismos resistentes a los antibióticos.

Uptake, transport and toxicity of engineered nanomaterials (ENMs) into plant cells are complex processes that are currently still not well understood. Parts of this problem are the multifaceted plant anatomy, and analytical challenges to visualize and quantify ENMs in plants. We critically reviewed the currently known ENM uptake, translocation, and accumulation processes in plants. A vast number of studies showed uptake, clogging, or translocation in the apoplast of plants, most notably of nanoparticles with diameters much larger than the commonly assumed size exclusion limit of the cell walls of 5–20 nm. Plants that tended to translocate less ENMs were those with low transpiration, drought-tolerance, tough cell wall architecture, and tall growth. In the absence of toxicity, accumulation was often linearly proportional to exposure concentration. Further important factors strongly affecting ENM internalization are the cell wall composition, mucilage, symbiotic microorganisms (mycorrhiza), the absence of a cuticle (submerged plants) and stomata aperture. Mostly unexplored are the roles of root hairs, leaf repellency, pit membrane porosity, xylem segmentation, wounding, lateral roots, nodes, the Casparian band, hydathodes, lenticels and trichomes. The next steps towards a realistic risk assessment of nanoparticles in plants are to measure ENM uptake rates, the size exclusion limit of the apoplast and to unravel plant physiological features favoring uptake.

Removal of Emerging Contaminants from water via Granular Activated Carbon columns. Breakthrough curves obtained for each contaminant and adsorption models applied. The system removed endocrine disrupters more efficiently than pharmaceuticals. The Modified dose–response model gave the best results among the models examined. Microbiological growth observed, indicating biodegradation as a removal mechanism. a b s t r a c t The objective of this study was to evaluate the efficiency of adsorption at Granular Activated Carbon (GAC) columns on the removal of selected Emerging Contaminants (ECs) from water at concentrations found in the aquatic environment (from ng/L to few lg/L) and to obtain breakthrough curves for each substance. For this scope several fixed bed column experiments have been conducted in a pilot-scale GAC column system. The ECs examined were the Endocrine Disrupting Compounds (EDCs) Bisphenol-A (BPA) and Triclosan (TCS) and the Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Ibuprofen (IBU), Naproxen (NPX) and Ketoprofen (KFN). All experiments were performed with tap water spiked with the target compounds at concentrations up to 2 lg/L. For the evaluation of the breakthrough curves of each EC several adsorption models were used (Bohart–Adams model, Thomas model, Yoon–Nelson model, Wolborska model and Modified dose–response model). According to the results all target compounds could effectively be removed by GAC adsorption. EDCs were more effectively removed from the water than NSAIDs. Among target compounds, TCS exhibited the highest removal efficiency. For a 3.1 m/h surface velocity, the removal rates on the 5th day of continuous operation were 74.7% for BPA, 86.7% for TCS, 57.4% for IBU, 65.6% for NPX and 61.4% for KFN for a bed depth of 8 cm, whereas practically complete removal was achieved for all target compounds for a bed depth of 16 cm. During the experiments microbiological activity was observed, which resulted in the stabilization of the breakthrough curves which significantly extended the column service time.

The management of contaminants of emerging concern (CECs) in water bodies is particularly challenging due to the difficulty in detection and their recalcitrant degradation by conventional means. In this review, CECs are characterized to give insights into the potential degradation performance of similar compounds. A two-pronged approach was then proposed for the overall management of CECs. Light-driven oxidation processes, namely photo/Fenton, photocatalysis, photolysis, UV/Ozone were discussed. Advances to overcome current limitations in these light-driven processes were proposed, focusing on recent trends and innovations. Light-based detection methodology was also discussed for the management of CECs. Lastly, a cost–benefit analysis on various light-based processes was conducted to access the suitability for CECs degradation. It was found that the UV/Ozone process might not be suitable due to the complication with pH adjustments and limited light wavelength. It was found that EEO ...

Despite being one of the most important oil producing provinces in the United States, information on basinal hy-drogeology and fluid flow in the Permian Basin of Texas and New Mexico is lacking. The source and geochemistry of brines from the basin were investigated (Ordovician-to Guadalupian-age reservoirs) by combining previously published data from conventional reservoirs with geochemical results for 39 new produced water samples, with a focus on those from shales. Salinity of the Ca–Cl-type brines in the basin generally increases with depth reaching a maximum in Devonian (median = 154 g/L) reservoirs, followed by decreases in salinity in the Silurian (median = 77 g/L) and Ordovician (median = 70 g/L) reservoirs. Isotopic data for B, O, H, and Sr and ion chemistry indicate three major types of water. Lower salinity fluids (b 70 g/L) of meteoric origin in the middle and upper Permian hydrocarbon reservoirs (1.2–2.5 km depth; Guadalupian and Leonardian age) likely represent meteoric...

The influence of phytoplankton-derived soluble extracellular polymeric substances (EPS), pH, and ionic strength (IS) on the dissolution, speciation, and stability of
nano-CuO, nano-Cu, and Kocide (a micron sized Cu(OH)2- based fungicide) was investigated over 90 days. EPS improved the stability of commercial copper-based nanoparticles (CBNPs) in most conditions, in addition to influencing their
dissolution. The dissolution rate was pH 4 ≫ pH 7 > pH 11. The presence of EPS correlated with higher dissolved Cu at pH 7 and 11, and lower dissolved Cu at pH 4. More dissolution was observed at higher IS (NaCl) due to complexation with
Cl−. Dissolution of nano-CuO at pH 7 increased from 0.93% after 90 days (without EPS) to 2.01% (with 5 mg-C EPS/L) at 10 mM IS. Nano-CuO dissolved even more (2.42%) when IS was increased to 100 mM NaCl (with EPS). The ratio of free-
Cu2+/total dissolved Cu decreased in the presence of EPS, or as pH and/or IS increased. On a Cu mass basis, Kocide had the highest dissolved and suspended Cu at pH 7. However, dissolution of nano-Cu resulted in a higher fraction of free Cu2+, which may make nano-Cu more toxic to pelagic organisms.

Time-dependent aggregation, sedimentation, dissolution, and transformation of three copper-based engineered nanomaterials (ENMs) of varied properties were measured in eight natural and artificial waters. Nano-Cu and Cu(OH)2 aggregated rapidly to >103 nm while the aggregate size of nano-CuO averaged between 250 and 400 nm.
Aggregate size for both nano-Cu and nano-CuO showed a positive correlation with ionic strength with a few exceptions. Aggregate size did not correlate well with sedimentation rate, suggesting sedimentation was influenced by other factors. Controlling factors in sedimentation rates varied by particle: Cu(OH)2 particles remained stable in all waters but groundwater, nano-Cu was generally unstable except in waters with high organic content, and nano-CuO was stabilized by the presence of
phosphate, which reversed surface charge polarity at concentrations as
low as 0.1 mg PO43− L−1. Dissolution generally correlated with pH, although in saline waters, dissolved copper formed insoluble complexes. Nano-Cu was rapidly oxidized, resulting in dissolution immediately followed by the formation of precipitates. These
results suggest factors including phosphate, carbonate, and ENM oxidation state may be key in determining Cu ENM behavior in natural waters.

In general, it is important to examine the whole spectrum of interrelated fields while comprehending pollution, climate change or the environment, because some of their relevances are expected and others not. This study aims at comparatively examining different but interrelated ways of acquiring and communicating information on environmental changes, focusing on pollution in the Arctic, in particular Greenland. In the context of climate change, it discusses how heavily polluted and stressed Arctic marine ecosystems may be affected when ice melts. Bridging cultures of knowledge, this study claims that traditional knowledge together with natural science and studies of contaminants in Arctic marine ecosystems can indicate behavioural factors, elements acting as additional stressors on animals and communities relying on them. Furthermore, it explains the role of scientific engagement with local communities in not only the identification and verification of stressors, enhancing our understanding of them, but also the proposal of solutions to related problems.

Exogenous application of chelators towards enhancing heavy metals extraction efficiency of bioenergy crop has received considerable attention in recent time. However, little is known about optimal application rate, comparative evaluation of degradable versus non-degradable chelators and their impact on cadmium (Cd) speciation and uptake, physiological and biochemical activity of sweet sorghum grown under Cd stress. Four chelators namely, Nitrilotriacetic acid (NTA), tetrasodium N,N-diacetate (TDA), Ethylenediamine tetraacetic acid (EDTA), iminodisuccinic acid (IDA) and control (CK) were applied and compared at rates of 2, 5, and 10 mmol kg À1 towards augmenting phytoextraction efficiency of sweet sorghum for Cd remediation in a screen house study. Results showed that sweet sorghum augmented with TDA significantly (P < 0.05) increased biomass, enhanced Cd uptake and accumulation when compared to EDTA at application rate of 2e5 mmol kg À1. TDA influenced Cd speciation via increasing acid-soluble, reducible, oxidizable, and residual fractions of Cd, thus increasing Cd bioavailability. NTA and TDA increased proline concentrations, antioxidant enzymes and net photosynthetic activity rate (Pn) comparably to EDTA in sweet sorghum, thus enhancing stress tolerance and stabilizing photosynthetic activities. Overall, exogenous application of degradable TDA at 2e5 mmol kg À1 could be recommended as replacement for non-degradable EDTA in a chelate assisted approach towards augmenting bioenergy crop for phytoremediation of Cd polluted soil.

Models developed for solute transport vary in their assumptions on macropore continuity and tortuosity. It is unclear how much simplification can be made in computer models to characterize macropore effects on water and solute transport through soils. The objectives of this study were to assess how the importance of macropore continuity and tortuosity varies (1) with various initial and boundary conditions (this paper) and (2) with simplifying model assumptions for macropore description (companion paper). The above assessments were made with a computer model based on 2- D Galerkin finite element solution of Richards’ equation for water flow and convective–dispersive equation for solute transport. The model can simultaneously handle macropores of varying length, size, shape, and continuity. Model predictions were in agreement with laboratory data for different macropore shapes and continuities under transient flow conditions. Simulations for various initial and boundary conditions showed that surface connected macropores under ponded conditions and under high intensity rainfalls favored the rapid transport of solutes. However, solute transport was delayed if the solute was initially incorporated in the soil even when macropores were connected to the soil surface. Macropores not connected to the soil surface only slightly accelerated solute transport for any boundary conditions. Macropore tortuosity did not influence breakthrough curves as much as the continuity but greatly influenced solute distribution in the profile. The importance of macropore continuity and tortuosity on preferential transport increased with an increase in solute retardation. General guidelines for simplifying continuity and tortuosity for modeling solute transport are presented for various initial and boundary conditions.

Advances in our understanding of the fate and transport of bacteria introduced into aquifers, including the potential use of genetically engineered bacteria for biorestoration, are highlighted by new findings in the following areas: modeling of bacterial attachment during transport through porous media, the long-term survival of a chlorobenzoate-degrading bacterium injected into a contaminated sandy aquifer, and molecular techniques that may be used in tracking genetically engineered bacteria in groundwater environments.

This essay follows the Nachleben of Kairos in five steps: semantics and rhetoric, Kairos and ekphrasis, Kairos iconography as chronotopos, Kairos iconography as pseudomorphosis, and finally some Kairotic elements in the Annunciation. Not only I wish to test the literary-historical impact and iconographic Nachleben of Kairos, but also the concept of opportunity as a paradigm for art history. Indeed, Kairos offers an alternative hermeneutic in which the image can be seen as chronotopos, epiphany and interruption. In this manner, my lecture aims insights into how Kairos can function as a hermeneutic key when it comes to the image and its Warburgian embedding in cultural historic dynamics

Methods to predict the bioaccumulation potential of per- and
polyfluorinated alkyl substances (PFAS) are sorely needed, given
the proliferation of these substances and lack of data on their properties and behavior. Here, we test whether molecular docking, a technique where interactions between proteins and ligands are simulated to predict both bound conformation and interaction affinity, can be used to predict PFAS binding strength and biological half-life. We show that an easy-to-implement docking program, Autodock Vina, can successfully redock perfluorooctanesulfonate (PFOS) to human serum albumin with deviations smaller than 2 Å. Furthermore, predicted binding strengths largely fall within one standard deviation of measured values for perfluorinated alkyl acids (PFAAs). Correlations with half-lives suggest both membrane partitioning and protein interactions are important, and that serum albumin is only one of a number of proteins controlling the fate of these chemicals in organisms. However, few data are available for validation of our approach as a broad screening tool, and available data are highly variable. We therefore call for collection of new data, particularly including proteins other than serum albumin and substances beyond perfluorooctanoic acid (PFOA) and PFOS. The methods we discuss in this work can serve as a framework for guiding such data collection.

Watershed hydrologic processes and water quality is significantly influenced by changes in land use land cover (LULC) and climate change. Changes in rate of Interception, evapotranspiration (ET), infiltration, and runoff have impacts on soil loss and nutrient loads in watershed. Hence, there is a need to evaluate combined influences of LULC and climate change on watershed system for developing effective conservation policies. This study aims to model these synergistic effects using LULC change and climate change as drivers of watershed system. Study is done in Sudbury, Assabet and Concord (SuAsCo) watershed in Massachusetts that has runoff, and high levels of sediments and nutrients loading issues. A watershed simulation model (HSPF) is used to simulate hydrologic processes and water quality changes and is calibrated and validated using field-measured data. Downscaled regional projections from Global Climate Model (GCM) models and a regional built out scenarios of LULC are used to assess the impacts of projected LULC and climate change. The results indicate that the simultaneous changes in LULC and climate significantly affect the water resources in the SuAsCo river watershed. There is a potential for reducing runoff, sediments and nutrients loads by using conservation strategies such as best management practices (BMPs), cost sharing and incentives. This study provides valuable information to watershed managers and landowners about protecting those watershed systems that are undergoing urbanization and climate impacts.