International Journal of Environmental Science and Development
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Coral bleaching occurs when cell density or the concentration of photosynthetic pigments of the endosymbionts, zooxanthellae are decreased. This incident may possibly be caused by some environmental stresses, especially under conditions of elevated temperature, decrease in water salinity, or a combination of these factors. To determine the role of temperature and salinity on zooxanthellae and coral bleaching this study was conducted in aquariums under laboratory conditions on cauliflower coral Pocillopora damicornis. The samples were collected from three sites around Samaesan Island, Chonburi, Thailand. Three sets of experiments were conducted at three levels of temperature: room temperature 27 (control), 30, and 33 oC respectively. At each temperature level, three levels of salinities; 10, 20 and 30 (control) psu were tested as well. Coral bleaching percentage and zooxanthellae density in the water column were observed every 6 hours during the period of 72 hours. The results showed that when coral exposed to the highest temperature (33 oC) under the lowest salinity (10 psu), 50-90% bleaching was found and higher symbiont densities in the water column were detected. These results suggested that the combination of the high temperature and low salinity had synergistic effects on coral bleaching and zooxanthellae.

Hyper Pure Germanium (HPGe) radiation detector was used to estimate the activity concentration of fifteen soil and palm oil samples collected from the oil palm plantations in the southwestern, southeastern, and south southern states of Nigeria, and the risk assessments was evaluated. The activity concentrations at a soil depth 0 – 15 cm ranged from 187.4 to 514.4, 2.328 to 6.571, and 1.509 to 6.121 Bq/kg for 40K, 238U, and 232Th, respectively. The activity concentrations at a soil depth 15 – 30 cm ranged from 163.4 to 3188.8, 1.345 to 9.410, and 1.476 to 6.275 Bq/kg for 40K, 238U, and 232Th, respectively. The activity concentrations in the palm oil ranged from 122.3 to 968.0, 1.240 to 6.651, and 1.199 to 8.061 Bq/L for 40K, 238U, and 232Th. For the risk assessments of surface soil samples, the absorbed dose rate (D) ranged from 5.09 to 24.54 nGy/h, while the annual effective dose equivalent (E) ranged from 0.612 × 10-2 to 16.49 × 10-2 mSv/y. The radium equivalent, gamma absorbed dose rate, and the annual effective dose rate in the palm oil samples ranged from 9.981 to 88.00 Bq/L, 4.315 to 46.29 nGy/h, and 0.53 × 10-2 to 56.90 x 10-2 mSv/y, respectively. The activity concentrations reported for soil and palm oil samples were lower than the recommended world average values given by UNSCEAR. Hence, the hazard and risk assessments indicated a low radiation risk within the studied areas.

This paper focuses on the performance assessment of the green filtration system that incorporated with evaporative cooling that used to enhance indoor air quality. This system was invented in an attempt to thrive in a clean environment that becomes a solution for certain places. Indoor air quality (IAQ) and public health risk related to each other, it is due to the percentage of the city population that stays indoors rather than go outdoors. Indoor air contamination is originated from mixed origins such as volatile organic compounds (VOCs) and indoor airborne particulate matter (PM). The results show that the green filtration system manages to filter PM and VOCs in the air but not as efficient as modern air filters in the market. Furthermore, the evaporative cooling system possesses a huge deal in energy-saving within hot and arid climatic regions.

Drought is a natural disaster that significantly affects environmental and socio-economic conditions. It occurs when there is a period of below average precipitation in a region, and it results in water supply shortages affecting various sectors and life adversely. Droughts impact the ecosystems, crop production, and erode livelihoods. Monitoring drought is essential especially in the United Arab Emirates (UAE) due to the scarcity of rainfall for an extended period of time. In this study, drought is assessed in Sharjah UAE using monthly precipitation and average temperature data recorded for 35 years (1981-2015) at the Sharjah International Airport. The standardized precipitation Index (SPI), and the Reconnaissance Drought Index (RDI) are selected to predict future droughts in the region. SPI and RDI are fitted to the statistical distribution functions (gamma and lognormal) in an annual time scale and then, a trend analysis of index values is carried out using Mann-Kendal test. The correlation between SPI and RDI indices was found to be high where both showed high drought frequencies and a tendency to get drier over time, thus indicating the need of appropriate drought management and monitoring.

Compared to other petroleum, the natural gas combustion remains the cleanest and the one showing less CO2 emission. These reasons make the natural gas combustion one of the important issues to study. The separation of NGL is energy intensive. This operation is performed through a series of column including the debutanizer column. The present work is devoted to optimize the energy consumption at the level of the debutanizer column. The response surface technique and deploying a central composite numerical design is followed makes use of available data from a refinery. Using a multiple linear regressions, the optimization method leads us to three reliable models. Each of the three models takes as input the reflux ratio and the head pressure in order to predict the condenser heat duty, the reboiler heat duty and the purity of the produced butane. Suggested mathematical models were validated and their reliability was assessed via a set of statistical analyses. The optimization aims to simultaneously minimize the energy consumption of the condenser and reboiler, and maximize the purity of the ejected Butane. This optimization step allowed us to define the optimal values of reflux ratio and head pressure, with desirability function equal to 99 %. Under the determined optimal values, operating energy and cost of the industrial process were reduced by 38 % and 37 %, respectively, and besides, a high purity of butane was noticed reaching 99 %. From an economic point of view, separation NGL with optimal values of pressure and reflux ratio, may contribute to a decrease of CO2 emission and increases the energy efficiency.

In arid lands, rainwater harvesting can play an important role in making more water available since most of the rainfall runoff evaporates. If rainwater can be collected, it will form a useful resource. Jordan is classified as one of the poorest countries regarding water resources with an arid and semi-arid climate. For these limited and vital sources of water, good estimation of rainfall runoff quantity and quality can enhance the sustainability of water harvesting projects. The hydrologic estimations of runoff quantities and qualities are essential, and several techniques to achieve that exist. Revised Universal Soil Loss Equation (RUSLE) is one of the widely used techniques to assess the soil erosion due to runoff, by assessing other physical factors that affect the soil loss. RUSLE combined five parameters to identify the soil loss rate: rainfall erosivity, topographic, soil erodibility, vegetation cover and management, and land management. Based on RUSLE results, areas are classified as a highly soil loss rate if the annual rates exceeded 20 tons per hectare. The Asreh watershed is a 196 km2 area that is mostly wasted land and receives an annual rainfall between 50 and 300 mm per year. The RUSLE equation inputs parameters for the study area are found and the equation is applied for the watershed. Results of RUSLE application on the Asreh watershed showed that the average annual soil loss rate is about 7.8 tons per hectare, about 73% of the area are classified as low soil loss rate with less than 10 tons per hectare per year, and only 13% of the area is classified as a high soil loss rate of more than 20 tons per hectare per year.

Banjarnegara is one of the regions in Central Java which is very vulnerable to landslide disaster. This condition is motivated by the geological conditions and the metoerological conditions of Banjarnegara Regency that contributed to the high potential for landslides. One area in Banjarnegara Regency which is prone to landslides is Karangkobar Sub-District. From 2018, there have been 23 landslides in Karangkobar Sub-District, out of a total of 152 landslides that occurred in Banjarnegara. This study intended to determine the level of landslide threats in Karangkobar Sub-District and the level of community capacity in dealing with landslide threats in Karangkobar Sub-District. The method used in the study is scoring, geographic information systems, descriptive, Gutman scale, and comparative descriptive. Parameters used to determine the threat of landslides are rainfall, slope, soil type, land use, soil texture, soil drainage, and soil depth. While the parameters for the level of capacity are the rules and institutions for disaster management, early warning and disaster risk assessment, disaster education, reduction of basic risk factors, and preparedness development for all lines. Based on to the result, we know that the level of landslides in Karangkobar Sub-District consists of low landslide threat level that covers only 1% of the Karangkobar area, moderate landslide threat that covers 74% of the Karangkobar area, and High level of landslide threat that covers 25% of the entire Karangkobar area. Based on the research result shows that most of the Karangkobar Sub-District area still has a low capacity in dealing with disasters. The low capacity of the community in Karangkobar Sub-District will be a serious problem because of the large threat of landslides in the area. For this reason, disaster mitigation efforts are needed in the Karangkobar Sub-District community.

Greywater is the major part of water consumption in houses. Greywater should be treated to complying with the specifications for several purposes such as toilet flush, landscaping irrigation, and agriculture. The treatment efficiency of both MBR and RBC systems was investigated by using a verified mathematical model. The simulation program GPS-X (version 6.0) was used to simulate both MBR and RBC systems. The simulation model for biological treatment for both MBR and RBC systems is based on Activated Sludge Model 1 (ASM1). The experimental data for model calibration and verification for the MBR system were taken from experimental work done at Tubitak, Marmara Research Center, Turkey ATASOY. As well as the RBC proposed model was verified also by using RBC experimental results for a pilot plant according to BABAN. The RBC pilot plant consists of three units, The first is the RBC unit, the second unit is the settling tank and the last unit is the disinfection tank. The results of the MBR plant showed that the removal efficiencies of the greywater were: 95% for COD; 95% for BOD5; 96% for TKN; 92% for NH4+ and 99% for TSS. Whereas, the results of the RBC show that, The BOD efficiency removal was ranged between about 93.0 to 96.0 %, and for the total SS removal was ranged between 84.0 to 95.0 %. The MBR system provides complete nitrification and suspended solid removal. The RBC system provides less nitrification process and suspended solid removal. The effluent of the rotating biological contactors units for the greywater could be reused after filtration and disinfection with minimal cost of operation. The effluent of the membrane bioreactor unit needs only disinfection before reuse.

Environmental impact assessment (EIA) is a preemptive tool used by engineers, environmental consultants and planners to avoid the most likely adverse consequences of development projects. As a planning tool, EIA should curb the harmful effects from all stages of a project lifecycle. Landslides and flash floods are the most common problems faced by Malaysians almost yearly due to rapid development, especially that involving modification of watercourses, clearing of land and projects on hill slopes. Despite such issues, existing legislation and new guidelines have been enacted by the Malaysian government and must be followed by any proposing project team before starting development projects. The Department may have accepted an EIA report of the project. Still, several developments may have neglected the guidelines, especially during construction involving earthworks and exposure of the surrounding environment, place and people to a high risk of disaster caused by mishaps and accidents. The incidence of landslides and flash floods as reported in newspapers, journals, reports and books since 1919 is explored in this study to determine the details of the losses and locations. Despite the enactment of the new EIA law, landslides and flash floods continue to occur. This situation justifies the need to revise the approach based on sizes and include other factors, namely, the risk indices for disaster to happen and the effectiveness of EIA in reducing disaster risks in projects.

Water bodies play a significant role in its surrounding thermal environment. Thermal comfort in university spaces is critical that affects the students’ health and performance as well as the staffs. This study investigated thermal environment and comfort near lakeside and non-lakeside tropical university spaces. Standard Effective Temperature (SET*) have been calculated using recorded air temperature, relative humidity, globe temperature, air velocity, clothing insulation and metabolic rate to evaluate the thermal comfort in outdoor and indoor spaces. The effects of weather parameters have been clearly visible on the comfort index. The calculated SET* values indicate that the outdoor thermal comfort near a lake is much closer to the standard comfort zone than non-lakeside outdoor space. In the case of indoor thermal comfort, however, slightly a different scenario has been observed. To achieve the desirable indoor thermal environment, some design considerations are recommended based on findings.