The present study was carried out to investigate the adsorption and leaching behavior of Cu2+, Zn2+ and Pb2+ by sediments collected from the western banks of three different sectors along River Nile at Aswan governorate, Egypt. The feasibility of sediments for the removal of Cu2+, Zn2+ and Pb2+ from aqueous solutions was tested under the effect of three conditions (pH, initial metal concentration and contact time). By increasing pH, the adsorption of Cu2+ and Pb2+ by sediments decreased while that of Zn2+ increased. The optimum pH values for Cu2+, Zn2+ and Pb2+ removal were determined as 5, 8.5 and 5, respectively. The adsorption capacities of sediments for metal ions were in the order of Pb2+ > Cu2+ > Zn2+. The maximum uptake for Cu2+, Zn2+ and Pb2+ by sediments occurred at contact times of 48 h, 24 h and 72 h, respectively. Adsorption data were fitted well by Freundlich, Dubinin–Radushkevich and Temkin isotherms. The experimental results obtained were analyzed using two adsorption kinetic models, pseudo-first-order and pseudo-second-order, in which pseudo-second-order equation described the data more than pseudo-first-order one. The average leaching percentages of Cu2+, Zn2+ and Pb2+ from sediments were 0.77%, 2.72% and 0.38%, respectively, with respect to pH, 0.83%, 2.49% and 0.38%, respectively , with respect to temperature, and also 0.79%, 2.34% and 0.38%, respectively with respect to contact time. The leaching percentages of metal ions from sediments were in the order of Zn2+ > Cu2+ > Pb2+.

Surface water contains a large number of pollutants, particularly human pathogens, organic toxicants and heavy metals. Due to the toxic nature of heavy metals towards marine organisms, its removal from the environment has been a growing issue. The biosorption of heavy metal ions from surface water using fish scales has emerged as an environmentally friendly technique. This study assessed the degree of heavy metals accumulation in the scales of Oreochromis niloticus and determining its efficiency as a bioindicator for Cu, Mn and Fe ions removal in the environment of Wewe and Owabi rivers. This study shows that the levels of Cu, Mn, Fe adsorbed from the Owabi river were 685.70 ± 16.51, 247.06 ± 50.46 and 892.90 ± 96.29 mg/kg, respectively. Moreover, the levels of Cu, Mn and Fe adsorbed from Wewe river were 501.60 ± 77.78, 300.89 ± 54.61     and 413.04 ± 9.92 mg/kg, respectively. Under best optimum adsorption conditions, Cu was the best removed heavy metal ions in both surface water reservoirs. Multivariate analysis showed that Cu and Mn showed association in Owabi river, while Mn and Fe were correlated in Wewe river signifying their similarities to a common anthropogenic activity. The Fourier–transform infrared spectrum revealed the existence of a nitro, amine, and carbonyl groups in the biosorption process. This study highlighted that Oreochromis niloticus scales was an efficient bio–sorbent in removing Cu, Mn and Fe ions from Owabi and Wewe rivers.

This study carried out to investigate the production of hydrogen using the organic fraction of municipal solid waste OFMSW, where the anaerobic digester was depended as a method for disposing and treating OFMSW and producing bio-hydrogen. Bio-hydrogen production had been studied under different parameters including pH, solid content T.S%, temperature and mixing ratios between the thick sludge to OFMSW. The optimal conditions were found at pH, T.S%, temp and mix ratio of 7, 8%, 32oC, and 1:5, respectively where the hydrogen yield was (138.88 mL/gm vs).  To found the most important parameters in this process, the ANN model had been applied. The effectiveness of temperature, total solid, mixing ratio and pH comes in the following sequence 100%, 75.8%, 71.9%, and 57.2% respectively, with R2 of 95.7%. Multiple correlation model was used to formulate an equation linked between the hydrogen production and the parameters effected on. Gompertz model was applied to compare between theoretical and experimental outcomes, it also given a mathematical equation with high correlation coefficient R2 of 99.95% where the theoretical bio-hydrogen was (141.76 mL/gm vs) under best conditions. The first order kinetic model was applied to evaluate the dynamics of the degradation process. The obtained negative value of (k = - 0.0886), indicates that, the solid waste biodegradation was fast and progresses in the right direction.

The Kolleru Lake is a famous Ramsar wetland of international significance. In this study heavy metal contents in water and sediment samples are reported. It is found that certain potentially toxic metal ions like chromium (4.5-80 µg/L), copper (1-20 µg/L), manganese (1-313 µg/L) and zinc (1.2-57 µg/L) are present in variable quantities in the lake water. When normalized with respect to concentration of each element in clean surface waters, the normalized ratio is found to be highly heterogeneous (chromium=4.5-80, copper=0.3-3.3, manganese=0.07-20.8, zinc= negligible to 2.8). At several places, the normalized ratio is greater than 1, indicating anthropogenic input.  The concentration of iron (4-20 µg/L) in water, however, is less compared to the clean surface waters.  Chemical analyses and quality assessment of Kolleru Lake sediments have been carried out through estimation of four pollution indices, which include enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF) and pollution load index (PLI). Evaluation of these contamination indices with respect to average sediment composition of Taylor & McLennan (2001) confirmed that the Kolleru Lake sediment is polluted with a number of heavy metals that include cobalt (EF=2, Igeo=0.64, CF=2.4) , chromium (EF=1.5, Igeo=0.18, CF=1.7), copper (EF=1.6, Igeo=0.29, CF=1.9), manganese (EF=1.3, Igeo=0, CF=1.4), vanadium (EF=1.5, Igeo=0.19, CF=1.7) and zinc (EF=1.5, Igeo=0, CF=1.5). The level of contamination, however, is minor to moderate and is in good agreement with the heavy metal chemistry of the lake water. Based on these results some measures for environmental rehabilitation of the lake and its surroundings have been proposed.

Advanced Oxidation Processes (AOPs) have been employed to degrade biorefractory organic matters. This study investigates the combination of classical Fenton reaction with electrochemical oxidation, the electro-Fenton process, for the treatment of semi aerobic landfill leachate, collected from Pulau Burung Landfill Site (PBLS), Penang, Malaysia. The investigation has been carried out in batch reactors with aluminum electrodes to establish the optimal treatment conditions. The effects of applied current, pH, reaction time, electrodes separation distance, H2O2/Fe2+ molar ratio, and H2O2 and Fe2+ concentrations, significant process parameters by themselves, have also been investigated. According to the obtained results, electro-Fenton process is very efficient for the treatment of landfill leachate. Optimum oxidation efficiency has been achieved when neither H2O2 nor Fe2+ are overdosed, so that the maximum amount of OH radicals is available for the oxidation of organic compounds. The highest COD and color removals have been 92% and 93%, respectively; obtained at initial pH=3, H2O2/Fe2+ molar ratio=1, applied current= 2A, treatment duration= 30 min, and electrodes separation distance= 3 cm. The current efficiency declines from 94% to 38% when the current rises from 0.5A to 2A.

Over the last few decades, Anzali wetland has been at risk of pollutants, especially from heavy metals. The present research analyzes some physical and chemical properties and heavy metals concentration in 27 points in nine stations of Anzali wetland. The samples of each station have been mixed, acidic digested, and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The mean concentrations of Fe, Mn, Pb, Zn, As, Cd, Cu, Hg, Ni, and Cr have been 50527.2, 1210, 23.3, 79.4, 8.8, 0.23, 32.1, 0.25, 31.6, and 31.5 mg/Kg, respectively. In addition, it can be seen that the concentrations of Cd (0.31 mg/Kg) and As (25.47 mg/Kg) in Hendekhale station, Hg (0.52 mg/Kg) in Pirbazar station, and Pb (52.69 mg/Kg) in Khazar villa station surpass world surface rock average. According to contamination factor (CF), in case of Mn and Pb, both Hendekhale, and Khazar Villa stations have been in considerable contamination level. The calculation of Pollution Load Index (PLI) shows that Hendkhaleh and Khazar Villa stations have had moderate pollution. The mCd index survey indicates that only in Hendekhale station, has heavy metals contamination been at a low degree level of contamination. According to PER index, mercury metal contamination in Hendekhale station faces medium risk. The calculated mean ERM quotient indicates the probability of heavy metals toxicity, equal to 21% in the examined stations.

Coal mining and related industry can increase heavy metals (HMs) concentrations in soil, atmosphere and wheat, thereby posing metal-associated human health risk via food ingestion.  In this study, 58 samples of soil, wheat, and dust were collected from Xuzhou coal mine eastern China, six kinds of HMs Pb, Cd, Cu, Zn, As and Cr were studied for their spatial distribution in wheat, enrichment in different wheat organs (roots, stem leaf, glumes, and grains), pollution level and potential human health risks. Results show that the spatial distribution of HMs in wheat grains were likely to coal while dissimilar to soil.  Most of heavy metals enrichment in wheat organs retained in glume and stem leaf after roots, and followed by grains, indicating that HMs was accumulated more from atmospheric dust as compared to other sources. Meanwhile, 71% of wheat grains were contaminated by HMs comprehensively in Xuzhou coal mine area. The potential health risk indicated that ingestion of food was the main exposure route causing non-carcinogenic and carcinogenic risk for inhabitants. This study provides basic information to control HMs enrichment from atmospheric dust and human health risk management policies in the mining area.

In the present work WRF model is used to generate meteorological fields for the HYSPLIT dispersion model. Sensitivity and validation of the WRF model, is conducted by utilizing different combinations of physical parameterization schemes. For this purpose, eight different configurations are examined. Assessment of the predictions of the WRF model is carried out by computing the statistical parameters including correlation coefficient (CC) and root mean square error (RMSE). As an example of the results of the WRF model utilizing proper physical configuration at Bousher syoptic station at 03/01/2005 leads to CC=0.82007 and RMSE=1.91783 for wind speed parameter. Once the proper configuration of the WRF model is obtained, dispersion simulations and annual effective dose for adult age group are carried out by WRF-HYSPLIT coupled model under normal conditions for Bushehr power plant. Simulated annual effective dose for adult age group by the coupled model for the years 2014, 2015 and 2016 are 5.8E-08 Sv/yr, 6.7E-08 Sv/yr and 1.1E-07 Sv/yr respectively. Results show that simulation and prediction of effective dose with coupled WRF-HYSPLIT model are in good agreement with observations and indicates the validity of the simulations. The ratio of predicted annual effective dose to dose limit (1E-04 Sv/yr) for normal operation is obtained less than 0.2 percent (

The present paper aims at investigating the applicability of hybrid cells in the series model for pollution transport inside the layered porous media. For this purpose, four layers of rock material have fallen inside the experimental flume, with eight sensors installed longitudinally inside the media to obtain experimental BTCs. In order to measure time parameters of the model, named , two different methods of LSCF and MM have been examined. The model's sensitivity as well as its temporal equations with different parameters have been assessed. Finally, results show that at the fixed time step, the model is more sensitive to parameter (advection zone time parameter) rather than residential time parameters, to which the moment relations are more sensitive. A detailed computation of the related transport parameters has been operated and the Peclet number, crossing velocity, dispersion coefficient, time to the max, and maximum concentration have been calculated. Eventually, the model's applicability for large-scale porous media has been proven with only one unit of the cells.

With the growth and development of chemical plants, the amount of mercury released in wastewater has increased. Mercury in wastewater contains harmful compounds which are hazardous to the human health and living organisms. Therefore, its removal from wastewater is significant. There are various techniques or methods available for removing mercury from aqueous solutions. This study focused upon the removal of mercury from aqueous solution with commercial activated carbon and activated carbon from sugarcane bagasse.  Activated carbon produced from sugarcane bagasse was used as adsorbent. This adsorbent was used to remove mercury from aqueous solution. For this purpose, first, the optimal mercury solution pH for mercury removal was obtained. Effective parameters such as contact time, initial concentration of mercury, adsorbent dose and agitation speed were investigated. The mercury adsorption was increased when the mass of activated carbon was increased. Increasing the initial mercury concentration leads to decrease in mercury adsorption efficiency. The results of experiments indicated that the speed of the stirrer was not considered to be an effective factor in the mercury adsorption. Experiments were also carried out on a commercial activated carbon. Adsorption results obtained for sugarcane bagasse activated carbon were compared with commercial activated carbon.  The adsorption efficiency was increased as the contact time was increased.  Finally, the experiment was carried out on water samples released from South Pars platforms. In addition to the mercury removal, other heavy metals removal such as lead and cadmium were also carried out.