Management of solid wastes is considered as an economic and environmental issue in the building stone industry. The current study uses raw and calcined calcareous sludge, generated in the stone cutting factories, in order to remove sulfur dioxide. Sludge characterization has been performed, using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) analyses. The removal experiments of sulfur dioxide have conducted under different humid contents and adsorbent doses. The results showed that the higher the adsorbent dosage and humidity content, the greater the SO2 adsorption.. The calcination process at temperatures of 400, 500, 600, and 700℃ revealed that with rising calcination temperature and humidity content, the adsorbent capability is enhanced considerably. This method could be developed for the management of stone sludge produced from the stone cutting industry through its conversion into an effective and low-cost adsorbent for desulfurization process.

The present study synthesizes a novel adsorbent by coating Fe3O4 magnetic nanoparticles with amino functionalized mesoporous silica. The FTIR spectrums indicate that silica has been successfully coated on the surface of Fe3O4 and 3-aminopropyl tri methoxysilane compound have been grafted to the surface of silica-coated Fe3O4. The XRD analysis shows the presence of magnetite phase with cubic spinel as a highly crystalline structure, before and after silica coating. The study also investigates the potentials of amino functionalized silica-coated Fe3O4 magnetic nanoparticles for extraction of Pb2+ and Cd2+ cations from aqueous solutions, where it has used flame atomic absorption spectrometry to determine ion concentration in both recovery and sample solutions. The optimum conditions of removal of Pb2+ and Cd2+ ions turn out to be pH= 4-8 with a stirring time of 20 minutes. The minimum amount of 3M nitric acid to strip ions from functionalized magnetic nanoparticles is 10 mL. The experimental data show the adsorption isotherms have been well described by Langmuir isotherm model, with the maximum capacity of the adsorbent being 1000.0 (± 1.4) μg, 454.5 (± 1.6) μg of Pb2+, and Cd2+ per each mg of functionalized magnetic nanoparticles, respectively. Finally, the proposed adsorbent is successfully applied to remove Pb2+ and Cd2+ ions in wastewater samples.

Finding an environment-friendly and affordable method to remove contaminated soils from Polycyclic Aromatic Hydrocarbons (PAHs) has now become an attractive field for researchers, with super-critical fluid extraction being an innovative process in the field of contaminated soil treatment. Extraction with super-critical fluid is a simple and rapid extraction process that uses super-critical fluids as solvents. The present study has investigated the extraction of contaminated soil with Polycyclic Aromatic Hydrocarbons (PAHs) by means of batch supercritical water reactor, employing variables like pressure (100–300 bar), temperature (60–140 ◦C), residence time (0.5–3 hours), and base, acidic, and neutral pH values. In order optimize the process parameters, Response Surface Methodology (RSM) has been used. Results show that removal efficiency of PAHs is between 82%-100%, where the highest PAHs removal efficiency (100%) has been observed in Test No. 22, with a pressure of 300 bars, temperature of 500°C, acidic pH equal to 5, and duration of 3 hours. In addition, the lowest removal efficiency of these compounds (82%) has been obtained in Test No. 26, with a pressure of 300 bars, temperature of 350°C, base pH of 9, and duration of half an hour. According to the results from this study, it has become clear that residence time is the most important and most effective parameter for removing PAHs from contaminated soil. Afterwards, temperature and pH are most influential with pressure showing the least effect. Using supercritical water method in appropriate conditions can eliminate more than 99% of aromatic contamination.

Greenhouse experiment was conducted for four months using Leucaena leucocephala and Pleurotus tuber-regium to determine their bioremediation potentials. Leucaena leucocephala, Pleurotus tuber-regium and Leucaena leucocephala combined with Pleurotus tuber-regium were tested for their ability to improve nutrient (N, P, K, total organic carbon) and reduce heavy metals (Zn, Ni, Pb, Cu) of soil polluted with spent engine oil [5% (w/v)] and soil without spent engine oil was used as control. Bioaccumulation of nutrients and heavy metals in Leucaena leucocephala and Pleurotus tuber-regium were also determined. The highest reduction in Zn, Ni, Pb and Cu (41%, 48.39%, 61.60 and 52.72% respectively) were recorded in soil remediated with Leucaena leucocephala alone, reduction of 30.40%, 26.53%, 48.07% and 39.60% respectively were recorded in soil remediated with Pleurotus tuber-regium alone while in soil remediated with combined Pleurotus tuber-regium and Leucaena leucocephala, reductions of 32.7%, 33.43%, 88.41% and 46.22% respectively were recorded. Bioaccumulation of Zn, Ni, Pb and Cu in Leucaena leucocephala increased by 73.41%, 85.46%, 3366.04% and 125.53% respectively, similarly in Pleurotus tuber-regium by 30.16%, 21.67%, 71.11% and 53.21% respectively. These studies have shown that Pleurotus tuber-regium and Leucaena leucocephala are capable of bioremediating spent engine oil polluted soil although, treatment with Leucaena leucocephala alone tends to be most effective of these treatments.

Municipal solid waste landfills are significant parts of anthropogenic greenhouse gas emissions. The emission of significant amount of landfill gas has generated considerable interest in quantifying such emissions. The chemical composition of the organic constituents and potential amount of landfill gas that can be derived from the waste were determined. The chemical formulae for the rapidly biodegradable waste (RBW) and slowly biodegradable waste (SBW) were determined as C39H62O27N and C36H56O20N, respectively. The triangular method was used to calculate landfill gas obtainable from rapidly biodegradable waste over a 5-year period and for slowly biodegradable waste over a 15-year period. A plot was obtained for a landfill life span of 20 years. The volume of methane and carbon dioxide from RBW were 12.60 m3 and 11.76 m3 respectively while those from SBW were 6.60 m3 and 5.48 m3 respectively at STP. For the initial deposit of 2002 the highest landfill gas emission rate occurred in 2007 at 0.2829 Gg/yr with an average cumulative emission of 0.3142 Gg while for a landfill closed after five years the highest landfill gas emission rate was in 2010 at 1.2804 Gg/yr with an average cumulative emission of 1.5679 Gg while this cumulative emission will start declining by the year 2029.

In the present study, analytical solutions are developed for three-dimensional advection-dispersion equation (ADE) in semi-infinite adsorbing saturated homogeneous porous medium with time dependent dispersion coefficient. It means porosity of the medium is filled with single fluid(water). Dispersion coefficient is considered proportional to seepage velocity while adsorption coefficient inversely proportional to dispersion coefficient. Solutions are derived for both uniform and varying plane input source. The source geometry, including shape and orientation, broadly act major role for the concentration profile through the entire transport procedure. Initially the porous domain is not solute free. It means domain is throughout uniformly polluted. With help of certain transformation advection-dispersion equation is reduced into constant coefficient. The governing advection-dispersion equation, initial and boundary condition is solved by applying Laplace Transform Technique (LTT). The desired closed-form solution for the line source in two-dimensions and point source in one-dimension of uniform and varying nature are also evaluated as particular cases. Effects of parameters and value on the solute transport are demonstrated graphically.

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+.

Biomass derived from Tamarindus indica partially activated seed coat was investigated for the removal of nitrate ions from aqueous solutions. Batch experiments were performed to evaluate the parameters like pH, contact time, sorbent dose and initial nitrate concentration. pH of the solution played vital role. The maximum sorption observed at pH=7, sorbent dose 300mg, contact time at 120min, initial nitrate concentration 5mg. Physicochemical properties of the biomass were evaluated using scanning electron microscopy (SEM), energy dispersive X-ray analysis and Fourier Transform infra red (FTIR) spectroscopy. The SEM and FTIR data reveals the suitable surface and the presence of chemical functional groups such as hydroxyl, amide, carbonyl strong acid and primary amine on the biosorbent surface contributes to biosorption. The equilibrium isotherms and kinetics were deliberated. Biosorption equilibrium followed Langmuir isotherm. Pseudo second order kinetics provided better correlation of the experimental data in comparison with pseudo-first-order kinetic model. The study indicated that Tamarindus indica partially activated seed coat biomass found to be a novel biosorbent for the removal of nitrates from aqueous solutions.

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.

This study was undertaken to evaluate a novel aerobic wastewater treatment model for the remediation of refinery effluents and to assess the removal efficiency of Bulkholderia cepacia strain AJI and Corynebacterium kutscheri strain AJ2 to clean oil waste from petrochemical company. Wastewater quality parameters including pH, BOD5, COD, TDS, OIL & GREASE, PHENOL concentration, TPH and THC were monitored at 5, 10 and 15 days of treatment and the removal efficiencies were calculated. Results indicated that the raw oily wastewater effluents used during this study had extremely high levels of all the tested parameters. The mean values  of  all physicochemical parameters  of the wastewater from primary tank at different treatment period were statistically different (P˂0.001) After 15 days of biological treatment, BOD5 ,COD, TDS, Phenol, TPH, Oil & grease level of the refinery wastewater were reduced by 95.60 %, 98.40 % , 66.34 % , 100 %, 97.60 %  and 96.20 % respectively. The detection of the catabolic genes in the bacterial isolates recovered from primary tank using polymerase chain reaction revealed that both Bulkholderia cepacia strain AJ1 and Corynebacterium kutsheri strain AJ2 carried alk B and C23O but C12O was not detected in both isolates. Naphthalene dioxygenase was detected in Bulkholderia cepacia strain AJ1 but not found in Corynebacterium kutscheri strain AJ2. After treatment the waste water was filtered in the secondary tank. The results of physicochemical parameters in the outlet vessel essentially confirmed that the mixed culture in the two column model successfully carry out bioremediation of refinery wastewater. Therefore, aerobic treatment model for the bioremediation of refinery Petroleum refineries generate great amounts of wastewaters that may become seriously dangerous, leading to the accumulation of toxic products in the receiving water bodies with potentially serious long term effects to aquatic biota. Due to extreme toxicity of contaminants in refinery wastewater, there is a need to develop an economical technique to remove the pollutants from the wastewater is highly recommended owing its environmental friendliness.