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Jiwan Singh,Ajay S. Kalamdhad,Byeong Kyu Lee 대한환경공학회 2015 Environmental Engineering Research Vol.20 No.3
Experiments were conducted on the immobilization of eight heavy metals (HMs) (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) during 20-day rotary drum composting of water hyacinth. The Tessier sequential extraction procedure was used to investigate the fractionation of HMs. The eco-toxicity risk of HMs was assessed by risk assessment code (RAC). In the results, the bioavailability factor (BAF) for different HMs presented in the following order: Mn > Zn = Fe > Cu > Cr > Cd = Pb > Ni. The total concentration of Pb was higher than that of Zn, Cu, Mn, Cd and Cr; however, its BAF was the lowest among these HMs. These results confirmed that the eco-toxicity of HMs depends on bioavailable fractions rather than on the total concentration. The greatest reduction in bioavailability and eco-toxicity risk of HMs occurred in lime 1% and 2% as compared to control and lime 3%. The eco-toxicity risk of Fe, Ni, Pb, Cd and Cr was reduced from low risk to zero risk by rotary drum composting. These studies demonstrated the high efficiency of the rotary drum for degrading compost materials and for reducing the bioavailability and eco-toxicity risk of HMs during the composting process.
Rapid Fenton-like degradation of methyl orange by ultrasonically dispersed nano-metallic particles
Jiwan Singh,Yoon-Young Chang,Janardhan Reddy Koduru,Jae-Kyu Yang,Devendra Pratap Singh 대한환경공학회 2017 Environmental Engineering Research Vol.22 No.3
This study investigates methyl orange (MO) degradation by an ultrasonically dispersed nano-metallic particle (NMP) assisted advanced Fenton process. The NMPs were synthesized from the leachate of automobile-shredder residue. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were performed for the prepared NMPs. Various parameters, such as the effects of the NMP dosage, the pH value of the solution, the initial concentration of MO, and the amount of H2O2 on the degradation efficiency of MO were studied. The MO degradation efficiency could be increased by approximately 100% by increasing the dosages of the NMPs and H2O2 to certain limits, after which in both cases the degradation efficiency was reduced when an excess amount was added. The MO degradation efficiency was found to be 100% at pH 2.0 and 2.5 with the 10 mg/L of initial concentration of the MO. The degradation of MO by ultrasonically dispersed NMPs was appropriate with the pseudo-first-order kinetics.
Effect of Rotary Drum on the Speciation of Heavy Metals during Water Hyacinth Composting
Jiwan Singh,Ajay S Kalamdhad 대한환경공학회 2013 Environmental Engineering Research Vol.18 No.3
Studies were carried out on the speciation of heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) during rotary drum composting of water hyacinth (Eichhornia crassipes) for a period of 20 days. Five different proportions of cattle manure, water hyacinth and sawdust were prepared for composting. This study concluded that, rotary drum was very efficient for the degradation of organic matter as well as for the reduction of mobility and bioavailability of heavy metals during water hyacinth composting. The results from the sequential extraction procedure of heavy metals shows that rotary drum composting changed the distribution of five fractions of Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr. The highest reduction in the bioavailability factors of Pb and Cd was observed during the process. The total concentration of Cu, Cr, and Cd was very low compared to the other metals (Zn, Mn, Fe, Ni, and Pb); however, the percentage of exchangeable and carbonate fractions of these metals was similar to other metals. These results confirmed that the bioavailability of metals does not depend on the total concentration of metals. From this study, it can be concluded that the addition of an appropriate proportion of cattle manure significantly reduced the mobile and easily available fractions (exchangeable and carbonate fractions) during water hyacinth composting in rotary drum.
( Jiwan Singh ),( Ajay S. Kalamdhad ),( Yoon-young Chang ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-
The bioavailability and speciation of heavy metals (Cu, Pb, Cd and Cr) assist an important role in the toxicity of heavy metals in the compost applied for soil conditioning. The study was carried out on bioavailability and speciation of heavy metals in the composting of water hyacinth in rotary drum for 20 days. The exchangeable (F1), carbonate (F2), reducible (F3) and oxidizable (F4) fractions of Cu were decreased in the control and all calcium hydroxide addition compost. Reduction of F1 (88.6%), F2 (76.7%) and F3 (89.4%) fractions (percentage of total fraction) was observed in lime treatment 2. F1 and F2 fractions of Cd, Cr and Pb were reduced, and F5 fraction was increased in lime treatments as compared to the control. Present study concluded that, the optimum amount of waste lime was greatly effective of reduction of water solubility, plant availability, and most boilable fractions (exchangeable and carbonate fractions) of selected heavy metals. The effect of waste lime is highly recommended for immobilization of heavy metals for water hyacinth composting in rotary drum.
Potential degradation of methylene blue (MB) by nano-metallic particles
Jiwan Singh,Yoon-Young Chang,Janardhan Reddy Koduru,Jae-Kyu Yang 대한환경공학회 2018 Environmental Engineering Research Vol.23 No.1
The degradation of methylene blue (MB) in an aqueous solution by nano-metallic particles (NMPs) was studied to evaluate the possibility of applying NMPs to remove MB from the wastewater. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the synthesized NMPs before and after the reaction. The effects of the NMP dosage, the initial pH, the initial concentration of MB and the amount of H₂O₂ on the MB degradation outcomes were studied. The highest removal rate of MB was achieved to be 100% with an initial MB concentration of 5 mg/L, followed by 99.6% with an initial concentration of 10 mg/L under the following treatment conditions: dose of NMP of 0.15 g/L, concentration of H₂O₂-100 mM and a temperature of 25℃. The SEM analysis revealed that the nano particles were not spherical in shape. FTIR spectra shows occurrence of metal oxides on the surfaces of the NMPs. The XPS analyses results represent that Fe, Zn, N, Ca, C and O were occurred on the surfaces of the NMPs. The degradation of MB was suitable for the pseudo-first-order kinetics.
Singh, Jiwan,Lee, Byeong-Kyu Elsevier 2015 Journal of environmental management Vol.161 No.-
<P><B>Abstract</B></P> <P>To investigate the leaching and recovery of heavy metals from low-grade automobile shredder residue (ASR), the effects of nitric acid (HNO<SUB>3</SUB>) and hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) concentrations, liquid/solid (L/S) ratio, leaching temperature and ASR particle size fractions on the heavy metal leaching rate were determined. The heavy metals were recovered by fractional precipitation and advanced Fenton process (AFP) at different pHs. The toxicity characteristic leaching procedure (TCLP) test was also performed in the residue remaining after heavy metal leaching to evaluate the potential toxicity of ASR. The heavy metal leaching efficiency was increased with increasing HNO<SUB>3</SUB> and H<SUB>2</SUB>O<SUB>2</SUB> concentrations, L/S ratio and temperature. The heavy metal leaching efficiencies were maximized in the lowest ASR size fraction at 303 K and L/S ratio of 100 mL/g. The kinetic study showed that the metal leaching was best represented by a second-order reaction model, with a value of R<SUP>2</SUP> > 0.99 for all selected heavy metals. The determined activation energy (kJ/mol) was 21.61, 17.10, 12.15, 34.50, 13.07 and 11.45 for Zn, Fe, Ni, Pb, Cd and Cr, respectively. In the final residue, the concentrations of Cd, Cr and Pb were under their threshold limits in all ASR size fractions. Hydrometallurgical metal recovery was greatly increased by AFP up to 99.96% for Zn, 99.97% for Fe, 95.62% for Ni, 99.62% for Pb, 94.11% for Cd and 96.79% for Cr. AFP is highly recommended for the recovery of leached metals from solution even at low concentrations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nitric acid combined with H<SUB>2</SUB>O<SUB>2</SUB> greatly increased the leaching of metals from ASR. </LI> <LI> The leaching rate of metals increased with increasing temperature and L/S ratio. </LI> <LI> The second-order kinetic model was best fitted (R<SUP>2</SUP> ≥ 0.99) with the metal leaching. </LI> <LI> The leaching rates of metals were controlled by both diffusion and chemical processes. </LI> <LI> Application of the advanced Fenton process greatly increased the recovery of metals. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Singh, Jiwan,Lee, Byeong-Kyu Elsevier 2018 PROCESS SAFETY AND ENVIRONMENTAL PROTECTION Vol.116 No.-
<P><B>Abstract</B></P> <P>This study investigated the effects of nano-TiO<SUB>2</SUB> particles on cesium uptake by soybean plant, which was conducted in a plant growth chamber with adding different concentrations of <SUP>133</SUP>Cs to the soil. This study identified compositional and functional group changes of the elements contained in the soybean root and shoot due to the accumulation of <SUP>133</SUP>Cs. With use of nano-TiO<SUB>2</SUB>, the accumulation of <SUP>133</SUP>Cs identified in the shoot (731.7μg/g dw) was higher than that in the root (597.8μg/g dw). The Cs 3d peaks identified in the XPS spectrum analysis of the shoot and root biomass could be an evident for <SUP>133</SUP>Cs accumulation. The appearance of the new FTIR peaks on the root and shoot biomass can be explained by new bond formation of <SUP>133</SUP>Cs or nano-TiO<SUB>2</SUB> with biomass matrix. Therefore, the application of nano-TiO<SUB>2</SUB> in Cs contaminated soil can significantly enhance <SUP>133</SUP>Cs uptake and its accumulation in plants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phytoremediation was one of the safest tools for <SUP>133</SUP>Cs remediation from the soil. </LI> <LI> Application of nano-TiO<SUB>2</SUB> to soil increased the accumulation of <SUP>133</SUP>Cs in soybean. </LI> <LI> FTIR spectra proved variation of the functional groups in different treatments. </LI> <LI> Highest accumulation of <SUP>133</SUP>Cs was found in shoots compared to roots. </LI> <LI> TF value >1 confirms the soybean is favorable for the phytoremediation of <SUP>133</SUP>Cs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>