• Energy Research

Abstract: This study reports a feasible method for heavy metal ions removal from aqueous via modified nylon fibers. Modified nylon fibers were used as sorbent materials in batch experiment. The amine/amide groups on nylon fibers’ surface were modifies by acrylic acid graft copolymerization and ethylenediamine solution. Surface modification was observed to enhanced the sorption capacity of nylon fibers by more than about 90% and 20% for Pb(II) and Cr(IV) removal, respectively. These caused of ability of the amine/amide chelating groups on the fiber. The experiments also investigated the influencing of pH, initial concentration, and contact time. The adsorption mechanisms of Pb(II) and Cr(IV) were following Freundlich’s isotherm and pseudo second-order reaction.

The performance of chemically modified textile waste for a heavy metal treatment is reported in this study. Two sorbents, which were prepared by a simple and concise method, were able to bind two heavy metals including Pb(II) and Cr(VI), with very high efficiencies. The binding mechanisms were studied through adsorption tests such as the influence of contact times, heavy metal concentrations as well as elution study. The overall results showed that the adsorption kinetics was very fast and attained an equilibrium within 180 min in all metals studied. The maximum single metal uptakes were 11.81 mg/g and 1.97 mg/g, for Pb(II) and Cr(VI), respectively. The sorbent could potentially be effective in treating large volumes of wastewater. Keywords: Modified textile, Textile waste, Chemisorption, Graft copolymerization, Amino chelating, Ion exchange

Modified tapioca starch wastewater (MTSW) contains organic and inorganic matters that affected on biological wastewater treatment and biogas production. Especially, the wastewater from chemical modification processes contains high salinity that can inhibit microorganism activities. Zero valent iron is expected to be helpful for creating an enhanced anaerobic environment that might improve the performance of the anaerobic process. The bio-electrochemical system can promote microbial metabolism thereby leading to higher biochemical performance. Result in this study aimed at enhancing performance of upflow anaerobic sludge blanket reactors a treatment for biogas production from MTSW. Three improving methods were compared that included of bio-electrochemical system (BES-UASB), zero-valent iron (ZVI-UASB) and salt tolerance microbial systems (STM-UASB). The experiments were operation by varying hydraulic loading rate HLR) and organic loading rate (OLR) with values of HLR 0.02, 0.25 m3/m2-h and OLR 7.5, 25 kgCOD/m3-day, respectively. Overall organic removal efficiencies were more than 70% of COD removed for three methods. The highest COD removal was found in BES-UASB that was about 82% of COD removed. The biogas production yields were about 0.33, 0.32 and 0.28 m3/kg-CODremoved for BES-UASB, ZVI-UASB and STM-UASB, respectively. As well as, the highest bio-methane production was found in BES-UASB reactor with more than 60% of biogas compositions. Keywords: Modified tapioca starch, High salinity wastewater, Biogas production, Bio-electrochemical system (BES), Zero-valent iron (ZVI), Salt tolerance microorganism