Wasterwater treatment using bioprocessesand nanofiltration

Abstract

The water pollution is one of the environmental problems due to the bioaccumulation tendency of toxic materials. The purpose of present study was to treat wastewater through bioprocesses, in combination with nanofiltration (NF) as a post treatment process to remove heavy metals (Cu(II) & Pb(II)), and reactive dyes (Drimarine Yellow HF-3GL & Drimarine Black CL-B) from aqueous solutions. The bioprocesses were conducted in batch and column mode. The biosorption characteristics of immobilized heat inactivated hybrid biosorbent (HI HB) and Active hybrid biosorbent (Active HB) for metal ions and dyes removal were assessed as function of biomass dosage, contact time, pH, initial dye/metal ion concentration and temperature. Maximum uptake of Cu(II), Pb(II), Drimarine Black CL-B & Drimarine Yellow HF-3GL was 213.53, 365.90, 14.57 and 7.82 mg/g at pH 5, 4.5, 3 & 3, respectively, by immobilized HI HB. The biosorption capacity did not increase with increase in biomass dosage. Langmuir isotherm described well the biosorption process. The kinetic data fitted well to pseudo-first and pseudo-second-order kinetic models. Thermodynamic study illustrate that process was feasible at low temperature. Removal of Cu(II), Pb(II), Drimarine Yellow HF-3GL & Drimarine Black CL-B with immobilized Active HB was also explored as a function of pH, biomass dosage, initial dye/metal ion concentration, contact time and temperature. The results demonstrated that all studied parameters influenced the process. Increase in initial dye/metal ions concentration and bed height was found to be favorable conditions for maximum dye/metal ions removal in column mode study. Characterization of biosorbent was carried out by FTIR, SEM, TEM, XRD and TGA analysis. FTIR analysis of biomass showed participation of –OH, and –COOH as major functional groups involved in sequestering of metal ions and dyes from aqueous solution. Furthermore, NF increased the % removal of studied metal ions and dyes. The study provides understanding on treating wastewater through adsorption in combination with NF for Cu(II), Pb(II), Drimarine Yellow HF-3GL & Drimarine Black CL-B removal.