Sanak Ray

NH3 and COD removal from wastewater using biological process: kinetic with optimization studies

AbstractStudies on heterotrophic biomass conversion (HBC) process were carried out for the removal of N–NH3 and organic carbon from wastewater. Ammonium sulfate and glucose were used as nitrogen and organic sources, respectively. A range of parameters were studied such as time, concentration variations of N–NH3, and organic nutrients keeping the biomass (total volatile suspended solids, TVSS) concentration invariable in all the cases. The kinetics followed dual rates, i.e. an initial faster phase, followed by the slower one. The rates of N–NH3 and chemical oxygen demand (COD) removal depended on their initial concentrations. The consumption of N–NH3 and COD followed first order kinetics. The unified rate equation was also established. Two other kinetic models, such as Monod and diffusion, were studied. The pH during the HBC process showed a decreasing trend. Other parameters studied were: , N2O, , and DO. A part of N–NH3 utilized for emission of N2O may be due to heterotrophic nitrification (HN). Statisti...

Emission of nitrous oxide and methane from alluvial soil through incubation

AbstractMethane and nitrous oxide emission from alluvial soil under incubation using varying doses of urea and water content were studied for Tangibanta and Sorada. The N2O emission was observed to increase with time and tapers off after attaining the peak. The theoretical emission was evaluated using empirical equations and matches well with the experimental values. The CH4 and N2O emission both increased with the increase in Water Filled Pore Space (WFPS) and urea concentration. The nitrification and denitrification reaction rates were determined with and without acetylene. Michaelis-Menten equation was used to evaluate the Km and Vmax values. The rate of emission of N2O increased with increase of WFPS and urea concentration whereas the emission factor showed a reverse trend. The CH4 emission rate was observed to be comparatively low with respect to N2O emission rate around a factor of 10.

Kinetics with optimization studies of nitrogen and organic elimination from wastewater via heterotrophic biomass conversion process

AbstractHeterotrophic biomass conversion (HBC) research was carried out for the removal of N-NH3 and organic carbon from synthetic wastewater. Ammonium nitrate and glucose were used as the nitrogen and organic carbon source, respectively. In this study, N-NH3 and organic nutrient concentrations were varied, keeping the biomass concentration invariable. The kinetics followed dual rates, i.e. faster initial rate followed by a slower one. The consumption of N-NH3 and COD followed first-order kinetics. Kinetic model such as Monod was studied. The pH during the HBC process showed an increasing trend which may be due to heterotrophic nitrification (HN). Parameters like N-, N2O, N-, time, and dissolved oxygen were studied. A part of N-NH3 utilized for the emission of N2O may be due to HN. Analyses of variance were carried out for better interpretation of results. Optimization studies were carried out to minimize N2O emission and maximize N-NH3 along with COD removal.