Expounding the role of interference on the recovery of nutrient fractions from aqua matrix using calcined gastropod shell

Abstract

The need to elucidate the influence of the presence of the major components (i.e. organic matter phosphate and nitrate) of nutrient-rich wastewater on the process of nutrient recovery, using calcined gastropod shell (CGS), necessitated this study. The time–concentration profiles of the recovery of organic matter, phosphate and nitrate were studied in synthetic feed water that contained single adsorbate of interest. Both the single and binary component equilibrium isotherm parameters were derived to explicate and quantify the impact of the presence of each constituent of the nutrient rich wastewater on the process of resource recovery. The time-concentration profiles of all the recovery processes showed that the process of nitrate recovery is the rate limiting step in the use of CGS as the reactive material. The pseudo second order kinetic equation gave the best description of both the nutrient and organic matter recovery but the processes were described by different equilibrium isotherm equations. The determination of the efficiency of interference on nutrient recovery showed that nitrate and organic matter exhibited minimal influence on phosphate recovery but the presence of phosphate and organic matter significantly impacted nitrate recovery. The recovery of organic matter was not vitiated by the presence of either phosphate or nitrate. The real life implications of the findings from this study showed that the use of CGS as a reactive material in resource recovery from a nutrient-rich wastewater would provide a double-pronged approach for resource recovery and appreciable treatment of wastewater for reuse.