Algal bacterial processes for the treatment of agroindustrial wastewatwers: a biodegradability screening

Abstract

The potential of photosynthetic oxygenation for the removal of carbon, nitrogen and phosphorus from 5 agroindustrial wastewaters (at several wastewater dilutions) was investigated in enclosed batch biodegradation tests using a mixed microalgae consortium and activated sludge as model microorganisms. The target wastewaters were obtained from potato processing (PW), fish processing (FW), animal feed production (MW), coffee manufacturing (CW) and yeast production (YW). The maximum final organic carbon (TOC) and nitrogen removal efficiencies were recorded for 2 fold diluted FW (64±2 % and 85±1%, respectively), while the maximum P-PO43- removal was 89±0.01% for undiluted PW. Nitrogen removal via biomass assimilation was the main nitrogen removal mechanism since neither nitrification nor stripping were recorded regardless of the wastewater and dilution evaluated. The biodegradable TOC was the most common limiting component in the wastewaters evaluated. The C/N ratio of the biomass generated was not correlated with the initial C/N ratio of the wastewater