Evaluation of advanced sewage treatment processes for reuse of wastewater using bioassays

Four advanced sewage treatments (sand filtration, ozone/hydrogen peroxide t reatment (AOP), microfiltration (MF), and reverse osmosis (RO)) were compar ed in terms of their capability to reduce estrogenicity, genotoxicity, and acute toxicity, assuming portable reuse of the effluents. Yeast estrogen sc reening and an enzyme-linked immunosorbent assay indicated that both overal l estrogenicity and 17 beta-estradiol concentration were significantly redu ced by RO and AOP (removals more than 97 % were achieved) while sand filtra tion and MF were not sufficient. This tendency of similar toxicity levels f or RO and AOP effluents, was consistent with genotoxicity and mutagenicity results for Ames test, umu test, and B. subtilis rec-assay and acute toxici ty (Microtox(R)). However, a different trend was observed for total organic carbon (TOC) removal (i.e., higher removal by RO than AOP). This implies t hat AOP is capable of reducing the toxicity even if TOC is not completely m ineralized. Results show that AOP and RO are much more effective than sand filtration and MF for the reduction of the estrogenicity, genotoxicity and acute toxicity of secondary effluent.