Toxicity-based assessment of the treatment performance of wastewater treatment and reclamation processes

Abstract

The reclamation and reuse of wastewater is one of the possible ways to relieve the serious fresh water resource crisis in China. Efficient reclamation treatment technologies ensure the safe reuse of reclaimed water. In order to screen out and evaluate technologies appropriate for reclamation treatment, a great deal of efforts have been brought to bear. In the present study, a toxicity-based method including a Photobacterium phosphoreum test for acute toxicity and SOS/umu test for genotoxicity, accompanied by the traditional physicochemical parameters DOC (dissolved organic carbon) and UV 254 (absorbance at 254 nm), was used to measure the treatment performance of different reclamation processes, including the anaerobic-anoxic-oxic biological process (A 2 O) and subsequent physical/chemical reclamation processes (ultrafiltration, ozonation, chlorination). It was found that for the secondary effluent after the A 2 O process, both the toxicity and physicochemical indices had greatly decreased compared with those of the influent. However, chemical reclamation processes such as ozonation and chlorination could possibly raise toxicity levels again. Fortunately, the toxicity elevation could be avoided by optimizing the ozone dosage and using activated carbon after ozonation. It was noted that by increasing the ozone dosage to 10 mg/L and employing activated carbon with more than 10 min hydraulic retention time, toxicity elevation was controlled. Furthermore, it was shown that pre-ozonation before activated carbon and chlorination played an important role in removing organic compounds and reducing the toxicity formation potential. The toxicity test could serve as a valuable tool to evaluate the performance of reclamation processes.

Comparative analysis of toxicity reduction of wastewater in twelve industrial park wastewater treatment plants based on battery of toxicity assays

“…The only exception was the QD that used the A 2 /O + MBR process. The good removal efficiency of A 2 /O -based process could also be reported in the literatures 33,34 . For example, Shi et al .…”

Performance and fate of organics in a pilot MBR–NF for treating antibiotic production wastewater with recycling NF concentrate

“…Biological toxicity tests are a useful tool for investigating the effects of all the bioavailable contaminants and their interactions, and they are widely used to evaluate the safety of environmental samples. Wei et al (2012) developed a simple assessment method based on the Photobacterium phosphoreum test for toxicity tests and found that it could serve as a valuable tool for evaluating wastewater reclamation processes. In this study, the same method for acute toxicity tests was used to investigate the toxicity variations in the MBR-NF and antibiotic production wastewater treatment station in the 2nd stage.…”

A toxicity-based method for evaluating safety of reclaimed water for environmental reuses

“…The toxicity tests indicated that both the acute toxicity and genotoxicity had great decrease after the A 2 O process. However, advanced chemical reclamation processes such as ozonation and chlorination could possibly cause toxicity increase again (Wei et al, 2012).…”