Simultaneous ozone and granular activated carbon for advanced treatment of micropollutants in municipal wastewater effluent

A battery of bioassays, including biological toxicity as well as in vitro mouse spleen lymphoproliferative responses and cytokine production, was conducted to compare the effectiveness of tertiary treatment methods such as coagulation (Coag) and absorption on granular activated carbon (GAC) and disinfection processes such as chlorination and ozonation in removing toxic or stress inducing agents from reclaimed wastewater. Whole effluent toxicity (WET) testing of secondary treated (ST) wastewater using as test species Vibrio fischeri, Daphnia magna and Tetrahymena thermophila as well as phytotoxicity revealed moderate toxicity effects that depend on the organism used. All bioassays exhibited decrease of the ecotoxicological responses after tertiary treatment. However, mitogenic responses were proved to be more sensitive. Endotoxin present in ST samples may be responsible for the increased strong lymphoproliferative activity as well as interleukin-1 (IL-1) production by mouse splenocytes. Tertiary treatment of ST with coagulation and/or adsorption on granular activated carbon (GAC) in combination with ozonation reduced WET to control levels. Ozonation alone or in combination with any other treatment removed endotoxin more efficiently than chlorination and thus reduced spleen lymphoproliferative responses and IL-1 production.

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Long-Term Toxicological Monitoring of a Multibarrier Advanced Wastewater Treatment Plant Comprising Ozonation and Granular Activated Carbon with In Vitro Bioassays

Water ◽

10.3390/w13223245 ◽

2021 ◽

Vol 13 (22) ◽

pp. 3245

Author(s):

Lam T. Phan ◽

Heidemarie Schaar ◽

Daniela Reif ◽

Sascha Weilguni ◽

Ernis Saracevic ◽

...

Keyword(s):

Wastewater Treatment ◽

Activated Carbon ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Granular Activated Carbon ◽

Advanced Treatment ◽

Modes Of Action ◽

In Vitro Bioassays

A set of CALUX in vitro bioassays was applied for long-term toxicity monitoring at an advanced wastewater treatment plant comprising ozonation and granular activated carbon filtration for the abatement of contaminants of emerging concern (CEC). During the 13-month monitoring, eight reporter gene assays targeting different modes of action along the cellular toxicity pathway were accessed to evaluate the suitability and robustness of the technologies. Two approaches were followed: on the one hand, signal reduction during advanced treatment was monitored; on the other hand, results were compared to currently available effect-based trigger values (EBTs). A decrease of the corresponding biological equivalent concentrations after the multibarrier system could be observed for all modes of action; while the estrogenic activity decreased below the EBT already during ozonation, the potencies of oxidative stress-like and toxic PAH-like compounds still exceeded the discussed EBT after advanced treatment. Overall, the long-term monitoring confirmed the positive effect of the multibarrier system, commonly evaluated only by CEC abatement based on chemical analysis. It could be demonstrated that advanced WWTPs designed for CEC abatement are suitable to significantly decrease toxicity responses not only in the frame of pilot studies but under real-world conditions as well.

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Perfluorinated chemicals (PFCs) in water purification plants (WPPs) with advanced treatment processes

Water Science & Technology Water Supply ◽

10.2166/ws.2010.707 ◽

2010 ◽

Vol 10 (1) ◽

pp. 87-95 ◽

Cited By ~ 12

Author(s):

B. R. Shivakoti ◽

S. Fujii ◽

M. Nozoe ◽

S. Tanaka ◽

C. Kunacheva

Keyword(s):

Activated Carbon ◽

Water Purification ◽

Tap Water ◽

Total Concentration ◽

Granular Activated Carbon ◽

Advanced Treatment ◽

Source Water ◽

Treatment Processes ◽

Perfluorinated Chemicals

A series of perfluorinated chemicals (PFCs) surveys were conducted in two water purification plants (WPPs) having ozonation and granular activated carbon (GAC) filtration processes. In each plant, six different processes samples (source water, influent, coagulation-sedimentation effluent, ozonation effluent, GAC filtration effluent, and final tap water) were collected for two times and eight PFCs were measured. The results showed that seven kinds of PFCs (PFHxS, PFOS, PFHpA, PFOA, PFNA, PFDA, and PFUnDA) were detected in both plants with concentration range of 0.5–53.5 ng L−1, while the range of total concentration of all seven PFCs was 31–90 ng L−1. All detected PFCs were not removed effectively in both dates but removal was observed to some extent for certain PFCs (PFNA, PFDA, PFOS, and PFUnDA) by GAC filtration tank.

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