Assessing the Impact of Semiconductor Wastewater on Biological Nutrient Removal Wastewater Treatment

Abstract

With passage of the CHIPS (Creating Helpful Incentives to Produce Semiconductors) and Science Act of 2022, growth of semiconductor facilities in the U.S. will increase, which will demand the need for treating industrial wastewater rich in xenobiotic compounds. One wastewater management option is disposal to municipal water resource recovery facilities (WRRFs). However, WRRFs are not conventionally designed for xenobiotics removal specifically associated with semiconductor facilities. Research herein interrogated the effects of reverse osmosis concentrate (ROC) derived from a water recycling system treating semiconductor wastewater on wastewater treatment. ROC impaired nitrification at the bench and eliminated nitrification at the pilot scale; impact at the pilot scale was almost immediate. Ammonia oxidizing bacteria were eliminated once ROC was added; also, no ammonia oxidizing archaea, Crenarchaeota, or comammox were detected. Bench-scale data suggested ROC might impair biological phosphorus removal; more critically, pilot scale effluent phosphorus increased 670%, while the relative fraction of phosphorus bacteria, interrogated at the Clade level, decreased 705%. Metabolomic data revealed key indicators of nitrification – fructose, 3-phosphoglyceric acid, and pyruvate – decreased with ROC addition. Moreover, the ROC-impacted metabolome exhibited the strongest correlations with amino acids. While no direct linkage between the amino acids and nitrification could be inferred, the predominance of these peptide building blocks combined with a significant loss of biomass suggests protein hydrolysis associated with bacterial die-off. Conversely, correlations without ROC were dominated by TCA cycle metabolites, indicating the predominance of oxidative reactions supporting energy production. Mitigation is possible; research focused on the acute effects of ROC addition, and attenuation in the sanitary sewer collection system may mitigate toxicity. Ultimately, municipal WRRFs need to approach receiving semiconductor wastewater with caution and careful study.