WANGJin-jiang,ZHANGPing,WANGXu,et al.Empirical Study on Nitrification Inhibited by Zinc Insoluble Substances[J].China Water & Wastewater,2022,38(11):79-82.
Empirical Study on Nitrification Inhibited by Zinc Insoluble Substances
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第38卷
Number:
第11期
Page:
79-82
Column:
Date of publication:
2022-06-01
- Keywords:
- zinc; insoluble substance; nitrification inhibition; activated sludge
- Abstract:
- Zinc ions can inhibit the nitrification of activated sludge, but the influent of wastewater treatment plants often contains alkaline substances, which lead to the existence of zinc in the form of insoluble substances in the influent suspended solids. The inhibition effect of zinc insoluble substances on nitrification of activated sludge was analyzed qualitatively and quantitatively based on the operation practice of a wastewater treatment plant. Firstly, the nitrification inhibition test in the mixed liquid and supernatant of the influent of the plant was carried out respectively, and the inhibition was determined to exist mainly in the influent suspended solids, and zinc insoluble substances were confirmed to be the main substances to inhibit nitrification by comparing the content of zinc and the degree of nitrification inhibition. Then, the inhibition of zinc insoluble substances on the nitrification of activated sludge was quantitatively analyzed, and it was concluded that the inhibition effect was not obvious when the zinc content in the system was less than 5 mg/L. However, the nitrification of activated sludge was significantly inhibited when the zinc content in the influent was above 7.5 mg/L. In addition, zinc insoluble substances were easy to accumulate in activated sludge and gradually enhanced their inhibition effect due to precipitation. The inhibition of zinc on nitrification did not disappear in a short period when zinc stopped entering the system.
Last Update:
2022-06-01