Effect of High Concentration Disinfectant on Microorganisms in Activated Sludge System
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第36卷
Number:
9 9
Page:
7-11
Column:
Date of publication:
2020-05-01
- Abstract:
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Aiming at the problem of filamentous sludge bulking in activated sludge system of a wastewater treatment plant (WWTP), effects of high concentration disinfectant on livability, extracellular polymer substances (EPS) content and activity of different microorganisms in activated sludge were explored. The activated sludge was from No.2 WWTP in Xi ’an,and the dosage of sodium hypochlorite was 15 mg/L. The high concentration sodium hypochlorite could effectively reduce the number of filamentous bacteria and further inhibit the filamentous bulking of activated sludge. In addition, parts of the inner microorganisms in the flocs were also affected along with the sterilization of the filamentous bacteria. The cell livability of different microorganisms was different, and the most vulnerable species was nitrite oxidizing bacteria (NOB). When the dosage of sodium hypochlorite was 15 mg/L, the total content of sludge extracellular polymer substances decreased by 15.48% after 3 hours of reaction, the nitrification activity was completely lost and never recovered, and the denitrification activity decreased significantly. After recovery for 7 days, the activity of the inner microorganisms could be effectively recovered, while most of the filamentous bacteria were still dead, and the total EPS content decreased continuously. In a word, the growth of filamentous bacteria could be inhibited after the action of high concentration disinfectant on activated sludge, but the nitrification and denitrification activities of sludge were also affected.
Last Update:
2020-05-01