Study on biodegradation of low concentration pollutants of effluent water from municipal wastewater treatment plants

Key words: 
• municipal wastewater treatment plant /
• biological zeolite aerated filter /
• advanced treatment /
• circulating cooling water

Abstract: Due to steady performance, low concentration pollutants of effluent water from municipal wastewater treatment plants are not easily removed. To explore a rapid direct enhanced method, an experimental study on removal effect of low concentration pollutants of effluent water from municipal wastewater treatment plants was carried out through a biological zeolite aerated filter with a clinoptilolite cation of rich divalent. The results showed that when the annual average concentrations of NH3-N, COD, BOD5, TP and turbidity of effluent water from municipal wastewater treatment plants were 27.4 mg/L, 57.2 mg/L, 20.4 mg/L, 1.7 mg/L, and 16 NTU,respectively. The final average concentrations of them were 0.13 mg/L, 7.55 mg/L, 0.78 mg/L, 0.6 mg/L and 0.13 NTU,respectively with the treatment of the two stage biological zeolite aerated filter series process, which meet the requirement of the circulating cooling water in heat and power plants. Operation conditions of the two stage biological zeolite aerated filter were the hydraulic retention time (HRT) of 1 h and the gaswater ratio of the first stage of 2∶1 and with the loading biological zeolite of 3 m height, and the hydraulic retention time (HRT)of 0.5 h and the gaswater ratio of the second stage of 1∶1 with the loading biological zeolite of 2 m height. The advanced treatment method provides an economical and effective reuse technology for effluent water from municipal wastewater treatment plants.