HAO Xiao-di,RAO Zhi-feng,LIU Ran-bin,et al.Impact and Mechanism of Celluloses on the Performance of Biological Wastewater Treatment[J].China Water & Wastewater,2021,37(21 21):1-6.
Impact and Mechanism of Celluloses on the Performance of Biological Wastewater Treatment
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
21 21
Page:
1-6
Column:
Date of publication:
2021-11-01
- Keywords:
- celluloses; nitrogen and phosphorus removal; flocs; oxygen transfer efficiency; simultaneous nitrification and denitrification (SND); energy saving and consumption reduction
- Abstract:
- Wastewater contains a certain amount of celluloses which is not only difficult to be degraded in the biological treatment process, but also increases the burden of the system. As a result, the separation of celluloses from wastewater has been studied and practiced. To further clarify the influence of celluloses on the performance of biological wastewater treatment, a lab-scale modified UCT reactor was constructed to study its impact on pollutants removal and the associated mechanisms. The results indicated that the presence of celluloses in the influent resulted in the deterioration of removing COD, nitrogen, and phosphorus in a short term due to the deficiency of dissolved oxygen (DO). The effluent quality was restored after doubling or tripling the aeration rate. In addition, the microscopic examination showed that the linear morphology and vast amounts of functional groups of celluloses could significantly increase the density of sludge flocs. Consequently, the mass transfer of DO in the flocs was undermined. This was also the reason why there was a need to increase the aeration rate to obtain a favorable performance when celluloses were present. However, this consolidation of sludge and the net trapping and sweeping effect had a positive effect on the simultaneous nitrification and denitrification (SND) capacity and the SS retainment. Overall, recovery of celluloses before the biological unit can reduce the energy input and costs, otherwise, they will contribute to the excess sludge production. In other words, the recovery of celluloses from wastewater can be valorized and leveraged to save energy and costs as well as to increase the capacity of wastewater treatment.
Last Update:
2021-11-01