内循环厌氧反应器处理制浆造纸废水的效能及影响因素

Performance and Impaction Factors of Internal Circulation Anaerobic Reactor for Pulping and Papermaking Wastewater Treatment

介绍了处理制浆造纸废水的内循环厌氧反应器工程实例,考察了有机物(COD和挥发性脂肪酸VFA)去除效果及其影响因素(进水容积负荷、进水预酸化度、环境条件)。在平均进水COD为1 562.1 mg/L、平均进水VFA质量浓度为684.0 mg/L、平均水力停留时间为3.7 h条件下,平均COD和VFA去除率分别达到53.7%和77.9%。既保持较高COD去除率又充分发挥反应器处理能力的最佳进水COD容积负荷为11.8 kg/(m3·d)。温度(32.2~39.5℃)、碱度(以CaCO3计)(1 712.2~2 683.5 mg/L)均在适宜范围内,pH(7.5~7.9)略高于适宜范围。进水酸化度不足和水力停留时间较短是进一步提高COD去除率的主要限制因素,可通过适当延长预酸化池和内循环厌氧反应器的水力停留时间来解决。

A full-scale internal circulation anaerobic reactor treating pulping and papermaking wastewater was introduced in this study, where the organic removal (chemical oxygen demand COD and volatile fatty acid VFA) and impaction factors (influent volumetric organic load, influent pre-acidification degree, environmental conditions) were investigated. Average removal for COD and VFA was 53.7% and 77.9%, respectively, under average influent COD of 1 562.1 mg/L, average influent VFA of 684.0 mgHAc/L and average hydraulic retention time of 3.7 h. The optimum influent volumetric organic load was 11.8 kgCOD/(m·3 d) to maintain high COD removal as well as take full advantage of treatment capacity of internal circulation anaerobic reactor. As for environmental conditions, temperature (32.2~39.5 ℃) and alkalinity (1 712.2~2 683.5 mgCaCO3/L) were in the optimum range while pH (7.5~7.9) was slightly higher than the optimum range. The insufficient influent pre-acidification degree and short hydraulic retention time were the main limiting factors for improving COD removal and could be solved via increasing hydraulic retention time of pre-acidification tank and internal circulation anaerobic reactor.