好氧-沉淀-厌氧工艺剩余污泥减量化的影响因素

Influence factors of excess sludge reduction of the oxic-settling-anaerobic technique

研究了好氧-沉淀-厌氧(OSA)工艺污泥减量效果以及ORP、污泥回流比、厌氧污泥浓度、厌氧污泥停留时间、有机负荷和废水种类等因素对OSA工艺污泥产率的影响.结果表明,连续流OSA工艺平均污泥产率为0.24g/g,比相同条件下传统活性污泥(CAS)工艺污泥产率下降44.34%.降低ORP主要从污泥衰减效果和能量解偶联两方面影响OSA工艺污泥产率.间歇实验结果表明,浓缩污泥ORP从-100mV降到-250mV时,污泥衰减更加显著,污泥产率从0.43g/g降至0.32g/g.污泥回流比是OSA工艺污泥产率重要影响因素,以实验运行稳定性和污泥产率相结合为原则,连续流实验的最佳回流比为0.33.提高厌氧污泥浓度,延长厌氧污泥停留时间,有利于污泥减量.Ns从0.41kg/(kg·d)提高到1.13kg/(kg·d),将乙酸钠为唯一碳源的配水改变为屠宰废水,均能使CAS工艺污泥产率提高,而OSA工艺污泥产率基本不受影响,因此OSA工艺污泥减量率相对于相同条件下CAS工艺提高6%左右.

Sludge reduction effect of the oxic-settling-anaerobic（OSA） technique and the influence of ORP, ratio of return flow sludge, anaerobic sludge concentration, anaerobic sludge retention time, organic loading and wastewater variety on sludge yield were studied. The average sludge yield of the continuous flow OSA technique was 0.24g/g, reducing by 44.34% in comparison with that of conventional activated sludge （CAS） technique. Reducing ORP mainly influenced the sludge yield of the OSA technique from two aspects of sludge decay and energy uncoupling. The batch test results showed that the sludge decay was more remarkable and sludge yield dropped from 0.43g/g to 0.32 g/g when ORP of the concentrated sludge dropped from -100mV to -250mV. The ratio of return flow was the important influence factor of sludge yield in the OSA technique. In a view of operation stability and sludge yield, the best ratio of return flow was 0.33. Enhancing anaerobic sludge concentration and prolonging anaerobic sludge retention time were favorable to excess sludge reduction. The sludge yield of the CAS technique was enhanced and that of the OSA technique was scarcely influenced whether Ns enhanced from 0.41 kg/（kg·d） to 1.13kg/（kg·d） or the wastewater changed from sodium acetate as single carbon source to slaughter wastewater. Thus the sludge reduction efficiency of the OSA technique enhanced about 6% relative to the CAS technique under the same condition.