生物裂解效应对污泥脱水减量的作用研究

Effects of biolysis pretreatment on sludge dewatering and reduction

从市政污水处理厂活性污泥中筛选培养出噬菌型细菌,并通过噬菌型细菌的富集与投加,探讨其对市政污泥生物裂解预处理的有效性及其所受环境影响因素与作用规律.研究结果显示,市政污泥中存在具有污泥裂解作用的广谱性噬菌型细菌,宿主菌的投加量可影响噬菌型细菌的富集浓度,但培养基营养物组成浓度对噬菌型细菌的生长增殖无明显影响.当筛选出的噬菌型细菌以106pfu/mL(污泥)与中性市政污泥在室温下共存培养24h即可有效裂解污泥细胞,污泥比阻与污泥体积较未投加任何菌剂的参照污泥降低了36%和15%.并可导致胞内营养物的释放,污泥液相中总氮与总磷浓度较参照污泥分别上升了245%和242%,溶解性COD与总COD比值(SCOD/TCOD)则提高了195%,但生物裂解作用效果并不与裂解时间始终保持正相关性,最佳污泥生物裂解时间为24h.

The predatory bacteria with high cell lysis capacity was isolated and screened from the activated sludge of amunicipal wastewater treatment plant.The efficiency of sludge biolysis with an addition of the enriched predatory bacteriafor enhancing its dewaterability was evaluated and the associated environmental impact factors were investigated.Theresults indicated that the predatory bacteria with a broad range of hosts were abundant in the municipal sewage sludgeand greatly benefited sludge lysis.The concentration of the predatory bacteria enrichment could be improved with theincrease of host dosage but not the concentration of the culture medium.When the neutral municipal sludge was incubatedwith the screened predatory microbes at the concentration of106pfu/mL for24h at room temperature,the values of thespecific resistance to filtration(SRF)and the volume of the treated sludge were36%and15%lower than the controlsludge without bacteria addition,respectively.Meanwhile,the cell lysis led to the release of intracellular nutrients.Theconcentrations of total nitrogen(TN)and total phosphorous(TP)in the liquid phase of the treated sludge were increasedby245%and242%,respectively and the ratio of SCOD/TCOD was increased by195%.However,there is no positivecorrelation between the biolysis effect and the reaction time and the optimal sludge biolysis reaction time was24h.