磷酸铁污泥的生物还原释磷及其影响因素研究

以污水处理厂化学除磷工艺产生的磷酸铁(FePO4)污泥为研究对象,在厌氧条件下,考察了铁还原细菌(IRB)还原FePO4释放磷的可行性,并探讨了不同碳源、C/Fe摩尔比、添加蒽醌-2,6-二磺酸盐(AQDS)对IRB利用FePO4还原释磷的影响.研究结果表明,通过驯化可从普通活性污泥富集IRB,且利用IRB可对难溶性沉淀FePO4进行生物还原.IRB能够利用葡萄糖、乙酸钠及丙酸钠作为唯一电子供体,使FePO4发生异化还原,产生Fe(Ⅱ)并释放磷酸盐,且泥水混合液中Fe(Ⅱ)累积量与上清液中磷累积量变化趋势一致.在等摩尔碳量前提下,葡萄糖为碳源时释磷率可达51.6%,比乙酸钠和丙酸钠分别高13.8%和20.3%;以葡萄糖为碳源,C/Fe摩尔比为5:1时释磷率最大;添加电子穿梭体AQDS可使FePO4污泥释磷率提高12.6%.

Phosphorous release from sludge containing ferric phosphate using microbial reduction and the influencing factors.

Ferric phosphate (FePO4) sludge, which is generated during the chemical phosphorus removal process in wastewater treatment plants, is the research object. The feasibility of phosphorous release from FePO4 using iron reducing bacteria (IRB) under anaerobic conditions was investigated. The effects of carbon source, C/Fe molar ratio and anthraquione-2, 6-disulfonate (AQDS) addition were studied. The results showed that IRB was enriched by acclimation of common activated sludge, and the insoluble ferric phosphate could be reduced by IRB. IRB could utilize glucose, sodium acetate, sodium propionate as the sole electron donor to reduce ferric phosphate and to generate Fe (Ⅱ) as well as to release phosphorus. The variation trend of Fe (Ⅱ) in the mixed liquor was consistent with the variation of phosphorus concentration in the supernatant. When glucose was used as carbon source, 51.6% of phosphorus was released, which was 13.8% and 20.3% higher than those released with sodium acetate and sodium propionate as the sole carbon source, respectively. When glucose was used as the carbon source and the C/Fe molar ratio was 5, the highest phosphorus release rate was achieved. With the addition of AQDS as electron shuttle, phosphorus release rate could be increased by 12.6%.