This work aims to study the enhancement of phosphorous (P) release from the waste activated sludge containing ferric phosphate (FePO4) by adding sodium sulfide (Na2S). First, effects of Na2S dosage and temperature on P release from FePO4 precipitation were investigated. Then, anaerobic fermentation of the sludge containing FePO4 was studied with different Na2S dosage, focusing on P release. The results showed that adding more Na2S could increase P release, and 100% of P can be released from iron phosphate when S/Fe molar ratio was 5:1 or more. Temperature mainly affected the reaction rate. During the anaerobic fermentation of the mixed sludge containing FePO4, when S/Fe molar ratio was 1:1, 3:1 and 5:1, P release efficiency was 60%, 93% and 100%, respectively; compared to the sludge without Na2S addition, the efficiency was increased by 26%, 59% and 73%, respectively. In addition, Na2S addition could promote volatile fatty acids production. When the S/Fe molar ratio was 3:1 and after 7days fermentation, the total VFA concentration was 4.3times of that without Na2S addition. However, Na2S addition has negative effect on methane production.%以污泥中磷酸铁(FePO4)沉淀为主要研究对象,研究了Na2S投加量以及温度对FePO4释磷的影响,分析了在厌氧条件下Na2S投加量对含FePO4污泥释磷以及厌氧发酵的影响.结果表明,在溶液中Na2S投加量越大,磷释放率越高,当S/Fe摩尔比为5:1及以上时,FePO4释磷率可以达到100%,温度主要影响反应的速率;在含FePO4混合污泥厌氧发酵过程中,投加Na2S可促进释磷,且FePO4释磷率随着Na2S投加量的增加而升高,当S/Fe摩尔比为分别为1:1、3:1、5:1时,FePO4释磷率分别为60%、93%和100%,相较于未投加Na2S的污泥释磷率提高了26%、59%和73%;此外,投加Na2S还可以促进污泥厌氧发酵产酸,投加量为S/Fe=3:1时,厌氧发酵7d后产酸量最大,是不投加Na2S时污泥产酸量的4.3倍,但投加Na2S对产甲烷不利.
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