Fenton試劑論文：Fenton氧化及厭氧消化對城市污泥脫水性能的影響研究

1、Fen to n試劑論文：Fenton氧化及厭氧消化對城市污泥脫水 性能的影響研究【中文摘要】 剩余污泥含水率高，體積龐大，需對其進(jìn)行脫水處理 以減小污泥體積，方便后續(xù)運(yùn)輸和處理處置。本論文研究了 Fenton 試 劑調(diào)理城市污水處理廠剩余污泥，通過測定污泥毛細(xì)吸水時間(CST)、 污泥比阻(SRF)和泥餅含水率來表征污泥脫水性能的變化，分別考察 了污泥初始pH H2O2 投加量、H2O2/Fe2+反應(yīng)溫度和反應(yīng)時間對污 泥調(diào)理效果的影響。綜合考慮，確定 Fenton 調(diào)理污泥的最佳條件為： pH=3 抽濾脫水和離心脫水 H2O2 最佳投加量分別為 3g/L 和 9g/L、 H2O2/Fe2+

2、(質(zhì)量比)最佳范圍為 812、反應(yīng)溫度 50C、反應(yīng)時間 60mi n。對污泥離心上清液中胞外聚合物(EPS)含量的研究表 明,Fenton 調(diào)理后污泥上清液中蛋白質(zhì)和多糖含量有大幅升高，說明 Fenton 試劑能有效氧化破解 EPS 從而提高污泥的絮凝性，改善污泥 的脫水性能。Fen to n 氧化后污泥顆粒粒徑變小，比表面積增大。研究 了剩余污泥在中溫厭氧消化條件下污泥脫水性能的變化及其作用機(jī) 理。剩余污泥厭氧消化過程中，消化污泥比阻(SRF)相比于剩余污泥有 一定的減小，消化污泥的過濾速度有一定的改善，但改善不明顯。PAM FeCI3 和 PAC 三種絮凝劑調(diào)理實(shí)驗(yàn)顯示，消化污泥的最佳投

3、藥量相對 于剩余污泥均有所增加，說明消化污泥脫水性能變差。分析了 2種污 泥中胞外聚合物(EPS)含量及污泥顆粒特性的變化，表明消化過程導(dǎo)致 EPS 的降解并向液體中釋放。 隨著 EPS 含量的減少，由 EPS 架橋形 成的較大絮體解體成為較小的污泥顆粒，污泥中小顆粒的比例增加，污泥的脫水性能變差。開展了板框壓濾機(jī)污泥深度脫水試驗(yàn)，結(jié)果顯 示,Fenton試劑+鐵鹽調(diào)理和鐵鹽/石灰調(diào)理污泥脫水效果較好，壓濾 脫水后泥餅含水率低于 60% Fenton 試劑+鐵鹽調(diào)理與鐵鹽/石灰調(diào)理 相比,Fenton 試劑+鐵鹽調(diào)理雖然進(jìn)泥時間偏長，但是污泥穩(wěn)定效果更 好；加入的無機(jī)質(zhì)較少，最終泥餅干固體量少

4、；泥餅熱值較高，泥餅 pH 值偏中性,有利于泥餅的資源化利用?！居⑽恼?Sludge with high moisture content needed to bedewatered to reduce the sludge volume for facilitati ng transportationand subsequent disposal. The parameters for thecon diti on of excess sludge by Fenton reage nt were inv estigated, andthe capillary suction time (

5、CST), the specific resistance to filtrati on (SRF)and the water content of sludge cake were measured to examine sludgedewatering performance. The effects of initial pH of sludge, H2O2dosage,H2O2/Fe2+ratio, reaction time and temperature on sludge conditioningwere investigated.The optimal con diti on

6、parameters for sludgecon diti oningweredeterm ined as follows:pH=3, H2O2 dosages of filtrati on and centrifugaldehydration were 3g/L and 9g/L respectively, H2O2/Fe2+ ratio (massratio)=8-12, temperature T=50C , andreacti on time was 60min. The prote in and polysaccharide contents inextracellular poly

7、meric substa nces (EPS) in creased after the excesssludge was con diti oned by Fenton reage nt, which dem on strated thatFenton oxidati on could effectively break EPSstructure and improve theflocculation and dewatering performanee of sludge. After Fenton oxidation,sludge particle size became smaller

8、 and the surface area in creased.Thecha nge of dewateri ng performa nee of digested sludge was studied aswell here. The result showed that SRFvalue of digested sludge was a littlesmaller than that of raw excess sludge, the filtrati on rate of digestedsludge in creased a little. PAM,FeCI3, and PACwer

9、e used in the sludge conditioning experiment, whichrevealed that the optimal dosages of digested sludge all in creasedcompared to excess sludge and dewateri ng performa nee of digestedsludge became worse. Through an alyz ing extracellular polymeric substances (EPS) content and the characteristics of

10、 sludge particle, it was foundthat digestion process led to the degradation of EPSand releasing intoliquid. With the decreasing of EPS content in sludge, the larger floc formedby the bridgi ng of EPS was dis in tegrated into smaller particles. Theproporti on of smaller particles in sludge in creased and dewateri ngper