摘要
针对城市污泥(初沉污泥、剩余污泥)和垃圾焚烧厂渗滤液2种市政废物的协同厌氧消化产气量不足的问题,采用投加零价铁的方式,探究零价铁对厌氧消化过程中产酸和产甲烷阶段的强化作用,并研究消化前后COD、VSS、氨氮以及上清液离子的变化。以初沉污泥与剩余污泥体积比4∶1、渗滤液添加量为15%的基质作为底物,投加不同浓度零价铁进行厌氧消化。结果表明:零价铁能有效提升协同厌氧消化系统中总挥发性脂肪酸产量、促进丙酸分解、进一步降解复杂有机物;当零价铁投入量为4 g·L^-1时,累计产甲烷量最高达189.65 mL·g^-1(以VSS计),相比对照组提升了30.1%,其产气速率符合一次函数和Scholl Canyon模型指数衰减规律;在25 g·L^-1和40 g·L^-1的高投加量零价铁条件下,产气高峰提前,但累计甲烷产量低于对照组;随着零价铁的投加量增加,COD降解率呈下降趋势,VSS降解率提升,氨氮变化不大;此外,消化液上清液中,正磷酸盐、硫酸根浓度明显减少,这与亚铁离子的混凝沉淀作用相关,同时也是削弱零价铁强化作用的原因之一。研究结果可为城市污泥和垃圾焚烧厂渗滤液协同厌氧消化提供参考。
In this study, zero valent iron(ZVI) was added to solve the problem of insufficient gas production from anaerobic co-digestion(ACD) of the two kinds of municipal wastes :municipal sludge(primary sludge,excess sludge) and leachate from waste incineration plant. The strengthening effects of acidogenic and methanogenic stages with addition of ZVI, and the changes of COD, VSS, ammonia nitrogen and ions in supernatant before and after ACD were studied. The mixture including primary sludge and excess sludge with the volume ratio of 4∶1 and 15% leachate was used as substrate to conduct the anaerobic digestion with the addition of ZVI of different concentrations. Results demonstrated that ZVI could effectively increase the total volatile fatty acids(TVFAs) production, promote the decomposition of propionic acid and further degrade complex organics in the synergetic ACD system. Compared with the performance of ACD without ZVI addition,the maximum cumulative methane production reached 189.65 mL·g^-1(VSS), and increased by 30.1% with the addition of 4 g·L^-1 ZVI. Furthermore, its gas production rate accorded with the first-order function and the law of exponential decay in Scholl Canyon model. The peak of gas production was advanced under high dosages(25 g·L^-1 and 40 g·L^-1) of ZVI, while the methane production was lower than that without ZVI addition. With the increase of ZVI dosage, COD degradation rate showed a downward trend, VSS degradation rate increased,and ammonia nitrogen did not change much. In addition, ZVI addition led to a significant reduction of orthophosphate and sulfate in digestive supernatant, which was related to the coagulation and sedimentation of ferrous ions, and was also a reason for weakening the strengthening effect of ZVI. The results of this study can provide a reference for ACD of municipal sludge and landfill leachate.
作者
汪雪
黄川
曾韵敏
王里奥
WANG Xue;HUANG Chuan;ZENG Yunmin;WANG Li'ao(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;College of Environmental and Ecology,Chongqing University,Chongqing 400044,China;College of Resources and Environmental Engineering,Yibin University,Yibin 644000,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2020年第7期1924-1933,共10页
Chinese Journal of Environmental Engineering
基金
重庆市科技计划项目社会事业与民生保障科技创新专项(cstc2015shms-ztzx20006)。
作者简介
第一作者:汪雪(1994—),女,硕士研究生。研究方向:固体废物处理及资源化利用。E-mail:759780500@qq.com;通信作者:黄川(1965—),女,博士,教授。研究方向:固体废物处理及资源化利用。E-mail:hclsjb@163.com。
