Trace metal requirements for anaerobic co-digestion of sewage sludge from rural areas and food waste in Japan
Trace metal requirements for anaerobic co-digestion of sewage sludge from rural areas and food waste in Japan
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DOI：
10.2166/wpt.2020.034
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发表时间：
2020-06
影响因子：
1.6
通讯作者：
Masato R. Nakamura;Hirohiko Shibata;M. Yamaoka;Fumiko Oritate
中科院分区：
文献类型：
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作者：
Masato R. Nakamura;Hirohiko Shibata;M. Yamaoka;Fumiko Oritate
对于日本农村地区的小型污水处理厂（WWTPRs），降低污泥处置成本是一个重要问题。来自WWTPRs的污泥和食物垃圾的共消化是降低维护成本和生产能源（如甲烷）的有前景的方法。本研究以污泥和厨余垃圾为原料进行共消化实验，从微量金属需要量的角度考察共消化的稳定性。在HRT为140-70 d的条件下，产气速率和pH值稳定。水力停留时间为30天时，pH值从7.0逐渐下降到6.5，VFA积累到2，200 mg/L的浓度，表明工艺失败。钴（Co）浓度约为先前研究报告所需量的十分之一。当Co被添加到消化器中时，pH和产气速率变得稳定，即使具有更高的VS负载速率。因此，不稳定的情况是由于缺乏钴的污泥。在日本的污水处理厂的污泥中的钴浓度普遍较低，类似于本研究中使用的污泥。需要添加Co以稳定地共消化来自WWTPRs的污泥和食物垃圾。
For small-scale wastewater treatment plants in rural areas (WWTPRs) of Japan, reducing sludge disposal costs is an important issue. Co-digestion of sludge from WWTPRs and food waste is a promising method of reducing maintenance costs and producing energy resources such as methane. In this study, co-digestion experiments using sludge and kitchen garbage were conducted to investigate the stability of the co-digestion from the perspective of trace metal requirements. The gas production rate and pH were stable in the digester with HRTs of 140–70 days. With a HRT of 30 days, the pH gradually dropped from 7.0 to 6.5, and VFA accumulated up to a concentration of 2,200 mg/L, indicating process failure. Cobalt (Co) concentration was approximately one-tenth of the required amount reported by a previous study. When Co was added to the digester, the pH and gas production rate became stable even with a higher VS loading rate. Therefore, the unstable situation was attributed to a lack of Co in the sludge. The Co concentration of sludge from WWTPRs in Japan is generally low, similar to the sludge used in this study. The addition of Co is required for stable co-digestion of sludge from WWTPRs and food waste.