Study of the morphological changes of copper and zinc during pig manure composting with addition of biochar and a microbial agent

• Published in: Bioresource technology 2019-11, Vol.291, p.121752-121752, Article 121752
• Main Authors: Li, Ran, Meng, Haibo, Zhao, Lixin, Zhou, Haibin, Shen, Yujun, Zhang, Xi, Ding, Jingtao, Cheng, Hongsheng, Wang, Jian
• Format: Article
• Language: English
• Subjects: Bioavailability; biochar; China; Composting; copper; fluorescence; Heavy metals; Immobilization ability; pig manure; technology; zinc
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121752

•High levels of heavy metals in fertilizers is a major source of pollution in China.•Composting can significantly decrease the bioavailability of these metals.•The effects of adding biochar and a microbial agent were investigated.•The conversion of copper and zinc, to forms with higher stability is associated with the formation of humic substances. Intensive and unregulated use of feed additives in China has led to high levels of heavy metals such as copper and zinc in fertilizers, considerable quantities of which find their way into the environment. Studies have shown that composting could significantly decrease the bioavailability of heavy metals. This study was to investigate the effects of addition of biochar and a microbial agent on the morphological changes in copper and zinc during composting. Results show that treatment T8 successfully immobilized 70.36% of copper as a result of biochar addition. Treatment T3 successfully immobilized 40.76% of zinc; transformation of zinc to a higher stable state was found to be closely related to the formation of fulvic and humic acids. Results of fluorescence spectrum analysis also corroborate that the conversion of copper and zinc to forms with higher stability was associated with the formation of fulvic and humic acid-like substances.