Cumulative effects of bamboo sawdust addition on pyrolysis of sewage sludge: Biochar properties and environmental risk from metals. (March 2017)

• Record Type: Journal Article
• Authors: Jin, Junwei; Wang, Minyan; Cao, Yucheng; Wu, Shengchun; Liang, Peng; Li, Yanan; Zhang, Jianyun; Zhang, Jin; Wong, Ming Hung; Shan, Shengdao; Christie, Peter
• Is Part Of: Bioresource technology. Volume 228(2017)
• Page Start: 218
• Page End: 226
• Publication Date: 2017-03
• Subjects: Sewage sludge -- Bamboo sawdust -- Pyrolysis -- Trace metals -- Potential environmental risk assessment; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.12.103
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Sludge was pyrolyzed with bamboo sawdust for metal immobilization. Metals were transformed from highly available to stable forms after pyrolysis. Addition of bamboo sawdust in sludge co-pyrolysis minimizes the risk from metals. Co-pyrolysis with bamboo sawdust at 600 °C is suitable for sludge metal stabilization. Abstract: A novel type of biochar was produced by mixing bamboo sawdust with sewage sludge (1:1, w/w) via a co-pyrolysis process at 400–600 °C. Changes in physico-chemical properties and the intrinsic speciation of metals were investigated before and after pyrolysis. Co-pyrolysis resulted in a lower biochar yield but a higher C content in the end product compared with use of sludge alone as the raw material. FT-IR analysis indicates that phosphine derivatives containing PH bonds were formed in the co-pyrolyzed biochars. In addition, co-pyrolysis of sludge with bamboo sawdust transformed the potentially toxic metals in the sludge into more stable fractions, leading to a considerable decrease in their direct toxicity and bioavailability in the co-pyrolyzed biochar. In conclusion, the co-pyrolysis technology provides a feasible method for the safe disposal of metal-contaminated sewage sludge in an attempt to minimize the environmental risk from potentially toxic metals after land application.