Mechanical Treatment of MSWI Fly Ash: A Way Forward to Inhibit PCB Reformation

Ishrat Mubeen ； Xiaoqing Lin ； Zhiliang Chen ； Alfons Buekens ； Mi Yan ； Shengyong Lu ； Dwi Hantoko ； Xiaodong Li ； Jianhua Yan

《Aerosol and Air Quality Research》 19卷8期 (2019/08) Pp. 1775-1784+ap1-15

https://doi.org/10.4209/aaqr.2019.04.0213

摘要

Fly ash from municipal solid waste incinerators has been classified as hazardous waste due to the presence of unintentionally-produced Persistent Organic Pollutants (POPs), with Polychlorinated biphenyls (PCB) being a major group among such POPs. Fly ash can be mechanically (MC) treated to destroy organic pollutants before final disposal or reuse. In this study, model fly ash (MFA) doped with 0.2% CuCl_2 was artificially prepared and subjected to high intensity ball milling for 0 (original sample), 1, 2, 4, and 8 h of treatment. Furthermore, to explore PCB reformation in the MC treated fly ash, de novo tests were conducted at single reaction time, temperature, and air flow rate. It was found that the sum of PCB, dioxin like PCB, and corresponding International Toxic Equivalent concentrations (ΣPCB, Σdl-PCB and ΣI-TEQ, respectively) were greatly reduced both in gas and in solid phase of MFA after 8 h of treatment. Though chlorination degree successively decreased with prolonged milling, the homologue and isomer signatures of PCB were varied in concentration. Reformation of few isomers was also observed. Results from present study suggest that MC treatment is an effective method to control reformation of pollutants in the long term. However, few suggestions are made for further ongoing research work on MC treatment of fly ash, which are based on surprising results and experimental limitations obtained in this study.

關鍵字

PCB ； Ball milling ； De novo formation ； Homologues ； Isomers ； Reformation