کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5117060 | 1485226 | 2017 | 7 صفحه PDF | دانلود رایگان |
- Biodegradation made a major contribution to the degradation of MDHB.
- The maximum removal efficiency of MDHB achieved 70.1% by the integrated process.
- The radiation dose of 600Â Gy was suitable for the mineralization of MDHB.
- The dechlorination efficiency reached 77.4% during the integrated process.
- The degradation pathway of MDHB by the integrated process was proposed.
Chlorinated paraben, namely, methyl 3, 5-dichloro-4-hydroxybenzoate (MDHB) is the by-product of chlorination disinfection of paraben and frequently detected in the aquatic environments, which exhibited higher persistence and toxicity than paraben itself. In this paper, the combined irradiation and biological treatment process was employed to investigate the removal of MDHB from aqueous solution. The results showed that the removal efficiency of MDHB and total organic carbon (TOC) by irradiation process increased with radiation dose no matter what the initial concentration of MDHB was. The maximum removal efficiency of MDHB was 100%, 91.1%, 93%, respectively, for the initial concentration of MDHB of 1Â mg/L, 5Â mg/L and 10Â mg/L with the radiation dose of 800Â Gy. However, the maximum removal efficiency of TOC among all the experimental groups was only 15.3% obtained with the initial concentration of 1Â mg/L at dose of 800Â Gy. The subsequent biological treatment enhanced the mineralization of MDHB. The suitable radiation dose for the subsequent biological treatment was determined to be 600Â Gy. In this case the removal efficiency of TOC increased to about 70%. Compared to the single biological treatment, the integrated irradiation and biological treatment significantly increase the degradation and mineralization of MDHB. Moreover, the dechlorination efficiency reached 77.4% during the integrated irradiation and biological treatment process. In addition, eight intermediates were identified during the combined process and the possible degradation pathway was proposed.
Journal: Journal of Environmental Management - Volume 189, 15 March 2017, Pages 29-35