Since the 2010 s, the authorities of Guangdong province and local governments have enhanced law enforcement and environmental regulations to abolish open burning, acid washing, and other uncontrolled e-waste recycling...Since the 2010 s, the authorities of Guangdong province and local governments have enhanced law enforcement and environmental regulations to abolish open burning, acid washing, and other uncontrolled e-waste recycling activities. In this study, ambient air and indoor dust near different kinds of e-waste recycling processes were collected in Guiyu and Qingyuan to investigate the pollution status of particles and polychlorinated dibenzo-pdioxins and furans(PCDD/Fs) after stricter environmental regulations. PM_(2.5) and PCDD/Fs both showed significantly reduced levels in the two regions compared with the documented data. The congener distribution and principal component analysis results also confirmed the significant differences between the current PCDD/Fs pollution characterizations and the historical ones. The estimated total intake doses via air inhalation and dust ingestion of children in the recycling region of Guiyu ranged from 10 to 32 pg TEQ/(kg·day), which far exceeded the tolerable daily intake(TDI) limit(1–4 pg TEQ/(kg·day). Although the measurements showed a significant reduction of the release of PCDD/Fs, the pollution status was still considered severe in Guiyu town after stricter regulations were implemented.展开更多
Polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)generated from municipal solid waste(MSW)incineration are considered as the key pollutants,which could pose serious risks to the environment and ecology.This study ...Polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)generated from municipal solid waste(MSW)incineration are considered as the key pollutants,which could pose serious risks to the environment and ecology.This study comprehensively investigated the effect of selective catalytic reduction(SCR)system on PCDD/F removal,phase distributions,and migrationtransformation characteristics of 17 congeners in a full-scale MSW incinerator.The three flue gas samples and two fly ash samples were separately collected for PCDD/F analysis.The results showed that the SCR system reduced the I-TEQ concentration of PCDD/Fs from 0.135 to 0.010 ng I-TEQ Nm^(−3)with a remarkable toxicity removal efficiency of 92.6%,through oxidation decomposition over V_(2)O_(5)-WO_(3)/TiO_(2)catalysts and chlorination process of low-chlorinated congeners.In addition,the de novo synthesis observed along the flue between SCR system and stack regenerated unexpected PCDD/Fs,which might enhance the PCDD/F emission level.This study verified the three pathways of SCR system on PCDD/F removal and inspired operating suggestions for SCR system,i.e.,keeping SCR system operated in stable and consistent conditions,regularly replacing V_(2)O_(5)-WO_(3)/TiO_(2)catalysts,and timely cleaning the dusts and inlet materials of SCR system,which would be beneficial for achieving the ultra-low emission of PCDD/Fs in full-scale MSW incinerators.展开更多
基金supported by the National Natural Science Foundation of China(No.91543202)the Ministry of Environmental Protection of the People's Republic of China(Nos.201409022,201409080 and 201509063)South China Institute of Environmental Science(No.PM-zx021-201510-015)
文摘Since the 2010 s, the authorities of Guangdong province and local governments have enhanced law enforcement and environmental regulations to abolish open burning, acid washing, and other uncontrolled e-waste recycling activities. In this study, ambient air and indoor dust near different kinds of e-waste recycling processes were collected in Guiyu and Qingyuan to investigate the pollution status of particles and polychlorinated dibenzo-pdioxins and furans(PCDD/Fs) after stricter environmental regulations. PM_(2.5) and PCDD/Fs both showed significantly reduced levels in the two regions compared with the documented data. The congener distribution and principal component analysis results also confirmed the significant differences between the current PCDD/Fs pollution characterizations and the historical ones. The estimated total intake doses via air inhalation and dust ingestion of children in the recycling region of Guiyu ranged from 10 to 32 pg TEQ/(kg·day), which far exceeded the tolerable daily intake(TDI) limit(1–4 pg TEQ/(kg·day). Although the measurements showed a significant reduction of the release of PCDD/Fs, the pollution status was still considered severe in Guiyu town after stricter regulations were implemented.
基金supported by the National Key R&D Program of China(Grant No. 2018YFC1902904)the National Natural Science Foundation of China (Grant No. 22008104)+4 种基金the Shenzhen Science and Technology Innovation Committee (Grant Nos. JCYJ20200109141642225,JCYJ20200109141227141, and JSGG20210713091810035)the Shenzhen Peacock Plan (Grant No. KQTD20160226195840229)provided by Basic and Applied Basic Research Foundation of Guangdong Province (Grant No. 2021A1515010148)Young S&T Talent Training Program of Guangdong Provincial Association for S&T(Grant No. SKXRC202230)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2018
文摘Polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)generated from municipal solid waste(MSW)incineration are considered as the key pollutants,which could pose serious risks to the environment and ecology.This study comprehensively investigated the effect of selective catalytic reduction(SCR)system on PCDD/F removal,phase distributions,and migrationtransformation characteristics of 17 congeners in a full-scale MSW incinerator.The three flue gas samples and two fly ash samples were separately collected for PCDD/F analysis.The results showed that the SCR system reduced the I-TEQ concentration of PCDD/Fs from 0.135 to 0.010 ng I-TEQ Nm^(−3)with a remarkable toxicity removal efficiency of 92.6%,through oxidation decomposition over V_(2)O_(5)-WO_(3)/TiO_(2)catalysts and chlorination process of low-chlorinated congeners.In addition,the de novo synthesis observed along the flue between SCR system and stack regenerated unexpected PCDD/Fs,which might enhance the PCDD/F emission level.This study verified the three pathways of SCR system on PCDD/F removal and inspired operating suggestions for SCR system,i.e.,keeping SCR system operated in stable and consistent conditions,regularly replacing V_(2)O_(5)-WO_(3)/TiO_(2)catalysts,and timely cleaning the dusts and inlet materials of SCR system,which would be beneficial for achieving the ultra-low emission of PCDD/Fs in full-scale MSW incinerators.
