Levels and Distributions of Hexachlorobutadiene and Three Chlorobenzenes in Biosolids from Wastewater Treatment Plants and in Soils within and Surrounding a Chemical Plant in China

Abstract

Although hexachlorobutadiene (HCBD) was recently proposed as a candidate persistent organic pollutant (POP) under the Stockholm Convention, information about its environmental levels and distributions is still very limited. In this work, HCBD was determined in the sewage sludge from 37 wastewater treatment plants (WWTPs) in 23 cities and 17 soils near a chemical plant in China. Three chlorobenzenes (CBs) (1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, and hexachlorobenzene) were simultaneously studied to help better understand the environmental behavior of HCBD. Concentrations of HCBD in sludge samples ranged from <0.03 to 74.3 ng/g dry weight (dw) with a median value of 0.30 ng/g dw, which was lower than those of the three CBs. Levels of HCBD were not correlated with capacity of the WWTPs and total organic carbon. For soils, high level of HCBD was found in the sample within the plant, with a rapid decreasing concentration trend with the increase of distance from the plant. It was suspected that releasing as a byproduct during manufacturing of chlorinated chemicals was the primary source of HCBD in the studied location. Further risk assessment indicated that the environmental risk of HCBD to soil organisms and the health risk to employees were very low through soil exposure within the plant.

Determination of synthetic phenolic antioxidants and relative metabolites in sewage treatment plant and recipient river by high performance liquid chromatography–electrospray tandem mass spectrometry

“…Alumina, florisil and silica gel were used to clean up the extracts of biological tissues and sludge matrix when analyzing alkylphenols, benzotriazole UV stabilizers, chlorobenzenes and polybrominated diphenyl ethers [22][23][24][25][26]. In this study, the optimization of the clean-up procedure was first carried out with pure standards.…”

Levels and distribution of organochlorine pesticides and hexachlorobutadiene in soils and terrestrial organisms from a former pesticide-producing area in Southwest China

“…Surprisingly, the HCBD level in soils was not high in the study area. Tang et al (2014) found HCBD concentrations between \0.02 and 3.10 ng g -1 dw in soils from an agricultural area in East China and Zhang et al (2014) reported that the concentrations in soil around a pesticide plant had a range of 0.04-3.33 ng g -1 dw. The HCBD concentrations in soils in this study were much lower than those reported in soils from plants producing perchloroethylene and trichloroethylene in the United States (USEPA 1976).…”

“…Hexachlorobutadiene (HCBD), a chlorinated aliphatic hydrocarbon, has been listed as a candidate persistent organic pollutant by the Stockholm Convention owing to its toxicity, persistence, and potential for bioaccumulation Zhang et al 2014). This molecule is usually generated as a by-product during the production of chlorinated solvents (POPRC 2013).…”

Polychlorinated naphthalenes in sewage sludge from wastewater treatment plants in China

“…Besides PCNs in the present work, HCBD, HCB, PBDEs, and SCCPs in the sludge samples collected during the same period were also analyzed in our previous investigations (Zeng et al, 2012;Sun et al, 2013;Zhang et al, 2014). Fig.…”

“…Residual hazard substances in the sludge may have harmful effects on soil organisms, vegetation, animals and human through secondary treatment of sewage sludge such as land filling, incineration and application on farm land (Clarke and Smith, 2011;ESWI, 2011). Several POP and POP candidates such as short chain chlorinated paraffins (SCCPs), hexachlorobutadiene (HCBD), polybrominated diphenyl ethers (PBDEs) and hexachlorobenzene (HCB) in sewage sludge from wastewater treatment plants (WWTPs) have been investigated to evaluate their spatial distributions and pattern profiles in China (Zeng et al, 2012;Sun et al, 2013;Zhang et al, 2014). Previous works have reported PCN levels in air, sediment and mussels from North China, air and surface soil from the Pearl River Delta, and yak samples from eastern Tibet-Qinghai Plateau (Lee et al, 2007;Pan et al, 2007;Pan et al, 2011;Zhao et al, 2011;Wang et al, 2012aWang et al, , 2012bLin et al, 2013;Pan et al, 2013), indicating that PCN contaminants are ubiquitous in China.…”