Impacts of heavy metals on 1,2-dichloroethane biodegradation in co-contaminated soil
Journal of Environmental Sciences
Discipline of Microbiology, School of Biochemistry, Genetics, Microbiology and Plant Pathology, Faculty of Science and Agriculture, Private Bag X54001, Durban, 4000, South Africa
1,2-Dichloroethane (DCA), a potential mutagen and carcinogen, is commonly introduced into the environment through its industrial and agricultural use. In this study, the impact of lead and mercury on DCA degradation in soil was investigated, owing to the complex co-contamination problem frequently encountered in most sites. 1,2-Dichloroethane was degraded readily in both contaminated loam and clay soils with the degradation rate constants ranging between 0.370-0.536 week-1 and 0.309-0.417 week-1, respectively. The presence of heavy metals have a negative impact on DCA degradation in both soil types, resulting in up to 24.11% reduction in DCA degradation within one week. Both biostimulation and treatment additives increased DCA degradation, with the best degradation observed upon addition of glucose and a combination of diphosphate salt and sodium chloride, leading to about 17.91% and 43.50% increase in DCA degradation, respectively. The results have promising potential for effective remediation of soils co-contaminated with chlorinated organics and heavy metals. However, the best bioremediation strategy will depend on the soil types, microbial population present in the soil matrices, nutrients availability and metal forms. © 2009 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.
Agricultural use; biostimulation; Chlorinated organics; Clay soil; co-contamination; Contaminated soils; Contamination problem; Degradation rate constants; Dichloroethane; Diphosphates; Microbial populations; Negative impacts; Nutrients availability; Soil matrices; Soil types; treatment additives; Biochemistry; Biodegradation; Bioremediation; Clay; Clay minerals; Contamination; Degradation; Glucose; Land use; Lead; Mercury (metal); Metals; Microbiology; Rate constants; Sodium chloride; Soil pollution; 1,2 dichloroethane; heavy metal; biodegradation; bioremediation; carcinogen; heavy metal; soil pollution; soil remediation; article; metabolism; soil pollutant; Ethylene Dichlorides; Metals, Heavy; Soil Pollutants