SUBSTITUTION CASE STUDY

Detection of traces of chlorinated compounds such as Dichloromethane and Chloroform in wastewater. 

June 2018

Abstract

Wastewater analysis of a textile mill showed the presence of chlorinated compounds such as Dichloromethane & Chloroform.  These substances were not found in the chemical inventory for the mill, and testing showed their presence in the municipal water supply being used. 

Alternative substances

Avoiding chlorinated compounds detected in waste water was achieved by using ground-water or other sources where the water had not been chlorinated.  

Application

  • Sector: Other sectors 
  • Process: Cleaning/washing/rinsing/dry cleaning 
  • Function of substituted chemicals: Other functions (Dry-cleaning agents for fabrics) 
  • Enterprise using the alternative: Tesco Stores Ltd (F&F Clothing), 6 Trident Place, Mosquito Way, Hatfield, Hertfordshire, AL10 9UL. 
    www.tesco.com cr.enquiries@tesco.com
  • State of implementation: pilot study
  • Date when alternative was implemented and in what country:  2018, Bangladesh
  • Availability of the alternative: ground water source
  • Reliability of information: there is evidence that the solution was implemented and in use at the time of publication

Substitution description

A Tesco supplier of knit garments, based in Dhaka, Bangladesh has a chemical management policy which complies with and goes beyond EU legislation. The mill recognizes the importance of evolving its chemical management policy in line with industry best practices and of minimizing the environmental impact of textile manufacturing processes. The company has committed to working with industry and other stakeholders to achieve the goal of zero discharge of hazardous chemicals within its textile and apparel supply chain by 2020.

A pilot study of a textile dyeing and printing mill in Bangladesh belonging to this supplier assessed current chemical usage and aimed to identify issues related to chemical management practices.  The study found traces of dichloromethane and chloroform in the mill's wastewater effluent. 

A review of the mill’s chemical inventory found the mill was not using any chemicals featuring these chlorinated compounds. Further evaluation of incoming materials and water sources revealed the municipal water supply used by the mill as the source.  This water is chlorinated for sterilization. When the mill switched to ground water/well water, the halogenated solvents no longer appeared, suggesting that the chlorine radical/ion might react with other organic chemicals present in the waste water in the presence of sunlight, forming dichloromethane, chloroform and carbon tetrachloride etc. as residues despite not being present in the chemicals in use at the facility.