Promotion of biodegradable chemicals in textile industry/SCORE (2008)

Funded by: Water Research Commission

Partner organisations: Partners in Development, eThekwini Water and Sanitation

Project description
South Africa is a relatively water scarce country with a growing demand for water in all sectors of society and the economy therefore the protection and management of both surface and ground water are critical national priorities. South African depends chiefly on surface water resources for most of its urban, industrial and irrigation requirements. Deterioration of the quality of surface water resources is one of the most important problems facing South Africa in trying to ensure an adequate (quality and volume) and environmentally sustainable water supply to meet its various needs.

The textile industry is not only amongst the largest industrial liquid waste generators, it is also chemically intensive. As a result, very large volumes of effluent containing a wide range of dyes, auxiliaries, salts, acids, alkalis and occasionally even heavy metals are often generated. Some pollutants in the textile effluent are of particular concern because they are not degraded in conventional wastewater treatment processes. These include colour residues, salinity, COD and compounds contributing to aquatic toxicity Preventing these pollutants getting into the effluent is the best way to control them.

The proposed Waste Charge Discharge Costs system expands the range of regulated determinands from COD and settleable solids to include conductivity, phosphorous and nitrogen compounds. In addition DWAF has becoming more stringent with respect to trade effluent toxicity. These developments will result in local authorities changing bylaws and modifying tariff procedures to bring them in line with the new national policy. Factories will have to conform to these changes or face penalty fees.

The clothing and textile industry is South Africa’s sixth largest employer in the manufacturing sector and the 11th largest exporter of manufactured goods. In South Africa, as in many other parts of the world, the textile and clothing industry is under threat from cheap imports from Asia. In order to position itself internationally, the South African textile industry needs to focus on the markets for high value products in developed countries. Important market imperatives for penetrating such markets are sound social and environmental practices.

The Score System is one of the many tools that can assist in the prevention of pollution and the replacements of potentially toxic chemicals with less harmful alternatives. It is a management tool which can be used to select or set priorities on chemicals that are deemed to be undesirable due to their environmental fate. The system was originally developed in Denmark and was identified as being potentially applicable to South Africa following two study tours to Denmark by role-players in the South African textile industry.
The Score system is based on four parameters which are important for characterizing the impact of chemicals and dyestuffs on the environment. These are:
  • A – Discharged amount of substance to drain over a given period,
  • B – Biodegradability
  • C – Bioaccumulation and
  • D – Toxicity.
Each parameter (i.e. A, B, C or D) is given a score between 1 and 4, with 1 indicating the least environmental impact and 4 indicating the most serious impact. In the case of missing information required to determine the parameter score, the highest score is assigned along with a remark “4u” (“u” indicating unknown).

The product of A, B and C (i.e. A x B x C) is called the Exposure score. The Exposure score gives an indication of the potential presence (level, persistence and distribution) of the substance in the environment.