Planet – Water quality
Water quality gradually improving
Organic pollutants in effluent require oxygen to be completely chemically oxidized. Hence the pollutant load of wastewater can be measured through the chemical oxygen demand (COD), expressed in tonnes of oxygen required.
Process wastewater in the chemicals, plastics and life sciences sector is typically treated either in public wastewater treatment plants (funded through the payment of taxes) or, more importantly, in-house, where waste water treatment plants can be shared between companies. The reported COD values relate to wastewater released by the industry into surface waters.
The sector has reduced its specific COD load by almost 70% since 2001. By implementing the best available techniques for wastewater treatment, it has continued to reduce the COD of its effluents, despite increases in production.