Land reclamation and river pollution problems in the Croal Valley caused by waste from chromate manufacture.
Abstract
Waste from chromate manufacture was toxic to plants, and in mixture with 7 parts of soil to 1 of waste would not support perennial ryegrass or Agrostis tenuis even at high levels of NPK; germination of most seeds was prevented. K2Cr2O7 was toxic to perennial ryegrass in John Innes potting compost at 500 mg Cr/kg, while chromic sulphate produced similar results at 5000 mg/kg; this was thought to be because chromic hydroxide and complexes with soil organic matter was formed, and it was considered that reclamation could be achieved by chemical reduction of the chromate in the waste.