Phosphates purification of waste water by natural materials and industrial wastes (comparative study)

Abstract

The management phosphates in freshwater has significant importance to regulate eutrophication. Phosphate excess leads to highly undesirable changes in ecosystems st ructure. The increasing of water body trophicity can result in water quality deterioration. This paper presents the testing results of reactive materials used for phosphorus removal from wastewater at sewage treatment plant. Twelve materi als of different origin available in Belarus were tested as potential reactive material s for phosphates removal. They are natural materials, industrial by-products and manufactured sorbents. Based on chemical composition the available and inexpensive materials rich in Al, Fe, Mg and Ca were selected. Relationship between purification degree of phosphates and specific material consumption (mg/mg PO[4]{3–} ) was investigated to choose potential reactive materials for phosphorus. Four materials (wa-ter conditioning sludge (WCS), dead-catalyst of petroleum hydrocarbon cracking (DCC), electric arc furnace slug (EAF-slug), dolomite burnt at 700°C) have been chosen for detailed sorption tests. WCS, DCC, EAF-slug and burnt dolomite have the apparent sorption capacities of: 13.6; 21.2; 35.3; 70.8 mg PO[4]{3-}/g respectively. Results have shown that the raw natura l materials (chalk, clay, dolomite and tripoli powder) and wastewater electric coagulation treatment sludge are of low efficiency. Results for experiments with synthetic solutions of phosphates are in correlation with results for actual wastewaters.