Research progress on removal of phosphate from aqueous solution by biochar and its metal modified materials

Abstract

Phosphorus is the main limiting factor of eutrophication. How to control the phosphate concentration in rivers and lakes is of great significance to control eutrophication. it is considered that adsorption is an economical, efficient and simple phosphorus removal method. However, how to select the appropriate adsorption material is the key to its application. The application of biochar to the removal of phosphate from water can provide a new way for the treatment of agricultural and forestry waste, livestock manure, activated sludge and invasive plants. The phosphate-absorbing biochar can be used to improve soil improvement. Methodology is of highly advantageous but difficult in phosphate removal from practical waste water. The current paper reviewed domestic and international research results pertaining to phosphate removal by biochar. The ability of biochar to remove phosphate was summarized. The mechanism of phosphate removal by biochar or metal modified biochar was explained. The effects of pH, temperature, co-existing ion, initial phosphate concentration and other reaction conditions on the removal of phosphate by biochar were analyzed, and the characteristics of the desorption of phosphate were briefly described. Lastly, to realize the industrial application of biochar in contaminated water, it was pointed out that the mechanism of modification and phosphate removal be further researched, and experiments should be conducted using natural water bodies with complex forms of phosphorus or adsorption columns, and the research and risk assessment about phosphate-absorbing biochar as a soil amendment should be further strengthened, and the cost of biochar manufacturing should be estimated.