Preparation of novel lanthanum coagulants and their deep phosphorus removal properties in low temperature and turbidity water
In view of the poor performance of Fe and Al coagulants in deep phosphorus removal in low temperature and low turbidity water,based on the specific affinity of lanthanum and phosphate,a series of polylanthanum coagulants(LXC)were prepared by sol-gel method with different lanthanum sources,organic ligands and raw materials(acid,alkali,alcohol,wa-ter).The mass fraction of lanthanum in the obtained materials was 30%~33%,and the particle size of the coagulation floc reached 1 600 μm.And the settlement process could be completed within 5 minutes.The deep phosphorus removal and turbidity removal performance of LXC on university river water[temperature of 4~6℃,phosphorus concentration of(1.0±0.1)mg/L],Yangcheng Lake water[temperature of 4~6℃,phosphorus concentration of(0.1±0.3)mg/L],and Shihu Lake water[temperature of 4~6℃,phosphorus concentration of(0.8±0.2)mg/L]were evaluated using LaCl3 and polyalu-minum chloride(PAC)as control samples.The results showed that under the same dosage,LXC had better phosphorus re-moval performance on different water samples than LaCl3 and PAC.Under suitable conditions,the residual phosphorus con-centration in the coagulated effluent was less than 0.02 mg/L,achieving deep phosphorus removal performance.This study provided new solutions for deep phosphorus removal and alleviating eutrophication in wave.
coagulationpolylanthanum coagulantslow temperature and turbidityphosphorus removalsol-gel method