Hydroxyapatite(HAP)was the low-cost,efficiency,safe,and low-carbon defluorider for water treatment.It was often prepared with wet chemical precipitation process.However,the heavy aggregate and compaction arose during its prepa-ration,which resulted in the poor performance of products.In this study,the chemicals of Ca(OH)2,H3PO4 and dispersants were used to preparate HAP with the re-direction addition process.The effects of dispersant on the HAP preparation were in-vestigated.It was shown that sodium dodecyl benzene sulfonate(SDBS)/ethylene glycol were desirable dispersant for HAP preparation,and the optimized mass ratio of ethylene glycol,SDBS and Ca(OH)2 was 1:1:1 000.With the optimized condi-tions of dispersant,the fluoride removal capacity of HAP product reached 16.56 mg/g,which increased by 32.90％.The pH value of reaction system increased with the dripping of calcium hydroxide emulsion,and it reached the maximum value of 12.96 at 105 min.Then it decreased continuously to 8.13 for the generation of HAP.The ratio of OH-consumption rate and the increase rate of defluoride quantity raised first and then lower.It increased to the maximum value of 4.98 at 180 min and was less than 1.00 after 235 min.The diameter of aggregated particle decreased with the increase of reaction time after 60 min.At 360 min,the d10,d50 and d90 of final product were 7.46,15.65 and 42.41 μm,respectively.Compared to the control group,its d50 andd90decreased by 56.83％and 52.21％,respectively.The HAP crystals were nano-level and they aggregated to form a micron particle.The fluoride in potable water could be removed quickly by the HAP prepared,and the fluoride removal con-formed to the proposed secondary dynamic model.
关键词
饮用水除氟/羟基磷灰石/颗粒团聚粒径/分散剂/乙二醇/十二烷基苯磺酸钠/除氟容量
Key words
fluorine removal of potable water/hydroxyapatite/diameter of aggregate/dispersant/ethylene glycol/sodium dodecyl benzene sulfonate(SDBS)/fluoride removal capacity
维普
万方数据