载体诱导HAP沉淀处理含PO_(4)^(3-)废水效果分析

Effect analysis on treatment of PO_(4)^(3-)wastewater by carrier induced HAP precipitation

以含PO_(4)^(3-)配水为处理对象、CaCl_(2)为沉淀剂,得到无载体时PO_(4)^(3-)去除最佳条件;在最佳条件下,对比12种备选载体诱导HAP(Ca_(5)OH(PO_(4))_(3))沉淀效果,选出最佳载体;考察不同来源最佳载体的诱导沉淀效果,分析了载体成分对诱导沉淀除PO_(4)^(3-)、Ni^(2+)、Pb^(2+)效果的影响。结果表明,无载体时最佳沉淀条件为:pH为10.0、沉淀剂投加摩尔比为4∶1、平衡时间为80 min;添加10种载体后,反应平衡时间均显著减少,PO_(4)^(3-)去除率均提高,其中白云石诱导沉淀效果最佳;白云石中CaO、MgO、SiO_(2)、Al_(2)O_(3)含量与PO_(4)^(3-)平衡去除率呈正相关,Fe_(2)O_(3)、Na_(2)O、K_(2)O含量与平衡去除率呈负相关,白云石诱导NiS、PbS沉淀与HAP有相似规律,以不同成分对平衡去除率影响程度为参数选择白云石,应选择其正相关成分影响程度大且含量高的白云石。

Using PO_(4)^(3-)-containing water as treatment object and CaCl_(2) as the precipitant,the optimal removal conditions for PO_(4)^(3-)without carrier are obtained.Under optimal conditions,the induced HAP[Ca_(5)OH(PO_(4))_(3)]precipitation effects are compared by using 12 natural minerals as carriers,and the best carrier is selected out.The effects of the best carriers from different sources on the removal of PO_(4)^(3-)by induced precipitation are investigated,and the effects of carrier components on the removal of PO_(4)^(3-),Ni^(2+)and Pb^(2+)by the induced precipitation process are analyzed.The results show that the optimum precipitation conditions without carrier are as follows:10.0 for pH,4∶1 for precipitant dosage ratio and 80 minutes for reaction equilibrium time.After adding 10 kinds of carriers respectively,the reaction equilibrium time is all shortened significantly and the removal rates of PO_(4)^(3-)all increase.Among 10 kinds of carriers,dolomite exhibits the best induction effect.The contents of CaO,MgO,SiO_(2) and Al_(2)O_(3) in dolomite are positively correlated with the equilibrium removal rate of PO_(4)^(3-),and the contents of Fe_(2)O_(3),Na_(2)O and K_(2)O are negatively correlated with the removal rate.The precipitation of NiS and PbS induced by dolomite is similar with that of HAP.If dolomite is selected as the carrier,the influence degree of its different component on the equilibrium removal rate shall be taken as the parameter.For the positive correlation,dolomite with large influence and high content shall be selected,while for the negative correlation,it is the opposite.