含铝酸性农药废水合成聚合硫酸铝混凝剂

采用农药三唑醇生产过程中产生的含铝酸性废水为原料,合成了聚合硫酸铝(PAS)液体混凝剂,并用于厂区污水站好氧池出水的混凝处理。考察了碱化剂用量、聚合温度、聚合时间等合成条件及PAS加入量、混凝pH等混凝条件对混凝效果的影响,并比较了PAS与商售聚合氯化铝(PAC)的混凝效果。实验结果表明:在n(碱化剂)∶n(硫酸铝)为2.1∶1、聚合温度为80℃、聚合时间为60 min的条件下,所得PAS液体混凝剂产品的w(Al2O3)为7.8%~9.0%,盐基度为45%~60%,pH为3.5~4.0,产量为0.75 t/t(以废水计);在PAS加入量为2.0 m L/L、混凝pH为10.0时,COD和SS的去除率则分别达到14.6%和83.0%;该PAS可替代厂区常规使用的商售PAC,日节约废水处理成本5 922元。

Synthesis of polyaluminium sulfate from acide aluminium-containing pesticide wastewater

The liquid polymeric aluminum sulfate（PAS）coagulant was synthesized using the acid aluminum-containing pesticide wastewater in triadimefon production as raw material,and was used for coagulation of effluent from aerobic tank in plant. The factors affecting synthesis and coagulation were studied. The coagulation effects on the produced PAS and commercially available PAC was compared with each other. The experimental results show thatUnder the conditions of n（alkalizer）∶n（Al₃SO₄）=2.1∶1,polymerization temperature 80 ℃ and polymerization time 60 min,the yield of the liquid PAS is 0.75 t/t with 7.8%-9.0% of w（Al₂O₃）,45%-60% of basicity and 3.5-4.0 of pH;When the PAS dosage is 2.0 mL/L and the wastewater pH is 10.0,the removal rates of COD and SS are 14.6% and 83.0% respectively;The liquid PAS can replace the conventional commercial PAC and 5 922 RMB of wastewater treatment cost can be saved every day.