CAJ | 학술논문

通过实验对三段石灰法处理重金属硫酸废水的工艺进行了改进,提出石灰消化时间由原来的4 h延长到24 h以上,一段硫酸废水混凝反应的pH由原来的3~5变为10~11,弃用一段沉淀污泥回流;二段处理把原工艺采用石灰乳调节pH改用氢氧化钠和磷肥厂的磷酸废水,出水pH控制在8~9;二段出水过滤设备把原来纤维球过滤装置改为砂滤,砂滤出水回用于工艺,滤料反冲洗采用硫酸废水,清洗采用清水池循环水.实验表明:通过改进,出水中Zn2+,Pb2+,Cd2+,Cu2+浓度小于1.0 mg/L,废水中重金属达标排放,同时大大降低了出水中Ca 2+浓度,缓解了出水循环利用工艺严重结垢问题,也解决了原工艺处理出水pH高形成较高浓度重金属配合物污染土壤河流问题.
통과실험대삼단석회법처리중금속류산폐수적공예진행료개진,제출석회소화시간유원래적4 h연장도24 h이상,일단류산폐수혼응반응적pH유원래적3~5변위10~11,기용일단침정오니회류;이단처리파원공예채용석회유조절pH개용경양화납화린비엄적린산폐수,출수pH공제재8~9;이단출수과려설비파원래섬유구과려장치개위사려,사려출수회용우공예,려료반충세채용류산폐수,청세채용청수지순배수.실험표명:통과개진,출수중Zn2+,Pb2+,Cd2+,Cu2+농도소우1.0 mg/L,폐수중중금속체표배방,동시대대강저료출수중Ca 2+농도,완해료출수순배이용공예엄중결구문제,야해결료원공예처리출수pH고형성교고농도중금속배합물오염토양하류문제.
The process of treating acidic wastewater containing heavy metals by three-stage lime is improved by small-scale test.The results show that the time of lime digestion is extended from 4 h to 24 hour.pH of flocculation reaction may change from the original 3~5 into 10~11 in first stage. Precipitation back-flow is not adopted.The pH is adjusted to adopting phosphoric acid wastewater and sodium hydroxide and the pH of effluent in the second stage is controlled within 8 and 9 .Filter equipment with fiber -ball replaced with sand filter.The effluent is reused to process.Acidic wastewater is used to backwashing of filter and recycled water is used for cleaning.The results show that the concentrations of Zn2+,Pb2+,Cd2+and Cu2+ion less than 1.0 mg/L,which meet effluent standard,and the concentration of Ca2+ion is reduced remarkably in effluent.The problem of seri-ous scaling is solved and the problem of soil pollution resulted from high concentration heavy metal clathrate is solved as well.