Research On Treatment Of Heavy Metals Contaminnated Soil Leaching Wastewater By HMC-M1 Combined With Flat Ceramic Membrane

The application of soil leaching is extensive as a core technology of heavy metal contaminated soil remediation.The engineering practice shows that the expensive chemical leaching agent,elution waste is difficult to deal with and eluent difficult to recycle has become a key points and special difficulties of the technology breakthrough in a long time.The dissertation focuses on treatment of the heavy metal contaminated soil leaching wastewater,tests were made on a combined technology consisting of heavy metal chelating agent and the ceramic plate membrane and the former is used for breaking and the latter for separation.And the technical feasibility of the processwas verified in the most widely used field of artificial and natural chelating leaching agent,And the design of the membrane chemical reactor for the treatment of heavy metal contaminated wastewater by artificial and natural chelating agents was summarized through the exploration of the effect of the combined process.Using five kinds of heavy metal chelating agent,solid DTCR,liquid DTCR,solid TMT,liquid TMT,heavy metal chelating agent HMC-M1 to process the simulated leaching wastewater initial copper ion concentration of 50mg/L and 500mg/L,found for copper,cadmium and lead,heavy metal chelating agent HMC-M1 trapping efficiency is better than the other four.In addition,by comparing the extraction method of effluent after reaction,using ceramic microfiltration membrane 220 nm tablet,the extract of copper,cadmium and lead ion content and leaching efficiency,the static precipitation supernatant are superior to ordinary.Through the test of copper,cadmium and lead contaminated soil washing wastewater and leaching soil contaminated wastewater,found that for several kinds of wastewater,little effect of p H,temperature,stirring time,the main factor is the collector EDTA dosage and theoretical content in wastewater ratio(M/E),stirring intensity.For the simulation of copper,cadmium and lead contaminated soil and its leaching wastewater,the optimal reaction conditions are: adjusting the p H,temperature,dosing ratio is 1.4,the stirring intensity stirring time was 140r/min,5min.Under this condition,whatever the initial concentration of copper,cadmium and lead in wastewater is 50mg/L,100mg/L,300mg/L,500mg/L,after the treatment of wastewater containing heavy metal ion removal rate is above95%,and the treated wastewater extraction liquid leaching efficiency has reached 80% of the corresponding amount of EDTA,namely the method of leaching recovery in wastewater EDTA.To find the actual application of industrial wastewater in Guangdong province Linxi site: the best conditions are: adjusting the p H,temperature,dosing ratio is 1.4,the stirringintensity stirring time was 180r/min,5min.At the same time,the leaching efficiency of the industrial wastewater treatment solution was more than 80% of the corresponding amount of EDTA.Because EDTA was originally leaching wastewater with copper,cadmium and lead ions to form a stable soluble complex,the leaching efficiency after treatment proved that HMC-M1 complex break the balance of the original in the reaction process,and copper,cadmium and lead ions to form new insoluble complexes,while the release of EDTA.In this process,there are two main aspects of HMC-M1: breaking the complex equilibrium release of EDTA and separating EDTA from M-(HMC-M1),which accords with the characteristics of membrane chemical reactor reaction and separation.It is necessary to design a membrane chemical reactor for this process.Because of the stage and periodicity of in-situ soil leaching.So the batch stirred reactor was used to treat the wastewater.Experimental results show that the reaction time of the reactor with 5min,precipitation time selection of 30 min,influent time control for 10 min,water pump and dosing pump at the same time,and 10 min after adding water,ceramic membrane suction pump starts to work,after20 min began to stop the water,membrane backwash and mud,membrane cleaning and mud30 min after the end of a cycle.In addition,the system uses two membrane reactors in parallel,to ensure that the soil leaching water 1H,leaching wastewater has been treated.