Feasibility Study On Co-Treatment Of Leachate With Domestic Wastewater In Chengdu Region

At present,landfill is the most important way of urban garbage disposal in China.One of the major pollutant is leachate.which has high concentrations of organic pollutants,refractory organic and toxic substances.as well as can be very great harm to the enviroment and hard to handling.Beacuse of the high investment and operating costs independently,some landfills have used lower costs approach in leachate treatment,such as directly co-treatment with urban wastewater or after pretreatment co-treatment.Author is surpposed to reseach the problems of before and after the co-treatment and analysis of the feasibility of the consolidation,which are all based on merger process of SanWaYao wastewater plant in ChengDu.First of all,according to the quality of leachate water,author obtained the features of mixed wastewater and the volume changes of water qualitySecondly,through three indicators,which are changes in water quality parameters below 10%;heavy metal poisoning effect of the minimum concentration of microorganisms and heavy metal 50%inhibition effect of the minimum concentration of heterotrophic bacteria,analyzed the content of ammonia,Zn and Cr are exceed.Directly co-treatment will cause security issues of the plant owing to nutrient imbalance and heavy metals inhibit microbial activity.The author proposes two solutions.One is regulation ratio for calculati- -on obtained critical mixing ratio is 0.2%.Anothcr is to increase pretrca- -ment link.Research shows that pretreatment should use chemical,which should use PAC as flocculant,at the same time,maintain the quality ratio between PAC and ammonia about 1:7.In addition,MgO+H₃PO₄ should be Precipitant,more -over,keeping the molar ratio of Mg₂+:NH₄+:PO₄+ at about 1.2:1:1.4 is positive.Of course, regulating wastewater pH at about 9 is also necessary.In fact,both methods have the technical feasibility.After cost estimates,it is found that regardless of how to adjust ratio of Pharmacy,too high pharmacy costs make the method of increaseing pretreatment link impractical.But another solution is simple,affordable,highly technical,economic feasibility.Generally speaking,if the wastewter plant is larger,the mixed proportion of leachate is small,directly merger is acceptable.For those processwho need to increase pretreatment links,Their cost-effectiveness only through savings in a separate leachate system deal with the huge investment to reflect.