Preparation Process And Evaluation Of Humic Acid Fertilizer Extracted From Concentrated Leachate By Coagulation Technique

In most countries, sanitary landfill is nowadays the most common way to eliminate municipal solid wastes (MSW). In spite of many advantages, generation of heavily polluted leachates, presenting significant variations in both volumetric flow and chemical composition, constitutes a major drawback. At present,3level-membrane filtration is widely used in leachate treatment and effluent meet the standards. However, this process will produce high concentrated intercept liquid which is rich in nutrient and humic acid. To extract humic acid from leachate is both good to the treatment of leachate and utilization of the humic acid in leachate.The present paper deals with the extraction of humic acid from leachate by using coagulation with FeCb. Experiments were performed to study the toxicity of leachate humic acid and the dosage of FeCl3. As a result, it was found that when the leachate was diluted in the ratio of20%, it could promote the plant growth, and the leachate can be utilized in maximum. The result also shows that the extraction rate of leachate increased with an increase in FeCl3dosage, and the optimum dosage of FeCl3was8ml/50ml, COD removal efficiency was above70%. The product's ICP report tells that the content of heavy metals exceeds standard.After the experiment, the preparation process of leachate humic acid fertilizer was analyzed with LCA. LCA is a kind of software to evaluate the potential environment impact of certain product, process and system. The output of LCA shows that1) the step of using FeCl3is the main origin of greenhouse gas,2) supernatant is the resource of water eutrophication,3) the contribution to greenhouse effect of using FeCl3and power are on equal items.