【摘要】：城市生活垃圾的主要處理方式是衛(wèi)生填埋,由此產(chǎn)生了垃圾滲濾液,其性質(zhì)和復(fù)雜的成分對環(huán)境危害大。在垃圾滲濾液的處理工藝中,混凝法可以適應(yīng)滲濾液成分的不斷變化,能穩(wěn)定地去除大部分污染物。本研究主要以南寧市上林生活垃圾填埋場的垃圾滲濾液為研究對象,以氨氮和COD的去除率作為指標,利用磁種混凝-磁分離技術(shù)作為預(yù)處理工藝,進行了混凝劑篩選和條件優(yōu)化的試驗,確定最佳混凝劑、磁種混凝條件及磁分離條件。對藥劑投加量、攪拌方式、溫度、pH值、磁場強度、水樣流速等影響因素進行了實驗研究,并確定了處理該垃圾滲濾液的最佳工藝條件;探索了處理后的懸浮液的過濾特性。實驗研究結(jié)果表明,聚合硫酸鐵(PFS)是適合處理該垃圾滲濾液的最佳混凝劑;曝氣處理能有效去除60%左右的氨氮和25%左右的COD。曝氣處理后,該垃圾滲濾液的最佳磁種混凝-磁分離工藝條件為:25℃,pH=10.0,PFS投加量16g/L,磁種投加量30g/L,攪拌方式為先250 r/min攪拌4 min再100 r/min攪拌15min,PAM投加量20mg/L,磁場強度150mT,水樣流速0.5 L/min。在此條件下,COD的去除率可達86.8%,含量為486mg·L-1,氨氮的去除率達到75.6%,含量為196mg.L-1。其中磁種混凝技術(shù)對氨氮和COD的去除起主要作用,而磁分離技術(shù)對氨氮和COD進一步的去除效果不大。過濾特性的研究結(jié)果顯示,污泥沉降至相同體積時,磁混凝花費的時間比混凝-絮凝快了 3.4倍,且在沉降60 min后,磁混凝污泥體積比混凝-絮凝的少了近一倍;磁混凝的污泥比阻比混凝-絮凝的小了613倍,其過濾常數(shù)值是混凝-絮凝的2.85倍,更易過濾。磁種不僅可作為絮凝核心,強化沉降效果,還使絮團具有較強的磁性,令其在磁場中實現(xiàn)固液分離,提高分離效果。磁種混凝-磁分離技術(shù)能有效去除垃圾滲濾液中的氨氮和COD含量,其具有處理效率高、分離效果好、設(shè)備簡單、占地面積少、易于實現(xiàn)凈化一體化、自動化等特點,在污廢水處理領(lǐng)域有著廣闊的應(yīng)用前景。
[Abstract]:The main treatment method of municipal solid waste (MSW) is sanitary landfill, which produces landfill leachate, whose properties and complex components are harmful to the environment. In the treatment process of landfill leachate, coagulation method can adapt to the continuous change of leachate composition and can remove most of the pollutants stably. In this study, the leachate of Shanglin Municipal solid waste Landfill site in Nanning City was taken as the research object, the removal rate of ammonia nitrogen and COD was taken as the index, and the magnetic coagulation-magnetic separation technology was used as the pretreatment process. The experiments of coagulant screening and condition optimization were carried out to determine the optimum coagulant, magnetic coagulation conditions and magnetic separation conditions. The influence factors such as dosage, stirring mode, temperature, pH value, magnetic field intensity and flow rate of water sample were studied, and the optimum technological conditions for the treatment of landfill leachate were determined, and the filtration characteristics of the treated suspension were explored. The experimental results show that polyferric sulfate (PFS) is the best coagulant for the treatment of landfill leachate, and aeration treatment can effectively remove about 60% ammonia nitrogen and 25% COD.. After aeration treatment, the optimum magnetic coagulation-magnetic separation conditions of the landfill leachate are as follows: 25 鈩，

本文編號：2492892