Ricky R, Shanthakumar S, Gothandam K M
Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology (VIT), Vellore-632014, India.
Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology (VIT), Vellore-632014, India; Centre for Clean Environment, Vellore Institute of Technology (VIT), Vellore-632014, India.
J Environ Manage. 2022 Dec 1;323:116237. doi: 10.1016/j.jenvman.2022.116237. Epub 2022 Sep 14.
Municipal solid waste (MSW) leachate is a highly polluted liquid that accumulates in the landfill and contains a high concentration of toxic pollutants which can pollute the surrounding surface water and groundwater as well, if not treated properly. In this study, an integrated approach of phycoremediation with photolytic ozonation was employed for the leachate collected from the MSW dumpsite which has high Chemical Oxygen Demand (COD) and ammonium (NH) levels. Photolytic ozonation treatment was employed as a pre-treatment step under operating parameters of pH: 9.0; Ozone dosage: 5 g/h; UV-C: λ = 254 nm; and contact time: 60 min, in which the COD and NH in the leachate was reduced up to 81% and 95%, respectively. The selected algae Chlorella vulgaris (C.vulgaris) was employed in a lab-scale study to optimize the inoculum conditions in the photolytic ozonated leachate (POL). The specific growth rate of C.vulgaris was observed as 0.14/d in the POL at the optimized condition (inoculum size of 25% (T25)) during the study period of 11 days. High-rate algal pond (HRAP) was employed for the pilot-scale study in controlled environmental conditions as in the T25 experimental run for the assessment of POL treatment and biomass production. C.vulgaris reduced the concentration of pollutants COD, NH, and heavy metals (Cu, Fe) in the POL up to 93%, 94%, and 71%, respectively, with the dry biomass productivity of 0.727 g/L/d which is 3 times higher than the biomass productivity of C.vulgaris in freshwater conditions. The biochemical composition (carbohydrates, proteins, and lipids) of the harvested biomass has higher lipid production with lipid productivity of 120 mg/L/d which can be used as a feedstock for the production of value-a dded products.
城市固体废弃物（MSW）渗滤液是一种高污染液体，积聚在垃圾填埋场中，含有高浓度的有毒污染物，如果处理不当，这些污染物会污染周围的地表水和地下水。在本研究中，采用了光解臭氧化与藻类修复相结合的方法来处理从城市固体废弃物垃圾场收集的渗滤液，该渗滤液具有高化学需氧量（COD）和铵（NH）水平。光解臭氧化处理作为预处理步骤，操作参数为：pH值9.0；臭氧剂量5 g/h；UV-C：λ = 254 nm；接触时间60分钟，在此条件下，渗滤液中的COD和NH分别降低了81%和95%。选用普通小球藻（C.vulgaris）进行实验室规模研究，以优化光解臭氧化渗滤液（POL）中的接种条件。在为期11天的研究期间，在优化条件（接种量为25%（T25））下，普通小球藻在POL中的比生长速率为0.14/d。在受控环境条件下，采用高速藻类塘（HRAP）进行中试规模研究，如同在T25实验运行中一样，以评估POL处理和生物质生产情况。普通小球藻使POL中的污染物COD、NH和重金属（Cu、Fe）浓度分别降低了93%、94%和71%，干生物质生产率为0.727 g/L/d，这比普通小球藻在淡水条件下的生物质生产率高3倍。收获的生物质的生化组成（碳水化合物、蛋白质和脂质）具有较高的脂质产量，脂质生产率为120 mg/L/d，可作为生产高附加值产品的原料。
