Parana Federal University (UFPR) - Polytechnic Center, Department of Hydraulics and Sanitation (DHS), Water Resources and Environmental Engineering Post-Graduate Program (PPGERHA), Curitiba, Brazil.
Parana Federal University (UFPR) - Polytechnic Center, Department of Hydraulics and Sanitation (DHS), Water Resources and Environmental Engineering Post-Graduate Program (PPGERHA), Curitiba, Brazil.
J Environ Manage. 2023 Oct 15;344:118387. doi: 10.1016/j.jenvman.2023.118387. Epub 2023 Jun 20.
Sewage sludge is a byproduct of sewage treatment, whereas landfill leachate is a complex wastewater generated by the decomposition of solid waste. These byproducts require adequate management, and one option for the sludge is the thermal treatment by pyrolysis to produce biochar. The resulting biosolid can be used as an adsorbent to treat landfill leachate. The main objective of this research was to remove recalcitrant organic matter from landfill leachate by adsorption onto biochar produced from sewage sludge. Aerobic and anaerobic sludges were pyrolyzed at 450, 650 and 850 °C, under residence times of 60, 90 and 120 min. Temperature had a positive and more significant impact on the characteristics of the biochars produced, and consequently on the adsorption of recalcitrant organic matter. However, the impact of residence time was less intense and, in some cases negative. Biochars produced from both aerobic and anaerobic sludge pyrolyzed at 850 °C for 120 and 60 min, respectively, showed higher specific surface areas (114.4 mg and 104.2 mg, respectively) compared with those pyrolyzed at 450 °C and 650 °C. The biochar from anaerobic sludge produced at 850 °C and 60 min showed the best performance regarding the adsorption process, with chemical oxygen demand (COD), dissolved organic carbon (DOC), and color removals from the leachate of 32%, 36%, and 41%, respectively. The results of adsorption capacity for this biochar from anaerobic sludge were 26.1 mg g for COD and 7.9 mg g for DOC. The adsorption of recalcitrant organic matter from leachate was evidenced by the decrease in the UV-Vis absorbances and fluorescence intensities. It indicates that recalcitrant and humic substances were removed mainly by biochars pyrolyzed at 850 °C. Thus, the results allow to stress that the pyrolysis of sewage sludge to produce biochar is a promising alternative to sludge treatment, and the biochar may be applied as a pre-treatment of landfill leachate since it successfully removed the recalcitrant organic matter.
污水污泥是污水处理的副产品，而垃圾渗滤液则是固体废物分解产生的复杂废水。这些副产品需要进行充分的管理，而污泥的一种处理方法是通过热解进行热解处理，以生产生物炭。所得生物固体可作为吸附剂用于处理垃圾渗滤液。本研究的主要目的是通过吸附到由污水污泥制成的生物炭来去除垃圾渗滤液中的难处理有机物。好氧污泥和厌氧污泥分别在 450、650 和 850°C 下以 60、90 和 120 分钟的停留时间进行热解。温度对所产生的生物炭的特性以及对难处理有机物的吸附有积极的和更显著的影响。然而，停留时间的影响较弱，在某些情况下甚至是负面的。分别在 850°C 下热解 120 分钟和 60 分钟的好氧污泥和厌氧污泥产生的生物炭的比表面积（分别为 114.4mg 和 104.2mg）高于在 450°C 和 650°C 下热解的生物炭。在 850°C 和 60 分钟下产生的来自厌氧污泥的生物炭在吸附过程中表现出最佳性能，对渗滤液的化学需氧量（COD）、溶解有机碳（DOC）和颜色去除率分别为 32%、36%和 41%。来自厌氧污泥的这种生物炭的吸附容量为 26.1mg/g 的 COD 和 7.9mg/g 的 DOC。从渗滤液中吸附难处理有机物的证据是紫外可见吸光度和荧光强度的降低。这表明难处理有机物和腐殖质主要通过在 850°C 下热解的生物炭去除。因此，结果表明，通过热解污水污泥生产生物炭是一种有前途的污泥处理方法，并且生物炭可以作为垃圾渗滤液的预处理方法，因为它成功地去除了难处理有机物。
