Sewage sludge, a semi-solid byproducts of municipal wastewater treatment processes, offers a sustainable and cost-effective feedstock for biodiesel production through the synthesis of catalytic heterogeneous catalysts. In this study, we developed a novel heterogeneous catalyst by impregnating aluminum nitrate and calcite, obtained from carbon dioxide-sequestering bacteria, onto DigSBiochar (Biochar derived from digested sewage sludge). The produced catalyst was subsequently immobilized with the lipase enzyme isolated from Bacillus sp., creating a bioactive material for the transesterification of lipids in sewage sludge. Comprehensive characterization of the biocatalysts was conducted using Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), and Field Emission Scanning Electron Microscopy (FE-SEM). Gas Chromatography-Mass Spectrometry (GC-MS) analysis of the resulting fatty acid methyl esters (FAMEs) demonstrated that the highest yield was achieved with the enzyme immobilized on the activated heterogeneous catalyst using methanol (99 %), followed by the activated heterogeneous catalyst with methanol (96 %), and methanol with Sulfuric acid (82 %). This study underscores the potential of utilizing municipal sewage sludge as a valuable resource for producing efficient heterogeneous catalysts, thereby advancing sustainable waste management practices and promoting renewable energy production.

中文翻译：

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制备用于生产城市污泥生物柴油的非均相催化剂


污水污泥是城市废水处理过程的半固体副产品，通过合成催化多相催化剂，为生物柴油生产提供可持续且具有成本效益的原料。在这项研究中，我们通过将从二氧化碳隔离细菌中获得的硝酸铝和方解石浸渍到 DigSBiochar（从消化的污水污泥中提取的生物炭）上，开发了一种新型非均相催化剂。随后，用从芽孢杆菌属中分离的脂肪酶固定所产生的催化剂，从而产生一种用于污水污泥中脂质酯交换的生物活性材料。使用能量色散光谱 （EDS）、傅里叶变换红外光谱 （FTIR） 和场发射扫描电子显微镜 （FE-SEM） 对生物催化剂进行全面表征。对所得脂肪酸甲酯 （FAME） 的气相色谱-质谱 （GC-MS） 分析表明，使用甲醇 （99%） 将酶固定在活化的非均相催化剂上可实现最高产率，其次是用甲醇 （96%） 和用硫酸的甲醇 （82%） 的活化非均相催化剂。这项研究强调了利用城市污水污泥作为生产高效非均相催化剂的宝贵资源的潜力，从而推进可持续的废物管理实践并促进可再生能源生产。