This work was aimed to utilise biocatalysts―enzymes derived from organic wastes mainly comprised of fruit garbage for remediation of used motor oil-contaminated soils. The fruit garbage used were orange and watermelon peels, which were allowed to ferment for 90 days for the derivation of enzymes. The enzymes identified in the extract solutions of the fruit garbage were protease, catalase, lipase, and amylase. Soils collected from the uncontaminated field were amended with used motor-oil at 5 and 10% (w/w) contamination levels. The amended soils were allowed to homogenise for 2 weeks before the experiment. The enzyme working concentrations were derived from Design Expert 7.0.0. matrix for 5 and 10% used motor-oil contamination levels as 0, 1, 5.43, 7.75 and 10% for 5% used motor-oil contamination level and 0, 1, 3.28, 6.62, and 10% for 10% used motor-oil contamination level. The experiment was run for six weeks. The minimum and maximum of 47 and 58% removal of oil and grease by orange garbage enzymes were recorded at 5 and 10% contamination levels, respectively at the end of six weeks experiment. Similarly, 41 and 52% removal of oil and grease were achieved with watermelon garbage enzymes at 5 and 10% contamination levels, respectively. Also, 62 and 74% of oil was biocatalytically removed in terms of Total Organic Carbon (TOC) by orange garbage enzymes at 5 and 10% contamination levels, respectively. In contrast, watermelon garbage enzymes showed an overall TOC removal efficiency of 45 and 39% for oil contamination levels of 5 and 10%, respectively. The differences observed in the biocatalytic remediation activities of the applied fruit garbage enzymes might be due to the difference in composition of the garbage enzymes. However, despite the differences in their enzymatic compositions, it is evident that extract solutions of fruit garbage enzymes of both orange and watermelon have the potential to remove oil from soil and hence could be applied for biocatalytic remediation of oil-contaminated soils.

这项工作旨在利用生物催化剂（源自有机废物的酶）（主要包括水果垃圾）来修复用过的机油污染的土壤。所用的水果垃圾为橙皮和西瓜皮，可发酵90天以衍生出酶。在水果垃圾的提取液中鉴定出的酶是蛋白酶，过氧化氢酶，脂肪酶和淀粉酶。从用过的机油对未污染田地中收集的土壤进行污染，浓度为5％和10％（w / w）。在实验前将修正的土壤均质化2周。酶的工作浓度来自Design Expert 7.0.0。5％和10％的机油污染水平的矩阵分别为0、1、5.43、7.75和10％5％的机油污染水平以及0、1、3.28、6.62，对于10％的使用过的机油污染水平，则为10％。实验进行了六周。在六周的实验结束时，分别记录了在5％和10％的污染水平下，橙色垃圾酶对油脂的最小和最大去除率分别为47％和58％。同样，西瓜垃圾酶分别以5％和10％的污染水平去除了41％和52％的油脂。另外，就总有机碳（TOC）而言，橙色垃圾酶分别以5％和10％的污染水平对62％和74％的油进行了生物催化去除。相比之下，西瓜垃圾酶在油污染水平分别为5％和10％时，总的TOC去除效率分别为45％和39％。所施用的水果垃圾酶在生物催化修复活性方面观察到的差异可能是由于垃圾酶的组成不同所致。然而，尽管它们的酶组成不同，但显然橙和西瓜的水果垃圾酶的提取液具有从土壤中去除油的潜力，因此可用于油污土壤的生物催化修复。