Composting has various benefits to achieve sustainability, such as substituting the use of fertilizers and preventing organic residues from being dumped in landfills. Thus, the objective was to evaluate nutrient and heavy metal release dynamics during composting with different mixtures of organic residues containing food wastes. The study was conducted in a community association in Mossoró, Rio Grande do Norte, Brazil, and the chemical analysis was carried out at the Universidade Federal Rural do Semi-Árido. Proportions between bovine manure (BM) and food wastes (FW) were Pile 1–0:3 (0% BM and 30% FW); Pile 2–1:2 (10% BM and 20% FW); Pile 3–1:1 (15% BM and 15% FW); Pile 4–2:1 (20% BM and 10% FW); Pile 5–3:0 (30% BM and 0% FW) (Pile considered as control), and the remaining 70% was filled with plant residues (tree prunings). Increment of BM proportion in compost piles with FW led to increase in C mineralization, but C mineralization decreased in the pile with only tree prunings and BM. Nitrogen immobilization occurred only in the pile with 15% BM and 15% FW; in the others, N was mineralized. Food wastes showed greater amounts of potentially mineralizable K fractions. For the micronutrients copper and zinc, in general, the initial contents decreased, whereas iron contents increased. The contents of all heavy metals diminished in the final product of the composting process, with no risk of contamination.

中文翻译：

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堆肥过程中有机残留物和食物垃圾混合物中释放的养分和重金属

堆肥具有实现可持续性的各种好处，例如代替肥料的使用以及防止有机残留物倾倒在垃圾填埋场中。因此，目的是评估堆肥过程中不同食物残渣有机残留物混合物中养分和重金属的释放动态。这项研究是在巴西北里奥格兰德州莫索罗市的一个社区协会中进行的，化学分析是在亚里米多联邦农村农村大学进行的。牛粪（BM）和食物垃圾（FW）之间的比例为1-0：3（0％BM和30％FW）；桩2–1：2（10％BM和20％FW）；桩3–1：1（BM的15％和FW的15％）；桩4–2：1（20％BM和10％FW）；5–3：0堆（30％的BM和0％的FW）（该堆作为对照），其余70％充满了植物残渣（修剪树木）。FW堆肥中BM比例的增加导致碳矿化的增加，但仅树木修剪和BM的堆肥中C矿化的下降。氮固定化仅发生在15％BM和15％FW的堆中。在其他国家，N矿化了。食物垃圾显示出更多的潜在可矿化的K馏分。通常，对于微量元素铜和锌，其初始含量减少，而铁含量增加。在堆肥过程的最终产品中，所有重金属的含量都减少了，没有污染的风险。食物垃圾显示出更多的潜在可矿化的K馏分。通常，对于微量元素铜和锌，其初始含量降低，而铁含量升高。在堆肥过程的最终产品中，所有重金属的含量都减少了，没有污染的风险。食物垃圾显示出更多的潜在可矿化的K馏分。通常，对于微量元素铜和锌，其初始含量减少，而铁含量增加。在堆肥过程的最终产品中，所有重金属的含量都减少了，没有污染的风险。