With the aim to recommend an integrated alternative for the combined treatment of olive mill wastewater (OMW) and cotton residues (CR), and the production of high value and environmentally friendly products, two compost piles were set up. The first pile (control, pile 1) consisted of ginned CR, whereas the second (pile 2) was made of CR with the addition of OMW. A series of physicochemical parameters and the culturable microbial diversity in both piles were assessed. Co-composting (pile 2) displayed higher temperatures during the whole process, a prolonged second thermophilic phase and temperature values higher than 40 °C even after the thermophilic stage. Comparing the physicochemical parameters of the pile 2 with those of the pile 1, it was deduced that pH in the former was more acidic during the onset of the process; the EC values were higher throughout the process, while the levels of ammonium and nitrate nitrogen, as well as the NH₄⁺/NO₃⁻ ratios, were lower at most of the sampling dates. By evaluating the abovementioned results, it was estimated that the co-composting process headed sooner toward stability and maturity, Isolated microorganisms from both piles were identified as members of the genera Brevibacillus, Serratia, Klebsiella, and Aspergillus, whereas active thermotolerant diazotrophs were detected in both piles at the 2nd thermophilic phase emerging a promising prospect upon further evaluation for enhancing the end-product quality. Our findings indicate that co-composting is an interesting approach for the exploitation of large quantities of agro-industrial residues with a final product suitable for improving soil fertility and health.

为了推荐用于联合处理橄榄厂废水 (OMW) 和棉花残渣 (CR) 以及生产高价值和环保产品的综合替代方案，建立了两个堆肥堆。第一堆（对照，第 1 堆）由轧花 CR 组成，而第二堆（第 2 堆）由添加了 OMW 的 CR 制成。评估了两个堆中的一系列理化参数和可培养的微生物多样性。共堆肥（堆 2）在整个过程中显示出更高的温度，延长的第二个高温阶段和温度值高于 40 °C，即使在高温阶段之后。将桩 2 的理化参数与桩 1 的理化参数进行比较，推断前者的 pH 在该过程开始时更呈酸性；₄ ⁺ /NO ₃ ^-比率在大多数采样日期都较低。通过对上述结果的评估，估计共堆肥过程更快地趋于稳定和成熟，从两堆中分离出的微生物被鉴定为短杆菌属、沙雷氏菌属、克雷伯氏菌属和曲霉属的成员，而在第二个嗜热阶段的两个堆中都检测到活性耐热固氮菌，这在进一步评估以提高最终产品质量后出现了有希望的前景。我们的研究结果表明，共同堆肥是一种有趣的方法，可用于开发大量农工业残留物，最终产品适合提高土壤肥力和健康。