Czech University of Life Sciences, Faculty of Agrobiology, Food, and Natural Resources, Department of Agro-Environmental Chemistry and Plant Nutrition, Kamycka 129, Prague 16500, Czech Republic.
Czech University of Life Sciences, Faculty of Agrobiology, Food, and Natural Resources, Department of Agro-Environmental Chemistry and Plant Nutrition, Kamycka 129, Prague 16500, Czech Republic.
Ecotoxicol Environ Saf. 2023 Sep 15;263:115255. doi: 10.1016/j.ecoenv.2023.115255. Epub 2023 Jul 19.
Even though sewage sludge (SS) contains a high level of pollutants, it is rich in essential plant nutrients and has the potential to enhance soil fertility. However, the SS must be further treated through pre-composting plus vermicomposting to make it safe for use on food crops. More research and data are needed to determine how different carbon-to-nitrogen ratios (C/N) affect the feasibility and quality of composting vs vermicomposting of SS. Therefore, in this study we comprehensively evaluated the feasibility and end-product quality of compost and vermicompost produced from SS under different C/N ratios. SS was mixed with pelletized wheat straw (PWS) at various proportions to produce C/N ratios of 6:1, 18:1, 28:1, and 38:1, then pre-composted for 14 days followed by vermicomposting using the earthworm Eisenia andrei for 120 days. Agrochemical properties were measured at 0, 30, 60, 90, and 120 days. Results revealed significantly higher levels of agrochemicals in vermicompost compared to compost, including total potassium (37-88%) and magnesium (4.3-12%), nitrate nitrogen (71-98%), available potassium (53-88%), available phosphorus (79%), available magnesium (54-453%), available boron (48-303%), and available copper (2.5-82%). However, lower levels of ammonium nitrogen by (59-85%), available iron (2.3-51.3%), available manganese (29.7-52.2%), available zinc (10.5-29.8%), total carbon (0.75-4.5%), and total nitrogen (1.6-22.2%) were measured. Comparison of the various C/N ratios, showed that vermicompost with an 18:1 C/N ratio outperformed compost and demonstrated the highest earthworm population (165 pieces/kg). Thus, vermicomposting SS at an 18:1 C/N ratio is strongly recommended as a sustainable technology for producing high-quality vermicompost from SS.
尽管污水污泥 (SS) 含有高水平的污染物，但它富含植物必需的营养物质，具有提高土壤肥力的潜力。然而，SS 必须通过预堆肥加蚯蚓堆肥进一步处理，以使其在食用作物上使用安全。需要更多的研究和数据来确定不同的碳氮比 (C/N) 如何影响 SS 堆肥和蚯蚓堆肥的可行性和质量。因此，在这项研究中，我们综合评估了不同 C/N 比下 SS 制成的堆肥和蚯蚓堆肥的可行性和终产物质量。SS 与颗粒化麦秸 (PWS) 以不同比例混合，产生 C/N 比为 6:1、18:1、28:1 和 38:1，然后预堆肥 14 天，再用蚯蚓赤子爱胜蚓进行 120 天的蚯蚓堆肥。在 0、30、60、90 和 120 天测量农用化学品性质。结果表明，蚯蚓堆肥中的农用化学品含量明显高于堆肥，包括总钾 (37-88%) 和镁 (4.3-12%)、硝态氮 (71-98%)、有效钾 (53-88%)、有效磷 (79%)、有效镁 (54-453%)、有效硼 (48-303%) 和有效铜 (2.5-82%)。然而，铵态氮的含量较低 (59-85%)、有效铁 (2.3-51.3%)、有效锰 (29.7-52.2%)、有效锌 (10.5-29.8%)、总碳 (0.75-4.5%) 和总氮 (1.6-22.2%)。不同 C/N 比的比较表明，C/N 比为 18:1 的蚯蚓堆肥优于堆肥，表现出最高的蚯蚓种群 (165 条/kg)。因此，强烈建议将 SS 以 18:1 的 C/N 比进行蚯蚓堆肥，作为一种可持续的技术，从 SS 生产高质量的蚯蚓堆肥。
