CHẤT THẢI CHĂN NUÔI CÔNG NGHIỆP: MỘT GÓC NHÌN TỪ PHƯƠNG PHÁP XỬ LÝ

The experiment aimed to determine the effects of treatment conditions (aerobic, anaerobic) and seasons (Spring, Summer) on the composting process of industrial livestock waste (cow, chicken, pig). The wastes were co-composted with biochar at a ratio of 9:1 (v/v) under different conditions to analyze the changes during composting. The results showed that aerobic treatment conditions were suitable for all types of waste. The anaerobic composting method, which produced compost product with higher nutritional and organic content but carried harmful microorganisms (E. coli, Salmonella) exceeding the standard. After 30 days of composting, cow manure possessed highest organic content (46.54-47.67%) and a total NPK content of 4.04-4.43%, but C/N ratio was higher than the regulation (> 12). In contrast, chicken waste compost possessed lowest organic matter content (36.46-37.59%), but highest total NPK content (5.05-5.44%) and met the standard for C/N ratio. In addition, pig waste compost possessed an average organic matter content and lowest total NPK content value. In both Spring and Summer, chicken waste and biochar, which were treated aerobically, had NPK nutrient content, pH, C/N ratio and heavy metal content (As, Pb, Cd, Hg) meeting the organic fertilizer standards according to QCVN 01-189-2019.