Abstract: In order to improve the problems of low phosphorus and low potassium content in biogas residue and cow dung compost, biomass fly ash was added to compost heap, and the physical and chemical characteristics of compost heap were analyzed. The fly ash supplemental levels of 8%, 12%, 20% and 25% were selected, and the changes of water content, electrical conductivity, total carbon, total nitrogen, total phosphorus and total potassium were recorded every 10 days according to the quartering method, and the effects of fly ash supplemental levels on biogas residue and cow dung composting were analyzed and studied. The results showed that when the addition of fly ash increased from 8% to 25%, the moisture content of the compost increased, but when the addition amount exceeded 12%, it had little effect on the moisture content, which was maintained at about 58% in the end; the existence of alkali metals and other substances in the fly ash neutralized the acid produced in the aerobic fermentation process, increased the pH value of the heap, and also increased the conductivity of the compost improved the fermentation environment of the compost; the biochar and potassium in the fly ash increased the total carbon and total potassium content of the compost. After 60 days of decomposing, the total carbon content of the compost increased by 37.37% to 47.81%, the maximum value of total potassium content reached 35.74 g/kg, but the effect on total nitrogen and total phosphorus content was not obvious. However, excessive fly ash addition would inhibit the growth of microorganisms, thereby reducing the fermentation rate and product quality.

Key words: biogas residue, cow dung, biomass fly ash, mixed composting, aerobic fermentation, biochar

摘要： 为改善沼渣、牛粪共堆肥低磷和低钾等问题，向共堆肥肥堆中添加生物质飞灰，对堆肥过程中堆体理化特性进行分析。选取飞灰添加量为8%、12%、20%和25%，按四分法每10天取样记录含水率、电导率、总碳、总氮、总磷和总钾等变化，分析研究飞灰添加量对沼渣、牛粪共堆肥的影响。结果表明：当飞灰的添加量由8%增加到25%，堆体的含水率增加，但是当添加量超过12%时，对含水率影响不大，最终维持在58%左右；飞灰中的碱金属等物质的存在，中和好氧发酵过程产生的酸，提高堆体的pH值，同时还提高堆体的电导率，改善堆体的发酵环境；飞灰中的生物炭和钾等成分提高堆体的总碳和总钾含量，60天腐熟后，堆体的总碳含量由37.37%增加到47.81%，总钾含量最大值为35.74 g/kg，但是对总氮和总磷含量的影响不明显。然而过高的飞灰添加量会抑制微生物的生长，从而降低发酵速率和产品质量。

关键词: 沼渣, 牛粪, 生物质飞灰, 堆肥, 好氧发酵, 生物炭