Effects of mushroom residue and straw on aerobic composting of sewage sludge

Different proportions of mushroom residue and straw were added into the sewage sludge to study the effects on aerobic composting.Changes of temperatures,moisture contents,pH values,conductivities,total phosphorus,total nitrogen,ammonia nitrogen,nitrate nitrogen and heavy metal contents during composting were measured.The results showed that the heavy metals,germination indexes and maturities of the composts met the national standard for agricultural application.The proportion of sludge,mushroom residue and straw by wet weight at1.000∶0.600∶0.025 had the best composting effect among three treatments,in which the temperature ran up faster and maintained above 55 ℃ for 16 d,with the least nitrogen loss of 27.62% and lower water content,and the seed germination index was 86.1%.This study might be valuable for recycling application of sewage sludge.