عنوان مقاله [English]
Evaluation of Characteristics of Municipal Waste Compost Enriched with Blood Meal, Bone Meal and Phosphate Soil
Introduction Composting from municipal organic waste is a rapidly growing technology that plays a role in replacing and reducing the use of high-risk fertilizers. Municipal waste includes waste produced by residential areas, institutions, offices and public buildings. The amount of compostable materials in many developing countries is 80-85%.
Materials and Methods In order to investigate the effect of enrichment of municipal waste compost using blood powder, bone powder and phosphate rock in a completely randomized and factorial design in three replications in 1394 in the waste recycling complex of Mashhad Waste Management Organization. Experimental factors include blood powder treatment at two levels (zero and 1% based on dry weight of waste) and bone powder treatment at two levels (zero and 1% based on dry weight of waste) and phosphate soil treatment at two levels (zero and 5% per Dry weight basis was added to them (Table 1). At first, after the stage of sieving the waste and removing the waste leachate, the same amount of waste was prepared in the amount of 60 kg and then, in order to better control each treatment, it was poured into plastic barrels with a volume of 100 liters, so that one third of the upper volume was empty. Was. At the end of composting period (90 days) and stability in compost handling factors, characteristics including acidity, electrical conductivity (percentage of organic carbon (TOC)), total nitrogen content, C / N ratio, amount of phosphorus, potassium, sodium, iron , Zinc, humic acid (HA), fulvic acid (FA) and other parameters including homogenization ratio (HR) and homogenization index (HI) and degree of polymerization were obtained.
Results and Discussion of the effect of experimental treatments on the pH of municipal waste compost showed that the application of none of the experimental treatments on pH was significantly different. The simple effect of bone powder treatment caused that the electrical conductivity of 1% bone powder treatment (6.68 dS / m) compared to its zero level (6.29 dS / m) was significantly equal to + 6.2% increase (p < 0.05) Find. The triple interaction of the treatments had a significant difference at the level of 5% and the highest electrical conductivity was observed in the treatment of 1% blood powder and bone powder in combination with the zero level of phosphate soil treatment with 6.92 dS / m. The results of analysis of variance of treatments on TOC enriched compost showed that the simple effect of blood powder, bone powder and phosphate soil treatments on the percentage of organic carbon had a significant difference at the level of 1% and had a decreasing effect in all experimental treatments. In the interaction effects, the lowest percentage of organic carbon was related to the interaction of the second levels of all three factors with 19.5% and the highest was related to the zero level treatment of all three treatments with 22.07%. This can be due to the use of treatments of 1% blood and bone powder and 5% soil phosphate powder in compost, which increases microbial activity and further decomposition of organic carbon, increases respiration and ultimately leads to less organic carbon. The use of blood powder, bone powder and phosphate rock has caused the dual interactions of treatments at the level of 1% and the triple effects of the treatments on the concentration of iron in compost at the level of 5% to be significant. The C / N ratio decreases during the composting stage due to the loss of carbon compounds, which reflects the decomposition of organic compounds. In the treatment of 5% phosphate soil compared to its zero level, a significant increase of 198.6% is shown. Dad. Which can be due to the presence of phosphorus in blood powder and its large amounts in phosphate soil. The interaction between blood powder and soil phosphate was observed at the level of 1%. The effect of experimental treatments on the percentage of humic acid extracted from urban waste compost showed that different levels of blood powder on humic acid had a significant difference at the level of 1%. So that the percentage of humic acid reached 5.16% with the use of 1% blood powder, but this treatment was not significant on fulvic acid and HA / FA ratio. Regarding the ratio of humic acid to fulvic or the same degree of polymerization, there was a significant difference. Not observed between treatments.
Conclusions this experiment showed that the use of additives increases some elements in municipal waste compost, also increasing humic acid as an indicator of organic matter stability and its role in providing elements can be considered.