The Impact of Input Material on Compost Quality Using Aerated Static Piles in Rural Areas (Case Study: Sooleghan Village)

In this study the process of producing bio-compost from rural separated solid wastes using aerated static piles method was investigated. The combination of waste ingredients, conditions and duration of processing, analysis of key parameters governing the process, the quality of the final product as well as economic assessment of costs and revenues were the most important parameters that were considered.

After the separation of rural wastes, two compost piles, one containing 100 percent of putrescible wastes and another one containing 75% putrescible wastes and 25% of cow dung were created. To better estimating the variables related to process maturity and identifying the errors, three replications were applied. Four main variables including: moisture, pH, temperature and carbon to nitrogen ratio were measured for each of the piles. Comprehensive statistical analysis including the comparison of the variables, correlation between variables and analysis of one-way variance was performed for the measured parameters.

Total Coliform reduction in both kinds of waste compositions observed in approximately about 3log. Reduction of parasite eggs in piles containing 100% organic wastes was about 75.8% and in piles containing 75% organic wastes & 25% cow dung obtained about 95%. Heavy metals such as lead, cadmium and nickel, were not found in the piles. For finished compost the average of C/N and pH were recorded 12.35 & 8.05 respectively.

Comparing the final product by Iranian, American and Canadian standards showed that static method stabilized solid wastes in both kinds of piles and eventually was led to the production of good compost. The economic evaluation showed that the internal rate of return (IRR) for producing compost, using aerated static piles method, is equal to 12.4%.