windrow method

It is important to determine the quality of the compost to use compost properly. The aim of this study was to determine the effect of mixing ratio of bulking agent on stability and maturity indices in poultry waste compost.

Two piles of sawdust mixture with poultry wastes and volume ratios of 1:1 (W1) and 2:1 (W2) were prepared by Windrow method and a pile containing poultry manure was used as control (W0). In order to determine the stability and maturity indices in compost, the most important physicochemical and biological parameters were studied.

The thermophilic phase lasted about 7 weeks for W1 and about 4 weeks for W2. The initial C/N ratios in the W0, W1 and W2 were 27.10, 31.40 and 56.24, respectively, which eventually reached less than 20. The reduction of organic matter in the three piles was 8.30%, 62.59% and 85.53%, respectively. The thermophilic phase caused a sharp decrease in the population of indicator and pathogenic microorganisms in all piles. The highest dehydrogenase activity in W1 pile was 2.95 mgTPF/gDW.h and by decreasing temperature until the last day, its value decreased to 0.29 mgTPF/gDW.h.

The best ratio for mixing sawdust with poultry manure was 1:1 (v:v). Microbial and enzymatic activities are useful parameters for monitoring poultry composting process and determining the rate of compost stability, and the use of this compost in agriculture will improve soil quality.

One of the main problems in composting in Iran is a production of leachate in high volume. The main aim of this study was to evaluate the quality and quantity of municipal solid waste composting leachate from different stages of Isfahan composting plant.

This descriptive study was performed to determine the chemical quality of leachate samples from different stages of the composting process, in the 4 season and was done monthly as grab sampling. Leachate flow measurements were carried out at the site. Chemical parameters including pH, COD, TSS, EC, ammonia, phosphorus and heavy metals (Cd, Zn, Pb, and Cr) from 4 ports (Receiving hall, Shredding, Press and fermentation site) was analyzed.

The composting plant average flow was 0.4L/s that the maximum and the minimum flow were measured 1.2 and 0.2 L/s respectively. Effluent flow of receiving hall, Shredding, Press and fermentation site was measured 0.04, 0.08, 0.08 and 0.3 L/s respectively. The average COD concentration of leachate from receiving hall, Shredding, Press and fermentation site was 39864, 104643, 29898, 119592 and 99660 mg/l respectively.

The maximum flow and organic pollution load of leachate originates from fermentation site. The minimum of mentioned parameters and the maximum of heavy metals were measured in the Shredding part. Source separation and waste recycling is the most important way to reduce the production of leachate.