Composting; anaerobic digestion of organic wastes and mixtures on a laboratory and industrial scale; estimation of total nitrogen, organic carbon, pH, temperature, enzyme activities, and toxicity of wastes and waste mixtures; and estimation of biogas volume and content.
The experiments conducted and the results obtained:
Industrial and municipal organic wastes were characterized according to organic matter, C and N content, physical properties, and eco-toxicity. Mixtures of the wastes with opposite properties were composed. Effectiveness of co-digestion, based on biogas volume and content and toxicity of digestate, and effectiveness of co-composting, based on the end of the period of fluctuations in phytotoxicity and microbial parameters, were evaluated. It was shown that co-digestion of sewage sludge and the organic fraction of municipal waste (30%:70%) permitted biogas with 70% methane to be obtained. The effective time for digestion was 14 days, and the bacterial and archaeal communities of the waste mixture differed from the microbial communities of sewage sludge and the organic fraction of municipal waste digested separately. Besides, costs of the treatment processes were calculated. Based on the results obtained, a computer program for determining the most effective treatment of organic wastes was developed (and protected with a patent). The results obtained were applied on an industrial scale.
Please see the following publications: