AVALIAÇÃO DA TEMPERATURA, pH E UMIDADE DE COMPOSTOS DE LODO DE ESGOTO ASSOCIADA COM DIFERENTES RESÍDUOS

Abstract

The main characteristic of agro-industrial waste is the high concentration of organic material. In a dairy industry, the wastewater treatment plant generates, at the end of the process, biological sludge as a by-product of the treated effluent obtained, which mainly comes from the washing of equipment within the industry. This work aimed to evaluate the variation of volume, weight and C / N ratio of dairy sludge resulting from composting combined with different residues. In the experiment the composting process was carried out, combining four types of waste generated in the industry itself (sewage sludge, cattle manure, grass pruning and boiler ash) in proportions to present carbon / nitrogen ratio (C / C ratio). That provide adequate decomposition to the waste. The evaluated treatments consisted of pure sewage sludge (T1) and mixtures of sludge with other residues, being (T2) sludge + manure; (T3) sludge + ash; (T4) sludge + gram; (T5) sludge + gram + ash; (T6) sludge + dung + ash and (T7) sludge + grass + dung + ash. A randomized factorial arrangement was used, with seven treatments and three repetitions. Composting has proven to be an efficient method for treating sludge produced in a dairy effluent treatment plant, producing high quality fertilizers. The addition of grass pruning remains to the sewage sludge (Treatment 4) in the composting process provided the largest weight and volume reductions, adequate pH, moisture content and C / N ratio.