Composting of wastewater treatment sludge with different bulking agents

Abstract

The main objectives of this study were to investigate the compostability of wastewater treatment sludge (WTS) containing different bulking agents (BAs) and to determine the most efficient BA. Four different compost trials consisting of mixtures of wheat straw (WS), plane leaf (PL), corncob (CC) and sunflower stalk (SS) with WTS were performed in laboratory reactors. In all experiments, a mixture of 60% WTS and 40% BA (wet basis) was used. The temperature, dry matter (DM), organic matter (OM), pH, electrical conductivity (EC) and C/N ratio were monitored during the composting process. Evaluation of the operational parameters showed that the highest organic matter degradation (i.e. 37.6%), loss of dry matter (i.e. 29.6%) and temperature (i.e. 64°C) were achieved for the WTS-CC mixtures. Results also showed that the WTS-SS mixture was also successful in terms of these operational parameters. Use of bulking agents for the treatment of wastewater treatment sludge in composting process is an important issue with regards to process efficiency, economy and disposal of agricultural waste. Corncob and sunflower stalk that were previously not used for the composting of WTS from food industry were shown to be highly successful BA materials in this study.Implications: The compostability of wastewater treatment sludge from the food industry with different bulking agents was studied. Wheat straw, plane leaf, corncob, and sunflower stalk were used as bulking agents. The required microbial stabilization and degree of mineralization were achieved with corncobs and sunflower stalks. PAPER HISTORY

Variation in the key indicators during composting of municipal solid organic wastes

“…It not only enhances the microbial activity but also adjusts the porosity of a raw material and thus improves the overall aeration [9]. Several researches have been carried out on the effect of bulking agents during the composting of various types of sludges (sewage and industrial sludge) using distinct composting methods [10,11]. An experimental study was also performed to evaluate the effect of bulking agents during the composting of municipal wastes and animal manure [12].…”

Heat Energy and Gas Emissions during Composting of Sewage Sludge

“…The rapid development of urbanization and industrialization all over the world, including Europe, has significantly increased the amount of sewage [1][2][3]. Large amounts of sludge are generated in various biological, chemical, and physical wastewater treatment processes and its volume is constantly growing.…”

The Influence of Aeration Ratio on Energetic Aspects of Composting Process of Sewage Sludge With Agricultural Waste

“…Especially in agricultural areas, the use of agricultural waste seems to be beneficial to improve the properties of the compost mixture (Ucaroglu andAlkan 2016, Grau et al 2017). Such co-substrates will create favorable water and air conditions inside the pile or in-vessel.…”