Energy recovery of sewage sludge treatment by anaerobic co-digestion

Abstract

Sewage sludge produced from wastewater treatment is one of the challenges facing many countries in their development process; therefore, the sewage sludge needs treating suitably. Besides, recovering energy from waste to save operating costs in treatment plants is also being considered. The study was conducted by mixing urban sludge samples with substrates (agricultural residues) to create different C/N ratios from 16.6 to 32.5, then evaluating the quantity and quality of methane) the gas generated from the test pieces. This method not only solved the environmental problem but also had benefited from biogas produced from the digestion process. The initial results showed that the quantity of biogas from anaerobic co-digestion of sewage sludge and rice husk (ratio 4:1) are 160ml/g VS. Furthermore, the quality of methane can be up to 60% and near twice as much as mono-digestion. The study results estimate that the potential of recovering electricity from the sludge for the wastewater treatment plant of Binh Hung (Vietnam) is about 0.2 MW/year or higher.

Heavy Metal Accumulation in Soil and Water in Pilot Scale Rice Field Treated with Sewage Sludge

“…The field was divided into three square fields with each field having the area of 30 × 30 m. Each sub field represented one out of three possible control and treatments. In the first sub field (Treatment 1), 50 kg of treated sludge [11], obtained from Binh Hung wastewater treatment plant [12], were mixed in the surface soil of the field at the beginning of the rice cultivation period. Treatment 2 was prepared similarly but with the weight of the sludge increased to 150 kg.…”

Exploring the influence of agrochemicals on beneficial microbial communities in soil

“…The emergence of microbial fertilizers has met the needs of farmers by increasing crop yields, improving soil quality, while avoiding pollution and reducing investment costs [4]. Microbial fertilizers, relying on various strains of microorganisms, can decompose organic substances in sludge [5], waste [6], agricultural residues [7], and by-products, resulting in biomass that is beneficial for both plants and information and chemical composition indicated by the manufacturer. The containers must be unopened and in their original packaging.…”