Influences of magnetic powder addition on the anaerobic digestion of municipal dewatered sludge

Abstract

Magnetic materials were recently developed for sludge disposal because of their advantages. However, the role of magnetic materials in the process of anaerobic digestion of municipal dewatered sludge remains unclear. The aim of this present study is to investigate the magnetic effect factors such as static magnetic field, magnetic nanoparticles, and ordinary magnetic particles on the anaerobic digestion of municipal dewatered sludge. In addition, the biogas production variations and relevant physicochemical properties of municipal dewatered sludge under anaerobic digestion are also evaluated by adding anaerobic bacteria. Results indicated that the magnetic nanoparticles are superior to both ordinary magnetic particles and static magnetic field at total biogas production; moreover, the aerobic bacteria could shorten the duration of anaerobic digestion. For the sludge dewatering, the organic matter degradation rate, chemical oxygen demand degradation rate, and dewatering rate under the treatment condition with magnetic nanoparticles are 32.1%, 87.1%, and 70.9%, respectively. It is suggested that the magnetic nanoparticles are much suitable for sludge dewatering than ordinary magnetic particles. As combined with bacteria, magnetic nanoparticles can effectively increase gas output, methane content, and shorten the anaerobic digestion period. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 374–379, 2019

Anaerobic Digestion Technology for Methane Production Using Deer Manure Under Different Experimental Conditions

“…Results have shown that the disintegration performance of waste-activated sludge was effectively improved in the presence of a magnetic field [37]. The magnetic field could improve the AD of municipal sludge to produce biogas [38]. A correlation between the time of exposure to the constant magnetic field and the values of parameters characterizing the methane production was found in the AD of algal biomass [39].…”