Enhancement in mesophilic aerobic digestion of waste activated sludge by chemically assisted thermal pretreatment method
Journal
Bioresource Technology
Journal Volume
119
Pages
105-113
Date Issued
2012
Author(s)
Abstract
The effects of hybrid microwave (MW)-alkali pretreatment methods on the efficiency of mesophilic aerobic digestion were studied. The MW-alkali pretreatment (95°C-pH 12) was observed to enhance the sludge solubilization synergistically from 0.5% (raw) to 52.5% (MW-NaOH) and 48.7% (MW-KOH), which are 20% greater than the additive value of MW only and alkali only (16%MW+28.4%NaOH=44.4% and 16%MW+25.5KOH=41.5). The higher VSS solubilization was observed for hybrid MW-NaOH (53.9%) and MW-KOH (47.4%) methods. The batch mesophilic (35°C) aerobic digestion system led to 81.1% TCOD degradation and 72.4% VSS degradation at 20days of retention time, with 35% higher TCOD and VSS reduction in comparison with the control system. The filterability of microwave-alkali pretreated sludge was improved remarkably after aerobic digestion. Moreover, the proposed method is capable of effectively sanitize the sewage sludge and produce Class A biosolids. © 2012 Elsevier Ltd.
Subjects
Class A biosolids; Mesophilic aerobic digestion; Microwave-alkali pretreatment methods; Sludge solubilization; Waste activated sludge
SDGs
Other Subjects
Class A biosolids; Mesophilic; Pretreatment methods; Sludge solubilization; Waste activated sludges; Biological materials; Biosolids; Degradation; Digestive system; Sewage sludge; Solubility; Sludge digestion; potassium hydroxide; sodium hydroxide; volatile agent; activated sludge; chemical oxygen demand; degradation; efficiency measurement; microwave radiation; oxic conditions; sanitation; sewage treatment; solid waste; solubilization; alkalinization; anaerobic digestion; article; chemical oxygen demand; degradation; filtration; mesophile; microwave radiation; particle size; physical chemistry; priority journal; sludge treatment; solubilization; Alkalies; Bacteria, Aerobic; Heating; Microwaves; Sewage; Water Purification
Type
journal article