Enhanced efficiencies of sludge dewatering and domestic wastewater treatment by using the bioflocculant from rice stover

Abstract

Potential of a bioflocculant from rice stover was studied in sludge dewatering and domestic wastewater treatment. Production of this bioflocculant showed good correspondence to cell growth, after fermentation for 60 h, the fermentation liquor was obtained, from 1.0 L of which a value of 2.37 g bioflocculant can be extracted, and the main backbone of this bioflocculant was polysaccharides. Without adjusting the sludge's initial pH value of 6.5, when incubated with 18 mg/L of this bioflocculant, dry solids (DS) and specific resistance to filtration (SRF) of the typical wastewater activated sludge reached 18.5% and 4.7 3 10 12 m/kg, respectively, which was better than the ones achieved by Al 2 (SO 4 ) 3 and FeCl 3 flocculants. For domestic wastewater treatment, after treated by 12 mg/L of this bioflocculant at pH value of 7.5, removal efficiencies of chemical oxygen demand (COD) and turbidity can reach 91.8 and 89.7%, respectively, which were better than the ones achieved by the traditional flocculants such as Al 2 (SO 4 ) 3 , FeCl 3 , and polyaluminum chloride (PAC). This study suggested that the bioflocculant from rice stover has great potentials as an alternative flocculant to conventional flocculants in sludge dewatering and domestic wastewater treatment.

Feasibility and Mechanism of Combined Conditioning with Coagulant and Flocculant To Enhance Sludge Dewatering

“…This information was similar to that reported by Wang et al, while a different biopolymer component (mainly protein) was reported by Peng et al The different nutrition components and biophysical environments may account for the discrepancy in biopolymer components. Gel permeation chromatography indicated that the approximate molecular mass of the BF-ADSW was 4.21 × 10 5 Da, a relatively high molecular mass, compared to those of the biopolymers produced by Aspergillus flavus and Rhodococcus erythropoli. , The higher molecular mass, the greater the number of adsorption points and the stronger the bridging ability supplied to the sludge particles. , Furthermore, the ζ potential of the BF-ADSW was determined to be 13.2 mV, a positive charge that can effectively combine with a negative sludge particle, which further enhanced the sludge dewatering.…”

Synthesis, Characterization, and Sludge Dewaterability Evaluation of the Chitosan-Based Flocculant CCPAD

“…The water molecule and sludge particles are closely connected such that the sludge particles form a stable colloidal suspension [9]. This characteristic hinders the separation of mud and water, and the performance of direct sludge dewatering is poor [10]. Therefore, sludge conditioning before sludge dewatering is particularly important.…”

Comparison of Agro-Wastes For Dewatering Enhancement For Dredged Sludge From Sewers

“…Sludge dewatering is one of critical steps in sludge treatment as it reduces signi cant water from the mixed sludge which creates favorable conditions for next sludge treatment process. Studies on dewatering enhancement have been done quite a few and mostly with sewage sludges from WWTPs; such as using chemicals (Guo et al 2016 Addition of agro-wastes for dewatering enhancement has also been paid much attention from researchers within the past decade (Liang et al 2018;Wójcik 2019;Guo et al 2019). This approach is considered attractive as it is quite environmentally friendly, energy saving, and the waste-blended sludge can be reused as great potential materials for composting, or post-treatment by incineration.…”