New biopolymer from biomass for conditioning and dehydration of sewage sludge: application on the sludge of Bouira WWTP.

Abstract

Sewage treatment plants in Algeria produce huge quantities of sludge expressed in tons annually. This sludge produced is unfortunately contaminated because of the use of synthetic polyelectrolytes. Recently several kinds of research have been carried out on natural flocculants for sludge conditioning, because of several advantages they present such as their renewable source and their non-toxicity. This work aims to evaluate the potential use of protonated pectin extracted from orange waste of N'GAOUS juice factory as an eco-friendly flocculant in the chemical conditioning of sludge. Protonated pectin effectiveness was compared with synthetic cationic anionic and ionic polyelectrolytes (SUPERFLOC 8396, AF400, NF102). In this context, raw sludge samples from Bouira WWTP were tested. Specific resistance to filtration (SRF), cakes dry solid content were analyzed to determine filterability, dewatering capacity of conditioned sludge, and the optimum dose of each conditioner. So that our goal was to obtain greater dryness, which is the case with the addition of protonated pectin and even the addition of Superfloc, which allowed us to obtain dryness of 33.01% and 29.19%, respectively, for the same doses that gave the lowest SRF. Based on the results found and the analysis of the specific resistance to filtration (SRF) and the dryness, and compared with the values observed for the dewatered sludge by the method used in the Bouira WWTP. Band filters (18-22%) and raw sludge (4.8-5.7%).