Evaluation of the Efficacy of Polyacrylamide Coagulant Aid Modified with Aluminum Oxide Nanoparticles in Sludge Dewatering of Wastewater Treatment Plant of Yazd

Introduction and Purpose:

Production of large quantities of sludge is a major problem in wastewater treatment plants, which necessitates adopting proper economical and environmental approaches for its management and treatment. The aim of this study was to investigate the effect of polyacrylamide polymer, modified with aluminum oxide nanoparticles, on dewatering of sludge produced from municipal wastewater treatment.

In-vitro preparation and dewatering of sludge by combination of polyacrylamide activated with aluminum oxide nanoparticles were carried out in two main steps of determination of pH and optimal dose of activated coagulant aid. For measuring sludge dewatering capability, tests of time of filtration (TTF), sludge cake moisture content, turbidity, and total suspended solids of effluent from sludge cake filtration were evaluated.

Modified coagulant aid with aluminum oxide nanoparticles in optimum pH and concentrations of 5 and 4 mg/l, respectively, had the best efficiency and was more suitable than a primary coagulant without any modification. The levels of TTF, sludge cake moisture, turbidity, and total suspended solids of effluent reduced 24.4%, 11.2%, 57.2%, and 58%, respectively, in comparison with the control group.

The results showed that polyacrylamide coagulant aid modified with aluminum oxide nanoparticles could be appropriate for sludge dewatering. Therefore, it can be employed as an alternative coagulant aid for sludge dewatering.