A microsieve-based filtration process for combined sewer overflow treatment with nutrient control: Modeling and experimental studies

Tiziana Venditto; Michele Ponzelli; Siva Sarathy; Ajay K Ray; Domenico Santoro

doi:10.1016/j.watres.2019.115328

A microsieve-based filtration process for combined sewer overflow treatment with nutrient control: Modeling and experimental studies

Water Res. 2020 Mar 1:170:115328. doi: 10.1016/j.watres.2019.115328. Epub 2019 Nov 20.

Authors

Tiziana Venditto¹, Michele Ponzelli², Siva Sarathy³, Ajay K Ray⁴, Domenico Santoro⁵

Affiliations

¹ Department of Chemical and Biochemical Engineering, Western University, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada. Electronic address: tvenditt@uwo.ca.
² Department of Science and Engineering of Materials, Environment and City Planning, Polytechnic University of Marche, P.zza Roma 22, Ancona, Province of Ancona, 60121, Italy.
³ Department of Chemical and Biochemical Engineering, Western University, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada; Trojan Technologies, 3020 Gore Rd, London, Ontario, N5V 4T7, Canada.
⁴ Trojan Technologies, 3020 Gore Rd, London, Ontario, N5V 4T7, Canada.
⁵ Department of Chemical and Biochemical Engineering, Western University, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada; Trojan Technologies, 3020 Gore Rd, London, Ontario, N5V 4T7, Canada. Electronic address: dsantor@uwo.ca.

PMID: 31785559
DOI: 10.1016/j.watres.2019.115328

Abstract

Combined sewer overflows contain a highly variable, wide range of contaminants, both in particulate and soluble form, making conventional water treatment processes unable to offer adequate public health protection. In this study, an integrated treatment process designed to simultaneously remove typical combined sewer overflow pollutants (suspended solids, chemical oxygen depends, turbidity) in conjunction with nutrient (nitrogen and phosphorus), was developed. The removal of particulates as well as dissolved nitrogen and phosphorus was achieved by first adsorbing soluble pollutants on zeolite and powdered activated carbon, and subsequently applying filtration carried out by polymer-enhanced microsieving. Laboratory experiments were designed using design-of-experiment techniques and carried out to assess the effects of the various treatment variables (cationic polymer, zeolite, powder activated carbon and microsieve size) in the designed combinations. A response surface model was fitted to the experimental dataset in order to capture and describe the non-linear relationships between treatment variables and treatment objectives. Finally, an optimization study was carried out using Pareto analysis showing that cationic polymer, zeolite, and powdered activated carbon, followed by fine mesh microsieving, worked synergistically in the integrated treatment process. Several optimal process conditions emerged, in particular, a treatment combination consisting of 1.1 mg/L of the cationic polymer, 250 mg/L of zeolite, 5 mg/L of powdered activated carbon, and a 370 μm mesh size. Under this condition, expected performance would be reductions of 72%, 56%, 35%, and 75% for turbidity, total Kjeldahl nitrogen, total chemical oxygen demand, and total phosphorous, respectively. The findings presented in this paper demonstrate the possibility of achieving multiple treatment objectives in a single and integrated treatment step, hence providing municipalities with viable treatment options where the issues of combined sewer overflow and nutrient management are simultaneously tackled.

Keywords: Coagulation-flocculation; Combined sewer overflow; Micro-sieving; Pareto analysis; Response surface methodology; Wastewater.

MeSH terms

Cities
Nutrients
Sewage
Waste Disposal, Fluid
Water Pollutants, Chemical*
Water Purification*

Substances

Sewage
Water Pollutants, Chemical