Session: 18-01-04: Sustainability in Industry

Paper Number: 149401

149401 - Low-Maintenance, High-Performance Enhanced Coagulation Technology for Water Treatment and Recycling 

Over 120 interviews with industry professionals in the United States were conducted, to ascertain the most pertinent challenges faced by the American water sector. Most interviewees pointed to the fact that the environmental problems affecting the watersheds, combined with the aging water infrastructure, pose a threat that makes for an uncertain future for reliable long-term water supply for communities, agriculture, and industry alike. In rural areas, this issue is compounded by depopulation, skilled workforce shortages due to migration to larger cities, as well as inadequate capacity-building because of financial stressors and the loss of institutional knowledge. While maintenance and upgrades to existing water infrastructure in these regions are fundamental to improving the situation, there is a strong need for newly developed technologies that could respond to emerging challenges for the sector and provide access to water in a low-cost, energy-efficient, and sustainable manner.

The proposed enhanced coagulation technology addresses those problems by decreasing both the capital and operational expenses, while at the same time reliably complying with the US Environmental Protection Agency (EPA) water quality standards. The tested solution is characterized by 1) a very low hydraulic retention time of just 1.5 h, which allows for effective automatic control while facilitating retrofits into existing systems, 2) a low energy demand due to its reliance on gravity-powered processes and passive components, and 3) a self-cleaning design for reliable operation and easy maintenance. It was pilot-tested at two municipal drinking water treatment facilities from December 2023 to September 2024, and the conducted experiments evaluated two potential areas to apply the tested setup: surface water treatment and the direct reuse of the greensand filter backwash stream.

Both applications have yielded promising results. Using a novel sludge blanket clarifier and a horizontal flow rapid sand filter allows for consistently achieving effluent water turbidity below 0.1 NTU and for an average 60% removal of dissolved organic matter, expressed as a decrease of the UV254 absorbance. The sludge blanket process was proven to be particularly effective during the continuous treatment of the influent stream contaminated with a high concentration of total suspended solids, allowing for the recovery of high quality water which met the drinking water turbidity standard established by the US EPA. The reliable water recovery from the greensand filter backwash was achieved continually, despite the turbidity of the influent exceeding 500 NTU. Additionally, the pilot’s low energy demand and sludge production at a rate of 0.8% of the overall throughput minimizes its environmental footprint, outperforming currently used sludge blanket clarifiers in terms of environmental metrics.

The conducted experiments confirm the applicability of the tested system for both surface water treatment and for direct reuse of the industrial wastewaters contaminated predominantly with high load of total suspended solids. Potential applications of the studied system include, but are not limited to, municipal drinking water treatment, water recovery from filter backwash stream, mineral recovery and thickening of mine tailings, as well as substrate recovery from the reaction mixtures.
 

Presenting Author: Marcin Sawczuk First Water Technology Co.

Presenting Author Biography: Marcin Sawczuk is a doctoral candidate at Cornell University School of Civil and Environmental Engineering, as well as a founder of First Water Technology Co. – a technology company dedicated to innovation in the water sector. He is a seasoned engineer with multiple years of experience in the fields of R&D and quality control, from various locations in Latin America, Africa, Middle East and Europe. His last appointment prior to Cornell was a Commissioning Engineer position at FLSmidth A/S, a Danish provider of technology and consulting services to cement and mining sector.

Marcin Sawczuk is a Chemical Engineering graduate from the Technical University of Denmark and holds MSc. degree in Petroleum Engineering from the same institution.

Authors:

Marcin Sawczuk First Water Technology Co.
Avni Bhalla First Water Technology Co.