Concentrate Minimization through Development of an innovative In-line Static Mixer

Project ID: 20058
Principal Investigator: Saied Delagah
Research Topic: Desalination and Water Treatment
Funded Fiscal Years: 2020, 2021 and 2022
Keywords: None

Research Question

The goal of this project is improve concentrate minimization and overall system recovery by developing an in-line static mixer that causes precipitation with the least amount of energy input. An economic assessment will be completed as a part of this study to demonstrate the economic value of this mixer. The expected outcome is the creation of a novel mixer that can reduce concentrate volumes cost-effectively and increase overall system recovery which will allow for more wide-spread use of desalination to augment water supplies in inland areas.

Need and Benefit

Tired of hearing the words "concentrate management"? Have you lost hope that cost-effective concentrate management is possible? What is concentrate management and why does it matter? Concentrate is the reject water from a desalination treatment process that contains all the salts and constituents in the feed sans the pure water that is removed by the desal process. Depending on the size of treatment process, typically in the order of 1 to 25 million gallons per day, and the recovery of the process, typically between 50 to 85%, a large volume of concentrate (millions of gallons) at high salinities (10,000 to 30,000 ppm) remains on a daily basis that requires management. Management could be disposal into sewer or deep well injection into the ground, which are dependent on permitting, geology and/or other factors. Concentrate can also require additional treatment which adds to costs or requires other means to handle large volumes of saline stream that is unwanted from the desal process.

Due to the volume and salinity of this stream, concentrate management today is the bottleneck for more widespread adoption of desalination for inland communities looking to treat impaired water sources such as brackish ground and surface waters, potable reuse of wastewater, and other water types. Existing solutions available today are not viable due to their high cost, complexity or lack of long-term sustainability. Another drawback to concentrate is that depending on the recovery of the treatment technology, a large amount of water is confined in the concentrate stream and is managed/disposed with the concentrate, which is a loss of this valuable resource.

This proposal, if funded will develop an innovative in-line mixer that does not require chemical addition or significant energy input to reduce concentrate volumes. The proof of concept for this mixer has been demonstrated in our previous studies and this work builds off of our previous findings by designing and fabricating a novel mixer that induces precipitation of solutes at a desired point in the process. Precipitation of solutes from concentrate leaves a stream that can be treated further to produce more potable water and lead to increased overall process recovery in a cost-effective and sustainable manner.

The remaining concentrate has minimal water content and gets close to zero liquid discharge. The lower volume of concentrate decreases the cost of concentrate management significantly, making a viable alternative to treat inland impaired waters and creating potable water supply from non-potable sources.

Contributing Partners

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Research Products

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Last Updated: 6/22/20