Reducing water consumption using Filtration and RO

A brewer reaches ultrapure water standards.

Side view of the RO system. Courtesy of RWL Water
Side view of the RO system. Courtesy of RWL Water

Because water is an increasingly valuable resource across the globe, the treatment and reuse of water, which was once used and discarded, are becoming more and more necessary — and more and more profitable.

When a global leader in beer production wanted to reduce its water consumption, it hired Argentina-based wastewater treatment experts to engineer, manufacture and assemble an industrial wastewater reuse plant.

The water treatment company has treated wastewater and process water so it can be reused for crop irrigation, power generation, food production or even human consumption. With sustainability a key concern, its treatment solutions are also engineered to save energy.

The challenge

The goal of the beer production reuse project was to produce demineralized, bacteria-free water to be used in steam generation, cooling systems and pasteurizers. The treated wastewater had to meet high standards while minimizing water and energy consumption.

The plant’s existing wastewater treatment system used anaerobic digestion in a high-rate reactor, followed by an aerobic polishing stage with activated sludge treatment and a secondary clarifier.

The solution

The new treatment train, which picks up after secondary clarification, was added to the existing system and included:

• Ultrafiltration

• Ultraviolet disinfection with medium-pressure lamps and hydro-optical control

• A cooling step

• Reverse osmosis (RO) using membranes with high salt rejection and very low fouling

• Transfer systems to service lines

Because of the high purity standard set for the final treated water (silica concentration of less than 0.5 parts per million), membranes were chosen that combine high silica rejection with low energy consumption.

The RO system was designed to operate at different recovery rates to maximize recovery at all operational temperatures. The new treatment train not only produced high-quality, demineralized water, but it also ensured the control of bacteria through ultraviolet disinfection.

The ruggedness and reliability of the plant allowed the client to meet production targets. Table 1 shows ultrafiltered water quality, the client’s requirements and parameters measured in the treated water after commissioning.

The RO design has an average flux of 14.6 liters per square meter per hour (l/m2/h) in the case of a 50-cubic-meter-per-hour (m3/h) capacity and an average flux of 15.7 l/m2/h with a 54 m3/h capacity, which is important.

Both design parameters fall between the flow rates that were recommended by the membrane manufacturer for ultrafiltered wastewater.

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Table 1. Water quality measured in the treated water after commissioning

The results

The project was completed in modality engineering, procurement and construction with a finance scheme of a 24-month leasing plan. It lasted 90 days, because that was the requirement of the brewer.

Commissioning the plant in such a short period presented a challenge in terms of scheduling and coordination, but since the additions went online in January 2017, water quality standards have been met.

Juan Pablo Camezzana received a chemical engineering degree from Universidad Nacional de Mar del Plata in Argentina. With more than eight years in the water market, he has served as application engineer and executive account manager in leading companies in the market. He is currently a business developer for RWL Water, based in Argentina.

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