The system has provided continuous, quality feedwater to a downstream RO system for almost a year
Dow Water & Process Solutions, a business unit of the Dow Chemical Co., announced the results of a recent piloting focused on Dow ultrafiltration (UF) technologies that was carried out at its Global Water Technology Center in Tarragona, Spain, and has seen continuous high-quality feedwater supply to the reverse osmosis (RO) system downstream over a prolonged period.
The pilot program aimed to monitor the quality of the feedwater produced by the UF system in order to provide support for the company’s range of UF technologies. The data generated are used both to prove the success of its existing solutions, and to validate and qualify new products before their launch into the market. The results of piloting confirm the sustainable and stable operation of the commercial modules as a pretreatment for the RO system downstream for more than 300 accumulated days, demonstrating success in a real wastewater reuse application with relatively high organic content.
In order to provide real wastewater conditions, the pilot system was fed with secondary effluent from the Vilaseca municipal wastewater treatment plant. Typically, due to wastewater feed quality and characteristics, the RO system cannot be fed directly from the secondary effluent of the wastewater treatment plant without interruption. Therefore, to guarantee the required feed quality to the RO system, a Dow UF SFP-2880 system was integrated upstream.
The autopsies carried out on the UF modules following the piloting demonstrated the absence of broken or damaged fibers, as well as no reported loss in tensile strength and mechanical properties. Based on these test results, it can be concluded that these elements are suitable pretreatment for RO systems. The permeate produced by the system downstream is suitable for a number of applications, including irrigation, agriculture and golf courses. The agricultural sector represents 80% of water use in the country, so integrating advanced technologies into the sector can help increase efficiency.
Another important finding from the study is the associated cost reduction resulting from the combination of the company's UF and Filmtec RO technologies. For instance, the UF systems require a smaller footprint when compared to other methods of conventional pretreatment technologies, such as sand filtration. In addition, fewer chemical cleanings are required in the RO system downstream due to the more suitable feedwater provided by the UF system, resulting in longer membrane life, higher plant availability and lower replacement rate of cartridge filters.