Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/513849
SHOWCASE | 24 | Desalination & Water Reuse | May-June 2015 PolyPore suPPlies ultrafiltration for Disney Membrane manufacturer, Polypore, has supplied its Membrana ultrafltration units for Shanghai Disney Land to curb corrosion in the resort's cooling water system. Under its design and build contract with International Tourism Resort (Disney), consultant CHD incorporated Membrana's Liqui-Flux W10-07 ultrafltration (UF) modules as pre-treatment in a reverse osmosis plant and Liqui-Cel gas transfer membranes as the post-treatment to remove dissolved oxygen and carbon dioxide. The combined technologies remove suspended solids, colloidal substances, chemical oxygen demand (COD), salt, and dissolved gases from the system. The entire system is designed to handle 960 tonnes/d of recirculated cooling water with two independent UF units with a capacity of 640 tonnes/day for each rack and degassing units with a capacity of 480 tonnes/day for each rack. Separating the UF and degassing systems into two racks allowed for a more mobile design said CHD. The UF plant is designed to operate at 65 l/m²/h fux with 40 min of fltration time and 250 l/m²/h backwash fux. A backpressure above 2.0 bar is maintained due to downstream equipment requirements and piping demands. The feed water pressure is expected to remain above 3.5 bar. In operation, the feed water pressure is maintained at 4.0 bar and module tolerance pressure is 4.0 bar at 30˚C. An in-line turbidity meter is installed for real-time monitoring of the outlet water and a once-a-day chemical enhanced backwash system is installed. Liqui-Cel Gas Transfer Membranes, also known as membrane contactors, are installed with four in parallel and two in series to improve oxygen removal effciency said CHD. Liqui-Cel Contactors are used for degassing because the technology can reach a dissolved oxygen concentration of fve parts per billion (ppb) which is diffcult with conventional gas removal processes and exceeded the client's expectations said the system builder. Dissolved oxygen levels remain below 5 ppb, which exceeded the customer's expectations and the system only uses one quarter of the nitrogen sweep gas that was anticipated based on the original design, even when operating at full operating capacity. No chemicals are needed to operate the system. The integration of Membrana's UF and GTM technologies before and after RO exceeds design requirements, in producing high-quality water with low operating costs. The UF modules tolerate the customer's pressure and harsh water requirements and the Liqui-Cel Membrane contactors continue to remove dissolved oxygen effciently with minimal maintenance according to the manufacturer. Koch to suPPly ultrafiltration for são Paulo treatment Plant eXPansion Membrane fltration frm, Koch Membrane Systems, is to supply its Puron HF reinforced, hollow-fbre ultrafltration (UF) system for the a major expansion of a drinking water treatment plant in the city of São Paulo, Brazil. The Alto da Boa Vista plant produces drinking water using conventional technology (coagulation, focculation, sedimentation, sand fltration, and chlorine disinfection) for more than fve million people in São Paulo. In 2014, the plant installed and launched the frst UF drinking water system in South America, which deployed Koch's Puron UF membranes. The new project was initiated to double the treatment capacity of the existing UF system to 7,200 m 3 /hr. Raw feed water is drawn from the Guarapiranga reservoir more than 20 km from the treatment plant. During dry seasons a high concentration of algae present in the reservoir has historically posed a challenge for the sand flters, limiting production capacity. The high solids load-handling capacity of Puron UF system will help to alleviate this problem according to Koch. Xylem signs eXclusive DisK filter Distribution Deal for north america Water technology company Xylem has signed an exclusive agreement with Nuove Energie SRL to distribute a tertiary disk flter system for wastewater reuse and discharge requirements in the US and Canada. The ultrascreen disk flter will be distributed by Xylem under the company's Leopold brand for customers who have a particular need for tertiary treatment to meet stringent requirements for both discharge and reuse applications. "With tertiary treatment growing at a rate of 6% and water reuse increasing at 7% annually in North America, the agreement provides further opportunity for Xylem to expand into these markets and offers complete North-American channels to market," the company said. According to Xylem's product manager, Robert Wiley the Leopold Ultrascreen disk flter "provides ease of operation at the lowest life cycle costs in the industry." Its stainless steel components include the fltering mesh which can last for more than ten years, said Wiley, "dramatically lowering the life cycle cost compared to other disk flters in the industry which rely on woven plastic mesh or felt material." The AISI 316L stainless steel screens can handle high hydrostatic pressure and are easily treated chemically to remove colloidal materials that permanently foul other disk media said Xylem. This, combined with the patented "dynamic tangential fltration" operating principle delivers "exceptional performance at higher loading rates with unprecedented durability," the company claimed. Dynamic tangential fltration is the result of deploying a continuously rotating screen that forms an acute angle with the direction of water to decrease the screens' opening size, trapping smaller particles while allowing higher hydraulic and solids loading rates than other disk fltration systems Xylem explained. Screen rotation produces a stable forward fow rate, even during backwashing, to improve the effciency of ultraviolet disinfection which is further enhanced by the Ultrascreen disk flter. The flter also lowers chlorine or ozone demand, to reduce costs, Xylem claimed. The flter is validated by Title 22 California Code of Regula tions to treat fows up to 16 gallons per minute per square foot of flter area which, according to Xylem, is up to 2.5 times higher than fow rates tolerated by other media disk flter systems. The ultrascreen flter can handle spikes in total suspended solids loading rates of up to 150 mg/l without clogging, compared to 50-70 mg/l for cloth disk flters said Xylem.