Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/133796
TECHNOLOGY enabling the UF unit to further reduce turbidity to 0.05 NTU. In addition, the Tequatic Plus filter eliminated the need for cartridge filters and related inventory, eliminating the waste that would have been generated by spent cartridge filters, further reducing operational costs and environmental impact. Bottom line: the filter was notably easier to implement than the expensive DAF option, at a fraction of the capital cost (at least 50% less). It also enabled the BVWD to optimize cost-performance while achieving adherence to regulations for wastewater reuse. PrEfiLTEr TO Uf fOr WasTEWaTEr rEUsE Sewer Authority Mid-Coastside WE UNDERSTAND DESALINATION & REUSE TECHNOLOGIES At Severn Trent Services we offer innovative treatment solutions to meet a variety of desalination and water reuse needs. - TETRA® DeepBed™ tertiary filters are an economical solution for the removal of TSS <2 NTU or <5 mg/l TSS and < 0.2 mg/L phosphorus. TETRA Filters account for >10% of the world's water reuse capacity. - TETRA® LP Block™ lateral underdrains are ideal for pretreatment filtration at desalination plants. - UAT™ desalination systems are suitable for treating a wide range of salinity application up to 10+ MGD (1,500+ m3/hr). UAT EDI systems are offered to polish RO permeate. - MicroDynamics® microwave UV disinfection systems offer efficient and effective disinfection of secondary and tertiary wastewater effluent. For more information on desalination and water reuse solutions e-mail info@severntrentservices.com or visit www.severntrentservices.com | 36 | Desalination & Water Reuse | May-June 2013 The Sewer Authority Mid-Coastside (SAM) Wastewater Treatment Plant (WWTP) serves about 25,000 residents in Half Moon Bay, California. Producing between 0.6 and 1.35 MGD (5,110 m3/d) of wastewater, the plant wanted to improve the sustainability of its operations by selling a wastewater byproduct to local irrigation customers. To meet stringent California Title 22 regulations for wastewater reuse, it needed a cost-effective prefiltration solution that would resist fouling, tolerate difficult-totreat feedstreams and protect downstream UF equipment. An outside engineering firm recommended the Tequatic Plus fine particle filter. It cited the filter as an innovative, high-solids removal product that could optimize cost performance. TUrbidiTY rEdUCEd OvEr 65% The SAM WWTP worked with CFT to pilot the Tequatic Plus as a prefilter to an existing UF unit. A 2-in unit with a 20 μm filter and 35 gpm (2.21 L/s) filtrate capacity was installed. The SAM WWTP piloted the product for 8–10 hours per day, five days a week over three months during September-November 2009, seeking to reduce turbidity by half – from a feed source of >10 NTU to a UF feed quality of <5 NTU. Other operational parameters included a feed pressure of 20 psi and a pressure drop across the filter of 1–3 psi. The filter exceeded expectations for the SAM WWTP by reducing the incoming water turbidity by over 65% compared to a goal of 50%. The Tequatic Plus filter consistently reduced turbidity on average from 10.4 NTU to 3.5 NTU despite elevated and highly variable levels of water quality in the range 7–19 NTU. The UF modules performed as designed with respect to the cleaning-cycle frequency, indicating that the filter is an effective prefilter. The Tequatic Plus filter also performed as needed, and the pilot system was able to meet California Title 22 standards. In the SAM WWPT pilot, the filter exceeded expectations. It handled variable water qualities, operated without a single backwash cycle, never fouled and required no maintenance or intervention – increasing uptime. In addition, it eliminated the need for cartridge filters as recommended by the UF manufacturer – further reducing operational costs and environmental concerns associated with disposal.l