Water. desalination + reuse

May/June 2014

Water. Desalination + reuse

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TECHNOLOGY | 32 | Desalination & Water Reuse | May-June 2014 Deposition factors determined with MFI-UF using test membranes varying between 100 and 5 kDa for feedwater (pretreated with UF) to a seawater RO pilot plant in Jacobahaven (the Netherlands) showed Ω ranged between 0.20 to 0.45 (see table 1). References 1. ASTM, D4189 - 07(2014). 2014, ASTM International: West Conshohocken, PA. 2. JC Schippers, and J Verdouw, Desalination 1980. 32: p. 137-148. 3. A Nahrstedt and J Camargo Schmale, Water Sci Tech: Water Supply, 2008. 8(4): p. 401-412. 4. A Alhadidi et al. J Mem Sci, 2011. 381(1-2): p. 142-151. 5. A Alhadidi et al. J Mem Sci, 2011. 384(1-2): p. 205-218. 6. RM Rachman et al. Desalination Water Treat, 2013. 51(4-6): p. 1091-1103. 7. JC Schippers et al. Desalination, 1981. 38: p. 339-348. 8. JC Schippers, 1989, Rijswijk: Keuringinstituut voor waterleidingartikelen KIWA N.V. 179. 9. SFE Boerlage, et al. Desalination, 2004. 161: p. 103-113. 10. SG Salinas Rodríguez, 2011, Delft: CRC Press/Balkema. ISBN 978-0-415-62092-5 11. SG Salinas Rodríguez et al. Desalination Water Treat, 2012. 42: p. 155-162. 12. SFE Boerlage et al. J Mem Sci, 2002. 197(1-2): p. 1-21. 13. SFE Boerlage et al. J Mem Sci, 2003. 211: p. 271-289. 14. EMV. Hoek, and M Elimelech, Env Sci Tech, 2003. 37: p. 5581-5588. 15. LN Sim et al. Desalination, 2011. 273: p. 184-196. 16. LO Villacorte, 2014, Leiden: CRC Press/Balkema. ISBN 978-1-138-02626-1 with membranes having pores of 10 kDa at a constant flux of 60 L/m 2 h. The data shown in Figure 11 originate from 5 different plant locations including lake, river and seawater. CONCLusiONs aNd RECOmmENdaTiONs The presented results illustrate the benefit of the MFI-0.45 test to the industry to determine the particulate fouling potential of both high and low fouling feedwater. The MFI is corrected for temperature and pressure and has a linear relation with suspended/ colloidal matter. Semi- and fully automated equipment is available on the market to simultaneously measure MFI-0.45 and SDI on-line. The observed deficiencies in the SDI test and the demonstrated advantages of MFI have led the ASTM Committee charged with recertifying SDI to revisit the protocol for SDI and to start the approval process for a second standard based on the MFI test method. MFI-UF provides insight into the fouling potential of a feedwater due to particles smaller than 0.45 µm and enables one to measure the effect of different pretreatment processes on these particles. Three major aspects need to be addressed in further developing the MFI test: • MFI test membranes with even smaller pores, ideally close to the nanofiltration range, and preferably down to 5, 1, and 0.5 kDa. Unfortunately, membranes, in flat sheet form, and having sufficient permeability are not yet available on the market. Consequently, pencil capillary membranes modules need to be applied, complicating further research and application. • Measuring the deposition factor Ω in a multitude of full-scale plants to define the "safe MFI". This requires operational data on fouling rates in RO systems. Differentiation between particulate fouling and biofouling is also required. • Measuring the enhanced osmotic pressure effect due to fouling in full- scale plants. International collaboration of research organizations and the industry worldwide is proposed in order to establish a database of operational data and MFI-UF measurements for a wide range of RO feed water, pretreatment options and operational regimes. Such a database would be of considerable value to process engineers and plant operators in designing and operating desalination plants. l The performance of pretreatment processes at the Jacobahaven SWRO demonstration plant was assessed using MFI-UF measured with 100, 50 and 10 kDa test membranes as shown in Figure 10. The Amiad strainer showed only a small reduction in MFI-UF, as expected, with a relatively large aperture size of 50 µm. Whereas, the reduction in MFI- UF (and fouling) observed following UF (nominal MWCO of 150 kDa) was much larger, ie, of 94%, 93% and 88% reduction for 100 kDa, 50 kDa and 10 kDa MFI-UF test membranes, respectively. These results clearly illustrate that the MFI-UF can be used (at any temperature) to measure low and high fouling feedwater and for UF permeates. FOuLiNG POTENTiaL iN uF aNd mF sYsTEms Predicting the rate of fouling in MF and UF systems, ie, development of pressure during operation at constant flux, seems to be less complicated than in RO systems, since filtration is conducted in dead-end mode. Hence, the deposition factor Ω is 1.0, completely eliminating the need to measure Ω. Moreover, the MFI can be measured using the same membrane as applied in the full scale plant, so that Equation 2 can be applied to predict the development of the pressure during one cycle. Recently transparent exopolymer particles (TEP) have been identified as potential foulants in MF, UF and RO. These foulants, originating from algal activities and other aquatic life, have been overlooked by the industry for many decades. Villacorte 16 recently developed a method to semi-quantatively measure the concentrations of TEP down to a size of 10 kDa. A good correlation was observed between TEP10 kDa and MFI-UF measured Table 1: Deposi on factor measured with various MFI test membranes (PES) at a SWRO pilot plant, determined 11 May 2010. 10 Deposi on factor Ω Membrane, MWCO 100 kDa 0.23 50 kDa 0.29 10 kDa 5 kDa 0.20 0.45 SHOWCASE May-June 2014 | Desalination & Water Reuse | 33 | Forward-osmosis companies launch international association Four companies specializing in forward osmosis membrane technology launched the International Forward Osmosis Association (IFOA) on 7 April 2014. According to IFOA's website forwardosmosis.biz the aims of the association are: • Advocating for the global adoption, understanding and benefits of forward osmosis • Establishing and promoting forward osmosis industry standards, specifications, procedures and terminology • Providing a professional network for information exchange all topics related to forward osmosis • Providing a single industry voice between its membership and the general public • Encouraging cooperation between industry and government institutions for acceptance, regulation and performance standards for forward osmosis. The founding companies are Modern Water (UK), Hydration Technology Innovations, Trevi Systems and Porifera (all USA). Each company supplies one director: William Harvey (Modern Water), Walt Schultz (HDI), John Webley (Trevi) and Oljika Bakajin (Porifera). IFOA will hold an Annual World Summit on 18-19 September 2014, in Lisbon, Portugal, just prior to the International Water Association's world congress, which will provide a platform to promote information exchange. macarrier helps new Ge mBr Beat touGh orGanics A membrane bioreactor (MBR) with a carbon-based membrane accommodating carrier (MACarrier) designed to help industrial companies meet stringent water discharge requirements and enable greater water reuse was launched at the IFAT Entsorga 2014 exhibition in May by GE. Developed in GE's China Technology Center as a solution for tough-to-treat water, MBR with MACarrier combines a highly efficient MACarrier with GE's ZeeWeed 500D membranes. This integration enhances the removal of recalcitrant organics and toxicity and can achieve a chemical oxygen demand (COD) reduction of more than 50% compared to a MBR without MACarrier. The ability of the MACarrier to be biologically regenerated in the bioreactor cuts down on operational costs. "Our new MBR with MACarrier provides a solution for treating wastewater that is high in COD, toxicity, BOD 5 , phenols and other contaminants," said Yuvbir Singh, general manager, engineered systems - water and process technologies for GE Power & Water. "We are proud of this new innovation that helps our industrial customers safely discharge and reuse their wastewater." can chemical-Based desalter Become new idol? A patents-pending chemical desalination process, which won the Water Technology Idol contest in Paris in April 2014, can reduce concentrations of total dissolved solids (TDS) in excess of 300,000 mg/L to less than 150 mg/l. Advanced Water Recovery (AWR)'s process uses a recoverable chemical saturation to concentrate and precipitate dissolved salts out of any water stream at ambient temperature, making all of the water suitable for reuse or surface water discharge. The resulting >80% dry solid waste can be selectively separated for valuable byproducts, or disposed of in an ordinary landfill. TDS reduction is accomplished at dramatically reduced operating and capital costs, compared with existing treatment technologies, says AWR. The process has wide-ranging applications, from toxic mine water treatment to economical total water recovery on existing desalination plants, converting high dissolved solids liquids into clean usable water and zero liquid waste. The South Dakota-based company is currently constructing a commercial produced water treatment facility in the Marcellus shale region in Pennsylvania, which is expected to be operating in summer of 2014. The company is currently seeking commercialization partners. aquamost selects texas company as sales aGent Wisconsin-based AquaMost Inc, developer of a patented water treatment system that kills bacteria without the addition of chemicals, announced today that it has appointed Extra Energy Solutions (EES) as its exclusive sales representative in the US. EES, a Texas-based service provider that specializes in the oil and gas industry for water management and enhanced oil recovery solutions, will begin marketing the AquaMost products immediately. AquaMost specifically designed the SX Reactor for the oil and gas industry. The operator safe system, successfully deployed at numerous sites in Texas, Colorado and Utah, has proven to deliver superior results, significant cost reductions, and operational simplicity in all water types, regardless of salinity. "We chose Extra Energy Solutions to represent our products because of their extensive knowledge and depth of contacts throughout the oil and gas industry," said Todd Asmuth, CEO of AquaMost. "We look forward to working with Extra Energy Solutions to grow our customer base into every oil & gas basin in the United States," The AquaMost device is a simple plug-and-play system that allows seamless integration into new and existing water treatment programs, whether stationary or mobile, with flexibility for stand- alone operation. AquaMost initially offers operators a 30-60 day trial for use at the wellhead, disposal wells or fixed plant facilities. The Aquamost SX Reactor

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