作者: R Valladares Linares , None
DOI: 10.4233/UUID:B9DC8FDE-B23D-4D14-9D09-8B2B7AA924F5
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摘要: Since more than 97% of the water in world is seawater, desalination technologies have potential to solve fresh crisis. The most used technology nowadays seawater reverse osmosis (SWRO), where a membrane as physical barrier separate salts from water, using high hydraulic pressure driving force. However, use imposes cost on operation these systems, addition known persistent fouling problems associated with (RO) filtration systems. Forward (FO) an alternative process that uses osmotic difference FO concentrated draw solution generate pressure, which extracts across semi-permeable feed solution. Afterwards, can be obtained when diluted regenerated second treatment step, e.g., low (LPRO). Research has identified for hybrid forward osmosis/low-pressure (FO/LPRO) systems several applications, including desalination, and reduce propensity producing impaired-quality sources, compared conventional RO One main advantages limited amount external energy required extract solution, only very recirculate one side membrane, while passively contact other membrane. objective this research evaluation system osmosis, primary or secondary wastewater effluent, purpose recovering impaired quality sources minimum pressure. This two clear advantages: (i) resulting dilution further treated LPRO unit produce less SWRO systems; (ii) effluent produced by enables low-cost processing. results show recovers wastewater, rejects nutrients micropollutants, outperforms traditional terms resistance control, having flux recovery applying cleaning methods. Water A study revealed ability integrate municipal drinking production (Chapter 2). showed rejection chemical oxygen demand, phosphate trace metals, moderate ammonia total nitrogen. Organic carbon analysis tested was unable reject molecular weight acids neutral compounds, such sodium acetate urea. Biopolymer-like substances played dominant role formation surface. reliable effectively contaminants either allowing clean pass through, providing possible significant energy-saving strategy combine (integrate) promote sustainable urban management reuse coastal cities. Furthermore, another 3), practical conditions membranes were able organic micropollutants spiked water; rejections hydrophilic compounds (44 – 95%), hydrophobic (48 92%), ionic (96 99%). coupled effective rejecting exceeding 89%. For rest greater 99%. FO/LPRO serves double against pharmaceutically active hormones pollutants. Characterization foulants both performed 4). (liquid chromatography detection (LC-OCD) three-dimensional fluorescence excitation emission matrices (3-D FEEM)) suggest biopolymers protein-like substances, present form layer reducing thus, affecting efficiency process. Transparent exopolymer particles (TEP) support contains particles, Physical methods effort set protocol 5). Natural matter reversibility, up 90% in-situ air scouring 15 minutes technique. Chemical mixture Alconox, industrial detergent containing phosphates, ethylenediaminetetraacetic acid (EDTA) improve reversibility (93.6%). Osmotic backwashing 4% NaCl deionized (DI) proved ineffective recover due salt diffusion phenomena occurring at (the separation layer). same layer; 95% recovered, showing chemically irreversible order 5.5%, might adsorption some TEP residuals layer. (air scouring) way control fouling. Biofouling influence spacer thickness (28, 31 46 mil, 1 mil = 0.0254 mm) performance biofouling development 6) led following conclusions: biomass alone does not determine decline: found all thicknesses after run time flow, reduction decreased thicker spacer; decline caused accumulation reduced (iii) spatial distribution biofilm differed thickness. Findings are agreement reported data cross-flow systems: spacers impact performance. result clearly contradicts observations particulate colloidal osmosis. Outlook emerging range applications (desalination recovery). An overview advantages, challenges, costs knowledge gaps given 7). With current commercial technology, proven higher capital technologies. Nevertheless, demonstrated lower operational each m3 desalination/water (i.e. ultrafiltration/RO systems). There key benefits RO: storage may capital, maintenance savings, piping costs, flexible units, (iv) overall sustainability process, water. major challenges commercially viable are: developing capable maintaining elevated internal concentration polarization (ICP) effect, availability appropriate solutions, recirculated via efficient better understanding occurrence, assuring produced, (v) hybridization increase recovery, production, etc.). Numerical modeling useful tool understand processes approaches prevention/reduction. Along this, future experimental studies should focus modified novel strategies. It strongly suggested upscale into pilot scale facility comprehensive parameters done, facilitating life cycle assessment FO-LPRO), will give important information direction taken develop robust