出版社：Polish Society of Ecological Engineering (PTIE)
摘要：Survey shows that high operational costs of membrane facilities and large amounts of effluentsare mainly attributed to fouling and scaling.Research of scaling and fouling mechanismsshowed that these processes depend not only on hydraulic and hydrodynamic factors, but on membranetype, material and channel configuration as well.Operational parameters of different membraneconfigurations show that spiral wound modules demonstrate best hydraulic and hydrodynamiccharacteristics combined with lowest price.Main ways to develop new fouling-free techniques are outlined that require modified «open-channel» spiral wound membranes.Elimination of «deadlocks» as a main cause of scaling and foulingprovide new technological approach to develop water treatment techniques without pretreatment facilitiesand chemicals.Modification of channel provides possibility to reach high recoveries andhigh supersaturation values due to strong stability of calcium carbonate solutions.Membrane transport is not only purification instrument it is also a reactor to coagulate, concentrateand precipitate water constituents on membrane surface.Several examples of water treatment flowdiagrams are presented to demonstrate principles of zero concentrate flow discharge.Coagulatedsuspended matter after membrane flushes is collected, sedimented and finally dewatered.The dewateredsludge contains averagely 0,8 per cent of initial water.Due to the use of an «open-channel»modules membrane brine flow could be concentrated by many times without a fear of scaling andadded to the sludge.Thus the excessive salts and impurities could be withdrawn from water systemstogether with partially dewatered sludge.Similarly excessive calcium carbonate could be also concentratedin membrane modules and subsequently precipitated, sedimented and dewatered.Solutionof fouling problems thus provides a new approach to save operational costs and to increase ecologicalefficiency of membrane water treatment tools.
