According to different shapes, the membrane can be divided into hollow fiber membrane (PVDF), flat film (MBR), tube film and roll membrane. The shape of the membrane is determined by the fabrication and assembly process, and the hollow fiber membrane is widely used in water treatment applications. Flat films are generally used only in some of the processes in the field of water resources, such as partial membrane bioreactors (MBR), which are mainly used for landfill leachate treatment and high solids liquid separation.
First, the membrane of water treatment technology classification
(MBR), continuous membrane filtration (CMF), immersion membrane filtration (SMF) and bi-directional membrane filtration (TWF), according to the technical category.
1, membrane bioreactor (MBR), is a high efficiency membrane separation technology and activated sludge combined with a new type of sewage treatment technology. The main process principle is to use ultra / microfiltration membrane separation technology to replace the traditional activated sludge method of secondary sedimentation tank and conventional filter unit to achieve efficient solid-liquid separation and the retention of biological flora, the treated effluent directly to high Quality of recycled water standards. MBR as the core of the three water treatment system is the best, with a certain cost-effective protection of water and drinking water sources of the solution, more for the sewage discharge standards of traditional sewage treatment plant to mention the transformation, expansion project, or new Compact and efficient sewage treatment system. Effluent quality far more than the next few years of discharge standards, the water can be safely discharged to sensitive water environment, in agricultural irrigation and industrial production in re-use, and groundwater recharge. At present in China's municipal sewage treatment field MBR use is more common.
2, continuous membrane filtration (CMF), is a hollow fiber super / microfiltration membrane module as the central processing unit, with a specially designed pipeline, valves, self-cleaning unit, dosing unit and self-control unit, the formation of closed-circuit continuous operation System, raw water under a certain pressure through the microfiltration / ultrafiltration membrane for filtration, to achieve the purpose of physical separation and purification.
3, immersion membrane filtration (SMF), is a low-pressure hollow fiber membrane technology and continuous membrane filtration technology combined with a new type of membrane filtration process. It uses the open hollow fiber membrane module, the membrane directly placed in the pool filled with water to be processed, through the pump's negative pressure suction and atmospheric pressure, so that water through the membrane surface, from the hollow fiber membrane inside to filter The purpose of purification. CMF and SMF are mainly used to treat relatively clean water such as surface water, groundwater, sewage treatment plants or pretreatment tailings, desalination and pretreatment of reverse osmosis (RO) membrane modules during the preparation of pure water. Water supply depth purification treatment CMF, SMF application is relatively wide.
4, two-way flow membrane filtration (TWF), is in the membrane separation process, through the raw water into the direction of the cycle of switching, in the separation of filtration at the same time, the use of raw water on the contaminated side of the heavy cleaning to keep the film well Permeability effect, to achieve continuous and stable effect of raw water separation and purification.