Experimental Study On Performances Of Crossflow Microfiltration Through Flat Membrane

Industrial wastewater with solid is the main source of the waste water in China,along with the sustainable development strategy being put forward, the environmentprotection law and the law on prevention and control of water pollution in our countrymake strict demands on the protection of water resource and the control of waterpollution. It is urgent for us to purify and recycle the industrial wastewater for reuse.Under such a background, the paper designs a new kind of device for solid-liquidseparation-a kind of flat membrane crossflow filtration device, in order to takeadvanced and clean treatment for industrial waste water, and select five different kindsof plate membrane and made an experimental investigation on them.Firstly, basic properties of flat membrane with water as the raw material havebeen tested. The variation law of each flat membrane permeation flux in waterconditions has been studied, so as to find out the basic properties of flat membrane,and as a controlled trial for the suspension experiment.Then through the experiment on crossflow filtration device filtering slimesuspension, we found the changing law of the permeation quantity of each membraneplate with inletflowrate, operating pressure and filtering time. The law of thepermeation quantity of each membrane plate with inletflowrate, operating pressureand filtering time are same. The permeation quantity increases with the inlet flowrate.It also increases with the operating pressure. It decreases with the filtering time andfinally goes to be stable. But the increasing rate and decreasing rate are different.Through comparison we found the filtration performance of the titanium membraneplate is the best in all the flat membrane selected.In order to make the crossflow filtration equipment can apply to industry, thepaper carried through a deep study. It demonstrated the feasibility of the titaniummembrane plate applying to industry. The experiment also compared the crossflowfiltration capability between titanium membrane plate and titanium membrane tube,whose results show that under the same operation conditions, plate membranefiltration shows better effect, and more power energy will be saved, and proves itsvalue for popularizing in practical application.Finally, we apply the resistance calculation formula under the condition ofcrossflow microfiltration, and combine with the experimental data fittin. To taketitanium flat membrane for an example, we analyze the resistance changing with timeand transmembrane pressure according to a third-degree polynomial in the early stageof membrane cross-flow filtration, with the inletflowrate changing consistently withthe law of a exponential function.