供排水工艺--化水(国外英文资料).docVIP

供排水工艺--化水(国外英文资料) Three 、 chemical water treatment 1 and MF: microfiltration. The pore size is about 0.02 microns to 1 microns. 2 and UF: ultrafiltration, filtration pore size in the range of 0.002 microns to 0.1 microns. 3 and NF: nanofiltration is between UF and RO, which mainly removes solute particles with diameter of about 1nm, and the molecular weight is more than 200. It is a kind of ultra-low pressure reverse osmosis membrane. 4, RO: reverse osmosis can remove the deep solution of water, desalination rate of more than 97%. 5, the concentration polarization: reverse osmosis process, through water molecules, increasing salinity film interface, the formation of high concentration layer, this layer and the water flow concentration to form concentration gradient, this phenomenon is known as the membrane concentration polarization. 6, what is infiltration and reverse osmosis? Answer: when the permeability is a natural process of fluid across the membrane barrier. If a box of water with a semipermeable membrane vertically divided into two parts, both pure water and ideal semipermeable membrane at the same temperature and pressure contact, not across the semipermeable membrane in the condition of water flow, because the chemical potential on both sides of the film completely equal. If the dissolved salt is added to one side, the chemical potential at the side of the salt solution decreases. The pure water then seeps to the side of the salt solution, creating a percolating stream until the chemical potential is lowered. The pure water then seeps to the side of the salt solution, creating a porous flow until the equilibrium of the chemical potential is reestablished. Reverse osmosis is when the new equilibrium is reached, an additional pressure is applied to the salt solution at the same time as the osmotic pressure, and the original equilibrium will be affected. The applied pressure will increase the chemical potential on the side of the salt solution, allowing the s