| Clean water has become a scarce commodity in many parts of the world. To supply the demand for the potable water for the world's population and high quality water for industry the available sources of water often need to be treated. The main pollutions in water are heavy metal, organics and bacteria. When heavy metals return to the environment they cannot be biodegraded. The metals can adsorb onto the soil, runoff into rivers or lakes or leach in the groundwater, which is an important source of drinking water. Because the heavy metals may pose serious problems on building up at various stages during the ecobiological cycle, to purify wastewater containing metal ions is necessary. Organic pollutions widely lie in water. Most of them would harm to people directly or indirectly. Moreover some of them could change the DNA of cell in human tissue, and cause cancer, abnormality and mutation. Bacteria are a kind of original biology with single cell, which are distributed widely in the nature. Bacteria have a consanguineous relationship with the human. They badly affect human's health. The main separation technologies have been researched a lot. These procedures, however, are in principle rather costly for implementation on a large scale system. And most of them are used to removing high concentration pollution but seldom aim at low concentration pollution. Application of ion exchange, activated carbon adsorption and membrane separation processes may lead to high cost especially when metal concentrations in wastewaters are low. Although reverse osmosis and ion exchange are the mature technologies, which are used for removing low concentration metals, they are always combined in a system. Many steps work together to realize water purifying. So we hope the material we developed can realize the efficient treatment of a dilute pollution waste and especially it can be used solely in a simplest way. To further research this novel nano-water-purifying material, a kind of nanofiltration we design a series of experiments. The main bodies of this nanofiltration are composite nano-particles and carrier fiber. We researched them respectively. To nano-particles: composite nano-particles were compared to pure nano γ- Al2O3 and γ- Al2O3 in normal size. Three kind of nanofiltration were prepared respectively by three kind of particles. Then we used them to purify water. The result showed that composite nano-particle has the best purifying effect among them. To carrier fiber: three kinds of fiber with adsorption ability, activated carbon fiber, microcrystal cellulose and polyethylene fiber, were chosen. The results showed that activated carbon fiber has the best purifying effect among them. According it the composite nano-particles and activated carbon fiber were chosen as the raw materials. Then the water-purifying effect of this nanofiltration was researched. And heavy metal, organics and bacteria were the main removal targets. The nano-particles are composite nano-alumina which has orthorhombic structure. The ratio surface area of the nano particle in the nano-water-purifying material is very large. Because having the especial structure of alumina this kind of nano-particles are of strong ability of adsorption. Those particles have high surface activity and superfluous surface energy. At the same time, the fiber carrier would be used for pollution sorption at high capacities. So the water-purifying was realized.In this paper adsorption capacity and maximum adsorption capacity were also caculated. Adsorption capacity is an important capability guideline which used to evaluate the effect of water-purifying. the formulate is as follows:adsorption capacityï¼(C0 – C)*1000V/M accumulated adsorption capacityï¼Î£ [C。(tn-tn-1)*Vn-1～n-Cn(tn-tn-1)*Vn-1∽n]/Mmaximum adsorption capacity is another important capability guideline which used to evaluate the effect of water-purifying. The maximum adsorption capacity on the nanometer Al2O3/Carbon material is determined using Thomas model. Thomas model is described... |
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