1. Introduction
        Since the industrial revolution, with the rapid development of industry and agriculture in the world, environmental pollution is becoming increasingly serious, which has caused a serious negative impact on the earth's ecological system and human society. Various physical, chemical, biological environment decontamination technologies and methods have emerged as the times require. In recent years, with the rise and development of nanotechnology, nanomaterials and nanotechnology has been widely used in the field of environmental decontamination. Nanomaterials, which are composed of nanostructure unit, have different characteristics with conventional material in light, electricity, magnetism, heat and mechanical properties, which have many new characteristics of the radiation, absorption, catalysis, and adsorption. Compared with the traditional method, the nanotechnology occupies a small area, human and energy consumption is small, which has the advantages of conventional methods cannot match.
2. R&D
        The nanofiltration membrane technology is a kind of new membrane separation technology between reverse osmosis and ultrafiltration membrane. It is currently one of the hot topics in the research field of water treatment of the world. The nanofiltration membrane with nanoscale aperture, usually negatively charged surface, the selectivity between reverse osmosis and ultrafiltration. It can efficiently remove all kinds of pathogenic microorganisms, low molecular weight organic matter, heavy metal ions etc. under the lower operating pressure, while effectively retained the beneficial trace elements and minerals in water. Nanofiltration membrane technology is an important means of large-scale sewage treatment.
        Photocatalytic technology is the use of light activated semiconductor oxide photocatalyst, to produce a variety of active substances on its surface, driven surface oxidation reduction reaction, so as to effectively oxidize organic matter, reducing heavy metal ions, killing bacteria and eliminate odor, etc. Due to the mild operation conditions, harmless, non-toxic, economic and non pollution of the light catalytic technology, it is a new type of green environmental decontamination technology with wide application prospect, and it has a very attractive prospect in soil, water and air pollution control. At the same time, because of the super hydrophilic property of partial light catalyst, it can be used in the preparation of anti fog and self cleaning materials, and has the function of killing cancer cells, which can be used in medical care.
       Bioremediation technology is the use of specific microorganisms to absorb, transform, remove or degradation environmental pollutants, so as to eliminate or reduce environmental pollution. The bioremediation technology has received great attention in recent years, has been applied to many types of environmental pollution control. Because of the mild and diversity of microbial metabolism, compared with physical and chemical methods, the bioremediation technology has obvious advantages in operating conditions and treatment costs.