Schedule of Graduation Thesis (Design) for Undergraduates of Jiageng College, Xiamen University Studen t Guidan ce teache r Su Yang Bo Environmental Stude nt ID Liu Specialty Science and Engineering Jiageng Xing Qiang ESE10086 Title associate professor Subordin ate unit College, Xiamen University Phase 1: Selection of topics 1.Graduation Thesis (Design) Common Sense Guidance (Students Fill in) Guidance time: January 2, 2013 Instruction form: face-to-face instruction Place of guidance: Master 3 #812 Main contents: 1 Determine the title of the paper 2 Preliminary development of research plans and timetables 3 Guidance on filling in student form 1 and student form 2 4 Outline requirements for guiding papers Student Signature: Fill in Date: 2.Selected topics (students fill in) Title: Preparation of nano-zinc oxide and its removal from wastewaterCr6+ Student Signature: Fill in Date: Oct. 8, 2013 3.Opening report Subject Demonstration (Students Fill in) The contents should include the following points: (1) Subject selection basis (purpose, significance, research status, feasibility) (2) Main Contents (Outline of Thesis) (3) Theory and method of application (4) Expected objectives and results The Basis of Choosing a Topic Electroplating industry is a high water consumption, heavy pollution industry, in light industry, Chinese style is second only to paper industry.Therefore, electroplating wastewater is classified as one of the three most abundant wastes in heavy pollution industry. The production process of electroplating is complex, the water consumption is large, and the tannery wastewater discharged every year is large. There are many harmful substances in the wastewater, such as chromium, sulfur, suspended matter, chemical oxygen consumption (CODcr), biochemical oxygen demand (BOD5), SS, etc.It can be seen that the electroplating industry will cause considerable environmental pollution.In addition, a large number of chemical materials, such as acid, alkali, salt, nickel, gold citrate, cyanide, zinc and copper, are used in the electroplating process, and a large part of these materials are absorbed into the wastewater.The characteristics of electroplating wastewater are high chroma, many suspended solids, complex composition, high pH value, high content of heavy metals, high fluctuation of water quality and certain toxicity.[3][4] Electroplating industry has been listed as one of the heavy pollution industries in China. The composition of electroplating wastewater is complex, its pH value is high and it has certain toxicity. It will discharge the treated boiling water directly into the environment, which will cause serious pollution to the environment.Therefore, the treatment and recycling of pollutants from electroplating wastewater in China has been continuously studied and improved.Hexavalent chromium ion is one of the pollutants in chromium plating wastewater. As a heavy metal with strong toxicity, its toxicity is far greater than trivalent chromium.Hexavalent chromium ions have serious toxic effects on animals, plants and human beings.If human beings have ingested more hexavalent chromium through different ways, the body may lead to deformity, carcinogenesis, mutagenicity, damage to human liver, stomach and other parts.Hexavalent chromium is one of the most important pollutants in China, and it has attracted much attention in the treatment of chromium-containing wastewater.[5] Cr6+Water, air and food enter the body through three ways. Indoor dust and soil are also found to be ingested into the body.It has been proved that hexavalent chromium compounds can not be degraded naturally and accumulate in organisms and human bodies for a long time. It is a kind of environmental pollutant.Cr6+ Nano-zinc oxide (ZnO) is a new kind of inorganic material with multifunctional properties, whose particle size is between 1 and 100 nm.Due to the refinement of grains, the surface electronic structure and crystal structure have changed, resulting in surface effect, volume effect, quantum size effect, macro tunneling effect, high transparency, high dispersion and other characteristics that macro-jade does not have.[11] Although nanotechnology as a whole is still in the stage of experimental research and small-scale production, from a historical point of view: in the 1970s, countries that attach importance to micron technology have become developed countries. Today, countries that attach importance to the develo