| The ecological environment of various cities has been seriously destructed by the rapid development of economy and society.Environmental pollution is an important issue that restricts the present urbanization process.In view of this,the pollution status and environmental quality of some representative soil and water systrems are carefully monitored and evaluated in this thesis.In addition,the strategies,theories,techniques and experimental researches on the restoration of polluted eco-environment are proposed in detail.The main research contents,findings and significances are listed as follows:1)The pollution status of the soil environment arounds various functional zones(i.e.,villages,grain producing areas,modern agriculture parks,drinking water sources,livestock and poultry farms and industrial parks)are monitored and evaluated by adopting both the single factor index and Nemerow multi-factor index methods.Five of the 41 rural soil monitoring sites are slightly polluted by lead and mercury.The comprehensive pollution index of the soils around the grain producing areas and modern agriculture parks in 2015 ranges between 0.32 and 1.57.For the three drinking water sources(i.e.,-Tangpu Reservoir,Changzhao Reservoir and Chencai Reservoir),the concentrations of copper,cadmium,nickel and zinc in five of the 15 soil monitoring sites exceed the drinking water quality standards.According to the Nemerow analysis,the comprehensive pollution index is calculated to be 0.48(clean)for Tangpu Reservoir,1.03(slight pollution)for Changzhao Reservoir and 1,65(slight pollution)for Chencai Reservoir,respectively.Two of the soil monitoring sites around the livestock and poultry farms are slightly polluted by cadmium.Three of the 18 soil monitoring sites arong the Keqiao dyeing,Shangyu chemical production and Zhuji electroplating industrial areas are slightly polluted by cadmium,nickel,arsenic,mercury,zinc and copper.The comprehensive pollution index is 0.29(clean)for Keqiao dyeing industrial area,0.64(clean)for Shangyu chemical production area and 0.74(clean)for Zhuji electroplating industrial area,respectively.chemical production area and 0.74(clean)for Zhuji electroplating industrial area,respectively.2)A careful environmental monitoring is performed towards the discharge situations of sewages and the main contaminates(e.g.chemical oxygen demand(COD),ammonia nitrogen,mercury,chromium,lead,arsenic,volatile phenol,cyanide and petroleum during the 12th Five-Year-Plan period.The results show that the discharge amounts of the foregoing pollutants are obvious lower than those during the 11th Five-Year-Plan period.The printing and dyeing industries with high pollution have been emphatically rectified and the water environment quality is greatly improved after the management.The environment qualities of rural drinking water at the monitoring sites are up to or better than the III grade of surface water standards.For the rural surface water systems,the environment qualities of nine monitoring sites are lower than the III grade of surface water standards.Specifically,six sites are the IV grade water qualities with fluoride,COD,ammonia nitrogen and petroleum as the main pollutants,one site is the V grade water quality with total phosphorus(TP)as the dominant contaminate and the other two sites are under the V grade water qualities with the main pollution factors of TP,ammonia nitrogen and permanganate index.3)In allusion to the heavy metal pollution of soil and water systems in Shaoxing city,a simple co-precipitation approach is adopted to synthesize fulvic acid(FA)decorated Fe3O4(Fe3O4/FA)magnetic nanoparticles for the decontamination of Ni(II),Pb(II),nitrogen,phosphorus and basic blue 3(abbreviated to BB3).Batch experiments are conducted to evaluate the removal performance of Fe3O4/FA as a function of environmental factors such as contact time,solution pH,ionic strength,solid dosage,coexisting ions,temperature,etc.The as-prepared Fe3O4/FA composite exhibits fast removal kinetics,favorable sorption capacity and excellent recycling property towards both the two heavy metal ions.The Fourier Transform Infrared Spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS)analysis suggests that inner-sphere surface complexation is the predominant sorption mechanism of Ni(II)and Pb(II)on Fe3O4/FA.In contrast,the removal mechanism of nitrogen,phosphorus and BB3 is mainly attributed to the electrostatic interaction.Considering the multiple advantages of easy synthesis,low price and environmental friendliness,Fe3O4/FA would be potentially applied for the cost-effective remediation of contaminated aquatic environment.4)Based on the present soil and water environmental problems status of Shaoxing city,a series of pollution control strategies are proposed from the aspects of economy,legislation,administration,talent cultivation and techniques as follows:1)to adjust the economic structure and develop environmental friendly industry projects;2)to promote companies to upgrade the manufacturing processes,evaluate the pollution emissions of various production lines and enhance the pollution control capacities of factories;3)to strengthen the prevention and control of potential environmental risks,implement the governance mechanism of industrial pollution sites and ensure the safety of soil environment;4)to promote the governance professes of sewage disposal,flood prevention,waterlogging drainage,drinking water supply and water resource saving so as to improve the water quality;5)to generalize the pollution control modes by considering the local conditions and ameliorate the whole outlook of rural ecological environment;6)to improve the level of environmental monitoring and ecological accident emergency,establish the long-term training system of environmental talents and promote the comprehensive development of environmental protection;7)to ameliorate the environmental legislation and enhance the punishment of environmental pollution events;and 8)to reinforce the public's environmental protection consciousness via scientific propaganda and perfects the supervision mechanisms on the enforcement of environmental laws. |
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