【作者】 查红平；

【导师】 董瑞斌；

【作者基本信息】 南昌大学 ， 环境工程， 2007， 硕士

【摘要】 农药废水浓度高、色度深、毒性大、污染成分复杂,难以生物降解。TiO₂多相光催化氧化法以其无毒、催化活性高、氧化能力强、稳定性好被广泛研究用于农药废水的处理。本文以钛酸丁酯为前驱体,通过溶胶—凝胶（Sol-Gel）法制备TiO₂纯品和不同浓度Fe³⁺、Cu²⁺、Ag⁺掺杂的粉末,并在500℃煅烧2h。XRD分析表明制备的粉末均为锐钛型纳米颗粒,粒径在11.2～49.8nm之间,对应粉末的比表面积为51.24～102.13 m²·g^-1。用TiO₂粉末在紫外光照射下处理甲基硫菌灵生产废水,废水COD_Cr浓度随反应时间变化的趋势可分为三类:纯品和掺杂1.5%Cu的TiO₂粉末使COD_Cr浓度降低;掺杂0.5%Fe、0.5%Cu和1.0%Ag的TiO₂粉末使COD_Cr浓度先降后升,但COD_Cr最终浓度低于初始浓度;其它掺杂情况下COD_Cr均呈增加趋势。废水中NH₃-N浓度变化趋势为:纯品和掺杂1.0%Cu、1.0%Ag、1.5%Ag的TiO₂粉末使NH₃-N浓度先降后升;掺杂Fe、0.5%Cu、1.5%Cu和0.5%Ag的TiO₂粉末处理的废水中NH₃-N浓度先升后降。光催化预处理使废水的可生化性提高3.5～4.3倍,BOD₅/COD_Cr值均大于0.30,8h处理后BOD₅/COD_Cr值依次为:1.5%Fe＞1.0%Cu＞1.5%Ag≈0.5%Cu≈1.0%Fe＞0.5%Fe＞1.0%Ag＞1.5%Cu＞0.5%Ag＞TiO₂。用TiO₂粉末在太阳光照射下处理废水,废水COD_Cr浓度随反应时间变化的趋势:纯TiO₂和掺杂0.5%Fe的TiO₂粉末处理废水的COD_Cr先降后升;掺杂1.5%Fe的TiO₂粉末使COD_Cr浓度先升后降;其它掺杂情况下COD_Cr均呈增加趋势。8h后COD_Cr的浓度顺序为:1.5%Cu＞0.5%Cu＞1.0%Ag＞0.5%Fe＞1.5%Ag＞1.0%Cu＞1.5%Fe＞1.0%Fe＞0.5%Ag＞TiO₂。废水中NH₃-N浓度变化趋势为:纯TiO₂处理的废水中NH₃-N浓度先增后降;掺杂0.5%Ag、1.5%Ag、0.5%Fe、1.0%Cu的TiO₂处理废水得到NH₃-N浓度先降后升;其余TiO₂粉末处理废水得到NH₃-N浓度单调增加。通过光催化预处理,废水的可生化性提高2.5～3.6倍,8h处理后各种催化剂的催化性能依次为:1.5%Fe＞1.0%Fe＞1.5%Cu＞0.5%Cu＞1.5%Ag＞0.5%Fe＞1.0%Ag≈1.0%Cu＞0.5%Ag＞TiO₂。紫外光与太阳光照射对比表明:纯品、掺杂0.5%Fe和1.0%Cu的TiO₂处理过程中前2hCOD_Cr的浓度差异(△COD_Cr)大于0;其余样品处理的各时间段△COD_Cr均小于0,且所有样品处理8h后,△COD_Cr都小于0,紫外光处理效果好于太阳光。纯TiO₂和掺杂1.0%Ag的TiO₂处理后的废水△NH₃-N也呈现先减后增的趋势;其余掺杂情况的TiO₂处理后的废水△NH₃-N均呈先增后减趋势。紫外光与太阳光处理下的可生化性差值△BOD₅/COD_Cr对所有催化剂均呈现先增后减的趋势,同时△BOD₅/COD_Cr均大于0。更多还原

【Abstract】 Pesticide wastewater has the properties of high concentration,deep chrominance, high toxicity and complex components and is difficult to be degraded by microorganism.TiO₂ is wildly used in multiphase photocatalytic oxidation owing to its innocuity,high photocatalytic activity,strong oxidation ability and good stability.As to the method discussed in this paper,pure TiO₂ and Fe³⁺,Cu²⁺,Ag⁺ doped powders were prepared in sol-gel method with Ti（OC₄H₉）₄ as its precursor,and the powders were calcined under 500℃for 2 hours.XRD analysis showed that all powders were anatase,with their grain diameters varying from 11.2nm to 49.8nm, specific surface areas varying from 51.24 to 102.13 m²·g^-1。Thiophanate-methyl industrial wastewater was treated by photocatalytic oxidation under UV-light with prepared TiO₂ powder.According to the relationship between time and concentration of COD_Crin wastewater,the powders are categorized into three types:pure TiO₂ and 1.5%Cu²⁺（n:n）doped TiO₂ made COD_Crin wastewater decreased with the passing of time;0.5%Fe³⁺,0.5%Cu²⁺and 1.0%Ag⁺ doped TiO₂ made COD_Crin wastewater decreased in the first 2 hours,then increased,and the final COD_Crvalue was lower than the initial ones;other TiO₂ powders made COD_Cr increased.Fe³⁺,0.5%Cu²⁺,1.5%Cu²⁺and 0.5%Ag⁺ doped TiO₂ made contents of NH₃-N in wastewater increased at first,then decreased;pure and 1.0%Cu²⁺,1.0% Ag⁺,and1.5%Ag⁺ doped TiO₂ also made contents of NH₃-N in wastewater decreased at first,then increased;photocatalytic oxidation made bioavailability of wastewater increased by 3.5 to 4.3 times,and BOD₅/COD_Cr＞0.3.After treating for 8 hours,the bioavailability of wastewater was presented in the following order:1.5%Fe＞1.0%Cu＞1.5%Ag≈0.5%Cu≈1.0%Fe＞0.5%Fe＞1.0%Ag＞1.5%Cu＞0.5%Ag＞TiO₂.Treating wastewater under solar light with prepared TiO₂ powders,and its results showed that:pure TiO₂ and 0.5%Fe³⁺doped TiO₂ made COD_Crin wastewater decreased at first,then increased;other TiO₂ powders made COD_Crincreased.After treating for 8 hours,the COD_Crin wastewater was presented in the following order: 1.5%Cu＞0.5%Cu＞1.0%Ag＞0.5%Fe＞1.5%Ag＞1.0%Cu＞1.5%Fe＞1.0%Fe＞0.5%Ag＞TiO₂.Pure TiO₂ made contents of NH₃-N in wastewater increased at first,then decreased;%0.5Fe,1.0%Cu,0.5%Ag and 1.5%Ag doped TiO₂ made contents of NH₃-N in wastewater decreased at first,then increased;other TiO₂ powders made content of NH₃-N in wastewater increased.Photocatalytic oxidation made bioavailability of wastewater increased by 2.5 to 3.6 times.After treating for 8 hours, the bioavailability of wastewater was presented in the following order:1.5%Fe＞1.0%Fe＞1.5%Cu＞0.5%Cu＞1.5%Ag＞0.5%Fe＞1.0%Ag≈1.0%Cu＞0.5%Ag＞TiO₂.Comparison between the UV-light and solar light as to their photocatalytic oxidation efficiency showed that:After treating for 8 hours,COD_Crin wastewater treated under UV-light were higher than that treated under solar light.Difference of contents of NH₃-Nin wastewater decreased at first,and then increased while treated wastewater with pure and 1.0%Ag doped TiO₂.Difference of contents of NH₃-N of other powders treated wastewater increased at first,then decreased.Difference of bioavailability between UV-light and solar light treated wastewater were positive,and theΔBOD₅/COD_Crincreased at first,then decreased.更多还原