【作者】 路璐；

【导师】 康建雄；

【作者基本信息】 华中科技大学 ， 环境工程， 2007， 硕士

【摘要】 餐饮废水成分复杂、有机物特别是动植物油含量高,同时水质水量变化较大,是一种较难处理的废水。目前,国内对餐饮废水尚无完善、彻底有效的处理方法。本文提出了远紫外光（UV-185nm）深度氧化法预处理餐饮废水的新思路。利用185nm波长高能远紫外光,打断油脂分子化学键,同时辐射水中溶解氧产生臭氧,生成羟基自由基,形成UV/O₃协同作用机制氧化降解有机物。研究了UV-185氧化餐饮废水的影响因素,确定了最佳反应条件;通过对纳米TiO₂光催化剂的XRD和TEM表征分析,从市购和自己制备的纳米TiO₂中选择一种最理想的催化剂用于光催化反应,并寻求最佳的工艺参数;用油酸甲酯模拟实际油脂,通过油脂的经典方法分析和GC-MS分析,得出其光氧化降解的中间体和可能的降解途径;以Tymoschuk数学模型为依据,完成了光催化法日处理10吨餐饮含油废水中试成套装置的设计,并进行经济分析。研究结果表明:（1）直接光氧化的最佳反应条件为:光照时间10min、pH值范围6.0～8.0。在此条件下,油脂去除率为80%～88%,COD去除率为48%～62%,BOD5去除率为35%～53%,氨氮去处率约为18%。COD和BOD5随着浓度的下降和水中溶解氧量的增加,各自的去除率逐渐升高;油脂初始浓度在2000mg/L～3500 mg/L时的去除率最高,受溶解氧量影响较小。COD的降解速度对COD的浓度为一级反应,初始浓度为3727.4mg/L时,建立的经验速度方程为:V COD = ?d CCOD/dt=0.0451CCOD（mg/L·min）。随着光照时间的增加,装置中臭氧浓度不断增大,50min后趋于稳定;水样中羟基自由基的浓度也随之增大,15min后不再增加。（2）用于反应的催化剂为锐钛矿型TiO₂,晶粒18.5nm,其以悬浮态形式存在于反应体系中时,最优反应条件为:TiO₂投加量150mg/L,无需调节原水pH值,空气通入量为40～60L/h。在此条件下,COD和BOD₅的平均去除率较之无催化剂时有显著提高,可分别达到64.02%和42.79%;油脂的去除率由于催化剂遮蔽导致紫外光穿透性减弱而下降,约68%～69%。（3）随着光照时间的增加,油脂的不饱和程度在逐渐降低,油脂及脂肪酸的平均分子量也在不断减小,同时生成大量过氧化物和羧酸;模拟油脂—油酸甲酯降解的初始中间产物为HOC（CH₂）₇COH和CH₃（CH₂）₇COOH。（4）污水处理达标排放的单位成本为2.37元/m³。研究结果显示,远紫外光氧化处理高浓度餐饮废水较之传统方法效果明显,无二次污染,处理成本低且易于管理。更多还原

【Abstract】 Oily wastewater discharged from restaurant contains highly pollutants and characterized by high levels of animal and vegetable oils. Meanwhile,because of its fluctuation of quality and quantity, it is a kind of wastewater difficult to be treated and there is still not an efficient method for its treatment.In this paper, the far ultraviolet oxidation technology was applied for the treatment of wastewater from restaurant. Advanced oxidation processes of UV （185nm） oxidation was investigated for its pretreatment in wastewater, has the characters of UV direct break on oil molecule chain and generation of ozone to form UV/O₃ operational mechanism to degrade organic compounds. The main factors affecting the UV oxidation have been studied and optimal reaction conditions have also been confirmed; XRD and TEM were used for crystal phase identification and estimation of the anatase to rutile ratio and the crystallite size of each phase present and consequently choosed one most ideal titanium dioxide catalyst from other three ones applies to photocatalytic reaction and seeking optimal technics parameters; the intermediates of simulant oi（lmethyl oleate）degraded by UV oxidation were concluded by the results of GC/MS and traditional analysis method and the possible oxidation pathway was still poorly defined.; furthermore,an photocatalytic apparatus dealing with 10 tons wastewater per day was designed by employing a Tymoschuk mathematical model and economic analysis was completed simultaneously.The main results are as follows:（1）Optimal reaction conditions of UV oxidation are: 10min of UV radiation time、range of pH is 6.0 to 8.0. Under optimal experimental conditions,the removal efficiency of oils was between 80 and 88%, COD was between 48 and 62%, BOD5 was between 35 and 53% and the ammoniac nitrogen was about 18%. The removal efficiencies of COD and BOD5 increased with their concentration decrease and dissolved oxygen descend, oil has the highest removal efficiency when the range of its initial concentration from 2000 mg/L to 3500 mg/L and has a slight effect from dissolved oxygen. The removal efficiency of COD versus its concentration is first oder at an initial concentration of 3727.4mg/L, equation is V_COD = -d C_COD/dt=0.0451 C_COD（mg/L·min）. The concentration of ozone and hydroxyl radical in equipment and sample increased with prolonging irradiation time, steadying in 50 and 15min respectively. （2） The photocatalyst used for reaction is pure anatase crystal titanium dioxide and has the particle sizes of 18.5nm. when it exists in suspension, the optimal reaction conditions are: dosage of titanium dioxide is 150mg/L, pH has been dispensed with adjusting , flow rate of air is 40～60 litre per hour. Under these conditions average removal efficiency of COD and BOD₅ increased notably just achieved 64.02 and 42.79 %, but the removal efficiency of oil droped to 68～69 % for catalyst limited the penetration depth of UV-radiation.（3）The unsaturation of oil gradually declined with prolonging irradiation time,the average molecular weight of oil and fatty acid are also fallen,at the same time have a mass of peroxide and acid come into being;the initial intermediates of methyl oleate degradation are HOC（CH₂）₇COH and CH₃（CH₂）₇COOH.（4） The unit cost of wastewater attaind permission to discharge is 2.37 yuan per m3.The research indicated that far ultraviolet oxidation applied to high concentration wastewater from restaurant treatment characterized by notable effect, no secondary pollution, low cost and easy operation compared with conventional methods.更多还原