响应曲面法优化均相Fenton深度处理皮革废水

均相Fenton深度处理皮革废水,试验用水为A/O反应池的出水,COD介于180～200mg·L-1.基于Box-Behnken响应曲面法,考察了初始pH值、H2O2/Fe2+摩尔比、过氧化氢投加量、反应时间的单独作用及交互作用,并建立COD去除率数学模型,结果表明:影响因子显著性顺序为:pH>H2O2投加量>反应时间>H2O2/Fe2+摩尔比,初始pH值与H2O2投加量的交互作用显著;数学模型回归性较好,预测最大COD去除率为55.87%,最佳条件组合为:pH=4.0,H2O2投加量=14.00mmol·L-1,H2O2:Fe2+=10.6:1,Time=3h及T=25℃,验证试验结果为53.35%,与预测值相比偏差为4.51%.采用均相Fenton深度处理皮革废水,可以满足《污水综合排放标准》(GB8978—1996)一级标准中对COD≤100mg.L-1的限制要求.     

Optimizing aerobic biodegradation of dichloromethane using response surface methodology

Response surface methodology (RSM) was employed to evaluate the optimum aerobic biodegradation of dichloromethane (DCM) in pure culture. The parameters investigated include the initial DCM concentration, glucose as an inducer and hydrogen peroxide as terminal electron acceptor (TEA). Maximum aerobic biodegradation efficiency was predicted to occur when the initial DCM concentration was 380 mg/L, glucose 13.72 mg/L, and H2O2 115 mg/L. Under these conditions the aerobic biodegradation rate reached up to 93.18%, which was significantly higher than that obtained under original conditions. Without addition of glucose, degradation efficiencies were 6 80% at DCM concentrations < 326 mg/L. When concentrations of DCM were more than 480 mg/L, the addition of hydrogen peroxide did not help to significantly increase DCM degradation efficiency. When DCM concentrations increased from 240 to 480 mg/L, the overall DCM degradation efficiency decreased from 91% to 60% in the presence of H2O2 for 120 mg/L.     

微藻固定化条件优化及其污水氨氮去除潜力分析

微藻污水处理被视为新概念引领下极具潜力的一项绿色技术,然而,微藻分离与采收一直是限制其大规模应用的瓶颈.本研究立足于固定化技术,以斜生栅藻(Scenedesmus obliquus)为研究对象,采用响应曲面法(RSM)耦合Box-Behnken设计,以固定剂浓度、交联剂浓度和交联时间为自变量,以藻球的机械强度、传质速率和生长速率为响应值,对固定化的过程参数进行优化,制备性能最优的固定化藻球;并探索和分析藻球对氨氮(NH4+-N)去除的最佳条件及其潜力.结果表明,固定剂浓度、交联剂浓度和交联时间分别为5%、2%和16 h为制备固定化藻球的最优条件,且包埋密度为1×106cells·m L~(-1),有机物(COD)浓度为300 mg·L~(-1)时,藻球混合培养去除NH4+-N的能力最强;此外,固定藻对高浓度NH4+-N的去除潜力显著优于自由藻,当初始浓度约为50和70 mg·L~(-1)时,固定藻混合培养5 d后NH4+-N去除率分别为(96. 6±0. 1)%和(65. 2±4. 5)%,而初始浓度约为30 mg·L~(-1)时,自由藻优势明显,3 d后NH4+-N去除率高达(97. 8±0. 6)%;但异养条件下固定藻对NH4+-N的去除率整体偏低且随浓度增加而降低,当初始浓度约为30 mg·L~(-1)时,去除率仅为(49. 0±3. 1)%.本研究为污水可持续处理提供了新思路,为资源回收提供了新途径,更为该技术推广应用奠定了较好的理论基础.     

乳化液膜法处理石油石化废水的研究

炼厂酸性汽提净化水中酚含量高，限制了汽提净化水回用效率，需进行脱酚处理。本研究采用煤油、span-80、液体石蜡、磷酸三丁酯和NaOH构建乳化液膜，探究其对酸性水汽提净化水的脱酚效率。运用以响应曲面法（RSM）为依据的Box-Behnken设计，以span-80投加量、液体石蜡投加量、油相/内相比和制乳转速为影响因素，建立了汽提净化水中苯酚去除率的二次回归预测模型，并优化了处理条件。结果表明，液体石蜡投加量对苯酚去除率的影响最为显著，其次是span-80投加量。通过RSM分析得到汽提净化水脱酚的最佳实验条件为：span-80投加量2wt%，液体石蜡投加量15%v/v，油内比为1:1，制乳转速取6000r/min，此时苯酚去除率为98.65%。反应后的液膜易于破乳，破乳率达98.33%，且回收油相可循环利用，从而大大节约成本实现资源化。