表面处理行业废水治理及中水回用工程实践

针对电镀等表面处理行业废水的水质特征,以浙江台州某表面处理有限公司为例,介绍了高压脉冲电凝机处理电镀综合废水与膜法反渗透中水回用工艺,经过近年的运行及实践证明,该工艺先进可行,效果好,不仅确保出水达标,而且75%中水回用,操作性强,工程投资和运行费用较低,无二次污染,是一种较实用的治理电镀综合废水与中水回用新技术。     

基于非分散红外技术的煤矿井下有害气体定量探测方法研究

煤矿井下有害气体的浓度监测对煤矿生产安全预警至关重要。介绍了一种基于非分散红外光谱技术能够同时定量探测煤矿井下一氧化碳、甲烷等有害气体的方法。入射红外光经过高速旋转的滤光轮,得到各种待测气体相应滤波通道的调制光信号,经怀特池中待测气体吸收后得到各种气体的吸光度。通过非线性最小二乘拟合吸收光与被测气体浓度,得到测量系统的浓度定标曲线,一氧化碳、甲烷和二氧化碳三者定标拟合相关系数分别为0.9992、0.9996和0.9998。分析了系统的测量精度,通过比较样气标准浓度与实测浓度大小,发现所有被测气体的这两组数据的相关性均大于0.998,测量误差均小于5%。实验结果表明,采用非分散红外光谱技术可以实现煤矿井下多组分有害气体的同步精确探测,为扩展煤矿安全预警技术手段提供了参考。     

xDLVO理论解析微滤膜海藻酸钠污染中pH值影响机制

用extended Derjaguin-Laudau-Verwey-Overbeek(xDLVO)理论定量解析不同pH值下海藻酸钠微滤膜污染过程中的界面相互作用,评价范德华力(LW)、双电层作用力(EL)、极性力(AB)对海藻酸钠微滤膜污染的相对贡献.结果表明,在pH5~9范围内,AB相互作用能起着关键作用,决定了总界面相互作用能的性质与强度.不同pH值下海藻酸钠微滤膜污染趋势(K)为pH 5 > pH 7 > pH 8 > pH 9. 由于与海藻酸钠之间的界面作用为引力,疏水性膜在过滤初期膜污染更为严重;污染后期亲、疏水性膜污染行为差异不明显,因为此时海藻酸钠之间的排斥性界面作用为主导.初始、后期阶段K值分别与膜-海藻酸钠界面自由能、海藻酸钠-海藻酸钠界面自由能有较强的线性相关性,说明xDLVO理论可以有效预测不同pH值下海藻酸钠微滤膜污染行为.     

牛粪堆肥过程中水溶性有机物演化的光谱学研究

采用紫外-可见吸收光谱、1H-核磁共振(NMR)和同步荧光光谱,研究了牛粪堆肥水溶性有机物(DOM)的结构特征及其演化规律.紫外-可见吸收光谱分析显示,SUVA254由堆肥起始的1.161上升至堆肥结束的2.543;E465/E665在整个堆肥过程中呈现上升趋势,变化范围在2.333~3.500;260~280,460~480,600~700nm范围内的面积积分A1、A2和A3均呈现出先增大后减小的趋势,峰值分别出现在26,14, 14d.1H-NMR分析显示,堆肥0d到堆肥41d,0.5~3.1δ面积积分所占比例从43.06%下降至8.63%,3.1~5.5δ从56.07%上升至89.68%,5.5~10δ不足总体的6%且变化趋势不明显.同步荧光光谱结果显示,经过41d 的堆肥,蛋白质类物质区积分面积比例(APLR)由0.331下降到0.252,而富里酸类物质区积分面积比例(AFLR)由0.325增加到0.336,同时胡敏酸类物质区积分面积比例(AHLR)由0.344增加到0.412;AFLR/APLR比与同步荧光光谱3个荧光峰峰高存在显著相关性,AHLR/AFLR与两个荧光峰光强的比值I351/I284和I382/I351存在显著相关性.上述结果表明,随着堆肥进行, DOM中的非腐殖质物质转化为类腐殖质,同时其芳香性结构增多,碳链结构发生氧化反应,分子量从小变大,堆肥腐殖化程度加大,稳定度增加.     

洱海沉积物不同分子量溶解性有机氮空间分布及光谱特征

利用超滤技术对洱海沉积物溶解性有机氮(DON)进行分子量分级,探究了DON各组分空间分布特征,并运用紫外-可见吸收光谱和三维荧光光谱对其结构进行了表征.结果表明,洱海沉积物总DON含量ω(DON)为23.46—61.40 mg·kg-1,平均值为37.19 mg·kg-1,空间分布总体呈现南部>北部>中部的趋势;分子量大于1K Da的大分子组分ω(>1KDa)占ω(DON)的比例为79.1%—93.0%,即洱海沉积物DON是以大分子为主.沉积物DON各组分的芳香性及腐殖化程度较高,芳香环取代基中活性官能团种类较多,且南部芳香性及腐殖化程度最高,北部芳香环取代基种类最多;大分子组分DON含有类富里酸荧光物质,其来源于陆源输入和微生物降解共同作用.由此可见,洱海沉积物DON主要由大分子物质组成,其腐殖化程度较高且含类富里酸荧光物质,而此类DON对藻类的生物有效性较低,这可能是洱海沉积物氮含量较高而上覆水氮浓度较低的原因之一,即沉积物DON分子组成及其结构特征可在一定程度上作为湖泊营养水平的衡量指标.     

膜吸收法脱除电厂模拟烟气中的CO2

以氨基乙酸钾、一乙醇胺和甲基二乙醇胺水溶液为吸收液,研究了聚丙烯膜接触器分离模拟烟气中CO₂的技术.分析了气液流速、吸收剂浓度、烟气CO₂浓度和吸收液CO₂负荷等对传质速率和脱除率的影响.结果表明:1mol·L^-1MEA在流速0.1m·s^-1,烟气流速0.211m·s^-1时,CO₂传质速率高达7.1mol·(m²·s)^-1;1mol·L^-1氨基乙酸钾在流速0.05m·s^-1,烟气流速0.211m·s^-1时,脱除率为93.2%;4mol·L^-1氨基乙酸钾在同样条件下脱除率达98%;而且在试验的较广烟气CO₂浓度范围内,氨基乙酸钾CO₂脱除率保持在90%以上.试验证明膜吸收法既适合目前最为普遍的PF和NGCC烟道气脱除CO₂,也是一种应用广泛、有良好发展前景的CO₂分离法.     

陶瓷膜处理废乳化液的实验

考察了在不同温度、不同浓缩倍数条件下陶瓷膜对废乳化液的处理效果及渗滤液通量变化情况。结果表明:温度为30℃时,CODCr和矿物油的截留率均达90%以上。此外还确定了膜的清洗方法,为实际应用提供基础数据。     

Effect of chemical dose on phosphorus removal and membrane fouling control in a UCT-MBR

Phosphorus removal was enhanced effectively by dosing aluminum sulfate and effluent phosphorus concentration was lower than 0.5 mg/L. Sludge activity was not inhibited but improved slightly with addition of aluminum sulfate. EPS concentrations both in mixed liquid and on membrane surface were decreased, contributing to the effective mitigation of membrane fouling. To enhance phosphorus removal and make the effluent meet the strict discharge level of total phosphorus (TP, 0.5 mg/L), flocculant dosing is frequently applied. In this study, the performance of aluminum sulfate dosing in a University of Cape Town Membrane Bioreactor (UCT-MBR) was investigated, in terms of the nutrients removal performance, sludge characteristics and membrane fouling. The results indicated that the addition of aluminum sulfate into the aerobic reactor continuously had significantly enhanced phosphorus removal. Moreover, COD, NH₄⁺-N and TN removal were not affected and effluent all met the first level A criteria of GB18918-2002. In addition, the addition of aluminum sulfate had improved the sludge activity slightly and reduced trans-membrane pressure (TMP) increase rate from 1.13 KPa/d to 0.57 KPa/d effectively. The membrane fouling was alleviated attributed to the increased average particle sizes and the decreased accumulation of the small sludge particles on membrane surface. Furthermore, the decline of extracellular polymeric substance (EPS) concentration in mixed sludge liquid decreased its accumulation on membrane surface, resulting in the mitigation of membrane fouling directly.     

Experimental and computational assessment of 1,4-Dioxane degradation in a photo-Fenton reactive ceramic membrane filtration process

• 1,4-Dioxane was degraded via the photo-Fenton reactive membrane filtration. • Degradation efficiency and AQY were both enhanced in photocatalytic membrane. • There is a tradeoff between photocatalytic degradation and membrane permeation flux. • Degradation pathways of 1,4-Dioxane is revealed by DFT analysis. The present study evaluated a photo-Fenton reactive membrane that achieved enhanced 1,4-Dioxane removal performance. As a common organic solvent and stabilizer, 1,4-Dioxane is widely used in a variety of industrial products and poses negative environmental and health impacts. The membrane was prepared by covalently coating photocatalyst of goethite (α-FeOOH) on a ceramic porous membrane as we reported previously. The effects of UV irradiation, H₂O₂ and catalyst on the removal efficiency of 1,4-Dioxane in batch reactors were first evaluated for optimized reaction conditions, followed by a systematical investigation of 1,4-Dioxane removal in the photo-Fenton membrane filtration mode. Under optimized conditions, the 1,4-Dioxane removal rate reached up to 16% with combination of 2 mmol/L H₂O₂ and UV₃₆₅ irradiation (2000 µW/cm²) when the feed water was filtered by the photo-Fenton reactive membrane at a hydraulic retention time of 6 min. The removal efficiency and apparent quantum yield (AQY) were both enhanced in the filtration compared to the batch mode of the same photo-Fenton reaction. Moreover, the proposed degradation pathways were analyzed by density functional theory (DFT) calculations, which provided a new insight into the degradation mechanisms of 1,4-Dioxane in photo-Fenton reactions on the functionalized ceramic membrane.     

老龄垃圾渗滤液中溶解性有机物在SAARB和MBR处理过程的转化特征

生物法是常用的垃圾渗滤液处理工艺,然而垃圾渗滤液中有机物组成极为复杂,在生物处理过程有机物被完全去除、新产生、减少、保留和增加的5种情形不明.本文采用了超高分辨质谱电喷雾电离傅立叶变换离子回旋共振质谱从分子层面研究老龄垃圾渗滤液中溶解性有机物（DOM）分别在矿化垃圾床（SAARB）和膜生物反应器（MBR）处理过程的转化特征.结果表明,老龄垃圾渗滤液含有5000多个DOM分子式,主要由CHO、CHON、CHOS和CHONS类物质组成,分子组成十分复杂.经过SAARB和MBR处理后,出水中DOM数量分别小幅降低至4909和4864种,SAARB和MBR作为生物法对老龄垃圾渗滤液中有机物分子去除特性相似,被完全去除和减少的物质组成主要为生物可利用性较高的脂肪族类物质（H/C ≥ 1.5）、高度不饱和物质和酚类物质（0.50 ≥ AI,H/C<1.5）,这部分DOM表现出还原饱和的化学特性.新产生、保留和增加的部分物质主要是传统意义上指代的难降解有机物,其主要是高度不饱和物质和酚类物质（0.50 ≥ AI,H/C<1.5）以及芳香指数更高的多酚类物质（0.66 ≥ AI>0.50）,表现为氧化不饱和和还原不饱和的化学特性.本文揭示了老龄垃圾渗滤液在生物处理过程中DOM分子层面的转化特征,为老龄垃圾渗滤液在生物法高效处理提供理论参考.