SO32-活化S2O82-降解偶氮染料废水的机制研究

为深度处理偶氮染料废水,以甲基橙（MO）为目标污染物,研究了亚硫酸盐活化过硫酸盐产活性物种的新型高级氧化处理方法,并对活化机制、氧化机理及动力学理论进行分析.通过对SO₃^2-/S₂O₈^2-,S₂O₈^2-,SO₃^2-3种体系进行降解对比和ESR等技术表征对比,发现亚硫酸盐能显著活化过硫酸根产生硫酸根自由基,其能氧化破坏MO偶氮双键形成的共轭体系,有较好的脱色降解效果.考察了亚硫酸盐和过硫酸盐摩尔比、过硫酸盐投加量、初始pH值对降解效果的影响,结果表明当初始pH值为3.0,摩尔比1：1,投加量为20.0mmol/L、反应时间在300min下对MO降解率能达到96.1%,进一步发现该体系对初始pH值的适应范围较广（3.0~11.0）.基于Box-behnken设计的响应面模拟和方差分析得到了可达显著水平的二次响应曲面模型,影响因子对MO降解的贡献排序为：过硫酸盐投加量 > 初始pH值 > 摩尔比.初始MO浓度动力学分析发现不同初始浓度下对MO的降解过程遵循准二级反应动力学规律,反应动力学常数从1.8212×10^-4~2.4649×10^-4min^-1.另一方面发现升高反应温度可以促进体系对MO的降解,根据不同温度下活化过程的反应速率常数的阿累尼乌斯准二级反应的活化能计算结果（E_a=44.9kJ/mol）,发现其相比常规金属活化方式较低,因此该体系对有毒有害的工业有机废水处理有潜在的商业应用价值.     

Nano-TiO2回收过程中SO42-对不同混凝剂混凝过程的影响

为了降低纳米TiO₂使用成本,采用不同混凝剂对纳米TiO₂悬浊液进行固液分离.通过考察浊度去除率、出水pH值的变化情况,并结合X射线光电子能谱（XPS）、傅里叶红外光谱（FTIR）、固体核磁（NMR）、扫描电镜（SEM）及能谱分析（EDS）表征,探究了纳米TiO₂回收过程中SO₄^2-对不同混凝剂混凝过程的影响.结果表明,当使用AlCl₃作混凝剂时（0.1mmol/L）,SO₄^2-浓度从0.0mmol/L增加到20.0mmol/L,浊度去除率降低了0.80%,絮体粒径从450μm下降到215 μm,而强度因子无明显变化.低聚合态的Al_a不与SO₄^2-结合,混凝过程中通过吸附架桥和网捕卷扫的作用形成大量无定形的Al （OH）₃.当使用Al₁₃作混凝剂时,再生长后絮体的粒径随着SO₄^2-浓度的增加而下降,S-O峰的红移证明有新的含S聚合物产生,Al 2p的峰均向较高的结合能移动证明生成的絮体不是Al （OH）₃.     

SO32-/HSO5-体系去除印染生化尾水溶解性有机污染物

印染废水常规生化处理尾水中仍残余一定浓度的溶解性有机污染物（DOM）和新标准严格管控的苯胺.采用亚硫酸钠活化过硫酸氢钾复合盐（SO₃^2-/HSO₅^-）产硫酸根自由基（SO₄^-·）高级氧化体系对尾水进行深度处理,并基于响应面法优化初始pH值、反应温度、SO₃^2-/HSO₅^-物质的量比和HSO₅^-投加量对COD和苯胺去除效果的单独及交互影响.结果表明该体系对苯胺具有非常显著的去除效果,同时对COD亦有一定的降解能力.影响因子对COD和苯胺降解效果贡献排序分别为：温度>n（SO₃^2-）/n（HSO₅^-）>n（HSO₅^-）>初始pH值和n（HSO₅^-）>n（SO₃^2-）/n（HSO₅^-）/初始pH值>温度.在实验优化后得到的最佳条件下（pH=6.8,温度为53℃,SO₃^2-/HSO₅^-物质的量比为1.6,HSO₅^-投加量为37.1mmol/L）反应10min,出水的COD和苯胺去除率分别达到33%和90%.进一步分析了印染生化尾水处理前后DOM的荧光和分子特性,三维荧光光谱（3DEEMs）发现芳香族蛋白质和溶解性微生物代谢产物是原尾水中DOM的主要组分,经不同氧化条件下出水中DOM的荧光强度明显降低且性质发生改变,荧光区域标准体积削减了42.03%~77.67%;同时观察到氧化出水中类色氨酸（Ex/Em=230~225nm/340~330nm）峰值发生了5~10nm的蓝移,推测尾水中稠环芳烃分解为小分子,共轭基团和芳香环数量减少;凝胶渗透色谱（GPC）结果表明DOM中大分子（0.45 μm~100kDa）物质比例为41%,中等分子（12~100kDa）物质的比例为48.9%,峰值分子量（Mp）为56.324kDa,Mw/Mn=2.168,处理后的出水Mp主要分布在12.28~17.56kDa范围内,小分子物质数量增多,结构和种类发生变化;气相色谱质谱（GC-MS）进一步揭示氧化出水中的烷烃类物质含量明显降低,主要副产物为一些酯类、醇类和脂肪酸物质,为后续进一步生化处理创造了条件.     

溴代甲烷在SO42-/TiO2上的光催化降解

采用溶胶-凝胶法制备了SO₄^2-/TiO₂催化剂,运用XRD、BET比表面测定,FTIR等技术对催化剂进行了表征,并在微型常压连续反应装置上进行CH₃Br光催化反应性能考察.结果表明,SO₄^2-引入TiO₂体系使得催化剂的结构和光催化性能得到显著改善.SO₄^2-负载量为9%,烧结温度为450℃时,SO₄^2-/TiO₂催化剂的光催化活性最高;SO₄^2-/TiO₂催化剂对反应物料中的水汽有很好的耐受性;当反应温度低于85℃时,提高反应温度,有利于改善对CH₃Br的光催化反应活性,表观活化能约为19.6kJ·mol^-1,反应温度在85℃～105℃区间时,CH3Br的光催化降解表观活化能为0.     

Reactions between the SO4·- radical and some common anions in atmospheric aqueous droplets

IntroductionThe conversion processes of some atmospheric pollutantsinside the aqueous droplets e .g. clouds , rains and fogspresent interesting topics to discuss . One typical example ofthis kind of pollutants was SO2. It can dissolve into thedroplets rea…     

HSO3-强化Fe3+/S2O82-降解水中双氯芬酸

采用HSO₃^-强化Fe³⁺/S₂O₈^2-降解水中双氯芬酸（DCF）,考察了溶液初始pH值,Fe³⁺、HSO₃^-和S₂O₈^2-用量,溶解氧对HSO₃^-/Fe³⁺/S₂O₈^2-体系降解DCF的影响;通过自由基淬灭实验,识别了体系中主要的活性物种;最后,探讨了DCF在该体系中的降解产物和转化路径.结果表明：HSO₃^-可以明显促进Fe³⁺/S₂O₈^2-对DCF的降解,初始pH 4.0时,DCF降解效果最佳.DCF的降解速率随Fe³⁺或S₂O₈^2-浓度的增大而增大;适量增加HSO₃^-浓度可提高DCF的降解,而过量的HSO₃^-对DCF降解有一定抑制作用.在通入氮气条件下,DCF去除率仅下降10.4%,无明显的抑制作用.自由基抑制实验表明,该体系含有SO₄^·-、HO^·和SO₅^·-3种活性自由基,其对DCF降解的贡献率分别为83.0%、12.8%和4.3%.在HSO₃^-/Fe³⁺/S₂O₈^2-降解DCF的反应中共检测出4种产物,据此提出DCF可能的转化路径为：羟基化、脱羧基、脱水和甲酰化反应.     

广州地区SO42-、NO3-、NH4+与相关气体污染特征研究

本文获得了2009年12月1日至2011年12月31日广州二次无机离子(SO2-4、NO-3、NH+4)及相关反应性气体(NOx/SO2/HNO2/HNO3等)的小时浓度数据,并分析了其污染特征.研究结果表明:PM2.5的浓度季节变化特征为冬秋春夏,SO2-4的浓度季节变化特征为秋冬春夏,NH+4的为冬秋春夏,NO-3则为冬春秋夏,SO2-4、NO-3和NH+4之和占PM2.5的比重大小为秋夏春冬;硫氧化率(SOR)均大于0.1,秋冬季节的值高于春夏季节,与SO2-4的浓度变化趋势一致;氮氧化率(NOR)日变化呈单峰形式,最大值出现在06时,最小值出现在14时,春冬季节的值高于夏秋季节,与NO-3的浓度变化趋势一致;广州地区NH3/NH+4除10—12月外,其月均值均大于1;在典型过程中,SO2-4、NO-3、NH+4、SOR、NOR和NH3/NH+4与能见度的变化都存在较好的对应关系,说明广州地区低能见度与二次离子(SO2-4、NO-3、NH+4)的生成有关.     

HRT对CO2-MBfR去除高SO42-废水中NO3--N的影响

针对含NO₃^--N与较高浓度SO₄^2-实际工业废水处理较难的问题,考察了不同水力停留时间（HRT）下连续运行的CO₂-氢基质膜生物膜反应器（CO₂-MBfR）处理模拟废水和实际工业废水的性能,结果表明,2种废水的出水NO₃^--N浓度均随着HRT的减小而增大,模拟废水中NO₃^--N的处理效果和电子通量分配比例均优于实际废水,但其电子通量分配的格局基本不变：NO₃^--N和SO₄^2-的电子通量分别在90.09%~97.49%和2.51%~9.91%左右.要实现实际废水总氮达到15mg/L的排放标准,需维持HRT不少于10.4h.     

COD/SO42-对青霉素菌渣厌氧消化影响

针对抗生素菌渣厌氧消化过程SO_4~(2-)的抑制问题,利用批试实验对不同COD/SO_4~(2-)比青霉素菌渣厌氧消化产气潜能以及产酸相物质利用特性进行了研究.结果表明,COD/SO_4~(2-)≥3时,微生物发生了适应性驯化,产气潜能在发酵10 d后逐渐恢复,累积产甲烷量(以TS计)超过208 m L·g-1,超过71%的COD转化为CH4;COD/SO_4~(2-)≤1.5时,产甲烷分别受到49%及完全抑制,有机物及SO_4~(2-)的去除率分别不足17%和5%,表明较高SO_4~(2-)负荷下产甲烷菌(MPB)及硫酸盐还原菌(SRB)同时发生抑制,COD平衡分析表明,转化为CH4的COD不足9.1%,而还原为SO_4~(2-)的COD保持在5.0%~9.0%,说明MPB比SRB对S2-的抑制更为敏感;S平衡分析表明,还原的SO_4~(2-)大部分以S2-的形式存在于发酵液中,少部分以H2S的形式存在于生物气中;产酸过程物质利用特性分析表明,溶解性蛋白质的甲烷化是在溶解性碳水化物甲烷化之后才开始.     

COD/SO42-值对硫酸盐还原率的影响

研究利用 UASB反应器考察了 COD和硫酸盐浓度的比值对硫酸盐还原的影响 ,同时分析了硫酸盐还原菌和产甲烷菌对COD的竞争情况 .发现在 HRT为 3.8h,SO₄^2- 负荷为 6～7kg·( m³· d)^-1,SO₄^2- 浓度为 1000mg·L^-1 条件下 :1在 COD不足时 ,SRB与 MPB在竞争中占微弱优势 ;对于产甲烷活性比较好的厌氧污泥要经过较长的时间 ,SRB才能确立优势菌种的地位 .2 COD/ SO₄^2- 比值决定了 SO₄^2- 的去除率 .比值等于2时 ,SO₄^2- 的还原率在 95%以上 ;当比值为 1.5时 ,SO₄^2- 还原率为 75% ;当比值为 1时 ,SO₄^2-的还原率为 60 % .     

亚硫酸盐/紫外体系的还原脱卤效能

水合电子(e-aq)是已知活性最强的还原物种之一.基于SO_3~(2-)受紫外光激发活化会释放e-aq的性质,提出了SO_3~(2-)/UV高级还原体系,用于降解稳定污染物.以7种卤乙酸为目标物,从卤素取代种类、卤代程度、实际水质本底影响等角度,考察了该体系对毒性卤代有机物(HOCs)的降解及脱卤效能,并探讨了相关机理.结果表明:HOCs的降解至少有直接光解和e-aq还原两条途径.卤素取代种类与卤化程度决定了HOCs的直接光解特性,其速率随氯、溴、碘取代顺序及卤化程度的增加而加快.SO_3~(2-)/UV体系显著提高了HOCs的降解及脱卤效率;对于直接光解慢的HOCs,其降解与脱卤主要由e-aq还原引起.SO_3~(2-)/UV体系在两种地表水质本底下仍具有较高的脱卤效能.     

Enhanced debromination of 4-bromophenol by the UV/sulfite process: Efficiency and mechanism

Halogenated aromatic compounds have attracted increasing concerns due to their toxicity and persistency in the environment, and dehalogenation is one of the promising treatment and detoxification methods. Herein, we systematically studied the debromination efficiency and mechanism of para-bromophenol(4-BP) by a recently developed UV/sulfite process. 4-BP underwent rapid degradation with the kinetics accelerated with the increasing sulfite concentration, pH(6.1–10) and temperature, whereas inhibited by dissolved oxygen and organic solvents. The apparent activation energy was estimated to be 27.8 kJ/mol. The degradation mechanism and pathways of 4-BP were explored by employing N_2O and nitrate as the electron scavengers and liquid chromatography/mass spectrometry to identify the intermediates. 4-BP degradation proceeded via at least two pathways including direct photolysis and hydrated electron-induced debromination. The contributions of both pathways were distinguished by quantifying the quantum yields of 4-BP via direct photolysis and hydrated electron production in the system. 4-BP could be readily completely debrominated with all the substituted Br released as Br-, and the degradation pathways were also proposed. This study would shed new light on the efficient dehalogenation of brominated aromatics by using the UV/sulfite process.     

Catalytic oxidation of calcium sulfite in solution/aqueous slurry

Forced oxidation of calcium sulfite aqueous slurry is a key step for the calcium-based flue gas desulfudzation(FGD) residue.Experiments were conducted in a semi-batch system and a continuous flow system on lab scales. The main reactor in semi-batch system is a 1000 ml volume flask. It has five necks for continuous feeding of gas and a batch of calcium sulfite solution/aqueous slurry. In continuous flow system, the main part is a jacketed Pyrex glass reactor in which gas and solution/aqueous slurry are fed continuously.Calcium sulfite oxidation is a series of complex free-radical reactions. According to experimental results and literature data, the reactions are influenced significantly by manganese as catalyst. At low concentration of manganese and calcium sulfite, the reaction rate is dependent on 1.5 order of sulfite concentration, 0.5 order of manganese concentration, and zero order of oxygen concentration in which the oxidation is controlled by chemical kinetics. With concentrations of calcium sulfite and manganese increasing, the reactions are independent gradually on the constituents in solution but are impacted by oxygen concentration. Manganese can accelerate the free-radical reactions, and then enhances the mass transfer of oxygen from gas to liquid. The critical concentration of calcium sulfite is 0.007 mol/L,manganese is 10^-4 mol/L, and oxygen is of 0.2-0.4 atm.     

Oxidation inhibition of sulfite in dual alkali FGD system

A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.     

均相/非均相体系中亚硫酸钙非催化氧化过程

将空气鼓入一个装有亚硫酸钙溶液 浆液且混合良好的鼓泡搅拌反应器中,反应器是有效容积为1000mL的五口烧瓶,空气连续鼓入反应器中实现亚硫酸钙的强制氧化.实验结果表明,对于亚硫酸钙的非催化氧化过程,均相体系与非均相体系之间既紧密联系,又具有不同的反应特征.均相体系中仅存在气 液传质和氧化反应过程,而非均相体系远比均相体系复杂,同时存在溶解 氧化 结晶过程,该过程对非均相体系的氧化过程产生巨大影响.以上2种体系的主要差别表现为氧化速率相差2个数量级,非均相体系更有利于氧化过程的进行.     

Effect of inhibitors on macroscopical oxidation kinetics of calcium sulfite

In the presence of inhibitors, the macroscopical oxidation kinetics of calcium sulfite, the main byproduct in wet limestone scrubbing, was studied for the first time by adding different inhibitors and varying pH, concentration of calcium sulfite, oxygen partial pressure, concentration of inhibitors and temperature. The mathematical model about the general oxidation reaction was established,which was controlled by three steps involving dissolution of calcium sulfite, mass transfer of oxygen and chemical reaction in the solution.It was concluded that the general reaction was controlled by mass transfer of oxygen under uncatalyzed conditions, while it was controlled by dissolution of calcium sulfite after adding three kinds of inhibitors. Thus, the theory was provided for investigating the mechanism and oxidation kinetics of sulfite. The beneficial references were also supplied for design of oxidation technics in the wet limestone scrubbing.     

紫外/亚硫酸钠还原降解三氯乙酰胺的效能

卤乙酰胺(HAc Ams)是一类具有高细胞毒性和高遗传毒性的饮用水含氮消毒副产物(N-DBPs),并在饮用水中被广泛检出,其中三氯乙酰胺(TCAc Am)的毒性显著高于传统DBPs.本实验以配置的TCAc Am溶液作为目标污染物,采用紫外(UV)活化亚硫酸钠(Na_2SO_3)体系降解水中的TCAc Am,并探究在该体系下光强、还原剂投加剂量(Na_2SO_3)和p H对还原降解TCAc Am效果的影响.结果表明,采用UV/Na_2SO_3体系可快速降解TCAc Am,其降解效果与光强、Na_2SO_3投加剂量和p H均呈正相关,且p H值对反应速率与降解率有显著影响,当p H值从6提高至9,TCAc Am的降解率在反应120 min时从12. 8%提高至99. 6%.在光强为450μW·cm~(-2),p H为9,Na_2SO_3投加剂量为1. 00 mmol·L~(-1),连续30 min光照条件下,TCAc Am降解率达到99. 4%.实验证明UV/Na_2SO_3体系是一种有效消减TCAc Am的高级还原技术,并且具备还原降解其他卤代DBPs的潜力,可用于饮用水中卤代DBPs的降解.     

氨法脱硫工艺S(IV)氧化动力学模型研究

目前,有关氨法脱硫技术对S(IV)氧化的研究未考虑HSO-3及离子强度等因素的影响.因此,本文根据氨法脱硫反应机理建立实验装置对S(IV)氧化动力学进行了研究,考察了SO2-3浓度、SO2-4浓度、pH值、温度和氧化空气量对S(IV)氧化速率的影响.结果表明,S(IV)的氧化速率与SO2-3浓度呈-0.5级关系,与SO2-4浓度之间的关系为r(IV)=0.00121exp(-0.89CSO2-4);HSO-3较SO2-3更容易被氧化,保持较低pH值时对S(IV)的氧化有利;S(IV)的氧化速率随氧化空气量和温度的升高而增大,反应的表观活化能约为28.0 kJ·mol-1.利用数学模型对S(IV)氧化过程进行了数值模拟,结果表明,该模型能够较好地反映氨法脱硫S(IV)氧化过程.     

水源水中有机物特性及其氯化活性研究

以西南某市一个地表水为水源水的M水厂为研究对象，对其原水中有机物进行富集，有机物按照操作定义分为6个部分，分别为：亲水性有机酸、亲水性有机碱、亲水中性物质、疏水性有机酸、疏水性有机碱和疏水性物质，通过富集、确定了原水中6种有机物的组成分布，研究各种有机物的消毒副产物形成潜力以及替代剂（氯胺、二氧化氯）对卤乙酸形成的影响，提出了控制消毒副产物的主要对策，研究结果表明：1）M水厂水源水属于腐殖质含量的天然水体，受污染较小；2）原水溶解性有机物中疏水性有机酸是卤乙酸的主要前体物；3）用氯胺和二氧化氯代替传统的消毒剂作为替代消毒剂，可大大降低THMs和HAAs的生成量。     

Prenatal diagnosis of molybdenum cofactor deficiency and isolated sulfite oxidase deficiency

Molybdenum cofactor deficiency and isolated sulfite oxidase deficiency are autosomal recessive inborn errors of metabolism with severe neurological symptoms resulting from a lack of sulfite oxidase activity. The deficiencies can be diagnosed prenatally by monitoring sulfite oxidase activity in chorionic villus sampling (CVS) tissue. In those families in which the specific defects have been identified, diagnosis can be achieved by mutation analysis or linkage studies directed at affected genes. These include MOCS1, MOCS2 or GEPH, in cases of molybdenum cofactor deficiency, or SUOX in patients with isolated sulfite oxidase deficiency. Copyright © 2002 John Wiley & Sons, Ltd.