Fenton深度处理渗滤液时DOM结构变化

为了提高垃圾渗滤液中有机物在深度处理阶段的去除率,通过Fenton高级氧化技术,研究垃圾渗滤液SBR处理的出水在Fenton氧化过程前后溶解性有机物(DOM)结构和官能团变化规律,利用XAD-8/XAD-4树脂将水样中的溶解性有机物(DOM)分级为疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI),HPO-A和HPO-N为SBR出水DOM中主要组分(占到其DOC总含量的67%).经Fenton高级氧化后,DOM的总去除率为60.01%,其荧光光谱特性发生了明显变化,DOM五个组分的SUVA均呈上升趋势,说明氧化过程中5个组分的芳香性增强.在傅立叶红外光谱(FT-IR)分析中,HPO-A和TPI-A均显示了很强的羧酸基团吸收峰,而HPO-N和TPI-N的谱图十分相近,有较强的脂肪烃吸收峰.Fenton反应后,HPO-A和TPI-A中的O—H、—COOH的含量降低,而苯环、C—O和CO含量升高,还生成了1-酰胺.     

二级处理出水中有机物的分级特性

为研究二级出水中有机物的化学特性,以哈尔滨市W污水处理厂为研究对象,利用XAD树脂将二级处理出水中的有机物分级为5个组分:疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).采用氯化反应实验、可生物降解溶解性有机碳和尺寸分布测定,以及紫外和红外光谱分析考察二级处理出水中不同有机组分的特性.结果表明:HPO-A是加氯消毒时产生三卤甲烷的主要有机组分.各有机组分中,溶解性有机碳(DOC)(<0.025μm)均是主要的有机碳形式和主要的三卤甲烷前体物.各组分的可生化性为:HPI>TPI-A>HPO-A>TPI-N>HPO-N.各组分的芳香性为:HPO-N>HPO-A>TPI-N>TPI-A>HPI.HPO-N和TPI-N中碳氢化合物的含量较高.在二级处理出水中,HPO-A和HPI的含量相对较高,是主要的有机组分.此外,不同有机组分的化学特性不同.     

二级处理出水中DOM在粉煤灰改性SAT系统中的去除

为进一步改善土壤含水层处理(SAT)系统对城市污水处理厂二级处理出水中溶解性有机物(DOM)的去除效果,在传统SAT系统中以不同的混合比例及填充方式加入粉煤灰对其进行改性,并通过紫外254^nm处吸光度(UV²⁵⁴)、溶解性有机碳(DOC)、比紫外吸收值(SUVA)及三维荧光光谱(EEM)技术对二级处理出水中三卤甲烷(THMs)前体物在粉煤灰改性SAT系统中的去除情况进行探讨．粉煤灰改性SAT系统对二级处理出水中的UV254、DOC、SUVA及三卤甲烷生成势(THMFP)的去除效果优于传统SAT系统．粉煤灰添加量的增加能大幅度提高SAT的处理效果,但会影响土壤中微生物的活性,故有效结合粉煤灰的吸附性与土壤层的生物降解作用可提高SAT的处理效果．量化的荧光强度数据表明,粉煤灰改性SAT系统可有效去除二级处理出水中以络氨酸类芳香性蛋白质、腐殖酸及富里酸类物质为主的THMs前体物．     

复合吸附剂对二级出水中溶解性有机物的吸附特性研究

使用壳聚糖(CS)和粉末活性炭(PAC)复配制备了一种复合吸附剂(CS-PAC),用于对污水厂二级出水中溶解性有机物(DOM)的吸附,以UV₂₅₄作为DOM浓度的检测参数,研究复合吸附剂对DOM的吸附性能及其动力学特性．实验结果表明,DOM去除率随吸附质浓度的增加而升高,随复合吸附剂投加量的增大和接触时间的延长先增大后趋于稳定,吸附60 min基本达到平衡,DOM最高去除率达到74.17%．吸附动力学研究表明,吸附过程更加符合Freundlich模型,由多层吸附主导;复合吸附剂对DOM的吸附过程适合用二级动力学描述,主要吸附作用为化学吸附．     

MIEX树脂预处理改善超滤膜过滤性能的试验研究

为控制超滤膜污染,采用新型磁性离子交换树脂(MIEX)进行预处理,降低超滤系统运行的跨膜压差.结果表明:MIEX树脂投量的通水倍数为800BV,聚合氯化铝(PAC)投量仅为14mg/L时,反洗后跨膜压差可有效恢复.MIEX-混凝沉淀-超滤(工艺1)对UV254,CODMn,DOC,三卤甲烷生成势(THMFP)和卤乙酸生成势(HAAFP)的去除率分别为87.2%,74.4%,69.5%,88.2%和87.3%;混凝沉淀-超滤(工艺2)对UV254,CODMn,DOC,THMFP和HAAFP的去除率分别为20.5%,42.9%,27.9%,35.6%和33.6%.MIEX树脂预处理去除大部分疏水性和荷电亲水性有机物,对中性有机物也有一定去除,对相对分子量小于3ku的有机物去除率达61.3%.2种工艺出水平均浊度为0.07NTU.MIEX预处理减小了膜过滤时膜孔堵及滤饼层阻力,降低了过滤阶段的总阻力,有效地控制了膜污染.     

城市污水生化处理后水中溶解性有机物的特性研究

采用XAD树脂分离技术和超滤膜法对青岛市某城市污水处理厂生物化学处理后出水中溶解性有机物（DOM）进行了分类分离,研究了出水中DOM的亲疏水特性及分子量分布规律,探讨了各类DOM组分与芳香度之间的关系.研究结果表明,在DOM中,酸性物质（包括过渡亲水酸性物质和疏水酸性物质）所占比例最高,占总溶解性有机碳（DOC）的79.8%,疏水非酸性物质的芳香度最高,并依疏水酸性物质、过渡亲水酸性物质、亲水性物质的顺序递减,且羰基、羧基、羟基、脂类对芳环的取代程度表现为亲水性物质〈过渡亲水酸性物质〈疏水非酸性物质〈疏水酸性物质;该污水处理厂二级出水中的DOM以小分子量有机物（相对分子质量小于1kDa）为主,其占总DOC的59.13%,表明水中腐殖酸类等难降解有机物质含量较高,增加了消毒副产物的生成势.因此,若该种水体需要深度处理时,应重点考虑提高对腐殖酸类等难降解有机物质的处理程度,确保回用水水质的安全性.     

东江水源水有机物分子量分布及其处理工艺选择

首先采用超滤膜法考察了泄洪时期东江水源水中有机物分子量分布特点,进而考察了常规混凝沉淀、粉末活性炭(PAC)吸附-混凝沉淀、高锰酸钾(KMnO4)预氧化+PAC吸附-混凝沉淀等工艺对东江水中不同分子量有机物的去除效果.结果表明,泄洪时,东江水源水中溶解性有机物(DOM)分子量主要集中在3 000以上,其中3 000～10 000和>10 000的有机物分别占30.8%和43.2%;连续流动态试验结果表明:常规混凝沉淀工艺主要去除分子量>10 000的有机物.KMnO4与PAC联用能发挥二者的协同作用,能提高对各分子量区间的有机物去除效果.KMnO4预氧化+PAC吸附-混凝沉淀工艺(KMnO4投量1.0 mg/L、PAC投量60 mg/L)对溶解性有机碳(DOC)的去除率为84.0%,比常规混凝沉淀工艺提高了54.2%.KMnO4预氧化+PAC吸附工艺可作为东江沿岸水厂应对泄洪期水质恶化的一种有效应急处理工艺.     

响应曲面法优化磁性离子交换树脂吸附水中溶解性有机物工艺

基于磁性离子交换(MIEX)树脂单因素吸附水源水中溶解性有机物(DOM)实验结果,选取MIEX树脂投加量、溶液pH值、水中溶解性有机碳(DOC)浓度、吸附时间等4个参数为响应曲面实验因素,以Box-BehnkenDesign模型建立二次多项式回归方程,优化MIEX树脂吸附水中DOM的工艺。结果表明：MIEX树脂投加量越...     

载银活性炭/超滤组合技术去除溶解性有机物

为了强化水中溶解性有机物的去除效果,采用载银粉末活性炭与超滤( ultrafiltraction,UF)组合工艺处理微污染原水,研究了溶解性有机炭( dissolved organic carbon,DOC)和紫外吸光度( ultraviolet absorbance,UV254)的去除效果、三维荧光特性、影响因素以及膜污染控制的影响.研究结果表明：与常规粉末活性炭相比,载银活性炭对DOC和UV254的去除效果有较显著改善;在载银量0.10%、0.50%、1.00%和投炭量50、60、80、100 mg/L的条件下,随着活性炭载银量和投炭量的增加, DOC和UV254去除率呈现增加的趋势;单位质量的载银活性炭对UV254和DOC的去除率随投炭量的增加而下降,投炭量80 mg/L、载银量0.50%符合出水水质要求;载银粉末活性炭可以更有效地去除紫外区类腐殖质物质;吸附时间20 min时达到吸附平衡,活性炭在酸性条件下更有利于对有机物的吸附.载银活性炭对膜污染的控制较好,超滤膜经反洗后膜通量恢复较好,膜污染指数增长缓慢.     

二级出水残留有机物对PVDF超滤膜污染行为研究

为进一步识别二级处理水中残留有机物对聚偏氟乙烯（PVDF）超滤膜的优势污染物,采用DAX-8／XAD-4树脂将二级出水残留有机物分割成强疏水性、弱疏水性和亲水性组分,分别进行膜污染实验;使用原子力显微镜结合自制的PVDF膜材料探针和相应组分的污染物探针分别进行膜-污染物、污染物-污染物之间的黏附力测试,同时进行污染膜表面形貌分析．结果表明:使用微观作用力可有效预测膜污染行为;亲水性有机物与PVDF膜之间的作用力最大,弱疏水性有机物与PVDF膜之间的作用力最小;针对同一组分污染物,膜-污染物之间的作用力皆大于相应污染物-污染物之间的作用力,表明膜-污染物之间的作用力是控制PVDF超滤膜污染的关键因素,强疏水性组分之间的作用力是控制PVDF分离膜运行稳定期膜污染的关键因素;对二级处理水而言,减小亲水性组分与PVDF之间的作用力是控制PVDF超滤膜污染的重要手段．     

臭氧投加量对二级出水中污染物去除效果的影响

采用“混凝沉淀-臭氧(O3)-生物砂滤-活性炭(GAC)”组合工艺处理污水厂二级出水,考察了臭氧投加量对组合工艺处理效果的影响.结果表明,当臭氧投加量在1 ～5 mg/L时,组合工艺对NH4+-N、NO2--N、UV254和色度的平均去除率分别在70.61％、54.92％、20.63％和42％,其中当臭氧投加量为3 mg/L时,组合工艺对上述各项指标的去除效果最好,其NH4+_N、NO2--N、UV254和色度的去除率分别为99.41％、80.13％、28.06％和58.33％.“混凝沉淀-O3-生物砂滤-GAC”组合工艺深度二级出水能够有效去除水中的污染物质,提高深度处理出水水质,具有很好的应用前景.     

Performance of the Full-scale Loop Hybrid Reactor Treating Coal[KH-*1] Gasification Wastewater under Different Recirculation Modes

This paper aims to investigate the simultaneous removal efficiencies of both COD and nitrogen in a single reactor treating coal gasification wastewater (CGW). A novel loop hybrid reactor was developed and operated under different recirculation modes in order to achieve simultaneous removal of refractory compounds and total nitrogen (TN) in a full-scale CGW treatment plant. Mid-ditch recirculation was superior to other operational modes in terms of the NH₃-N and TN removal, resulting in a TN removal efficiency of 52.3%. Although the system achieved equal COD removal rates under different recirculation modes, hydrophobic acid (HPO-A) fraction of effluent dissolved organic matter (DOMef) in mid-ditch recirculation mode accounted for 35.7%, compared to the proportions of 59.2%, 45.3% and 39.4% for the other modes. The ultraviolet absorbance to dissolved organic carbon ratio test revealed that effluent under mid-ditch recirculation mode contained more non-aromatic hydrophilic components. Furthermore, appropriate recirculation and anoxic/oxic (A/O) partitions were also demonstrated to remove some refractory metabolites (phenols, alkanes, aniline, etc.), which reduced the chromaticity and improved the biodegradability.     

Performance of the Full-scale Loop Hybrid Reactor Treating Coal Gasification Wastewater under Different Recirculation Modes

This paper aims to investigate the simultaneous removal efficiencies of both COD and nitrogen in a single reactor treating coal gasification wastewater( CGW). A novel loop hybrid reactor was developed and operated under different recirculation modes in order to achieve simultaneous removal of refractory compounds and total nitrogen( TN) in a full-scale CGW treatment plant. Mid-ditch recirculation was superior to other operational modes in terms of the NH3-N and TN removal,resulting in a TN removal efficiency of 52. 3%.Although the system achieved equal COD removal rates under different recirculation modes,hydrophobic acid( HPO-A) fraction of effluent dissolved organic matter( DOMef) in mid-ditch recirculation mode accounted for35.7%,compared to the proportions of 59. 2%,45. 3% and 39. 4% for the other modes. The ultraviolet absorbance to dissolved organic carbon ratio test revealed that effluent under mid-ditch recirculation mode contained more non-aromatic hydrophilic components. Furthermore,appropriate recirculation and anoxic / oxic( A/O) partitions were also demonstrated to remove some refractory metabolites( phenols,alkanes,aniline,etc.),which reduced the chromaticity and improved the biodegradability.     

Characterization of NOM and THM formation potential in eutrophic reservoir water

Resin adsorption technique with XAD-8 and XAD-4 was used to characterize the raw water from Erlong reservoir in Jilin province of China. The NOM chemical composition sequences of four organic fractions in the raw water,from high to low,are fulvic acid (FA) fraction,hydrophilic non-acid (HPINA) fraction,hydrophilic acid (HPIA) fraction,and humic acid (HA) fraction. Experimental results show that FA is the main precursor of THMFP among the four organic fractions. However,HA or hydrophobic acid exhibits the highest chlorination activity in forming THMs. It is also found that the value of FI/DOC or SUVA and the specific THMFP have better positive correlation. It is implied that certain source water has unique nature of NOM and DBPs.     

Removal characteristics of disinfection by-products formation potential by bioaugmentation activated carbon process

The high-active bacteria were screened from 8 dominant bacteria obtained from the natural water body,and then the bioaugmentation activated carbon was formed by hydraulic immobilization of the high-active bacteria. Plant-scale studies on removal characteristics of disinfection by-products formation potentials (DBPFP) by bioaugmentation activated carbon process were conducted for micro-polluted raw water treatment. The results show that the bioaugmentation activated carbon process has adopted better purification efficiency to THMFP and HAAFP than traditional biological activated carbon process,and that average removal efficiencies of THMFP and HAAFP can reach 35% and 39.7% during the test period,increasing by more than 10% compared with traditional biological activated carbon process. The removal efficiencies of THMFP and HAAFP are stable because of the biodegradation of the high-active bacteria and the adsorption of active carbon. The biodegradability of CHCl3 formation potential is better as compared with that of CHCl2Br and CHClBr2 formation potentials among THMFP,and high removal efficiency of CHCl3formation potential is obtained by bioaugmentation degradation of the high-active bacteria. The biodegradability of HAAFP is better in comparison with that of THMFP,and the chemical properties of HAAFP are propitious to adsorption of activated carbon. Thus,HAAFP is on predominance during the competitive removal process with THMFP.