垃圾渗滤液厌氧降解中溶解性有机物的光谱特性

为探讨渗滤液厌氧降解出水中有机物的构成特点和变化规律,采用XAD-8和XAD-4树脂将溶解性有机物(DOM)依亲疏水性和酸碱性特征分为5种组分,对不同水力停留时间(HRT)下厌氧序批式反应器(ASBR)出水中各组分的含量和特性进行了比较研究.结果表明:ASBR处理渗滤液中溶解性有机碳(DOC)去除率可达53.0%～94.7%;芳香类物质多存在于疏水性组分中,厌氧处理后各组分UV254明显下降,芳香类、羧酸和氨基化合物去除明显;随着HRT的延长,富里酸类荧光物质易在出水中累积而造成累计荧光强度Фi,n增大,而芳香性蛋白及溶解性微生物副产物较之更易降解.可见ASBR能有效降解渗滤液DOM各组分物质.     

生化-物化法处理渗滤液溶解性有机物光谱特征

为了研究垃圾渗滤液中溶解性有机物(DOM)在生化-物化组合工艺处理过程中的降解特性,采用XAD-8和XAD-4树脂将DOM分成五种组分,并结合紫外和荧光光谱对DOM及其组分降解变化进行探讨.研究表明,组合工艺能有效降低渗滤液中DOM,溶解性有机碳(DOC)去除率达99.64％,其各组分去除率在99.48％～99.73％...     

常规/臭氧生物活性炭去除有机物及亚硝胺前体物特性

该文考察运行18个月的常规/臭氧-生物活性炭(O3-BAC)组合工艺对中国华东地区某微污染湖泊水的处理特性。结果表明:此时该工艺去除有机物能力有限,但对消毒副产物亚硝胺前体物的去除能力高于其他有机物。工艺出水溶解性有机碳(DOC)质量浓度、UV254和溶解性有机氮(DON)质量浓度的平均值分别为3.12mg/L、0.053cm-1和0.171mg/L,平均去除率分别为34.9%、53.9%和32.7%;对亚硝胺前体物的去除率为72.3%。臭氧和炭池中的微生物在去除亚硝胺前体物中发挥了重要作用。小分子有机物、芳香性蛋白质和微生物代谢产物主要在活性炭单元中去除。因而,要关注长期运行的常规/O3-BAC组合工艺对有机物及其亚硝胺前体物的去除,充分发挥微生物作用。     

潜流人工湿地对污水厂尾水中有机物去除效果

采用凝胶过滤色谱(GFC)和三维荧光光谱(EEM)分析技术,研究了两种基质水平潜流人工湿地对城镇污水处理厂尾水中有机物的去除特征.结果表明:尾水经过人工湿地系统处理后,水中溶解性有机物(DOM)重均分子质量Mw均有明显降低;进水中表征出四类溶解性有机物,即色氨酸类芳香族蛋白质、溶解性微生物代谢产物、可见类富里酸、紫外类富里酸物质,经过人工湿地净化处理后相对荧光强度均有不同程度的降低;人工湿地对化学性质较为稳定、难以分解、不易被生物利用的类腐殖质有较好的去除效果.陶粒基质湿地水平潜流人工湿地对有机污染物向低碳小分子转化更为彻底,对污水处理厂尾水中有机污染物的去除效果更好.     

基于曝气生物滤池工艺处理老龄垃圾渗滤液

分别在小试和工业化规模上系统研究了基于曝气生物滤池(BAF)的工艺对老龄垃圾渗滤液的处理效果.在实验室中,对比传统生化处理工艺,BAF单元对COD的去除率提高了20%.将基于BAF的组合工艺(厌氧+BAF+膜生物反应器MBR+反渗透RO)应用于深圳某填埋场渗滤液处理,取得了较好的处理效果.BAF单元对COD、氨氮的去除率分别达到31%和94.2%.生物处理单元(包括BAF和MBR)对铜、锌的去除率达到70%以上,而对镍、铬、铅的去除率小于50%.RO膜对重金属的去除率均高于生物处理单元.该组合工艺既保证了生物降解的持续进行,又保证了RO膜的稳定运行.利用GC-MS对生物处理单元有机污染物成分进行了分析,并对其降解机理进行了初步探讨.     

净化南方水库源水的混凝-超滤组合工艺

针对南方微污染水源水质特点,以混凝-超滤组合工艺为对象,进行实验室序批式试验,研究其对污染物的去除效果及运行清洗方法。结果表明:工艺出水浊度小于0.02 NTU,对高锰酸盐指数(CODMn)、溶解性有机碳(DOC)和254 nm紫外吸光度(UV254)的平均去除率为38%,对溶解性有机质(DOM)荧光类物质去除效果优于常规工艺。其中,组合工艺对相对分子质量为1 000~2 000的有机物去除率大于48%,对相对分子质量为500~1 000的有机物去除率约10%。组合工艺对氨氮(NH3-N)、硝酸盐氮(NO3--N)、总磷(TP)的去除率为19%~29%。混凝可以提高超滤膜的运行效率。使用碱洗-酸洗或碱洗-EDTA清洗2种复合清洗方法可以达到更好的清洗效果。     

藻源型有机物氯化消毒副产物的生成特性

通过亲水、疏水组分分离和电渗析获得6种不同特性的铜绿微囊藻细胞胞内外富氮有机组分,其中溶解性有机氮(DON)的质量浓度范围为0.57~1.69 mg/L;三维荧光光谱图表明,疏水性有机物主要由类腐殖质物质组成,亲水性有机物主要由蛋白质组成.经过3天氯化培养实验,分析比较各有机物组分含碳(氮)消毒副产物的生成特性.结果表明,细胞内外强疏水性有机物组分的三卤甲烷生成潜能最大,以生成三氯甲烷为主;卤代酮生成潜能与细胞内外各有机物组分有明显相关性;细胞内亲水性有机物组分的含氮消毒副产物生成潜能(DBPFP)最大;各组分消毒副产物生成潜能并不完全由溶解性有机碳(DOC)与溶解性有机氮的质量浓度比值的大小决定,还由DON的性质决定;细胞外有机物组分的DBPFP高低与芳香性有机物的含量呈正相关,细胞内有机物组分的DBPFP还受芳香性有机物性质的影响;细胞外有机物组分消毒副产物生成总量的顺序为:强疏水性组分亲水性组分弱疏水性组分;细胞内有机物组分消毒副产物生成总量的顺序为:亲水性组分强疏水性组分弱疏水性组分.     

UBF-BAF固定化微生物系统处理中老龄垃圾渗滤液的研究

采用新型复合工艺UBF-BAF固定化微生物系统处理中老龄垃圾渗滤液.实验表明,在渗滤液进水CODCr和NH4 -N浓度范围分别为6000-14500mg/L和880-1500mg/L的条件下,出水CODCr浓度低于400mm/L,NH4 -N浓度低于10mg/L;CODCr、NH4 -N和TIN平均去除率分别达到93.8%、97.3%和84.1%左右.系统最佳水力停留时间为84h.系统中高游离氨浓度没有对污染物去除效率造成影响.采用GC/MS对低分子量有机污染物成分进行分析,结果表明出水中有机污染物种类明显减少,大部分有机物得到了有效去除.另一方面系统中生物量大,生物种类丰富,含有短杆菌、长杆菌和球菌等.该系统在渗滤液没有经过预处理、污染物浓度变化很大的情况下,能实现高污染物去除率,证明其处理垃圾渗滤液是可行的.     

生物炭在矿区农田土壤中与镉的纵向共迁移行为

以广东韶关大宝山矿山废水污染的农田为研究对象,利用超纯水和甲苯/甲醇提取的溶解性有机质(DOM)的三维荧光光谱平行因子分析(EEM-PARAFAC)技术,追踪荔枝树枝生物炭1年内在土壤层0~100 cm深度范围的迁移行为及其协同重金属镉(Cd)的纵向迁移性质. 结果表明:生物炭增加了0~60 cm深土壤层溶解性有机碳(DOC)的质量分数,增加了表层土壤的pH,对深层土壤pH无明显影响;EEM-PARAFAC解析得到3个DOM组分(1个类蛋白和2个类腐殖质组分),生物炭的添加增大了0~60 cm深土壤层类腐殖质的质量分数;并且甲苯/甲醇提取的DOM在0~60 cm深土壤层中均检测出生物炭特有的多环芳烃结构,说明生物炭在1年内发生了明显的纵向迁移;生物炭能够有效降低0~20 cm深土壤中有效态Cd的质量分数,但20~60 cm深土层中有效态Cd与对照组的相比最高增加了148%左右. 研究表明:需要特别关注生物炭协同重金属在土壤中纵向迁移行为所带来的环境影响.     

微电解/混凝/厌氧膜生物反应器组合工艺处理高浓度垃圾渗滤液

针对垃圾渗滤液COD、NH3-N浓度高,可生化性差等特点,本文采用了微电解法和混凝法预处理,厌氧膜生物反应器组合工艺,研究不同工艺处理条件下,该工艺对垃圾渗滤液中COD及NH3-N的去除特性.实验结果表明:采用微电解/混凝/厌氧膜生物反应器组合工艺处理垃圾渗滤液,特别是高浓度的垃圾渗滤液具有很好的效果.当原水COD高达9 160 mg/L,NH3-N高达3 000 mg/L,经该工艺处理后COD低于60 mg/L,NH3-N低于15 mg/L,均可满足国家一级排放标准.     

渗滤液生化出水DOM在深度混凝过程中的去除特征

采用3种高新絮凝剂, 对采集自垃圾填埋场渗滤液处理工艺生化单元出水的样品进行3个阶段的深度混凝处理。采用紫外–可见光谱(UV-Vis)、三维荧光光谱(EEM)和电喷雾傅里叶变换离子回旋共振质谱(ESI FT-ICR MS)对3个阶段的样品中溶解有机物(DOM)进行表征, 以此来探究DOM在混凝过程中的去除转化特征。UV-Vis光谱分析结果表明, 经过混凝处理, 水中小分子物质的比例增大, 腐殖化程度降低, 缩合度降低。EEM分析结果表明, 经过混凝处理后, 类蛋白质和类腐殖酸物质的去除效果十分显著。FT-ICR MS分析结果表明, 在不同的混凝阶段, 絮凝剂去除的DOM有较强的选择性。最终出水残留的DOM主要是一些分子量较小、含有大量杂原子、具有较低不饱和度、O/C <0.3和H/C>1.5的物质。     

Landfill leachate treatment by MBR： Performance and molecular weight distribution of organic contaminant

A membrane bioreactor (MBR) with an air-lift bioreactor and gravity flow is applied to treating landfill leachate. More than 99% of BOD5 (biochemical oxygen demand for five days) removal effi-ciency is achieved with less than 35 mg/L of BOD_5 in the effluent at less than 1.71 kg BOD5/m~3·d of BOD_5 loading rate. When DO (dissolved oxygen) is maintained at the range of 2.3―2.8 mg/L and the loading rate of NH_4~ -N (ammonium nitrogen) is kept at 0.16― 0.24 kg NH_4~ -N/m~3·d, the NH_4~ -N in the effluent is less than 15 mg/L. However, compared with high removal rates of BOD_5 and NH_4~ -N, the removal effi-ciency of soluble chemical oxygen demand (SCOD) varies between 70% and 96%. The investigation of molecular weight (MW) distribution has been carried out by the gel permeation chromatography (GPC) so as to understand the fate of organic matters in the MBR treating of landfill leachate. Results indicate that organic matters of the landfill leachate are composed of a high MW fraction (MW of the peak, MWp = 11480―13182 Da) and a low MW fraction (MWp = 158―275 Da). The high MW fraction is not biode-gradable, but can be decreased with microfiltration membrane. The most of the low MW fraction is bio-degradable, but the residue of the low MW fraction is able to permeate through the membrane, thus re-sulting in high SCOD in the effluent of the MBR.     

Evaluation of humic acid removal by a flat submerged membrane photoreactor

A flat submerged membrane combined with a TiO 2 /UV photocatalytic reactor (FSMPR) was employed in batch mode to remove humic acid (HA). HA removal efficiency was characterized by UV 254 absorbance, UV-vis spectra, dissolved organic carbon (DOC) concentration, specific UV absorbance (SUVA), and trihalomethane formation potential (THMFP). The FSMPR process was effective in removing more than 86% of DOC and nearly 100% of UV 254 absorbance, while the THMFPs of samples were reduced to < 19 μ g/L after 150 min of treatment. In addition, changes in transmembrane pressure (TMP) with and without UV were evaluated; TiO 2 /UV was effective at controlling membrane fouling by HA. Analysis of the molecular weight (MW) distributions and three-dimensional excitation-emission matrix (EEM) fluorescence spectra of HAs revealed that the effectiveness in membrane fouling control is a result of changes in HA molecular characteristics. The TiO 2 /UV photocatalytic reactor caused the degradation of high MW, hydrophobic humic-like molecules to low MW, hydrophilic protein-like molecules, although this fraction was not completely removed during 150 min of treatment and was less responsible for membrane fouling.     

聚硅酸铁对溶解性有机物与浊度的去除

采用透射电镜法及光子相关光谱法对自制的氧化性聚硅酸铁(PSF)与聚合硫酸铁(PFS)进行微观表征,同时以254 nm的吸光度A(UV_(254))溶解性有机碳质量浓度c(DOC)、色度及比紫外吸光值A(SUV_(254))作为溶解性有机物(DOM)的检测指标,对PSF降低以上各指标与浊度去除效果及相关性进行研究.结果表明:PSF由很短的链节样物种及枝状结构组成,形态尺寸及分维数较大,并且较稳定;PSF具有良好的混凝效果,对浊度及色度的去除率超过95%,对A(UV_(254)),A(SUV_(254)),c(DOE)的去除率分别达到85%,80%,60%;用于评价PSF去除DOM性能的各指标间及其与余浊之间均具有良好的相关性.     

贵阳市水环境中6种酞酸酯类污染现状研究

为了解贵阳市水环境中邻苯二甲酸酯类物质的污染情况,对贵阳市部分水样进行了气相色谱分析。每个采样点均检出邻苯二甲酸酯类物质,其中所有的采样点均检出邻苯二甲酸二丁酯(DBP)和邻苯二甲酸(2-乙基己基)酯(DEHP),最高含量分别为13.9μg.L-1和31.6μg.L-1。7个采样点检出邻苯二甲酸丁基苄基酯(BBP),最高含量为25.9μg.L-1。部分采样点中邻苯二甲酸二乙酯(DEP)也被检出。均未检出邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二辛酯(DOP)。结果表明贵阳市水体中的酞酸酯类污染物目前以邻苯二甲酸二丁酯、邻苯二甲酸(2-乙基己基)酯为主,并且污染比较严重。     

Fate of secondary effluent dissolved organic matter during soil-aquifer treatment

The reduction of mass and trihalomethane formation potential (THMFP) of dissolved organic matter (DOM) and its fractions from secondary effluent during laboratory-scale soil-aquifer treatment (SAT) soil columns were studied. Reduction in dissolved organic carbon (DOC), absorbance of ultraviolet light at 254 nm (UV-254), biodegradable dissolved organic carbon (BDOC) and nonbiodegradable dis- solved organic carbon (NBDOC) for the bulk DOM averaged 72.35%, 53.98%, 97.49% and 35.33% across the soil columns, respectively. Using XAD-8 and XAD-4 resins, DOM was fractionated into 3 fractions: hydrophobic acid (HPO-A), transphilic acid (TPI-A) and hydrophilic fraction (HPI). HPO-A was removed by 61.06%, TPI-A by 54.86% and HPI by 74.95% as DOC as a consequence of the laboratory-scale SAT, respectively. The reduction of THMFP from HPO-A, TPI-A and HPI was 27.24%, 26.24% and 36.08%, respectively. Proton nuclear magnetic resonance (1H-NMR) spectra revealed that the HPO-A isolated from the secondary effluent contained more aromatic functional groups than the corresponding TPI-A. Fourier-transform infrared (FT-IR) spectrum analysis illustrated that TPI-A had decreased hydrocarbon and increased aromatics content in the SAT columns. Specific ultraviolet light absorbance (SUVA) and specific THMFP for each DOM fraction increased across the soil columns and HPI exhibited greater increase in both than HPO-A and TPI-A. The most problematic THM precursor was found to be HPO-A with its high quantity present in recharged water and high chlorine reactivity.     

Efficient export of carbon to the deep ocean through dissolved organic matter

Oceanic dissolved organic carbon (DOC) constitutes one of the largest pools of reduced carbon in the biosphere. Estimated DOC export from the surface ocean represents 20% of total organic carbon flux to the deep ocean, which constitutes a primary control on atmospheric carbon dioxide levels. DOC is the carbon component of dissolved organic matter (DOM) and an accurate quantification of DOM pools, fluxes and their controls is therefore critical to understanding oceanic carbon cycling. DOC export is directly coupled with dissolved organic nitrogen and phosphorus export. However, the C:N:P stoichiometry (by atoms) of DOM dynamics is poorly understood. Here we study the stoichiometry of the DOM pool and of DOM decomposition in continental shelf, continental slope and central ocean gyre environments. We find that DOM is remineralized and produced with a C:N:P stoichiometry of 199:20:1 that is substantially lower than for bulk pools (typically >775:54:1), but greater than for particulate organic matter (106:16:1--the Redfield ratio). Thus for a given mass of new N and P introduced into surface water, more DOC can be exported than would occur at the Redfield ratio. This may contribute to the excess respiration estimated to occur in the interior ocean. Our results place an explicit constraint on global carbon export and elemental balance via advective pathways.     

Fenton技术在垃圾渗滤液处理工程中的应用

以去除垃圾渗滤液生化出水中的CODCr和腐殖酸相对含量（UV254)为研究内容,对Fenton技术应用及其工艺技术条件优化进行了实验室条件下的模拟试验研究。结果表明,1）快速Fenton工艺优化条件为:初始pH值为4.0,H2O2投加量为1500 mg/L,Fe2+投加量为500 mg/L,静置时间120 min,CODCr由处理前的652 mg/L降到处理后的300.06 mg/L,去除率达53.99%;2）光催化Fenton氧化优化条件为:初始pH值为4.0,H2O2投加量为1000 mg/L,紫外灯功率为72 W,反应时间为120 min,CODCr由处理前的300.06 mg/L降到处理后的86.4mg/L,去除率达71.18%。说明,该工艺对处理垃圾渗滤液生化出水是有效的,可进行大规模的中试研究。     

芬顿和双氧水紫外处理稳定渗滤液的光谱特征

为研究芬顿(Fenton)法和双氧水紫外(H_2O_2-UV)法处理稳定(填埋场)渗滤液过程中不同类别有机物的去除规律,采用三维荧光光谱(3D-EEM)和254nm波长紫外吸光度(SUVA254),结合荧光区域一体化(FRI)EEM数据处理方法,分析总有机物去除水平相近条件下,两种处理方法去除不同有机物水平和组分变化的特征.结果表明:两种处理方法中,均是蛋白质类物质比腐殖质类物质优先被去除,酪氨酸类物质比色氨酸类物质优先被去除;较高的总有机碳(TOC)去除率段比低去除率段能去除更大比例的最难降解腐殖质类物质.在相近的TOC去除水平下,H_2O_2-UV法比Fenton法对腐殖质类物质的去除更有效,且能更多地去除胡敏酸类物质;Fenton法处理中,Fe2+投加量的增加能更多地通过絮凝沉淀作用去除胡敏酸类物质.Fenton和H_2O_2-UV作为预处理方法应用时,为了既能达到较好处理效果又能节约成本,应选择对腐殖质类物质去除率更高的H_2O_2-UV技术作为预处理方法.