【作者】 童蕾；

【导师】 王焰新；

【作者基本信息】 中国地质大学 ， 环境工程， 2010， 博士

【摘要】 近年来,养猪废水带来的环境污染问题越来越受到国内外学者的高度重视。由于其污染量大,处理过程不完全,已成为水环境的重要污染源。养猪废水主要来源于动物粪便、尿液及养殖场冲洗水。其有机物、固体悬浮物和氮磷的含量均高于我国《畜禽养殖业污染物排放标准》的几十甚至几百倍。养猪废水中有毒有害的有机物可分为传统污染物和新兴污染物,传统污染物比如类脂化合物包括油脂、脂肪酸和甾醇等,挥发性恶臭类化合物包括芳香族酚类化合物、含氮杂环化合物、挥发性脂肪酸和硫醇等；部分新兴污染物,如在养猪饲料中添加的兽药抗生素也同样在废水中检出。据调查,养猪过程中超量添加抗生素的现象十分普遍,我国每年有8万人直接死于滥用抗生素,而对猪的滥用要比人的情况严重百倍千倍,害死的猪不计其数。由于大多数养殖场处理设施不完善或不加以处理,这些污染物将直接排放到河流,湖泊及附近的水体中,造成环境水体的严重污染。根据现有资料,关于养猪废水的研究课题多集中在传统污染物的分析上,如化学需氧量CODcr,生化需氧量BOD5,总氮TN和总磷TP等。废水中具有水质特征的特殊有机污染物却鲜有报道。本论文对养猪废水中有机物的特性和分布进行了全面解析,阐明了废水中溶解性有机物组分存在的差异,为探明其在处理过程中的降解行为提供了科学依据。同时对特殊污染物如恶臭类化合物和长链脂肪酸等的分析方法分别进行优化,并建立了废水中兽药抗生素的多残留检测方法。研究了在废水处理各环节污染物的去除效率,以及长期控制下的变化趋势。深入探讨了难降解大环内脂类抗生素的自然光降解过程,并充分利用获得的质谱信息对其降解产物进行一一鉴定,通过对原物质和产物的长期定量监测,模拟出自然条件下的降解趋势,为研究抗生素在自然环境中的迁移转化提供了理论和实践依据。论文的主要研究内容可以分为以下几个方面：1.养猪废水及其处理系统中有机物的分布特征及去除效果养猪废水水样来源于某种猪养殖场,废水经改进后的处理工艺净化后回用于农田。该处理工艺主要包括固液分离,酸化调节,厌氧发酵,仿生态自然氧化和快速渗滤等一系列措施。处理后的废水中污染物总量减少了90%以上,达到排放标准。由于养猪废水有机物成分差异大,为更全面地掌握其有机组成,我们采用三种典型的分组方法,将废水中的复杂有机物按照分子量不同,电荷特性不同及极性不同分成一系列结构、性质相对单一的物质组分,再根据其光谱及质谱特性进行研究。通过微滤及超滤技术将废水分成6种不同分子量的组分,M1(未经分离原水样),M2(小于1.0μm总组分),M3(小于0.45μm的溶解性组分),M4(介于0.45μm和1.0μm之间的微溶组分),M5(小于1 KDa的超滤液)和M6(介于1 KDa和0.45μm之间的胶体浓缩液)。经紫外光谱及特征性紫外吸收值SUVA分析,随着紫外吸收波长增大,组分SUVA吸收值具有一致的减小趋势：210 nm>254 nm> 280 nm.不同分子量组分的SUVA吸收值大小为：M5>M4>M6>M2>M3.各组分的红外吸收光谱具有相似性,都含有9条特征光谱带,但谱带强度略有不同。根据物质电荷特性不同,我们利用XAD-8树脂和阴阳离子交换树脂将可溶性有机物(DOM)组分(M3)进一步分成6个组分：憎水酸(HoA),憎水碱(HoB),憎水中性(HoN),亲水酸(HiA),亲水碱(HiB)和亲水中性(HiN)。通过紫外吸收光谱分析,在200nm至350nm紫外吸收区共有4条主要吸收光谱带,而重要的特征有机物光谱带产生在254 nm和280 nm。大部分有机物存在于憎水酸,憎水碱和亲水中性组分中。不同组分的红外吸收光谱差异很大,主要观测到9条光谱谱带,这与分子量组分测得的9条红外谱带并不完全一致。结果表明,废水中含有较高浓度的蛋白质和氨基酸,且P-H键的伸缩振动揭示了含磷化合物的存在。按照物质极性,我们将可溶性有机物(M3和M5)分成非极性、弱极性和极性三个不同组分。各组分样品经过富集、净化,气相色谱-质谱检测得出,主要的非极性组分以链状烷烃为主,从而推测出废水中含有的非极性可溶性有机物为碳链烷烃。在M3样品中,弱极性组分以芳香族酚类化合物为主,占到整个组分的一半以上。邻苯二甲酸酯(PAEs)和其它非极性脂类在M3样品中占整个组分的15%,而在样品M5中则占50%以上。在非烃类组分(即极性组分)中,甾醇和脂肪酸脂类占了整个组分的70%以上。同时,在非烃类组分中还检测出了6种药物的存在,这为废水中抗生素的研究提供了有用的信息。2.恶臭类和长链脂肪酸类污染物在水处理系统中的分布与去除恶臭类有机化合物的分布与去除：通过预处理条件的优化,顶空固相微萃取(HS-SPME)和固相萃取(SPE)两种富集方法的比较,建立了养猪废水中恶臭物质(4-甲基苯酚,4-乙基苯酚,吲哚和粪臭素)的测定方法。顶空固相微萃取采用PA萃取头,最佳萃取条件为：水样pH=4,离子强度为30%(氯化钠),恒温水浴温度70度,萃取时间30分钟,解析温度260度,解析时间3分钟。固相萃取采用Tenax吸附填料,自制固相萃取小柱,最佳萃取条件为：水样pH=7,离子强度为30%(氯化钠),样品过柱后,采用二氯甲烷和正己烷的混合溶液(1：2)作洗脱溶剂。采用最佳前处理条件,目标物的检出限范围在0.09μg L-1至1.48μg L-1之间,相对标准偏差低于15%。两种前处理方法在多项指标上进行了比较,比如方法的选择性,灵敏性和定量准确性等。结果表明,顶空固相微萃取法在最低定量检出限(LOQs)和精密度方面均优于固相萃取法。但固相萃取法因其操作简单、结果稳定的特点仍不失为有效的废水中半挥发性恶臭物质的定性定量测定方法。通过对不同处理出水中恶臭物质的组分分析,吲哚类恶臭化合物在生物处理过程中有部分去除,而酚类化合物降解效率低,不能有效去除。残留的毒性酚类化合物随出水排入到环境中将会给人类的健康带来危害。长链脂肪酸化合物的分布与去除：采用XAD大孔树脂吸附,气相色谱质谱联用(GC-MS)检测技术,建立了养猪废水中不挥发中长链脂肪酸的测定方法。实验结果表明,废水中含有的主要脂肪酸(占所有脂肪酸的相对百分比)为棕榈酸(C16：0)和硬脂酸(C18：0)两种,同时也是自然界中最常见的长链脂肪酸。作为废水中含量最高的一种饱和酸,硬脂酸的浓度达到1.4 mg L-1.与此同时,部分一元不饱和脂肪酸,如(C16:1, C18:1和C20：1)在样品处理过程中也一并洗脱下来,并检测出较高浓度。脂肪酸在废水处理过程中有不同的表现行为,大部分脂肪酸在厌氧生物处理过程中没有有效的去除,而有近一半的脂肪酸在自然氧化过程中得到去除(出水W2),并在接下来的快速渗滤系统中基本完全去除(出水W3)。结果表明,此废水处理工艺对脂肪酸的去除效果显著。3.兽药抗生素污染及去除效率研究建立了地下水,湖水和养猪废水中多种兽药抗生素,如四环素(TCs),磺胺(SAs),喹诺酮(FQs)和氯霉素(CAPs)等的多残留检测方法。采用优化的固相萃取前处理技术结合液相色谱串联质谱检测仪器(SPE-LC/MS/MS)进行抗生素的痕量分析。同时,利用液相色谱飞行时间质谱仪(LC-ToF-MS)和LC-MS/MS两种仪器性能比较,建立了废水中8种青霉素(PCs)的快速检测方法。两种仪器都具有速度快,操作简单的优点。在青霉素的测定中,LC-MS/MS比LC-ToF-MS的检出限更低,准确性更高,因此优先考虑用于定量分析。同时对大环内脂类抗生素,如阿奇霉素,红霉素等采用已有方法进行分析。对四环素,磺胺,喹诺酮和氯霉素等的测定结果表明,夏季猪场地下水,附近湖水,养猪废水出水,进水中含有的抗生素浓度范围分别是1.6-8.6,5.7-11.6,7.9-1172.3和8.5-21692.7 ng L-1,冬季分别是2.0-7.3,6.7-11.7,5.8-409.5和32.8-11276.6 ng L-1.另外,阿莫西林,阿奇霉素和红霉素也同样在废水中检出,其浓度分别为540 ng L-1,602 ng L-1和456 ng L-1。所有样品(地下水、湖水、废水进、出水)的抗生素分析方法检出限均较低。虽然检测到的废水及环境水样中抗生素浓度均较低,它们残留在环境中对人类健康的危害和长期的毒性效应必须引起高度重视。4.大环内脂类抗生素在水环境中光降解(模拟太阳光及自然光)过程研究为探讨光降解去除大环内脂类抗生素阿奇霉素的可能性,从光降解动力学及光解产物的环境持续性效应角度进行了降解机理研究。分析了六种不同模拟水样对阿奇霉素的降解速率影响：高纯水(HPLC water),地表水(Freshwater, FW),加硝酸根的地表水(FW+nitrate),腐殖酸(Humic acids, HA),加硝酸根和腐殖酸的地表水(FW+nitrate+HA),养猪废水(piggerywastewater)。结果表明,阿奇霉素的光降解过程遵循一级反应动力学方程：FW+nitrate+HA> HA> piggery wastewater> FW+nitrate> FW> HPLC water。光降解过程产生了7种降解中间产物,利用超高压液相色谱与四极杆、飞行时间质谱联用仪在正离子模式下(UPLC-(+)ESI-QqToF-MS2)对可能的7种降解产物(TP1, TP2, TP3, TP4, TP5, TP6和TP 7)进行了鉴定。将测得的产物质量数和参考标准相对照,得到其精确质量数,并与软件提供的可能元素组成及饱和度相对比,结合原物质的化学结构推断出7种降解产物的结构式。结果表明,阿奇霉素的降解途径可归结为：产物1和产物2主要来源于阿奇霉素在不同糖环上丢失一个甲基所得,而产物3是在产物1的基础上去氧氨基糖环开环并脱氧所得,而产物4是产物2在另一糖环上又丢失一个甲基的结果。产物5和6来源于阿奇霉素分别丢掉去氧氨基糖和红霉糖,而产物7的组成为15环的大环内脂环,可能来源于产物1-6,也可能部分直接从产物1脱双糖而得。采用超高压液相色谱与四极杆串联质谱仪(UPLC-QqQ-MS2)在多反应监测模式下对7种产物的相对定量分析方法进行优化,得到7种产物的多反应监测方法。不同样品基质中的产物1-5基本都在光照1小时之内产生,并在连续照射10小时内达到最大浓度。而产物6和产物7的产生时间差异很大,其最大浓度都在照射30-50小时才获得。大多数降解产物在经过70小时照射后还未完全降解,特别是产物1和产物6在养猪废水基质中经100小时照射后还不能降解完全。因此,降解产物虽然产生迅速,但持续时间却相当长。为探索实际环境中抗生素的迁移转化规律,我们将阿奇霉素添加到采集的河水样品中,经自然光照射后得到阿奇霉素在自然条件下的环境行为。结果表明,阿奇霉素在自然光照射下也遵循一级动力学方程,且半衰期为5.4天,超过70%的阿奇霉素在8天的自然条件下被去除。然而,传统废水处理工艺的水力停留时间远远少于8天,这对阿奇霉素的去除是远远不够的。经过半天时间照射,产物1和产物6同时出现在河水样品中,经过35天的自然光照射也未能去除。可见,环境水体中的阿奇霉素在自然光照条件下的降解速率非常低,而其降解产物的环境持续时间相当长。阿奇霉素及其降解产物的环境毒性及存在风险应当引起人们的更多关注。研究此类抗生素污染物的迁移转化规律可以为环境风险评估提供理论依据。更多还原

【Abstract】 As one of the most important environmental problems to be solved in many countries, piggery wastewater treatment and disposal raise a lot of attention in recent years. Piggery wastewater is a mixture of animal waste and flushing water, with high concentrations of organic matter, suspended solids, ammonia nitrogen and phosphorus, which far exceed the national discharging standards. Moreover, large numbers of toxic or harmful organic compounds existed in piggery wastewater, including conventional pollutants and emerging contaminants, such as lipoid substances including fats, fatty acid compounds and sterol, and odorants including aromatic phenols, nitrogen-containing heterocyclic compounds, volatile fatty acids, thiol, and two inorganic species, NH3 and H2S belong to the former. Some of the especially antibiotics which were belonged to emerging contaminants were also detected in piggery wastewater. These incomplete treated pollutants discharged into lakes, rivers or other water bodies, cause serious pollution of lakes and rivers.According to the previous studies, most of the attention has been paid to the conventional pollutants analyses, such as COD, BOD5, TN and TP. The specific organic components of piggery wastewater are real studied. In the present study, the overall characterization of organic matters of piggery wastewater has been reported, the optimized quantification methods for conventional pollutants and emerging contaminants are well established respectively. Removal effectiveness of these pollutants during wastewater treatment plant in pig farm has been evaluated, paying a special attention to transformation and degradation fate of MLs antibiotics under solar irradiation. The main points of this thesis are summarized as follows:Occurrence and removal of organic components in piggery wastewater. A new pilot-scale wastewater treatment plant containing preliminary treatment, RPAFR, MEOD and MFMI system was introduced. More than 90% pollutants were removed after treatment processes. Piggery wastewater was fractionated by three ways:different molecular size, resin absorption and polarity diversity. Different size fractions were operated by UF system into six parts from 1 kDa to 1μm: M1 (not fractionated), M2 (<1μm), M3 (<0.45μm), M4 (0.45μm～1μxm), M5 (<1 kDa) and M6 (1 kDa～0.45μm). The SUVA values at different wavelengths decreased with increase in UV absorbance:210 nm> 254 nm> 280 nm. The SUVA of different fractions changed in the following way:M5> M4> M6> M2> M3. The FT-IR spectra of organic matters of different fractions (M1-M6) were similar, and nine absorption bands were observed. DOM from sample M3 was fractionated into six fractions:HoA, HoB, HoN, HiA, HiB and HiN. From the UV spectra, the functional peaks appeared at 254 nm and 280 nm. Most of the organic matters were existed in HoA, HoN and HiB fractions. The FT-IR spectrum showed nine main bands. The existence of high concentration of protein and amino acids was revealed, and the P-H stretch was attributed to phosphorous substances. The main non-polar components were alkanes in both M3 and M5 fractions, indicating that non-polar organic pollutants were predominantly alkanes in the DOM fractions of the wastewater. For aromatic component, phenol-like compounds accounted for more than half of the aromatics fractions of organic compounds in sample M3, phthalates acid esters (PAEs) and other non-polar esters accounted for more than 15% of the aromatics compounds in sample M3, and more than 50% in sample M5. For non-hydrocarbons component, sterols and FAMEs accounted for more than 70% of the fractions. In this study, six pharmaceuticals were also identified in non-hydrocarbons fraction of M3 and M5.Occurrence and removal of malodorous substances and long chain fatty acids. The analytical conditions of malodor substance which pre-concentrated by HS-SPME and SPE were optimized respectively. For HS-SPME, the optimal extraction conditions were pH=4,30 min at 70℃, with 30%(m/v) NaCl addition; the desorption process was 3 min at 260℃. For SPE, the best conditions were pH=7, with 30%(m/v) NaCl additon and 10 mL DCM-Hexane (1:2) as eluting solvent. At the best condition, the detection limits ranged from 0.09 to 1.48μg L-1 and the measurement precision was less than 15% of most compounds. The two methodologies were compared in evaluating indicators, such as selectivity, sensitivity and odor quantification. HS-SPME showed better results in terms of LOQs and RSD than SPE, but the semi-validated method of SPE also provide appropriate alternative approaches for qualitative and quantitative analysis of volatile compounds in piggery wastewater. All of the odorants were not completely removed in wastewater treatment plant, the residual toxicity of which was a incipient fault for human health.The analytical method of long chain fatty acids determination is established by XAD resins separation coupled with GC-MS detection. The major fatty acids (considered as a relative percentage of the total) in the wastewater were palmitic acid (C16:0) and stearic acid (C18:0). Stearic acid achieved nearly 1.4 mg L-1 level in the wastewater as one of the saturated acid. Some unsaturated acids (C16:1,C18:1 and C20:1) were also coeluted and observed at relative high concentration. Most of the fatty acids were not well removed in RPAFR system. Nevertheless, more than half of the fatty acids were removed in MEOD system (effluent W2). Nearly all the fatty acids were completely removed after MFMI treatment (effluent W3). The obtained results showed that our pilot scale wastewater treatment process was suitable for fatty acids removal from piggery wastewater.Occurrence and removal of veterinary antibiotics in wastewater treatment processes. An optimized SPE-LC/MS/MS method to analyze multi-residues of selected TCs, SAs, FQs and CAP in groundwater, lake water and swine wastewater was presented. A method for rapid multi-residue screening of PCs using LC-ToF-MS and LC-MS/MS were compared in this chapter. Both of LC-ToF-MS and LC-MS/MS were rapid and simple in PCs analysis, however, LC-MS/MS presented lower limit of detection and high reliability. The concentrations of antibiotics residues in groundwater, lake water, final effluent and influent swine wastewater were respectively 1.6-8.6, 5.7-11.6,7.9-1172.3 and 8.5-21692.7 ng L-1 in summer; and respectively 2.0-7.3,6.7-11.7, 5.8-409.5 and 32.8-11276.6 ng L-1 in winter. AMOX, AZT and ERT were appeared in relative low concentration in effluent wastewater (540 ng L-1,602 ng L-1 and 456 ng L-1, respectively). The LOQ levels were relative rather low in groundwater, lake water, final effluent wastewater and influent wastewater. Even though the antibiotics were detected at relatively low concentrations, there are high risks of their toxic effects on non-target organisms and, finally, on human health.Photodegradation of macrolide antibiotics in the aquatic environment under simulated and natural sunlight irradiation. In order to explore the feasibility of photodegradation of macrolide antibiotics, the photodecomposition kinetics of AZT in six matrices (HPLC water, FW, FW+nitrate, HA, FW+nitrate+HA and piggery wastewater) were studied in photochemical reactor simulating solar irradiation. Photodegradation of AZT followed first-order kinetics in all six matrices with order of degradation rates as follows:FW+nitrate+HA> HA> piggery wastewater> FW+nitrate> FW> HPLC water. A UPLC-(+)ESI-QqToF-MS2 allowed to identify tentative major phototransformation products (TP 1, TP 2, TP 3, TP 4, TP 5, TP 6 and TP 7) of AZT was applied. TP 1 and TP 2 were generated by methyl radical loss from AZT. Further degradation of TP 1 and TP 2 leads to the generation of TP 3 and TP 4 via loss of·O·and methyl radical from two sugars, respectively, and then the formation of TP 5 and TP 6 by loss of desosamine and cladinose sugar from AZT, respectively, wile TP 5 and TP 6 could be degraded directly from AZT by sugar loss. The final product of TP 7 with macrolide ring was considered to be formatted from TP 1-TP 6 or directly from AZT. The optimized mass condition in MRM mode was used for TPs quantification by UPLC-QqQ-MS2. Most of the TP 1, TP 2, TP 3, TP 4 and TP 5 were generated less than 1 hour, and arrived at the highest concentration less than 10 hours in different matrices. While TP 6 and TP 7 were generated at very different time, and the highest concentrations were obtained between 30-50 hours irradiation. However, most of the TPs were detected in the final solution after 70 hours of irradiation. TP 1 and TP 6 persisted more than 100 hours in piggery wastewater under irradiation. The half life of AZT at 5.4 d in river water was obtained, and more than 70% of which was removed after 8 days. Transformation products of TP 1 and TP 6 appeared in half of one day in river water, and were also detected in the final sample under 35 days irradiation. Thus, the environmental risk of AZT and its degradation products need to be gained more attention, and the necessity of investigate the fate of these contaminants was evidenced in order to obtain a realistic estimation of the environmental impact.更多还原