Petroleum Pollutant Degradation by Surface Water Microorganisms (8 pp)

Background, Aims and Scope It is well known that the composition of petroleum or some of its processing products changes in the environment mostly under the influence of microorganisms. A series of experiments was conducted in order to define the optimum conditions for an efficient biodegradation of petroleum pollutant, or bioremediation of different segments of the environment. The aim of these investigations was to show to what extent the hydrocarbons of a petroleum pollutant are degraded by microbial cultures which were isolated as dominant microorganisms from a surface water of a wastewater canal of an oil refinery and a nitrogen plant. Biodegradation experiments were conducted on one paraffinic, and one naphthenic type of petroleum during a three month period under aerobic conditions, varying the following parameters: Inorganic (Kp) or an organic medium (Bh) with or without exposition to light. Methods Microorganisms were analyzed in a surface water sample from a canal (Pančevo, Serbia), into which wastewater from an oil refinery and a nitrogen plant is released. The consortia of microorganisms were isolated from the water sample (most abundant species: Phormidium foveolarum - filamentous Cyanobacteria, blue-green algae and Achanthes minutissima, diatoms, algae). The simulation experiments of biodegradation were conducted with the biomass suspension and crude oils Sirakovo (Sir, paraffinic type) and Velebit (Ve, naphthenic type). After a three month period, organic substance was extracted by means of chloroform. In the extracts, the content of saturated hydrocarbons, aromatic hydrocarbons, alcohols and fatty acids was determined (the group composition). n-Alkanes and isoprenoid aliphatic alkanes, pristane and phytane, in the aliphatic fractions, were analyzed using gas chromatography (GC). Total isoprenoid aliphatic alkanes and polycyclic alkanes of sterane and triterpane types were analyzed by GC-MS. Results and discussion. Paraffinic type petroleums have a significant loss of saturated hydrocarbons. For naphthenic type petroleum, such a trend has not been observed. The most intensive degradation of n-alkanes and isoprenoid aliphatic alkanes (in paraffinic oil) and isoprenoids (in naphthenic oil) was observed using the inorganic medium Kp in the light; the microbial conversion is somewhat lower with Kp in the dark; with organic medium Bh in the light the degradation is of low intensity; with the same medium in the dark the degradation is hardly to be seen. Steranes and triterpanes were not affected by microbial degradation under the conditions used in our experiments. Obviously, the petroleum biodegradation was restricted to the acyclic aliphatics (n-alkanes and isoprenoids). Conclusion Phormidium foveolarum (filamentous Cyanobacteria - blue-green algae) and Achanthes minutissima (diatoms, algae), microbial cultures isolated as dominant algae from a surface water in a wastewater canal of an oil refinery and a nitrogen plant, have degradable effects dominantly involving petroleum hydocarbons. Petroleum microbiological degradation is more intensive when inorganic medium (in the light) is applied. Having in mind that the inorganic pollutants have been released into the canal as well, this medium reflects more the natural environmental conditions. Polycyclic alkanes of sterane and triterpane type, in spite of the fact that these compounds could be degraded, have remained unchanged regarding abundance and distribution. Since this is the case even for naphthenic type petroleum (which is depleted in n-alkanes), it can be concluded that the biodegradation of petroleum type pollutants, under natural conditions, will be restrained to the n-alkane and isoprenoid degradation. Recommendation and Outlook Performed experiments and simulations of petroleum microbiological degradation may serve for the prediction of the fate of petroleum type pollutants, as well as for definition of conditions for bioremediation of some environmental segments.     

用于地表水反硝化的纤维素碳源选择研究

为了选取合适的天然有机物作为反硝化细菌碳源用于解决地表水中NO3--N污染问题,以江南大学校内湖水为接种物,选取8种天然纤维素碳源在缺氧状态不同的处理方式下对60 mg/L NO3--N的降解特性进行研究。结果表明,以碱处理作为预处理可明显提高反硝化速率,碳源脱氮率均在96%以上（树皮除外）。2种处理方式中均有NO2--N累积,部分碳源释放NH4＋-N并发生DNRA反应,树叶在2种处理中脱氮效果均较好。结合各碳源脱氮率、耗碳源量以及处理成本,选取基本处理的香樟叶作为最佳纤维素碳源。     

“引江济太”河段重金属在水体、悬浮颗粒物及表层沉积物中的含量特征研究及标准化分析

研究了"引江济太"河段(长江—望虞河—贡湖段)孔隙水、上覆水、悬浮颗粒物及表层沉积物中重金属的含量特征,并采用标准化分析方法推测了"引江济太"调水对太湖重金属含量及分布的影响。结果表明,"引江济太"河段的上覆水和间隙水中的重金属污染较轻,6种重金属(Cd、Pb、Zn、Cu、Cr和As)平均值大多低于《地表水环境质量标准》(GB 3838—2002)Ⅰ类标准,且低于美国优先污染物国家推荐水质基准持续浓度。悬浮颗粒物及表层沉积物中主要的重金属污染元素是Cd,其中Cd平均值分别为2.20、1.78μg/g,为中国水系沉积物平均值的16、13倍,且达到加拿大淡水沉积物保护准则最初影响水平的3倍左右。标准化分析结果表明,"引江济太"调水工程对太湖重金属含量的变化有一定影响,"引江济太"河段沉积物中的重金属可能经过再悬浮过程进入水体,造成水体二次污染。     

水体中17种持久性和可迁移有机污染物的检测

持久性和移动性有机污染物 (persistent and mobile organic contaminants, PMOCs) 在环境中降解缓慢,并且可以通过水体循环进行迁移。由于缺乏水体中PMOCs的高效富集和准确测定方法,导致关于PMOCs在水体中存在水平的可靠监测数据较少。通过优化固相萃取条件和高效液相色谱-串联质谱参数,建立了同时检测水中17种PMOCs的分析方法。采用HLB固相萃取柱对水样中的PMOCs进行富集,乙腈和含10 mmol·L⁻¹乙酸铵的水溶液作为流动相进行梯度洗脱,PMOCs检出限为0.04~0.35 ng·L⁻¹,定量限为0.13~1.16 ng·L⁻¹,回收率为65.01%~98.65%。在北京潮白河、广东北江和河北滹沱河进行布点采样,并测定其PMOCs的质量浓度。实验结果表明：17种PMOCs在潮白河、北江和滹沱河中均有检出,其ƩPMOCs平均质量浓度分别为604.69、740.45和505.11 ng·L⁻¹。潮白河地表水中安赛蜜、金刚烷胺和己内酰胺的质量浓度相对较高,分别高达261.75、143.84和153.71 ng·L⁻¹。北江中安赛蜜、磷酸三 (2-氯丙基) 酯和己内酰胺的质量浓度相对较高,分别高达433.14、444.46和108.76 ng·L⁻¹。滹沱河中金刚烷胺、己内酰胺和磷酸三 (2-氯丙基) 酯的质量浓度较高,分别高达218.10、101.14和222.60 ng·L⁻¹。本研究结果可为地表水和地下水水体中PMOCs的检测评价提供参考。     

模拟黑水的生物处理

针对以糖蜜配制的半人工黑水生物处理时除磷效率下降和污泥膨胀的现象,利用序批式反应器(SBR)进行了实验分析,比较了以蔗糖和糖蜜为主要碳源时除磷效果的差异,并探讨了污泥膨胀发生的原因。研究表明,以糖蜜为主要碳源配制模拟黑水时的除磷效果比蔗糖为碳源时差,主要是由于GAOs的竞争性代谢所致。以糖蜜为碳源的条件下,污泥的胞外聚合物含量是正常活性污泥的一倍以上,导致污泥沉降性能变差;糖蜜碳源时的夏季高温条件下丝状菌大量生长也是导致污泥膨胀的重要原因。     

响应面分析法优化给水污泥吸附除磷工艺

以给水污泥为吸附材料,对模拟含磷废水进行了吸附研究。在单因素实验基础上,选取投加量、pH和粒径3种因素为影响因子,以磷的去除率为响应值,采用Box-Behnken响应面分析法(BBD)研究了3种因素对磷去除率的影响以及各因素间的交互作用。建立了二次多项式回归方程预测模型,成功预测出最佳除磷工艺条件为污泥投加量3.88 g/L,pH=3.00,粒径1.00 mm,该条件下磷的去除率可达95.13%.因此,响应面分析法是优化给水污泥吸附除磷工艺的可行方法。     

城市水务系统碳排放测算及减碳对策分析：以成都市为例

城市水务系统是单位产值能耗较高且与各行各业联系紧密的行业。在“双碳”背景下,开展碳排放核算及减碳策略研究是水务系统高质量发展的重要内容。通过构建成都市水务系统碳排放框架,基于大量统计数据,对水务系统中各个环节 (取、制、供、排等) 产生的直接及间接碳排放进行统筹核算。结果显示,2019年成都市水务系统碳排放总量约为70.3万吨 (以CO₂计) ,主要碳排放领域为污水处理系统,其中的污水处理及污泥处理处置环节的碳排放贡献最为突出。基于核算结果,对水务系统减污降碳目标及实现路径进行系统分析及定量测算,提出包括“节水优先、高效管网、源头提质、低碳工艺及能源回用”的五大策略推进水务系统减碳转型,为成都市及类似城市的“双碳”水务系统建设提供参考。     

宽叶香蒲表面流人工湿地脱氮除磷效果研究

以运行A/O工艺的生化反应器出水为处理对象,在中试规模上研究了宽叶香蒲表面流人工湿地的脱氮除磷效果及影响因素.结果表明,在工况Ⅰ条件下,COD去除率为43.2%,COD面积负荷去除率为4.79 g/(m2·d),COD面积负荷去除率常数为0.18 m/d,SS、NH4+-N和NO-3-N的去除率分别为41.2%、9.4%、3.4%,TN去除率为11.8%,TN面积负荷去除率为1.36g/(m2·d),TN面积负荷去除率常数为0.04 m/d,TP去除率为30.1%,TP面积负荷去除率为0.29 g/(m2·d),TP面积负荷去除率常数为0.13 m/d;在工况Ⅱ条件下,COD去除率为18.7%,COD面积负荷去除率为1.19 g/(m2·d),COD面积负荷去除率常数为0.06 m/d,SS、NH4+-N、NO2--N、NO3--N的去除率分别为31.6%、29.8%、65.0%,29.2%.TN去除率为31.4%,TN面积负荷去除率为2.33 g/(m2·d),TN面积负荷去除率常数为0.12 m/d,TP去除率为29.4%,TP面积负荷去除率为0.22 g/(m2·d),TP面积负荷去除率常数为0.11 m/d.在COD面积负荷去除率,TN面积负荷去除率、TP面积负荷去除率分别为4.90～9.80、2.76～8.83、0.57～1.39 g/(m2·d),水力停留时间(HRT)为0.4～1.1 d条件下,随HRT,水温、(NO2+-N+NO3--N)/TN的增加,表面流人工湿地的TN面积负荷去除率线性增加.     

活性炭多维电极法去除水中腐殖酸过程与宏观动力学研究

采用活性炭多维电极法去除水中溶解态腐殖酸。实验结果表明 ,与活性炭单纯吸附法相比 ,活性炭多维电极法可显著提高对溶解态腐殖酸的去除率 ;在连续运行条件下 ,延长水力停留时间、升高槽电压、溶液偏碱性有利于腐殖酸的去除 ;高效液相色谱分析结果表明 ,电极的氧化还原作用可使有机物分子量变小或矿化 ,因而处理系统有可能延长活性炭的使用寿命     

Effects of T-2 toxin on histopathology,fatty acid and water distribution of shrimp (Litopenaeus vannamei) muscle

T-2 toxin (T-2), one of the naturally occurring mycotoxins, often accumulates in aquatic animals from contaminated feed. Shrimp (n?=?30 per group) were fed with different concentrations (0, 0.5, 1.5, 4.5 and 13.5?mg kg^?1) of T-2 for 20?days. Changes in histopathology, fatty acid and water distribution of shrimp muscle were analyzed. Histopathology of shrimp muscle showed dose-dependent marked degenerative and necrotic changes on exposure to dietary T-2. The T-2 significantly (P?<?0.05) affected the muscle fatty acid composition. ∑SFA, ∑MUFA and ∑PUFA initially decreased and then increased slowly in the high-dosed groups. C16:0, C18:1n-9 and C18:2n-6 were the main saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively. Also, T-2 significantly affected water distribution in shrimp muscle. High doses of T-2 reduced free water content, resulting in a reduction in the water holding capacity and hence changes to the shrimp muscle quality. Collectively, these results illustrated that T-2 significantly affects the fatty acid and water distribution, and also muscle histopathology, all of which would result in a reduction in the quality and nutritional value of shrimp.     

普通硅酸盐水泥和钙盐对氟污染地表水的除氟效果

水体氟污染问题受到了广泛关注,现行的除氟技术对自然水体中氟化物的去除效果不明显,无法大范围推广应用。选择碳酸钙(CaCO₃)、氯化钙(CaCl₂)2种钙盐和普通硅酸盐水泥(简称水泥)对山东省胶州市南胶莱河水样进行了处理,考察了3种材料及其相应的组合对氟离子的去除效果,并筛选出适用于地表水体除氟的材料;通过改变搅拌时间和搅拌速度研究了不同扰动程度对除氟效果的影响;通过扫描电镜、能谱仪、X射线衍射分析和傅里叶红外光谱分析讨论除氟机理。结果表明,当这3种材料单独使用时,CaCO₃和水泥表现出除氟效果,水泥除氟效果优于CaCO₃,在添加0.5 g·L⁻¹水泥的处理中,水样中的氟离子质量浓度由1.46 mg·L⁻¹降至1.23 mg·L⁻¹;CaCO₃和水泥组合的除氟率高于单独CaCO₃或水泥,可将水样的氟离子质量浓度由1.39 mg·L⁻¹降至1.09 mg·L⁻¹。改变搅拌时间和速度的实验结果表明,扰动程度增加,除氟率随之下降。表征分析结果表明,水样中氟离子主要依靠化学反应形成沉淀去除。使用水泥用于地表水除氟的步骤简单、效果明显,考虑到水泥与CaCO₃组合使用表现出的协同效果以及扰动程度对除氟效果的影响,未来采用水泥处理氟污染地表水时,建议与CaCO₃组合使用并采取撒施等对水体扰动较小的施工方式。     

高效液相色谱-串联质谱法同时检测地表水中13种药物及个人护理品

采用高效液相色谱-串联质谱(HPLC-MS/MS)检测,建立了地表水中13种药物及个人护理品的测定方法。水样用盐酸与氢氧化钠溶液调pH值至7.0左右,过固相萃取小柱进行富集,用14 mL甲醇洗脱。以C18柱为分离柱,0.01%甲酸的甲醇-0.01%甲酸水溶液为流动相,目标物在10 min内分离,在0.50~250 μg/L范围内,13种化合物峰面积与内标物质峰面积之比与质量浓度的线性关系良好(>0.99),检出限在0.05~0.5 ng/L范围内。基质加标实验结果表明,13种化合物在水中的回收率分别在56.2%~123.2%之间(加标水平5 ng/mL)和58.0%~107.8%(加标水平50 ng/mL),相对标准偏差在1.60%~19.9%(n=6)之间。应用该方法测定了从2条纳污河流采集的10份水样,结果表明,除美托诺尔和普洛萘尔未被检出外,其余11药物的检出频率在30%~100%之间。在13种目标物质中,咖啡因的检测浓度最高达287.5 ng/L,舒必利次之,为277.5 ng/L。本方法快速、准确,适用于地表水中PPCPs类的快速测定。     

沈阳市黑臭水体表层水DOM紫外光谱特征分析

为识别黑臭水体中DOM组成、结构及腐殖化水平,运用UV-vis(紫外-可见吸收光谱)与多元统计相结合的方式,对沈阳市5条黑臭水体的27个表层水样中DOM的UV-vis特征及9个紫外光谱指数进行研究。研究表明：27个表层水样中DOM的UV-vis吸收系数的变异系数在30%~80%之间,轻度黑臭水体相对于重度黑臭水体的紫外吸收峰在356、487、657 nm处分别发生了1、2、2 nm的蓝移;轻度黑臭水体紫外光谱指数SUVA254、S275~295、S350~400、A2/A1、A3/A1、A3/A2均高于重度黑臭水体,而E2/E3、E4/E6、E2/E4低于重度黑臭水体,轻度黑臭水体的腐殖化水平与腐殖化趋势高于重度黑臭水体。进一步分析得出：苯酚基(木质素和奎宁基团)决定了黑臭水体中DOM腐殖化进程,不同黑臭水体DOM的组分存在明显差异;轻度黑臭水体中DOM的腐殖化水平、芳香化程度、木质素与其他物质在腐殖化开始的比例、分子质量等均高于重度黑臭水体。多元统计与UV-vis技术对黑臭水体中DOM的组成及结构进行了定性,为黑臭水体的溯源和整治工作提供理论基础。     

地表水中隐孢子虫和贾第鞭毛虫微球的混凝去除

以向地表水中投加的隐孢子虫微球和贾第鞭毛虫微球为对象,研究通过对给水混凝工艺对其的去除效果进行比较,着重考察了不同混凝剂种类、投加量及水样pH值对去除效果的影响.结果表明,混凝工艺可较为有效地去除地表水中的两虫微球,去除率最高可达4 lg.相比常规的金属盐类混凝剂,高分子的PAC、PAFC混凝剂对两虫微球的混凝去除率更...     

水碳比变化对汽油氧化重整制氢影响的研究

本文用正辛烷代替汽油从理论和实验两方面研究了水碳比变化对汽油氧化重整制氢反应的影响。理论研究表明 ,在绝热反应条件下 ,对应确定的反应温度存在一个最佳的氧油比及水碳比 ;实验研究表明 ,在非绝热反应体系中 ,在一定的氧油比及反应温度条件下 ,反应体系的转化率及生成氢的选择性均随水碳比的增加而增加 ,为实现燃料电池汽油制氢自热反应 ,反应体系应在一定水碳比条件下进行 ,实验条件下最佳的水碳比范围是 1.5— 2 .5之间。     

Direct measurements of the tile drain and groundwater flow route contributions to surface water contamination: From field-scale concentration patterns in groundwater to catchment-scale surface water quality

Enhanced knowledge of water and solute pathways in catchments would improve the understanding of dynamics in water quality and would support the selection of appropriate water pollution mitigation options. For this study, we physically separated tile drain effluent and groundwater discharge from an agricultural field before it entered a 43.5-m ditch transect. Through continuous discharge measurements and weekly water quality sampling, we directly quantified the flow route contributions to surface water discharge and solute loading. Our multi-scale experimental approach allowed us to relate these measurements to field-scale NO₃ concentration patterns in shallow groundwater and to continuous NO₃ records at the catchment outlet. Our results show that the tile drains contributed 90-92% of the annual NO₃ and heavy metal loads. Considering their crucial role in water and solute transport, enhanced monitoring and modeling of tile drainage are important for adequate water quality management.     

碳源类型及进水量分配对CMICAO工艺脱氮除磷的影响

研究了分别以葡萄糖和乙酸钠为碳源时多点交替进水阶式A2/O(CMICAO)工艺氮磷的去除效果,以及在不同进水C/N比时各进水量分配对脱氮除磷效果的影响。结果表明,在相同的进水COD浓度下,乙酸钠比葡萄糖更适合作为碳源,更能提高脱氮除磷效率。以葡萄糖为碳源时,COD为200mg/L、C/N比为5、缺氧池与厌氧池进水配比为1:2时,出水COD、TN、氨氮和TP浓度分别为28.5、10.8、2.1和0.5mg/L,均达到国家一级A排放标准。若采用葡萄糖作为碳源,投加量以使进水C/N比为5~7.5为宜,外加碳源时缺氧池与厌氧池进水分配比可统一采用1:1。     

利用皂角粉促进污泥水解酸化

针对目前投加常用表面活性剂促进污泥水解酸化的方法存在二次污染与负面效应等问题,提出利用皂角粉促进污泥水解酸化的新方法,考察皂角粉投加量对促进污泥水解酸化效果的影响,分析发酵过程皂角粉与污泥混合体系VSS的变化情况。实验结果表明,投加皂角粉可有效地促进污泥水解酸化,水解酸化液中SCOD、DOC和ThODVFAs浓度均随皂角粉投加量增大而增大,皂角粉投加量/体系中污泥VSS质量为0.20 g·g-1的条件下,污泥水解酸化5 d时,三者分别达到最高值3 724.7、1 485.3和2 044.7 mg·L-1,分别约为不加皂角粉对照组的3倍、4倍和10倍;控制相同的初始体系VSS,改变不同体系中皂角粉占体系VSS的比例,发酵过程中不同体系的ThODVFAs含量相近。消耗相同的体系VSS时,VFAs生成量随体系中皂角粉所占比例的增大而减小,皂角粉作为表面活性剂的作用要远高于作为代谢基质的作用。研究表明,皂角粉是一种经济的环境友好的可用于促进污泥水解酸化的天然表面活性剂。     

Comparison of atmosphere/aquatic environment concentration ratio of volatile chlorinated hydrocarbons between temperate regions and Antarctica

For the purpose of understanding the transport and deposition mechanisms and the air–water distribution of some volatile chlorinated hydrocarbons (VCHCs), their atmosphere/aquatic environment concentration ratio was evaluated. In addition, for the purpose of differentiating VCHC behaviour in a temperate climate from its behaviour in a polar climate, the atmosphere/aquatic environment concentration ratio evaluated in matrices from temperate zones was compared with the concentration ratio evaluated in Antarctic matrices.In order to perform air samplings also at rigid Antarctic temperatures, the sampling apparatus, consisting of a diaphragm pump and canisters, was suitably modified.Chloroform, 1,1,1-trichloroethane, tetrachloromethane, 1,1,2-trichloroethylene and tetrachloroethylene were measured in air, water and snow using specific techniques composed of a purpose-made cryofocusing-trap-injector (for air samples) and a modified purge-and-trap injector (for aqueous samples) coupled to a gas chromatograph with mass spectrometric detection operating in selected ion monitoring mode. The VCHCs were retrieved in all the investigated matrices, both Italian and Antarctic, with concentrations varying from tens to thousands of ng m⁻³ in air and from digits to hundreds of ng kg⁻¹ in water and snow.The atmosphere/aquatic environment concentration ratios were always found to be lower than 1. In particular, the Italian air/water concentration ratios were smaller than the Antarctic ones, by reason of the higher atmospheric photochemical activity in temperate zones. On the other hand, the Antarctic air/snow concentration ratios proved to be largely in favour of snow with respect to the Italian ratios, thus corroborating the hypothesis of a more efficient VCHC deposition mechanism and accumulation on Antarctic snow.