苏州河底泥对上复水水质污染影响

研究了上海市苏州河底泥中有机物及营养盐释放对上复水水质的影响,分析了微生物与底栖生物底泥再悬浮对底泥释放过程的影响。研究表明,底泥中化学需氧量与水体中的化学需氧量成正比,底泥中生化需氧量与水体中的生化需氧量呈正比,再悬浮促进底泥中污染物向上复水体释放。底泥SOD与水体中DO成正比,底泥污染是影响苏州河水质的重要因素;对苏州河底泥进行疏浚工程可较好地提高水体中溶解氧的浓度、降低化学需氧量、生化需氧量及氨氮的浓度。     

有机污染物综合指标(一)

水体有机污染是水质污染的主要问题。衡量有机污染的程度,最好进行有机污染的全分析,但十分困难。除规定的有毒有机污染物外,一般只测定有机污染综合指标来定量地反映水质有机污染程度。 有机污染综合指标主要有:生化需氧量(BOD) 是间接表示水体中可被生物降解的有机物含量的指标。化学需氧量(COD)是表征水中能被强氧化剂氧化分解的有机物含量的参数。总有机碳(TOC) 是以水样中的含碳量来表示有机物含量的,总需氧量(TOD)表示水中含C、N、H、S、P、M(金属) 的有机物完全氧化生成稳定无机氧化态的需氧量。紫外吸收(UVA或UV)是利用芳香族和一些具有不饱和双键的化合物对220—250nm波段的紫外光有强烈吸收的特性来测定污水中有机物的含量。此外尚有碳-氯仿提取物(CCE)和碳-醇提取物 (CAE),它们是先用活性碳吸附,再用氯仿或乙醇提取,脱去溶剂,恒重残渣即得结果。此法对含有杀虫剂的水样测定有明显的优点。主要有机污染综合指标测定方法的比较见表1。     

北京市城市河道水体发臭分级评价方法

基于北京市城市河道水体发臭大量感官数据及水质监测数据,采用多元线性回归及有序Logistic回归建立北京市水体发臭回归模型.研究发现多元线性回归法与有序Logistic回归法整体准确率相似(78%—80%),但发臭评价准确率明显高于后者,更适合作为水体发臭回归方法进行评价.将该方法应用于北京市地表水发臭分级评价中,筛选确定了适合做水体发臭回归自变量的监测指标,发现溶解氧及氨氮起主要作用,对水体发臭贡献率约95%;有机类指标对解释水体发臭效果显著程度从大到小依次为:高锰酸盐指数五日生化需氧量化学需氧量,由于五日生化需氧量分析时间长、高锰酸盐指数多用于Ⅰ—Ⅲ类水体监测、化学需氧量是水环境污染物总量控制的关键指标,综合考虑建议采用化学需氧量为回归自变量;总磷不适合作为北京市城市河道水体发臭回归自变量.对2012年北京市部分城市河道水体发臭情况进行分析,结果发现本标准用于评价发臭程度与国家颁布的黑臭标准的评价结果吻合程度为95.6%,通过选取典型发臭水体进行分级评价,再次验证了该评价方法可行.     

市政污水TOC与COD相关性

总有机碳(TOC)相对于化学需氧量(COD)能够更全面地反映水体中有机物的污染程度，而且TOC测定仪操作简单，数据准确，用TOC监测代替COD监测有利于实现监测仪器化，自动化。通过对市政污水中有机污染物的COD与TOC监测数据的相关性研究，建立了二者之间的线性回归方程和理论值范围方程，为污水中有机污染物的TOC监测代替COD监测提供了实践依据。     

深圳市铁岗水库中有机污染物的GC-MS分析

目前,深圳市对生活饮用水源的无机污染物监测项目较多,但对有机污染物的监测仅限于化学需氧量(COD)、生化需氧量(BOD)等笼统的指标,有机污染物的种类较多,对环境的破坏和人体的危害差别很大.因此,开展饮用水源水中有机污染物的研究,对保证深圳市饮用水质、缓解缺水状况具有重要的社会意义.     

土壤水溶解态有机物质与重金属的络合作用

水溶解态有机物质与重金属离子的络合反应对土壤重金属化学行为的影响十分显著。文章综述了土壤水溶解态有机物质与重金属离子之间相互作用的研究进展，讨论了水溶解态有机物质与络合反应有关的性质，以及水溶态有机物质与重金属的络合作用的问题。     

北京市城市河道水体发黑分级评价方法

基于多元线性回归对北京市城市河道水体发黑感官数据及水质监测数据进行分析.通过比较与筛选发现,水色稀释倍数适合作为表征北京市城市河道水体发黑因变量,而溶解氧、化学需氧量、氨氮、总磷及总铁适合作为自变量,其中溶解氧、化学需氧量及总铁为主要因素.基于5项水质指标提出了北京市城市河道水体发黑分级评价方法,从非发黑到重度发黑共分4级,通过比较发现两个回归模型模拟计算结果与水色稀释倍数观测值大致相当.该评价方法首次将有机类污染指标同水中总铁结合,量化了北京市城市河道水体发黑程度,为未来"一河一策,消除黑臭"提供思路.     

岩溶地区土壤溶解有机碳的季节动态及环境效应

对桂林岩溶试验场土壤溶解有机碳(DOC)进行了逐月的观测，结果显示DOC是岩溶生态系统中活跃的有机碳组分，在岩溶地区碳循环中发挥着重要的作用。一年中土壤DOC的变化特征表现为3个阶段：(1)3-7月，随气温升高、降雨量增加，土壤生物活性和新陈代谢能力极大提高，土壤溶解有机碳呈升高趋势；(2)8-11月，气温保持较高的水平，但降雨量偏低，土壤干燥，土壤微生物活性极大地减弱，土壤DOC质量分数全年最低；(3)12月至次年2月，随温度的降低，土壤生物活性逐渐降低，土壤DOC呈缓慢升高趋势，且与土壤微生物量碳之间存在互为消长的关系。土壤碳酸盐岩的溶蚀速率季节变化与土壤DOC之间存在负相关。文章还提出了岩溶地区土壤碳循环模式及DOC在其中的作用。     

大亚湾的有机碳

本文基于实测资料,分别讨论了大亚湾的溶解有机碳、颗粒碎屑有机碳、沉积物有机碳及生物碳的含量、分布及其相互关系.     

Saguenay河溶解有机质光化学生成溶解无机碳的研究

溶解有机质作为水生生态系统中一种重要的活跃的有机组分,对生态系统中的碳循环起到重要的作用.利用模拟太阳光对Saguenay河溶解有机质的光氧化过程模拟,研究了溶解氧浓度、模拟太阳光波长范围和铁浓度对溶解无机碳产量的影响.研究表明,基于空气饱和样品前72 h的溶解无机碳产量1.39 μmol·L-1·h-1,氧气饱和条件下照射的溶解无机碳产量增加了52.5%,而氮气饱和条件下的照射则只有空气饱和样品的10%.实验以Mylar-D、有机玻璃UF-3和有机玻璃UF-4为滤光片研究了波长范围对溶解无机碳产量的影响,近似计算的结果表明UV-B、UV-A和可见光部分分别占无机碳产量的16.5%,55.4%和28.0%,表明溶解无机碳的生成可发生在紫外光无法到达的水体较深区域.铁在光化学催化氧化过程中起重要作用,当总铁浓度达到10 μmol·L-1时,有效的增加了溶解无机碳的生成速率,其生成速率约为初始样品的1.68倍(初始样品中总铁含量为3.2 μmol·L-1).     

溶解性有机碳的主要组成对青鳉鱼铜急性毒性的影响

为揭示溶解性有机碳(DOC)的组成对生物配体模型(BLM)预测铜的生物毒性准确性的影响,研究了不同浓度黄腐酸(FA)、腐殖酸(HA)和两者不同浓度比例混合物影响铜对青鳉急性毒性。结果表明:在相同水质条件下,黄腐酸或腐殖酸浓度增加时,铜对青鳉的LC50均增加;两者共存时,当腐殖酸质量百分比从10%增至90%时,铜对青鳉的LC50也增加。当天然水中DOC的组成不确定时,可假设HA和FA的组成比例为1∶1,此时BLM预测铜对青鳉的LC50的偏差最小。     

水溶性有机酸对萘溶解度及迁移性能的影响

通过热力学的方法,研究了水溶性有机酸对萘的溶解度及迁移性能的影响,结果表明,萘的溶解度和萘由纯水向不同浓度有机酸溶液的迁移能力随着有机酸浓度的增加而增加,但这种趋势并非简单的线性增加,当有机酸浓度超过一定数值后,萘的溶解度会突然增大,迁移趋势会明显增加.这种变化与在稀溶液中形成的水包有机酸笼合物结构有关.     

Photodegradation of chromophoric dissolved organic matters in the water of Lake Dianchi,China

Water samples were taken from Lake Dianchi, on the Yungui Plateau of southwest China, and experiments were conducted to simulate the photochemical degradation characteristic of chromophoric dissolved organic matter (CDOM) in the lake water. Three groups of experiments under different light conditions: ultraviolet (UV) light, visible light, and dark, were done and variations of fluorescence properties, UV absorbance, and dissolved organic carbon (DOC) concentrations during the experiments were analyzed to study the photodegradation process of CDOM with time. The result showed that light irradiation led to significant photochemical degradation of CDOM, resulting in changes in florescent properties, absorbance losses, decreases in aromaticity and average molecular weight, as well as decline in DOC concentration in the water. It was also observed that UV irradiation had greater effect than visible light did. However, various fluorophores had different sensitivities to the same irradiation condition, that is, protein-like fluorophore at the low excitation wavelengths is more sensitive to UV irradiation than the other fluorophores, and is more readily to undergo photo-degradation. In addition, visible light irradiation did not have significant impact on DOC in the water, with DOC concentration decrease by 5.57% –59.9% during the experiment time. These results may provide new knowledge on the environment behavior of CDOM in the water of Lake Dianchi.     

Characterization of dissolved organic carbon and Humic substances in the well water of the Blackfoot disease area in Taiwan

Since the early 1960s, many investigators have reported that blackfoot disease, a peripheral vascular disease, observed in southwestern Taiwan is due to drinking the higher arsenic concentration in well water. However, recent studies indicated that the relationship with blackfoot disease is not only with arsenic but also humic substances. This paper presents some results concerning the characterization (such as fluorescence, elemental composition, molecular weight and carbon distribution) of humic substances isolated from the Fuhsing well water of the blackfoot disease area. For comparison, the dissolved organic carbon (DOC) and humic substances in the normal well water from Chiuying and the Nanwan coastal water were also analyzed. In general, in the well water of the blackfoot disease area, extremely high concentrations of DOC (18.5mg/L) and fulvic acid (7.54mg/L) with high fluorescence intensity (59.1, equivalent to 0.0282uM quinine sulfate solution) and high percentages (over 50%) of low molecular weights of less than 1,000 were obtained compared with those of normal waters. C‐13 Nuclear magnetic resonance spectroscopy showed a high content (37.2%) of aromatic carbon. These higher concentrations of DOC and fulvic acid with the higher content of aromatic carbon in well water might be one of the key factors causing the blackfoot disease in Taiwan.     

Measuring dissolved organic carbon δ13C in freshwaters using total organic carbon cavity ring-down spectroscopy (TOC-CRDS)

This article reports the first application of coupled total organic carbon cavity ring-down spectroscopy (TOC-CRDS) for the analysis of the ??¹³C signature of dissolved organic carbon (DOC) in freshwater samples. DOC represents a major, dynamic component of the global carbon cycle. The export of DOC from soils into rivers and groundwaters may be highly climate sensitive, and much of this export may occur in ephemeral fluxes. Thus, a robust, simple and inexpensive method for the continuous determination of DOC concentration and quality is urgently needed. We detail recent advances made in the analysis of the ??¹³C signature of DOC using a TOC-CRDS system optimised for the analysis of DOC with natural abundances greater than 2.5?mg?L^?1 with no sample pre-concentration required and sample volumes of 40?mL. Precision between replicated samples was comparable to conventional analysis by gas-source isotope ratio mass spectrometry, yielding ??¹³C values with standard deviations of?±?0.5??? for DOC concentrations higher than 1.5?mg?L^?1. The utility of this technique for the analysis of DOC in samples with a broad range of compositions and concentrations (2.5?C25?mg?L^?1 DOC) is demonstrated. Since DOC ??¹³C can be measured continuously, ca. 45?min per measurement, this method enables the online monitoring of DOC in river water, water intakes and treated waters, allowing changes in DOC fluxes to be monitored in real time.     

Identification of sources,characteristics and photochemical transformations of dissolved organic matter with EEM-PARAFAC in the Wei River of China

• The source of DOM in surface water and sediment is inconsistent. • The DOC content changes differently in surface water and sediment. • The content of DOC in the surface water is lower than that in the sediment. • The DOM in the surface water had higher photodegradation potentials than sediment. Dissolved organic matter (DOM) in rivers is a critical regulator of the cycling and toxicity of pollutants and the behavior of DOM is a key indicator for the health of the environment. We investigated the sources and characteristics of DOM in surface water and sediment samples of the Wei River, China. Dissolved organic carbon (DOC) concentration and ultraviolet absorbance at 254 nm (UV₂₅₄) increased in the surface water and were decreased in the sediment downstream, indicating that the source of DOM in the water differed from the sediment. Parallel factor (PARAFAC) analysis of the excitation-emission matrices (EEM) revealed the presence of terrestrial humus-like, microbial humus-like and tryptophan-like proteins in the surface water, whereas the sediment contained UVA humic-like, UVC humic-like and fulvic-like in the sediment. The DOM in the surface water and sediment were mainly derived from microbial metabolic activity and the surrounding soil. Surface water DOM displayed greater photodegradation potential than sediment DOM. PARAFAC analysis indicated that the terrestrial humic-like substance in the water and the fulvic-like component in the sediment decomposed more rapidly. These data describe the characteristics of DOM in the Wei River and are crucial to understanding the fluctuations in environmental patterns.     

金属浓度,半透膜孔径,水温及配位体对半透膜囊吸收铜的影响

在实验室条件下，研究了影响树脂－半透膜囊吸收铜的主要因素，重点探讨了水相铜含量，半透膜孔径，温度以及天然河水中的有机配位体对吸收的影响。结果表明，半透膜囊吸收量与水相游离铜浓度，水温及半透膜孔径的非整数次幂成正比，其中包括ＥＤＴＡ，河水富里酸，以及河水中的各种天然有机物在内的配位体均与铜生成不能被半透膜囊吸收的络合物，研究结果进一步证实了半透膜囊对水环境中游离态微量金属进行长期监测的可行性。     

Fluxes and Transport of Organic Carbon and Trace Metals in the Tropical Tsengwen Estuary,Southwestern Taiwan

Distributions of organic carbon and trace metals were investigated in the tropical Tsengwen river end-member and in the estuary to better understand thoroughly the riverine fluxes and estuarine transports of constituents into the sea. Experimental results indicated that riverine fluxes of organic carbon and trace metals possessed a highly temporal variability, attributed primarily to temporal variation in river water discharge and suspended load. More than 70% of annual fluxes of dissolved constituents and >90% of particulate constituents arose from river floods caused by summer typhoons. the flushing time of fresh water in the estuary varied from a half month in the dry season to a half day in the flood period. Dissolved organic carbon (DOC) and nutrienttype metals (Cd, Cu, Zn) were conservatively transported through the estuary. Dissolved particle-reactive metals (Mn, Pb), however, were apparently transported non-conservatively through the estuary. Particulate organic carbon (POC) and trace metals (PTM) were transported non-conservatively by following the transport mode of total suspended matter (TSM) in the estuary. DOC slightly dominates the transport of organic carbon while particle-reactive PTM predominates the transport of trace metals through the estuary. Total organic carbon (TOC) in estuarine sediment was progressively enriched with ¹³C downstream, as derived by mixing the overlying TSM between terrestrial and marine end-members. Distributions of trace metals in sediment were subsequently controlled by sedimentary TOC and particle size. Based on results presented here, we believe that enrichments of trace metals in the estuary are attributed primarily to the natural processes of transport and sedimentation of fluvial TSM     

Removal of organic matter and disinfection by-products precursors in a hybrid process combining ozonation with ceramic membrane ultrafiltration

The performance of an integrated process including coagulation, ozonation, ceramic ultrafiltration (UF) and biologic activated carbon (BAC) filtration was investigated for the removal of organic matter and disinfection by-products (DBPs) precursors from micro-polluted surface water. A pilot scale plant with the capacity of 120 m³ per day was set up and operated for the treatment of drinking water. Ceramic membranes were used with the filtration area of 50 m² and a pore size of 60 nm. Dissolved organic matter was divided into five fractions including hydrophobic acid (HoA), base (HoB) and neutral (HoN), weakly hydrophobic acid (WHoA) and hydrophilic matter (HiM) by DAX-8 and XAD-4 resins. The experiment results showed that the removal of organic matter was significantly improved with ozonation in advance. In sum, the integrated process removed 73% of dissolved organic carbon (DOC), 87% of UV₂₅₄, 77% of trihalomethane (THMs) precursors, 76% of haloacetic acid (HAAs) precursors, 83%of trichloracetic aldehyde (CH) precursor, 77% of dichloroacetonitrile (DCAN) precursor, 51% of trichloroacetonitrile (TCAN) precursor, 96% of 1,1,1-trichloroacetone (TCP) precursor and 63% of trichloronitromethane (TCNM) precursor. Hydrophobic organic matter was converted into hydrophilic organic matter during ozonation/UF, while the organic matter with molecular weight of 1000–3000 Da was remarkably decreased and converted into lower molecular weight organic matter ranged from 200–500 Da. DOC had a close linear relationship with the formation potential of DBPs.     

低分子有机酸对土壤氟吸附的影响

用等温平衡吸附法研究了柠檬酸、草酸对砂姜黑土和潮土氟吸附的影响 ,提出了有机酸影响氟吸附的可能机理。实验结果表明 ,有机酸对土壤氟吸附有较大的影响 :(1)当有机酸处于低浓度时 ,土壤氟吸附量随浓度升高而增加 ;高浓度时 ,土壤氟吸附量随有机酸浓度升高而降低 ;(2 )在有机酸存在条件下 ,土壤氟的吸附量与平衡氟浓度间呈极显著的直线正相关或负相关