Application of the benthic index of biotic integrity to environmental monitoring in Chesapeake Bay

The Chesapeake Bay benthic index of biotic integrity (B-IBI) was developed to assess benthic community health and environmental quality in Chesapeake Bay. The B-IBI provides Chesapeake Bay monitoring programs with a uniform tool with which to characterize bay-wide benthic community condition and assess the health of the Bay. A probability-based design permits unbiased annual estimates of areal degradation within the Chesapeake Bay and its tributaries with quantifiable precision. However, of greatest interest to managers is the identification of problem areas most in need of restoration. Here we apply the B-IBI to benthic data collected in the Bay since 1994 to assess benthic community degradation by Chesapeake Bay Program segment and water depth. We used a new B-IBI classification system that improves the reliability of the estimates of degradation. Estimates were produced for 67 Chesapeake Bay Program segments. Greatest degradation was found in areas that are known to experience hypoxia or show toxic contamination, such as the mesohaline portion of the Potomac River, the Patapsco River, and the Maryland mainstem. Logistic regression models revealed increased probability of degraded benthos with depth for the lower Potomac River, Patapsco River, Nanticoke River, lower York River, and the Maryland mainstem. Our assessment of degradation by segment and water depth provided greater resolution of relative condition than previously available, and helped define the extent of degradation in Chesapeake Bay.     

渤海大气气溶胶元素组成及物源分析

利用电感耦合等离子体-光发射光谱法(ICP-OES)分析了2000年夏季渤海大气气溶胶样品,给出了渤海气溶胶污染物浓度分布特点,结合气象资料和富集因子进行了元素物源分析.分析结果表明,辽东湾的污染程度高于其他海区,气溶胶中含量最高的元素是Zn(1638ng/m3),含量最低的是V(2ng/m3).渤海气溶胶中Pb、Zn、Cu和Ni等具有较高的富集因子.辽东湾Pb的富集因子达4000以上,Zn的富集因子普遍大于其他海区.Pb、Mn、Cu、V等含量的相对大小与同期北京的分析结果一致.综合分析表明,渤海大气严重受到陆地人为排放污染物的影响.     

Diode laser system for measurement of gaseous ammonia in ambient air

The use of a second harmonic diode laser system for monitoring gaseous ammonia in tropospheric air is discussed. Using a 96 m White cell operated at 13 torr pressure in flow mode, a minimum detectable concentration lower than 1 ppbv was obtained.The NH₃ mixing ratio was determined by simultaneous spectroscopic analysis of an atmospheric CO₂ line used as a built-in calibration standard.     

Recovery of a freshwater wetland from chemical contamination after an oil spill

In March 2009, a cargo ship spilled 250 tons of heavy fuel oil off the Queensland coast of Australia. The pristine National Park Moreton Island, seven nautical miles to the east of the spill site, was most affected by the oil slick. Contamination of the island's shoreline was widespread, with freshwater wetlands particularly slow to recover as clean-up needed to be carefully managed to avoid damage to this sensitive ecosystem. During the clean-up process on Moreton Island a monitoring program was initiated using traditional chemical analysis in combination with bioanalytical techniques to assess the extent and variability in contamination at sites on the shoreline and freshwater wetlands. Water accommodated fractions (WAF) of oil residues from samples taken directly after the spill on the shoreline showed the same level of toxic potency as samples from the wetland while baseline-toxicity equivalent concentrations (baseline-TEQ) and 2,3,7,8-tetrachlorodibenzodioxin equivalent concentrations (TCDDEQ) were much lower in oil collected from the sandy beach. The umuC assay for genotoxicity and the E-SCREEN assay for estrogenic effects indicated the extracts were not genotoxic or estrogenic. PAH concentrations and toxicity in grab water samples were below detectable levels, however, extracts from time integrated silicone passive samplers deployed for several weeks at the contaminated sites gave measurable responses in the bioassays with TCDDEQ levels increased relative to the control site. The low levels of baseline-TEQ and TCDDEQ present after 8 months had further decreased 6 months later indicating satisfactory recovery of this pristine ecosystem after an oil spill.     

气相分子吸收光谱法测定海水中氨氮的干扰因素识别及预处理方法研究

采用气相分子吸收光谱法测定海水样品中的氨氮,重点考察海水中共存离子对氨氮测定结果的影响规律,识别测定过程中主要的干扰因素,并提出消除干扰的预处理方法.研究结果表明,碘离子会对氨氮的测定产生负干扰,当样品中碘离子质量浓度达到0.0765 g/L时,氨氮的测定结果与标准值相比明显降低,且在碘离子质量浓度达到0.1910 g...     

Influence of water pollution on the growth and pigment concentration of the microalgae <Emphasis Type="Italic">Phaeodactylum tricornutum</Emphasis> Bohlin (Bacillariophyta)

The aim of the work was to study the influence of the water taken from one of the most polluted parts of the Peter the Great Bay (the Japan Sea), the Nakhodka Bay, on the growth and chlorophyll a concentration in the cells of microalga P. tricornutum Bohlin (Bacillariophyta). The estimation of the dynamics of cell number growth and chlorophyll a concentration in the cells of microalga grown in the water from the Nakhodka Bay was made. At the same time, in 2007–2008, the main hydrochemical parameters, such as water salinity, dissolved oxygen concentration, BOD₅, organic and mineral phosphates concentration, anionic surfactants, and total petroleum hydrocarbons, were determined. It is shown that in July 2007, when most hydrochemical parameters were lower than the maximum permissible level, the culture growth and chlorophyll a contents in the cells did not differ from the control for certain. In other seasons these indices differed greatly from the control. The positive correlation between the concentration of dissolved oxygen, phosphates, petroleum hydrocarbons, and the number of microalga cells, grown in the water from the Nakhodka Bay, was shown.     

香溪河库湾氮的时空分布及影响因子分析

为研究解决香溪河库湾水体富营养化问题,需探明库湾水体氮的时空分布及影响因子。2010年12月—2011年11月对香溪河与水库干流交界处至香溪河库湾尾部共12个采样点进行连续监测,分析香溪河库湾氮的时空分布,结果表明,香溪河库湾氮存在明显的时空分布规律。空间上,回水末端处TN和NO₃^--N浓度低,河口处浓度高,随着与回水末端距离的增加,浓度逐渐升高。在时间上,香溪河库湾TN和NO₃^--N浓度的变异系数随着与河口距离的增加总体上逐渐增大,研究时间内的变化程度逐渐变大;且香溪河库湾TN和NO₃^--N浓度在三峡水库不同运行阶段的时间变化规律不同。     

Investigation of heavy metal content in the suspended particulate matter and sediments of inner Gokova Bay and creeks

The Bay of Gokova in Southeastern Aegean Sea (Turkey) is important by the potential of agricultural, municipal, and tourism activities. In addition, there is no industrial plant within the area in the Aegean Sea. Kad?n Creek (Azmak) and Ak?ap?nar Creek (Azmak) flowing into the inner Gokova Bay are one of the important factors in determining the character of the inner Gokova Bay. In this study, nine stations were selected in the inner Gokova Bay, Kad?n Creek, and Akcap?nar Creek. The concentrations of Cd, Cu, Fe, Pb, and Zn were measured in suspended particulate matter (SPM) and sediments. The samples of sediments and SPM were collected in between February 2008 and September 2008. The aim of the study is searching the change of concentrations of Cd, Cu, Fe, Pb, and Zn in suspended particulate matter and sediments in the inner Gokova bay, Kad?n Creek, and Ak?ap?nar Creek. It has been identified that the metal concentrations in the creeks are higher than the metal concentrations in the marine environment. It has also been observed that the concentrations of Pb, Cd, and Cu in summer season have been higher than in the winter season, but the concentrations of Fe and Zn have not shown a significant difference between in summer and winter seasons. The obtained results show that the some heavy metals are caused by the agricultural, municipal, and tourism activities operating in the coastal areas and terrestrial environment, and they are transported from the creeks to the Gokova Bay by suspended particulate matter.     

Ground water discharge and the related nutrient and trace metal fluxes into Quincy bay,Massachusetts

Measurement of the rate and direction of ground water flow beneath Wollaston Beach, Quincy, Massachusetts by use of a heat-pulsing flowmeter shows a mean velocity in the bulk sediment of 40 cm d^–1. The estimated total discharge of ground water into Quincy Bay during October 1990 was 1324–2177 m³ d^–1, a relatively low ground water discharge rate. The tides have only a moderate effect on the rate and direction of this flow. Other important controls on the rate and volume of ground water flow are the limited thickness, geographic extent, and permeability of the aquifer. Comparisons of published streamflow data and estimates of ground water discharge indicate that ground water makes up between 7.4–12.1% of the gaged freshwater input into Quincy Bay. The data from this study suggest the ground water discharge is a less important recharge component to Quincy Bay than predicted by National Urban Runoff Program (NURP) models.The high nitrate and low nitrite and ammonia concentrations in the ground water at the backshore well sites and low nitrate and high nitrite and ammonia concentrations in the water flowing from the foreshore suggests that denitrification is active in the sediments. The low ground water flow rates and low nitrate concentrations in the foreshore samples suggest that little or no nitrate is surviving the denitrification process to affect the planktonic community. Similarly, oxidizing conditions in the aquifer and low trace metal concentrations in the ground water samples suggest that the metals may be precipitating and binding to sedimentary phases before impacting the bay.     

An assessment of water quality and primary productivity in Perdido Bay,a Northern Gulf of Mexico Estuary

Perdido Bay is a shallow estuarine system of approximately 130 km² with three major freshwater inputs. On a seasonal basis the productivity and chlorophyll a concentration of phytoplankton in Perdido Bay are controlled by temperature. One input, Eleven Mile Creek, is influenced by a paper mill discharge. Eleven Mile Creek exhibits high levels of light attenuation, high concentrations of dissolved nutrients, and low rates of carbon fixation that are significantly different from the other inputs or areas of Perdido Bay and productivity in Eleven Mile Creek is light limited. Upper Perdido Bay had slightly elevated concentrations of dissolved nutrients which correlate with significantly higher rates of carbon fixation and phytoplankton biomass. Nutrients and color from Eleven Mile Creck are diluted by the Perdido River inflow, restricting nutrient and light limitations to the area at the mouth of Eleven Mile Creek.     

锦州湾海域生态系统健康状况评价

基于结构功能指标体系评价法,利用层次分析法构建锦州湾海域生态系统健康评价指标体系,并选择2005—2009年8月生态调查数据对其进行初步的定量评价。结果表明,可以通过海洋化学指标、生态学指标和社会经济学指标三大类33个指标来建立锦州湾生态系统健康评价指标体系;2005—2009年8月锦州湾生态系统的整合健康指数依次分别为1.01、1.90、2.00、1.45和1.10,均低于系统健康指数值2,锦州湾海域生态系统连续5年一直处于亚健康状态,且从目前海域的污染现状来看,这一海域的水质、沉积物和生物体污染均比较严重,要修复其生态功能需要投入巨大的物质和能量。     

内河涌氨氮污染的特征及其来源的研究

以佛山市雅瑶涌为研究实例,探讨了珠江三角洲河网地区围内河涌氨氮污染的特征,并对氨氮的来源进行了研究。内河涌的氨氮污染逐年严重,并呈现季节性的变化,已成为最主要的污染因子。研究结果表明,畜牧水产业和非点源都是比较显著的氨氮污染源,但未经集中式污水处理厂处理的生活污水,则成为内河涌最重要的氨氮污染源。     

Nitrate Leaching by Atmospheric N Deposition to Upper Groundwater in the Sandy Regions of The Netherlands in 1990

Anthropogenic increase in atmospheric nitrogen (N) deposition in nature areas results in nitrate leaching to groundwater, threatening its quality. Member states of the European Union are obliged to reduce groundwater nitrate concentrations and to monitor this reduction. The relationship between N deposition and groundwater nitrate concentrations is quantified using a field survey and geographical information. Nitrate concentrations of the uppermost metre of groundwater in nature areas in the sandy regions in 1990 were related to geographical data by means of regression analysis. In this way nitrate concentrations could be explained by potential ammonia deposition, soil type, vegetation and land use. We found that about 35% of 54 kg ha(-1) a(-1) atmospheric N deposition was leached to the upper groundwater as nitrate, resulting in a mean NO3 concentration of about 30 mg L(-1). The critical N load for exceeding the EC limit value (50 mg L(-1)) in the sandy regions of The Netherlands composed of natural vegetation will be about 80 kg ha(-1) a(-1). Leaching is less than expected for nature areas but comparable with leaching of N surpluses in pastures in The Netherlands. A reduction in nitrate leaching by 25% or more can currently be detected via a new field survey.     

气相分子吸收光谱法在海水无机氮测定中的适用性研究

为探究气相分子吸收光谱法在海水无机氮测定中的适用情况,在检出限的10～20倍、30～50倍、50～100倍3个浓度范围内开展了准确度、加标回收率和方法比对试验。结果表明,采用气相分子吸收光谱法测定海水亚硝酸盐氮(0～0.100 mg/L)、硝酸盐氮(0～0.400 mg/L)、氨氮(0～0.200 mg/L)时,标准曲线均具有很好的线性,线性拟合度均在0.999 3以上,检出限依次为0.000 8、0.004、0.004 mg/L,且该方法不具有盐效应,适用于海水样品的检测。当样品浓度太低时,气相分子吸收光谱法测定结果的准确度较低,因此,建议仅在亚硝酸盐氮浓度高于0.030 mg/L、硝酸盐氮浓度高于0.100 mg/L、氨氮浓度高于0.090 mg/L时使用该方法,对应的海域为河口及近岸等无机氮含量较高的海域。此外,为保证测定结果的准确度,每个样品需平行测定2～3次。     

北京市某典型污水处理厂氨气排放研究

在污水处理厂的格栅、沉砂池、初沉池、曝气池、二沉池采集气样,同时采集相应点位水样,分析各点位氨气排放特征及其与污水指标间相关性。在格栅间、污泥脱水间收集氨气浓度分析密闭车间氨气排放量,结果表明:水气界面格栅间氨气排放浓度最高,随着处理工艺的进行,氨气排放浓度呈下降趋势;氨气排放浓度与污水中氨氮浓度及总氮浓度有较好的线性关系;沉砂池及初沉池氨气挥发速率远高于曝气池和二沉池;各工艺段氨气排放量差异较大,污水厂污水氨气排放量为922 mg/m~3,初沉池对污水厂氨气贡献率最高,为78.8%。     

莱州湾表层沉积物中多氯联苯的测定方法及分布特征探究

以加速溶剂萃取法 (ASE)、索氏提取法/气相色谱法测定了莱州湾表层沉积物中的12种PCBs的浓度水平,探讨了它的分布特征并将两种方法进行了对比;同时测定了渤海湾北部海域表层沉积物中PCBs的含量,与莱州湾进行了比较。结果表明,莱州湾海域表层沉积物检测出8种多氯联苯(PCBs),浓度范围是N.D.~48.40 ng ·g ^-1dw。该海域多氯联苯的分布特征是近岸高,离岸低,由近岸向湾外延伸方向依次递减;渤海湾PCBs的浓度范围是0.15~68.30 ng ·g ^-1dw,和莱州湾差别不大。索氏提取法测定12种多氯联苯类化合物的基质加标回收率为78.00%~104.85%,相对标准偏差为0.95%~3.64%;加速溶剂萃取法的基质加标回收率为90.00%~102.00%,相对标准偏差为0.65%~2.75%;相对于渤海湾北部海域而言,莱州湾区域只是受到轻度污染,属于低风险生态区,不会对生物产生毒副作用;而前者则处于中度污染水平,可能会对生物产生毒副作用。     

Phytoplankton variation and its relationship with the environment in Xiangxi Bay in spring after damming of the Three-Gorges, China

Following the completion of the Three-Gorges Dam, there was a strong spring phytoplankton bloom in Xiangxi Bay of Three-Gorges Reservoir. However, our knowledge of relationship between spring phytoplankton bloom and environmental factors was still limited. In this study, phytoplankton species composition, biomass, chlorophyll a concentration and environmental factors at two sampling sites in Xiangxi Bay were investigated during 25 March to 18 May 2007. The Xiangxi Bay was eutrophic with the lowest values of total nitrogen and total phosphorus being 0.80 and 0.07?mg/L, respectively. A total of 66 algal taxa belonging to seven phyla and 45 genera were identified. Peridiniopsis niei Liu was the most abundant species which preferred standing water. Canonical correspondence analysis and correlation analysis revealed that nitrate was significantly associated with phytoplankton growth. The phytoplankton chlorophyll a concentration was correlated significantly negatively with nitrate concentration, and nitrate concentration was very low during bloom periods. Heavy rainfall was the main reason of phytoplankton chlorophyll a concentration and biomass decreasing and blooms disappearing. In addition, heavy rainfall also brought more nitrate into the Bay which provided sufficient nitrogen source for blooms occurring again.     

污水处理厂氮排放特征

为了更好地掌握污水处理厂运行和排放情况,在全国南方、北方分别选取3个省共11个城市122家污水处理厂,于2013年8—10月进行了专项监测。结果表明：75?4％的污水处理厂氨氮出水质量浓度小于2 mg／L,氨氮平均去除率达90?2％,但总氮的平均去除率仅为55?5％,污水处理厂排水中仍存在较多非氨氮形态的氮污染进入环境。氨氮排放达标的污水处理厂中,有约20％的总氮排放未达标。65?5％的污水处理厂出水氨氮占总氮的比例低于10％,而84?4％的污水处理厂进水中氨氮占总氮的比例高于50％。总氮是影响污水处理厂达标排放的主要污染因子。     

Pollution risk assessment based on QUAL2E-UNCAS simulations of a tropical river in Northern India

This paper exemplifies the application of U.S. Environmental Protection Agency's water quality model, QUAL2E-UNCAS in assessing the pollution risk of a tropical river. The rivers selected for study were Hindon (main river) and Kali (its tributary) flowing through Uttar Pradesh district of Northern India. The model application to the two rivers revealed poor water quality in terms of dissolved oxygen (DO), biochemical oxygen demand (BOD), and ammonia concentrations. Monte Carlo simulations were performed on two different data sets that were confirming to marked seasonal variations. The Monte Carlo simulation (MCS) derived 95 % confidence level for these parameters strengthened the fact that all point sources were exploiting the assimilative capacity of the two rivers. In order to ascertain probabilistically the risk at which two rivers were falling short of desired water quality, probability curves based on effluent standards and available water quality were prepared. On mapping the two curves, it was found that at 95 % probability, Hindon River was flowing with 53 to 100 % less of desired DO, up to 100 % more of minimum BOD, and probability with which ammonia concentration would not be more than the desired concentration was found to fall downstream. The Kali headwaters showed better quality during low river temperature but worsened downstream with up to 100 % violation in all the above observed parameters. It is expected that similar studies wherein the dependable levels with which a polluted river can be understood to fall short of desired water quality can prove to be useful in ascertaining the efficacy of effluent standards and/or follow-up of pollution control measures.     

高浓度含氨废水中氨氮的快速测定

依据铵盐与甲醛反应生成等物质量酸的原理,建立了一种快速测定高浓度含氨废水中氨氮含量的甲醛法。试验结果表明,甲醛法所测结果与国家标准分析方法比较无显著性差异。该方法的加标回收率范围为96％～103％,具有快速、简便的优点,对合成氨工业废水和生活污水中氨氮的测定结果令人满意。