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31.
古深3井是部署在松辽盆地西部断陷区古龙断陷敖南凹陷的一口风险预探井,目的层为营城组,在3180～4460 m非目的层井段实施气体钻井,层位为泉一段～登一段,总进尺1208.72 m。通过地层出水预测,结合气体钻井的特点,对井身结构设计、钻具组合设计、钻头及参数优选以及注气排量设计等进行了优化设计,同时优化钻井工艺,采用气液转换,机械钻速达6.36 m/h,比邻井古深1井同层位常规钻井平均机械钻速1.40 m/h提高了4.54倍,缩短了钻进周期43.56天,提速效果明显。同时创造了气体钻井单只钻头进尺674.87 m和单只钻头使用时间101.88 h的新纪录。 相似文献
32.
Sheila J. Logan 《新西兰海洋与淡水研究杂志》2013,47(4):699-714
Some aspects of the biology of Diloma (Fractarmilla) novaezelandiae (Anton) (= Zediloma subrostrata), a soft‐shore trochid gastropod, were investigated in Latham Bay, Portobello, South Island, New Zealand (45° 50’ 25” S, 170° 38’ 30” E). The distribution of D. novaezelandiae during September 1973 to June 1974 was recorded along three transects; pebble distribution, macroalgal cover, grain‐size distribution and organic carbon content in the sediment, range of water salinity, and length of time of exposure to air were also recorded along the transects. The greatest population density of D. novaezelandiae occurred between 0.8 m and 1.4 m above Chart Datum. The trochid was found to prefer a hard substratum to a soft substratum, and there was a positive correlation of organic content of the sediment with density of D. novaezelandiae. As the population density decreased towards low water the individual shell size increased. Size: weight relationships were calculated and the results showed that dry flesh weight and dry shell weight were both proportional to the cube of the shell diameter. 相似文献
33.
David Roper 《新西兰海洋与淡水研究杂志》2013,47(4):487-498
Abstract Benthos near a sewage outfall discharging 69 000 m3 d?1 of municipal sewage into Tauranga Harbour was studied to determine the nature and extent of the impact caused by a small organic input. Sediment samples were collected about the outfall and analysed for particle size, sorting, mud content, readily oxidisable carbon (ROC), total Kjeldahl nitrogen (TKN), total phosphorus (TP), “oil and grease” (OG), and macroinvertebrates. It is concluded that observed patterns of physical sediment characteristics are mainly natural. Levels of ROC, TKN, TP, and OG were all highest at or nearby the outfall. However, chemical changes in the sediment related to the discharge seemed to be limited to within less than 50 m distance of the outfall. The distributions of ROC, TKN, and TP in the sediments were closely related to natural changes in mud content. The outfall had little effect on the distribution of total numbers of taxa or individuals, or the composition of macro‐invertebrate assemblages. Rather, these were most closely related to the (probably natural) variability in sediment particle size and sorting. Analysis of the distributions of common species showed that several were responding to the discharge, but such responses were limited to within 10 m of the outfall. Trie absence of extensive impact on benthos from the outfall probably related to high water velocities (up to 0.5 m sr?1 on a mean tide) over the outfall diffuser, which would ensure that any drop in sediment oxygen levels is small. 相似文献
34.
35.
Xu J Ho AY Yin K Yuan X Anderson DM Lee JH Harrison PJ 《Marine pollution bulletin》2008,57(6-12):335-348
In 2001, the Hong Kong government implemented the Harbor Area Treatment Scheme (HATS) under which 70% of the sewage that had been formerly discharged into Victoria Harbor is now collected and sent to Stonecutters Island Sewage Works where it receives chemically enhanced primary treatment (CEPT), and is then discharged into waters west of the Harbor. The relocation of the sewage discharge will possibly change the nutrient dynamics and phytoplankton biomass in this area. Therefore, there is a need to examine the factors that regulate phytoplankton growth in Hong Kong waters in order to understand future impacts. Based on a historic nutrient data set (1986-2001), a comparison of ambient nutrient ratios with the Redfield ratio (N:P:Si=16:1:16) showed clear spatial variations in the factors that regulate phytoplankton biomass along a west (estuary) to east (coastal/oceanic) transect through Hong Kong waters. Algal biomass was constrained by a combination of low light conditions, a rapid change in salinity, and strong turbulent mixing in western waters throughout the year. Potential stoichiometric Si limitation (up to 94% of the cases in winter) occurred in Victoria Harbor due to the contribution of sewage effluent with high N and P enrichment all year, except for summer when the frequency of stoichiometric Si limitation (48%) was the same as P, owing to the influence of the high Si in the Pearl River discharge. In the eastern waters, potential N limitation and N and P co-limitation occurred in autumn and winter respectively, because of the dominance of coastal/oceanic water with low nutrients and low N:P ratios. In contrast, potential Si limitation occurred in spring and a switch to potential N, P and Si limitation occurred in eastern waters in summer. In southern waters, there was a shift from P limitation (80%) in summer due to the influence of the N-rich Pearl River discharge, to N limitation (68%) in autumn, and to N and P co-limitation in winter due to the dominance of N-poor oceanic water from the oligotrophic South China Sea. Our results show clear temporal and spatial variations in the nutrient stoichiometry which indicates potential regulation of phytoplankton biomass in HK waters due to the combination of the seasonal exchange of the Pearl River discharge and oceanic water, sewage effluent inputs, and strong hydrodynamic mixing from SW monsoon winds in summer and the NE monsoon winds in winter. 相似文献
36.
Melbourne Water's Eastern Treatment Plant (ETP) produces a secondary-treated sewage effluent which is chlorinated and discharged into Bass Strait at Boags Rocks, Victoria, Australia. Disappearance of the sensitive brown seaweed Hormosira banksii from rock platforms immediately adjacent to the shore-line discharge was identified in the early 1990s. Subsequently, Melbourne Water and CSIRO undertook an environmental impact assessment and review of land and marine effluent disposal options, which included ambient water quality monitoring, biological monitoring, bioaccumulation studies and toxicity testing of existing effluent to assess the nature and magnitude of the environmental effects. This paper presents data from the toxicity monitoring programs since 2001. Chronic toxicity testing using macroalgal germination and cell division (H. banksii), microalgal growth rate (Nitzschia closterium) and scallop larval development (Chlamys asperrima), confirmed that ammonia was the major cause of effluent toxicity. Results from this toxicity monitoring program were used to develop action trigger values for toxicity for each species, which were then used in a refined monitoring program in 2005-2007. An upgrade of the ETP is in progress to improve nitrification/denitrification in order to reduce ammonia concentrations and the toxicity of the effluent. Toxicity testing with a simulated upgraded effluent confirmed that ammonia concentrations and toxicity were reduced. Estimated "safe" dilutions of effluent, calculated using species sensitivity distributions, decreased from 1:140-300 for existing ETP effluent to 1:20 for nitrified effluent, further confirming that treatment improvements should reduce the impact on marine biota in the vicinity of the discharge. 相似文献
37.
The tannery industry influences the gross domestic product/economic activity of any country, but the uncontrolled release of tannery effluents causes environmental degradation and increases health risks to human. The reason for the toxicity of tannery effluents is the presence of high concentrations of organic and inorganic chemicals used in the production of leather goods. Untreated or partially treated effluents discharged into surface water results in an increase in both chemical and biological oxygen demand as well as in an increase in the levels of total suspended solids, dissolved solids, and toxic metals in environmental bodies, especially in soil, water bodies, and water sediments. Various treatment techniques, such as physicochemical, biological, and advanced oxidation methods, which include chemical precipitation, electrocoagulation, aerobic or anaerobic treatment, wetland construction, and Fenton, electro-Fenton, and photo-Fenton processes are also described. This review also discusses the technical appropriateness and economic feasibility of reducing the effluent pollution load and solid waste emanating from the tannery industry. Considering the enhanced health risks in the tannery waste treatment and management regime, some green and advanced technologies should be explored. A sustainable green technology that avoids the use of toxic chemicals in the tanning process is seen well for ecological health. 相似文献
38.
Yamini Gopalapillai Ismail I. Fasfous John D. Murimboh Tahir Yapici Parthasarathi Chakraborty Chuni L. Chakrabarti 《Aquatic Geochemistry》2008,14(2):99-116
Free metal ion concentration is generally considered a useful indicator of a metal’s bioavailability and ecotoxicity to aquatic
biota. This article reports the speciation of nickel in mining and municipal effluents from Sudbury (Ontario, Canada), and
also in model solutions containing a fully characterized laurentian fulvic acid (LFA) at environmentally relevant concentrations.
A column ion exchange technique (IET) using a cation exchange resin (Dowex 50W-X8) was applied to determine free nickel ion
concentrations. In model solutions, reasonable correlation was found between the predictions of an equilibrium-based computer
speciation code, Windermere Humic Aqueous Model (WHAM) VI, and the results obtained by IET at low nickel-to-fulvic acid ratios.
However at higher mole ratios, the WHAM VI predicted higher free nickel ion concentrations than IET. Only three out of six
effluent samples showed reasonable agreement between the IET and the WHAM VI results, indicating the need for further development
of IET for application to effluent waters. 相似文献
39.
In order to help evaluate the trends in the NO3-N concentration in groundwater with a view to preventing further degradation in water quality in the future, a distributed groundwater quality model was constructed for the Nasunogahara basin. The best fit for the groundwater table elevations by the flow component of the model was achieved with average mean absolute errors (MAEs) of 0·92 m for the calibration period and 0·83 m for the validation period. Moreover, the best fit for the NO3-N concentration by the water quality component was achieved with average mean relative errors (MREs) of 29·8% for the calibration period and 30·3% for the validation period. After developing a robust model, various change scenarios were tested; specifically, the effects of effluent load control and a decrease in paddy field area on the NO3-N concentration in groundwater were predicted. The most intensively farmed area contributed about 40% of the total effluent load because of livestock farming in the basin. When the effluent load from this area was decreased by 50%, the average NO3-N concentrations at sites S1, S2 and S3 were reduced by about 15%; however, the average concentrations at S4 and S5 were reduced by only 1%. Furthermore, when the total effluent load from the concentrated livestock area was removed completely, the average groundwater NO3-N concentrations at S1, S2 and S3 were reduced by about 30% as compared with the original calculated results. In contrast, decreasing the area of the paddy fields in the basin did not greatly influence the groundwater NO3-N concentration. In the case of a 70% reduction in paddy field area, average NO3-N concentrations increased by about 7% at S1, S2 and S3. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
40.
Viswanaathan Shashirekha Melatheru Ramanujam Sridharan Mahadeswara Swamy 《洁净——土壤、空气、水》2011,39(9):863-873
Trivalent chromium in the form of basic chromium sulfate (BCS) is used for tanning hides/skins and is a strong pollutant of the soil and water bodies. Significant quantities of unutilized chemicals, such as sulfates, chlorides, are also discharged, contributing to high levels of total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), etc. Though many treatment techniques are being practiced, biotechnological methods are gaining importance. Biosorption is recognized as a cost‐effective technology worldwide; one potential sorbent being blue–green algae (BGA), for treating metal‐bearing effluents. This work studies the feasibility of using a species each of Spirulina, Oscillatoria, and Synechocystis, individually and as a consortium, as sorbents to remove Cr3+ from a segregated stream, viz. exhaust chrome liquor (ECL) and synthetic BCS solution. The species studied were found to be effective in removing Cr3+ considerably at varying concentrations, besides reducing sulfates, BOD, COD, etc. The results of ECL experiments were more encouraging than those for BCS solution. The kinetic data on Cr3+ sorption onto algal biomass fit well into the pseudo‐second order model. The equilibrium data were analyzed using the classic Langmuir and Freundlich isotherm models, yielding good fits. The results of the experiments indicate that algal consortia could be good alternatives to the conventional treatment methods for leather and other industrial wastewaters containing chromium. 相似文献