Variations in physico-chemical and microbiological characteristics of water during breeding of Cyprinus carpio in a closed hatchery system

Physico-chemical and microbial characteristics of culture water were examined during the induced breeding of Cyprinus carpio in a controlled environmental system. Water temperature, dissolved oxygen, nitrate, phosphate, pH, ammonia nitrogen, total bacterial count, hardness, salinity, carbonate and bicarbonate were estimated before and after spawning and hatching. Average alteration in water pH before and after spawning was 7.91-7.57 and 7.86-7.58 respectively. Total hardness, carbonate and bicarbonate showed insignificant variations. Nitrate, ammonia nitrogen and phosphate contents significantly increased after spawning and hatching p < 0.05. The average increase in nitrate was from 2.94 to 8.62 microg l(-1) after spawning and 3.10 to 8.49 microgl(-1) after hatching. Ammonia nitrogen contents were sharply increased from an average of 0.011 to 1.87 mg l(-1) after spawning and 0.013 to 0.56 mg l(-1) after hatching. The average phosphates increased from 2.59 to 4.15 microg l(-1) after spawning and 2.61 to 4.03 microg l(-1) after hatching. Dissolved oxygen was sharply depleted even after a continuous aeration. Temperature played a vital role during breeding. No successful breeding was observed at a temperature of 17 degrees C or below and 31 degrees C or above. There is a significant association between temperature, spawning and hatching (p < 0.05). By optimizing temperature, the breeding success of this carp was achieved with a statistical significance of p < 0.05. Total bacterial count was significantly increased after spawning and hatching. It was related to the amount of discharge and may cause mass mortality of fish embryo and spawn in a closed hatchery system.     

The sands of Forvie (Scotland): A case study in geomorphology and conservational management

The Sands of Forvie, National Nature Reserve, Scotland is a complex coastal sand dune system which is associated with the dynamic estuary of the River Ythan. The dune system has developed over more than 5000 years. The south partis a peninsula of dunes, sandhills, sand arcs, erosion and deflation surfaces. The north part is superimposed on a rock plateau with a cliff coastline. This plateau is covered in glacial deposits and is essentially an upland heath landscape. Some of the best examples of large active parabolic dunes in Britain are found in North Forvie. The sequence of geomorphic development is described. As a nature reserve with a rich ecology it has been managed for conservational purposes since 1960s. As such it is an excellent case study of how conservational management has changed to become more flexible and more aware of the importance of dynamic processes.     

The sands of Forvie (Scotland): A case study in geomorphology and conservational management

The Sands of Forvie, National Nature Reserve, Scotland is a complex coastal sand dune system which is associated with the dynamic estuary of the River Ythan. The dune system has developed over more than 5000 years. The south part is a peninsula of dunes, sand hills, sand arcs, erosion and deflation surfaces. The north part is superimposed on a rock plateau with a cliff coastline. This plateau is covered in glacial deposits and is essentially an upland heath landscape. Some of the best examples of large active parabolic dunes in Britain are found in North Forvie. The sequence of geomorphic development is described. As a nature reserve with a rich ecology it has been managed for conservational purposes since 1960s. As such it is an excellent case study of how conservational management has changed to become more flexible and more aware of the importance of dynamic processes.     

Arkadolith土壤改良剂对内蒙沙区常见牧草生长状况的影响

通过盆栽试验,对土壤采用添加25%土壤改良剂、以及添加12.5%改良剂和12.5%腐殖质的2种处理方式,研究Arkadolith土壤改良剂对冰草（Agropyron desertorum）、沙打旺（Astragalus huangheensis）和准格尔苜蓿（Medicago sativa cv ＂Zhonggeer＂）3种沙生牧草的生长特性的影响。结果表明,3种牧草中,植株高度、生长力、发芽力以及产量都较土壤改良前有所增强,沙打旺和准格尔苜蓿的生长状况要明显好于冰草。含有多种矿物成分的Arkadolith土壤改良剂不仅可以改良贫瘠土壤,提高土壤肥力,促进牧草的增产,而且还可以减少化学肥料的施用,降低成本,做到绿色环保,因此其具有广泛的推广意义。     

Experimental degradation of oil in permeable sand from the Gulf of Aqaba,Red Sea

Degradation rates of light and heavy oil in permeable carbonate sands from the Gulf of Aqaba were investigated to evaluate the ability of sediments to degrade oil compounds. Silicate sands that are less permeable and different properties from carbonate sands were used for comparison. Estimates of oil degradation rates were based on oxygen consumption rates, calculated by incubating natural carbonate sands with oil. The degradation rates of light oil were twofold higher than those of heavy oil, which may be attributed to the presence of a higher carbon number in heavy oil compared with light oil. Degradation rates of light oil in carbonate sands were twofold higher than in silicate sands. Oil degradation rates calculated using the bottle incubation technique were three- to fourfold higher than rates from chamber incubations, indicating the importance of adequate mixing between oil particles and sediments during degradation processes. This study suggests that permeable sands, through their chemical and physical properties, increase oil biodegradation rates by enhancing flow through sediment particles and positively impacting bioturbation processes.     

Trace metal distribution in different chemical fractions of marine sediments along the eastern Aegean shelf

The major objective of this study was to carry out sequential chemical extraction for the partitioning of particulate trace metals in sediment samples, collected along the eastern Aegean shelf during cruises July‐August 1994, in the framework of a National Marine Measurement and Monitoring Programme for the Aegean Sea.

Five metals, Cd, Pb, Cu, Zn and Cr were examined in each of sediment samples. Three chemical fractions of the sediments were separated and concentrations of the trace metals were determined by AAS techniques. The three different leaches used were hydroxylamine hydrochloride‐acetic acid, hydrogen peroxide and nitric‐perchloric acids.

Metals were concentrated mainly in the fraction extracted by nitric‐perchloric acids. Lead in the first fraction were found in the sediments of Northern part of Aegean, where the concentration of organic material was high.

The total concentrations of Cd, Cu, Zn, Cr were higher in Izmir Bay than the other sampling points. The distribution of Pb concentrations was the highest in Edremit Bay and Izmir Bay.     

Mineral, chemical and radiological investigation of a black sand at Touzla Cape, near Thessaloniki, Greece

A black-sand formation located at Touzla Cape, near Thessaloniki city, Greece, was investigated using optical microscopy, powder-XRD, SEM-EDS, INAA and in-situ -ray spectrometry. This black sand is mainly composed of ilmenite, magnetite, garnet, zircon and rutile. Also present, in minor or trace amounts, are quartz, sphene, pyroxenes, sillimanite, feldspars, biotite, haematite, tourmaline, chromite, niobian-rutile and pyrrhotite. Niobian-rutile and pyrrhotite were found as inclusions in ilmenite and magnetite respectively. The radioactivity measurements indicated contributions of the uranium and thorium radioactive series and of 40K and 137Cs, and the maximum value of the total absorbed dose rate in air was found to be 62, 172, 8 and 2 nGy h-1 respectively. The main radioactivity of the uranium and thorium series is attributed to the fractions of zircon (304 µg Th g-1 and 157 µg U g-1), of ilmenite (89 µg Th g-1) and to a lesser extent to the fraction of garnet (5 µg Th g-1). The zircon fraction also contained 5076 µg Hf g-1. Some minerals and elements (Ti, Zr, Hf, Th, U) contained in the black sand could be of potential economic value. The high proportions of monomineralic grains along with the variations observed in mineral phases, in colour, in sphericity, in roundness, in grain size, in composition and in mineral inclusions, imply that the minerals and grains were subjected to several cycles of weathering and sedimentation, as well as being derived from multiple source rocks and areas.     

Trace element content in soils of the King George and Elephant islands,maritime Antarctica

Trace element concentrations were studied in soils of the King George and Elephant islands in the maritime part of West Antarctica. The lowest concentrations of Cu, Pb, Cd, Zn, Ni and Mn were typical for the pristine soil of Elephant Island. The highest concentrations of these elements were found in the Fildes Peninsula and revealed the influence of human activities in the area of the Bellingshausen station and adjacent waste disposal sites. Ornithogenic soils of the Fildes Peninsula have shown low concentrations of Cd and As. Using geoaccumulation indexes, all the pristine soils of King George and Elephant islands and ornithogenic soils of the Fildes Peninsula were classified as unpolluted; the human-affected soils were mainly identified as moderately polluted. Obtained data can be used as background concentration levels for further researches.     

流动沙丘上生态垫防风固沙效果初步评价

北京及其周边地区分布的大量裸露沙荒地是北京近年来沙尘暴频发的主要沙源之一,而增加其地表覆盖状况则是遏止就地扬沙起尘的有效措施之一。以北京西北部河北宣化黄羊滩为例,对流动沙丘上铺设生态垫并栽植灌木的防风固沙效果进行了初步研究。研究结果表明,与沙柳沙障相比,生态垫确实可以降低近地表的输沙率,提高生态垫下土壤的养分含量,一定程度上提高柠条的地径和高度,可见生态垫是一种很好的促进流沙固定和植被恢复的地表覆盖材料;与其它两种生态垫铺设方式(品字状和带状)相比,全铺可以显著降低近地表的输沙率,提高其下土壤的养分含量,但柠条的生长状况却略差,这可能与全铺降低了小雨入渗的可能性有关;就两种部分铺设的方式而言,无论从降低近地表的输沙率还是促进柠条的生长上来看,品字状都明显优于带状。从生态和经济的角度综合考虑,品字状铺设显然是该区域流沙防治措施中较好的选择。     

Trace element geochemistry of the Keana brines field,middle Benue trough,Nigeria

A trace elements study of various samples from the Keana brines field, middle Benue Trough was carried-out to determine the extent to which Pb–Zn–S and BaSO₄ mineralisations have affected the quality of the brines and the waters in the area. Different sample media such as well-water, pond water, brine spring pool water, stream water, stream sediments etc. were analysed. Geochemical results show that Cu, Zn, Pb, As and S are concentrated in the waters (0.3, 0.36, 0.05, 0.07 and 1 1.5 ppm respectively). These elements are more concentrated in both the spring and pond waters, suggesting that the spring water could have acted as the transport medium for these elements released from deep-seated sources. Transitions elements (Ti, V, Cr, Fe, Co, Ni and Sr) are concentrated in the waters. Compared to the World Health Organization (WHO) admissible limits, the well waters present very high concentrations in Cd (0.56 ppm) and Sb (0.40 ppm) (200× and 70× WHO admissible values respectively). There is a preferential concentration of transition elements (Ti, V, Fe, Co and Ni) in the sediments (41.38, 362, 52.21, 269 and 54 ppm respectively) than in the waters (0.70, 0.05, 5.6, 0.04 and 0.02 ppm respectively). Similarly, Cu, Zn, Pb and As are concentrated in the sediments (44, 72, 41 and 14 ppm respectively). The concentrations of transition elements (Ti, V, Cr, Fe, Co and Ni) in the refined salt were highly elevated (784, 363, 283, 105, 59.2 and 42.6 ppm respectively) (7000–10,000× well water). Similarly, the concentrations of As, Pb, Br and Sr in the refined salt were also alarming (11.6, 16.4, 16.4 and 122 ppm respectively), (1000, 700, 3000 and 20,000× well water values respectively). S on the other hand is absent. One of the striking features is the absence of I, Cd, Sb and Se in the refined salt crystals which were detected in the waters and the brines. Compared to WHO admissible values, the refined salt crystal concentrations for Ni (426 ppm) and Cr (283 ppm) were also very high (2000× WHO values respectively) and to a lesser extent Cu (26.9 ppm) and Zn (21.7 ppm) (12 and 7× WHO values respectively).     

滤层厚度对慢滤池深度处理污水的性能影响

将慢滤池用于污水二级出水的深度处理,并利用小试装置研究了滤层厚度对慢滤池性能的影响。选取浊度、COD和色度三个指标,在滤层不同深度处多次取样,分析各指标沿滤层厚度的变化。结果表明,采用粒径为0．4～0．6mm,滤层厚度为800mm的石英砂做滤床时,慢滤池对二级出水具有较好的净化效果：当进水浊度、COD和色度分别为1.3～6．9NTU、30．4～70．0mg·L^-1和20．6°～57．6°时,平均去除率分别达到86．5％、45．0％和46．3％。从试验结果可以看出,慢滤池类似一个微缩的污水二级处理系统,滤层表面的粘性滤膜起到类似初沉池的作用,可以对各指标实现较好的去除,58．6％的浊度、52．7％的COD和45．7％的色度是在滤层上部去除的;慢滤池中部起到类似曝气池的作用,下部起到类似二沉池的作用,对水质指标也能实现一定的去除。     

界面化学与水力学作用下的生物炭在砂柱中的迁移特性

通过柱淋溶实验,分别研究不同离子强度或不同流速作用下,生物炭在石英砂柱中的迁移特征及驱动机制.结果表明,淋溶结束时,在高离子强度条件下,生物炭从生物炭层向石英砂柱中迁移的总质量最大,与1号柱(CK)相比,迁移质量提高了62%;主要驱动力为界面化学作用,高离子强度抑制了生物炭内部碱性物质的释放,颗粒表面双电层被压缩,降低了ζ电位,更多生物炭颗粒滞留在不稳定的第二极小势能处,易迁移出炭层.在高流速条件下,生物炭在石英砂柱中径向迁移深度最大,最大迁移深度为3.5—4 cm.主要驱动力为水力学作用,流速的增加,产生的水动力剪切力促使生物炭大聚体分散成小聚体,有利于生物炭随水流向径向深处迁移.     

Assessment of physico-chemical properties and metal contents of water and sediments of Bodo Creek,Niger Delta,Nigeria

Some physico-chemical properties and the concentrations of the metals Fe, Mn, Ni, Cd, Cr, Co, Cu, Pb, and Zn in water and sediments were examined from September 2011 to January 2012 in Bodo Creek, where oil spills have been recurrent. Temperature, pH, total dissolved solid, conductivity, salinity, dissolved oxygen, biological oxygen demand (BOD), chemical oxygen demand (COD), total hardness, sulfate, nitrate, and phosphate were determined in surface water. Particle size, total organic matter (TOM), and pH were also determined in the sediments. The parameters were within permissible limits except the mean values of BOD, COD, total hardness, and sulfate that exceeded levels permissible for domestic use. The sediments consisted mainly of sand, with TOM ranging from 0.2% to 5.5%. With the exception of cadmium that was below detection limit, metal levels (mg kg^?1) in the sediments were 12 (Mn), 1070 (Fe), 10 (Cu), 10 (Zn), 5.3 (Cr), 1.1 (Pb), 1.0 (Ni), and 0.5 (Co) while in water they were 24, 98, 21, 6.9, 4.0, 0.6, 0.18, and 0.16, respectively. The latter were higher than World Health Organization recommended permissible levels for both surface and drinking water.     

Chemical composition and effects of water extracts of petroleum on eggs of the sand dollar Melitta quinquiesperforata

Sperm and eggs of sand dollars, Melitta quinquiesperforata (Leske), were subjected to two petroleum oils, and effects determined. The oils chosen were Kuwait crude and No. 2 fuel oil, supplied by the American Petroleum Institute. Water-soluble extracts (WSF) from oil-sea water mixes were prepared and the major aromatic components in the WSF of the fuel oil were identified. WSF of No. 2 fuel oil depressed respiration, mobility of sperm, interfered with fertilization and cleavage, and retarded larval development. The effects were detectable at dilutions of 4% and less (about 0.6 ppm of WSF). Kuwait crude was much less toxic. There was no effect on water permeability of the egg membrane. Results are compared with similar studies on other marine organisms.     

北京北部水源地水化学特征及硫同位素变化

分析了北京市北部水源地所在流域丰水期和枯水期的水化学特征和硫同位素变化.结果表明,研究区地表水pH值呈弱碱性,水化学组成以HCO3-和Ca2+为主,Mg2+和SO24-次之.通过对主离子组成的分析,发现研究区水化学特征的主要控制因素是岩石风化,其中绝大部分是受碳酸盐岩的影响.研究区内δ34S值在4.9‰—10.7‰之间,平均值为7.9‰,其中密云水库库区及潮河、白河δ34S平均值分别为8.7‰、6.0‰、8.2‰.研究区内SO24-离子浓度与δ34S值在一定程度上呈负相关,SO24-离子浓度十分集中,降水中的SO24-离子浓度很低,而δ34S值较高.根据质量守恒原理计算出硫元素来源于硫酸盐岩的溶解比例为30.72%—42.47%;来源于硫化物氧化的比例为21.74%—33.49%;来源于大气输入的比例为35.77%.     

Trace element concentration in wheat grain: results from the Swedish long-term soil fertility experiments and national monitoring program

Concentrations of trace elements in wheat grain sampled between 1967 and 2003 from the Swedish long-term soil fertility experiments were analyzed using ICP-MS. The long-term effect of inorganic and organic fertilization on trace metal concentrations was investigated including the impact of atmospheric deposition and myccorhiza, whereas other factors such as soil conditions, crop cultivar, etc. are not discussed in this paper. Mean values derived from 10 experimental sites were reported. Significantly declining Pb and Cd concentrations in wheat grain could be explained by lower atmospheric deposition. Mean Se contents in all samples were 0.031 mg kg⁻¹ grain dry weight. No samples had sufficiently high Se concentrations for human (0.05 mg Se kg⁻¹) or animal demand (0.1 mg Se kg⁻¹). Concentrations of Co in wheat grain were extremely low, 0.002–0.005 mg Co kg⁻¹ grain dry weight, and far below the minimum levels required by animals, which applied to all fertilizer treatments. A doubling of Mo concentrations in grain since 1975 resulted in Cu/Mo ratios often below one, which may cause molybdenosis in ruminants. The increase in Mo concentrations in crops correlated with the decline in sulfur deposition. Concentrations of Cu and Fe declined in NPK-fertilized wheat as compared to unfertilized or manure-treated wheat. Very low concentrations of Se and Co and low concentrations of Fe and Cu require attention to counteract risks for deficiencies. The main characteristic of the study is that there are few significant changes over time between different fertilizer treatments, but throughout there are low concentrations of most trace elements in all treatments. In general, good agreement between concentrations in wheat from the long-term fertility experiments and the national monitoring program indicate that values are representative.     

Trace metals in fish,sediment and water from the south west coast of the Arabian sea,Pakistan

Concentrations of ten metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Hg) in the edible muscle of Arius maculatus captured from eight different near‐shore and off‐shore sites off the south west coast of the Arabian Sea, Pakistan, were determined by atomic absorption spectrophotometry. Relevant water and sediment samples from the sites were also analysed for the metals. Zinc showed the highest metal concentration (6.763 μg/g, wet weight) in the muscle of the fish, while Mn and Hg showed lowest level (0.019 μg/g, wet weight). Of all the metals investigated, largest scatter (measured as σ) was observed for Zn (σ = 2.058 /μg/g) in fish muscle, for Fe and Mn in sediment (σ = 27481 and 44.50 μg/g) and for As in water (σ = 0.270 μg/L). The metal distribution data pertaining to water, fish and sediment were examined on the basis of simple metal correlations. The statistical study revealed that Ni, Cr, Pb and Cu had significant positive correlations (r > 0.830 at ρ = 0.01). The finding substantiated a trace metal concentration gradient in the area, thereby indicating that the local marine environment is contaminated by anthropogenic sources.     

南亚热带中小型水库沉积物中磷的形态与释放特征

以珠海6座典型中小型供水水库为研究对象,通过对水库沉积物中磷形态和释放速率的测定,分析这些水库沉积物中磷形态特征和释放速率及它们与水体磷的关系,了解库容和调水对沉积物中磷形态特点和释放速率的影响.从库容来看,小型水库沉积物中TP及各形态磷含量明显高于中型水库,且小型水库以无机磷为主,中型水库以有机磷为主.小型水库表层底泥的磷释放速率明显高于中型水库.从调水方式来看,抽水水库沉积物中TP及各形态磷含量明显高于非抽水水库且自表层向下大多有递减的趋势,层间波动较大,说明调水入库河流污染日趋严重以及水库调水量增长,沉积物中磷的含量有增加趋势.6座水库沉积物中PO4-P的释放速率与上覆水体TP的增加量以及沉积物中NaOH-P OP含量呈显著的相关性(r>0.80,p<0.05),说明底泥磷释放对水体中TP有很大贡献,而释放的PO4-P主要来源于沉积物中NaOH-P和OP.     

新型填料床-逐级曝气池一体化反应器水处理技术

为解决低浓度污水处理工艺脱氮除磷过程中存在的微生物碳源不足的问题,本文研制了新型填料床-逐级曝气串联反应器.填料床分别采用珊瑚砂、竹炭颗粒、钢渣为填料,在好氧、厌氧兼顾的环境下,实现化学除磷、生物除氮.试验采用模拟生活污水,COD、TN、TP、氨氮的浓度为170—190 mg.L-1、27—30 mg.L-1、8—10 mg.L-1,23—25 mg.L-1.反应器在第27天启动成功,100 d稳定运行结果显示,当HRT为14 h,曝气池DO为3.5 mg.L-1,反应器处理效果良好,出水中COD、TN、TP、氨氮的浓度分别为30.7 mg.L-1、5.59 mg.L-1、1.0 mg.L-1、4.67 mg.L-1,达到《城镇污水处理厂污染物排放标准》(GB18918—2002)中的一级B排放标准.经钢渣填料床处理后的污水,TP浓度降到1 mg.L-1左右,在不排泥的情况下,实现TP的高效去除,同时有效避免了除磷与脱氮过程对碳源的竞争,实现了生物法对水体中富余氮、磷的高效去除.     

两种富营养化水体对植物生长及光合荧光特性的影响

采用水培方法,研究水芹（Oenanthe javanica）、美人蕉（Canna indica）、菖蒲（Acorus calamus）在两种富营养化水体中生长、部分光合荧光特性的变化,结果表明：（1）营养盐对水芹、美人蕉株高、根长有显著影响,2种植物在低营养盐水体（L）中株高、根长增长率显著低于高营养盐水体（H）,生物量亦表现为L组〈H组,而菖蒲在2种水体中株高、根长,生物量等无显著差异（p〈0.05）;（2）水芹、美人蕉叶片的叶绿素a（Chla）,叶绿素b（Chlb）在L组中含量低,在H组中含量高,w（Chla）/w（Chlb）则随营养盐浓度的升高而降低。菖蒲叶片Chla,Chlb,Car、w（Chla）/w（Chlb）在两实验水体中无显著差异;（3）水芹、美人蕉叶片的Fv/Fm,Yield,qP,re,t,max值及其饱和光强随营养盐浓度的降低而显著降低,qN值变化趋势正好相反,表明在低营养盐水体中,两种植物光系统II（PS II）光能转换效率显著下降,且PS II将吸收过剩的能量通过热耗散的形式释放,以保护自身组织免受过剩光的损害,体现了两种植物在营养盐缺失下的自我保护机制,而菖蒲叶片Fv/Fm,Yield,qP,qN以及快速光响应曲线在L组、H组中均显著差异（p〉0.05）,表明在本文设定的营养盐浓度范围内,菖蒲叶片的光合作用能力未受到显著影响。