鲢鱼放养控制北京城市河湖水华试验研究

介绍了利用鲢鱼控制北京城市河湖水华的试验研究,通过不同放养密度(0、17、51和103 g/m3)的现场围隔试验,对鲢鱼放养对水体水质和浮游生物的影响进行了分析.研究结果表明,鲢鱼放养使有鱼围隔中浮游生物量极低,从而使浮游植物基本不受浮游动物影响,而直接受鱼类影响;同时,中等密度(51 g/m3)的鲢鱼放养使水华蓝藻和微小藻的生长均得到了有效抑制,使藻类生物量最低.     

螺、蚌对污水处理厂再生水环境的改善稳定作用

通过选用昆明市第五污水处理厂的一级A标出水和水处理厂外排污泥作为静态实验环境,研究不同混养密度下铜锈环棱螺、椭圆背角无齿蚌对污水处理厂再生水环境的净化性能,筛选出净化效果较好的放养密度。结果表明:放养30 d,铜锈环棱螺、椭圆背角无齿蚌对污水处理厂再生水环境的水质、底质均有一定的净化作用,扣减空白对照影响,水中COD、TP、NH3-N及底泥有机质平均去除率分别为22.26%、26.10%、25.60%和25.69%,底泥厚度平均减少3.8 cm;与对照相比,放养螺蚌45 d内水均能清澈见底,透明度均>70 cm,能明显稳定水体透明度,改善水环境。综合螺蚌生长适应性和净化效果考虑:污水处理厂再生水静态环境中,螺蚌混养密度应≤3 000 g/m3,在2 000～2 500 g/m3为宜,其中铜锈环棱螺的最适放养密度在400 g/m3,椭圆背角无齿蚌为1 600～2 100 g/m3。     

长江口边滩水库藻类增殖潜力及遮光控藻研究

从长江口及两个长江口边滩水库(陈行水库和宝钢水库)采集水样,在人工气候室内进行了藻类增殖潜力研究.结果表明,在完全不添加营养成分的前提下,在培养未灭菌水样时蓝绿藻可成为优势种而大量增殖;在灭菌水样中人工接种铜绿微囊藻时,该藻的藻细胞数最大现存量可达5.65×106个/mL.另一方面,采用遮光控藻思路,在上海交通大学致远湖中设置软体浮式人工围隔,待其发生水华后将围隔遮光,7 d后叶绿素a从发生水华时的176.9 μg/L降至21.4μg/L.因此,使用遮光技术可以达到有效控藻的目的.     

生物填料地下渗滤系统对生活污水的脱氮

将草甸棕壤、炉渣和活性污泥等基质按体积比13∶6∶1配制生物填料,研究了生物填料地下渗滤系统（subsurface wastewater infiltration system,SWIS）在不同的水力负荷和污染负荷条件下对校园生活污水的脱氮效果。场地实验结果表明,当BOD5负荷为12.0 g BOD5/（m2·d）,表面水力负荷为0.04-0.10 m3/（m2·d）时,SWIS对NH＋4-N和TN的平均去除率分别为92.4%和82.0%。当水力负荷为0.08 m3/（m2·d）,BOD5负荷9.3-16.8 g BOD5/（m2·d）时,SWIS对NH＋4-N和TN的平均去除率为92.7%和81.2%。SWIS中氧化还原电位（oxygen reduction potential,ORP）随进水水力负荷和BOD5负荷的增加而降低,脱氮效率下降。综合出水水质和处理效率,适宜的水力负荷和污染负荷分别为0.065 m3/（m2·d）和12.0 g BOD5/（m2·d）。在此条件下,SWIS的启动周期为25-30 d。出水水质均优于《城市污水再生利用-景观环境用水水质》（GB/T18921-2002）标准,且处理效果稳定,抗负荷冲击能力强。     

不同质量浓度黄菖蒲和狭叶香蒲对铜绿微囊藻的化感作用简

分别采用黄菖蒲（Iris pseudacorus L.）、狭叶香蒲（Typha angustifolia L.）和铜绿微囊藻（Microcystis aeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明，黄菖蒲在质量浓度大于10 g/L时对初始密度为1.0×10⁷ ind/mL的铜绿微囊藻具有较好的抑制作用，表现为黄菖蒲质量浓度为10、20和40 g/L时，第15天对铜绿微囊藻的抑制率分别为30.1%、51.8%和84.0%；狭叶香蒲在质量浓度大于20 g/L时对铜绿微囊藻有明显的抑制作用，表现为狭叶香蒲质量浓度为20 g/L和40 g/L时，第15天对铜绿微囊藻的抑制率分别为34.2%和77.7%，实验过程中，铜绿微囊藻叶绿素a含量逐渐减少，而藻密度、SOD活性及MDA含量先增加后逐渐降低，表明经过一段时间持续地化感胁迫，黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫，导致细胞结构严重损伤和叶绿素大量分解，从而强烈抑制铜绿微囊藻的生长。     

pH、溶解氧、叶绿素a之间相关性研究Ⅱ：非养殖水体

利用国内、外近20年的资料和饮用水水源地潘家口水库现场围隔实验结果,分析非养殖水体中pH、溶解氧（DO）和叶绿素a之间的相互关系。结果表明,当水体处于富营养化状态即叶绿素a平均含量高于10μg/L时,pH、DO与叶绿素a呈显著正相关。当叶绿素a平均含量低于10μg/L时,水体交换强或有机重污染的天然水体中DO与叶绿素a...     

2种新分离微藻的生长、氮磷去除和营养特性的比较研究

为了解2种新分离微藻的净化和资源化潜力，研究比较了其生长、氮磷去除和营养特性。结果表明，栅藻和月牙藻的最大生物量（干重）分别为0．78g／L和0．53g／L；最大生物量（干重）增长速率分别为0．05g／（L·d）和0．03g／（L·d）。培养至第23天，栅藻和月牙藻对TN的去除率分别为85．1％和72．5％；对TP的去除率为82．6％和79．7％，但栅藻较月牙藻更易释放较多的No2--N进入藻液。稳定期时，栅藻、月牙藻的粗蛋白质含量和粗蛋白产量（干重）分别为31．8％、19．2％和0．24g／L、0．09g／L；粗脂含量和粗脂产量（干重）分别为7．81％、9．26％和0．06g／L、0．05g／L。综上，与月牙藻相比，栅藻具有明显的生长、氮磷去除和营养优势，在进行水产养殖废水的净化和资源化利用上可作为优选藻种。     

“氧化镁/活性炭”新型吸附剂的制备及其对Cr（Ⅵ）的吸附研究

以氯化镁和造纸草浆黑液为原料,采用物理活化法制得＂氧化镁/活性炭＂新型吸附剂,其比表面积（BET）为388.96 m2/g、总孔容积为0.40 mL/g。测定了这种吸附剂对水中Cr（Ⅵ）的吸附性能,考察了吸附时间、pH值、吸附剂投加量、初始浓度等因素对Cr（VI）的吸附量和脱除率的影响,研究所得吸附水溶液中Cr（Ⅵ）的最佳条件为：吸附时间为120min,吸附剂投加量为2 g/L,pH值为2。＂氧化镁/活性炭＂新型吸附剂对Cr（Ⅵ）的吸附过程符合Freundlich等温式。     

蓄水型备用水源地藻类生长趋势及控藻技术研究

为了探明以洪泽湖为原水的某蓄水型备用水源地藻类生长情况，探索原位控藻方法，进行了为期1年的藻类数量测定，并进行了遮光控藻实验和清浑混合控藻实验。结果表明，备用水源地优势藻类为硅藻门(Diatom)的针杆藻属(Synedra),持续全年；7—8月出现蓝藻门(Cyanobacteria)的微囊藻属(Microcystis)。藻细胞数量夏季多、冬季少，在7—8月达到峰值(2.09×10⁷个/L),1月达到谷值(9.23×10⁶个/L)。藻类在复合湿地区比进水口下降约4.8%,在深水净化区比进水口增加0.3%。藻类在0.5 m水深处最多，表面、3.0 m水深处藻类数量分别是0.5 m水深处的92.1%和89.9%。遮盖率为40%、60%、80%、100%的水体稳态控藻率分别为24.2%、41.4%、47.0%、61.1%,稳态高锰酸盐(I_Mn)削减率分别为24.8%、36.5%、41.6%、47.7%。建议采用太阳能发电板遮蔽水面控藻，遮盖率取60%。清浑混合体积比为6∶4、7∶3、8∶2、9∶1的水体稳态控藻率分别为33.2%...     

青山水库的浮游植物与营养类型评价

共鉴定青山水库藻类58属101种，其中有多污水体指示种5种，α－中污水体指示种24种、β－中污水体指示种49种，寡污水体指示种21种。优势种为窄颗粒直链藻（Melosiragranulatavar.angustissima）、颗粒直链藻（M.granulata）和小颤藻（Oscillatoriatenuis）。浮游植物的细胞密度为8.53×107个／L，生物量为16.34mg／L，叶绿素a为16.86mg／m3。根据浮游植物群落结构和水化学分析结果，青山水库已属富营养型水体，并有继续发展的趋势，控制污染，保护水质已刻不容缓。     

Toxic effects of chlorpyrifos on lysozyme activities,the contents of complement C3 and IgM,and IgM and complement C3 expressions in common carp (Cyprinus carpio L.)

Chlorpyrifos is one of the organophosphate pesticides widely used in agricultural practices throughout world. It has resulted in a series of toxicological and environmental problems, such as impacts on many non-target aquatic species, including fish. In the present study, toxic effects of chlorpyrifos on lysozyme activities, contents of IgM and complement C3, and the expressions of IgM and complement C3 at mRNA level in common carp were evaluated by acute exposure of 15 (1/10 LC₅₀) or 75 μg L⁻¹ (1/2 LC₅₀) of chlorpyrifos for 7 d. The results of acute toxicity tests showed that the 96 h-LC₅₀ of chlorpyrifos for common carp was determined to be 149 μg L⁻¹. We also found that chlorpyrifos promoted lysozyme activities at the earlier stages of exposure but inhibited it at the late stages in the serum, hepatopancreas, and spleen of common carp. Furthermore, it was observed that chlorpyrifos-exposure decreased IgM contents in fish serum and spleen while increased it in kidney. No obvious change was found in the contents of complement C3 in fish spleen, while a slight increase of complement C3 was observed in fish serum and kidney after 1 d of chlorpyrifos-exposure. In addition, the results of quantitative real-time PCR showed that IgM and complement C3 expressions were up-regulated at the earlier stage of exposure but down-regulated at later stage. Our results indicate that chlorpyrifos causes immunotoxicity to common carp.     

Histopathological alterations in gill,liver and kidney of common carp exposed to chlorpyrifos

Histopathological alterations in gill, liver and kidney of common carp, Cyprinus carpio, intoxicated with sub-lethal concentrations of chlorpyrifos (O,O,-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothioate) pesticide (1 and 100 μg/L) for a period of 14 days were analyzed under light microscope. Gill exhibited hyperplasia and hypertrophy of gill epithelium, blood congestion, dilation of marginal channel, epithelial lifting, lamellar fusion, lamellar disorganization, lamellar aneurysm, rupture of the lamellar epithelium, rupture of pillar cells and necrosis. Alterations in hepatocytes were more pronounced, including nuclear and cellular hypertrophy, cellular atrophy, irregular contour of cells and nucleus, cytoplasmic vacuolation, cytoplasmic and nuclear degeneration, cellular rupture, pyknotic nucleus, necrosis and melanomacrophages aggregations. Histopathological lesions in kidney were cellular and nuclear hypertrophy, narrowing of tubular lumen, cytoplasmic vacuolation, hyaline droplet degeneration, nuclear degeneration, occlusion of tubular lumen, tubular regeneration, dilation of glomerular capillaries, degeneration of glomerulus and hemorrhage in Bowman's space. The most significant conclusion drawn from this study was that with the increased concentration and duration the toxicosis of chlorpyrifos would be enhanced as shown through the analysis of mean assessment value (MAV) and degree of tissue changes (DTC) also.     

Toxic effects of 2,4‐D herbicide on fish

Abstract

Acute and subacute 2,4‐D toxicity to carp (Cyprinus carpio L.) were investigated. Acute toxicity (LC‐ 50) was investigated in semi‐static test during a 24, 48, and 96‐ hours exposition. Subacute toxicity was investigated by exposing fish to different 2,4,‐D concentrations (150, 200, and 250 mg/L) for 14 days. Biochemical and morphological changes in certain organs and tissues were investigated.

LC‐ 50 values at 24 hours exposure was 310.0 mg/L, 295.0 mg/L for 48 hours, and 270.0 mg/L for 96 hours exposure.

Subacute toxicity tests show that 2,4‐D induce changes in the enzyme activities (AP, GOT, GPT) and morphological changes in the gills, liver and kidneys, but changes are of limited biological importance.     

Effects of synthetic pyrethroids and methidation on activities of some digestive enzymes in carp (Cyprinus carpio L.)

Abstract

The effects of pyrethroid pesticides (deltamethrin, permethrin and cypermethrin) and an organophosphate ester (methidation) on the activities of carp trypsin, α‐chymotrypsin, carboxypeptidase A and lipase were studied. The enzymes were isolated from the gastrointestinal tract and the effects of the pesticides were investigated during incubation for 5 min. The activity of trypsin was influenced only slightly by the presence of deltamethrin and methidation, whereas permethrin and cypermethrin caused significant inhibition. The pyrethroid pesticides at lower concentrations resulted in a slight activation of α‐chymotrypsin. Methidation inhibited the α‐chymotrypsin activity by about 20%. These pesticides modified the lipase activity to a lesser extent; the highest inhibition was measured with cypermethrin. The carboxypeptidase A activity was inhibited by both pyrethroid pesticides and methidation. The results suggest that these pesticides might interact with the active conformation of the studied hydrolytic enzymes, resulting in changes in their activities.     

Effect of a subchronic exposure to Simazine on energetic metabolism of common carp (Cyprinus carpio)

The energetic parameters, such as glycogen, glucose, proteins, lactate and adenosine triphosphate (ATP) content and lactate deshydrogenase (LDH) activity in tissues and blood of carps from simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) contaminated waters were investigated. In order to confirm the field results, a laboratory experiment was designed in which carps were exposed to simazine at the concentration level of 45 μ g. L^{? 1} (10-fold of the amount found in natural waters) for 90 days. Fish from a contaminated reservoir showed low glycogen concentrations in hepatopancreas and muscle, while fish in another contaminated reservoir showed high LDH activity together with an increase in lactate content in muscle. Laboratory findings did not confirm field results, and fish exposed to simazine did not show alterations in the parameters studied. The results suggest that carps were not stressed by the presence of the simazine at the concentration levels found in both studies and the mechanisms of defense covered the energetic demand.     

Evaluation of food chain transfer of the antibiotic oxytetracycline and human risk assessment

There has been recent concern regarding the possibility of antibiotics entering the aquatic food chain and impacting human consumers. This work reports experimental results of the bioconcentration of the antibiotic oxytetracycline (OTC) by the Asian watermeal plant (Wolffia globosa Hartog & Plas) and bioaccumulation of OTC in watermeal and water by the seven-striped carp (Probarbus jullieni). They show, for the first time, the extent to which OTC is able to transfer from water to plant to fish and enter the food chain. The mean bioconcentration factor (dry weight basis) with watermeal was 1.28 × 10³ L kg⁻¹. Separate experiments were undertaken to characterize accumulation of OTC by carp from water and watermeal. These showed the latter pathway to be dominant under the conditions employed. The bioconcentration and biomagnification factors for these processes were 1.75 L kg⁻¹ and 2 × 10⁻⁴ kg g⁻¹ respectively. Using an aqueous concentration range of 0.34–3.0 μg L⁻¹, hazard quotients for human consumption of contaminated fish of 1.3 × 10⁻² to 1.15 × 10⁻¹ were derived.     

Differences in Cu content in selected mushroom species growing in the same unpolluted areas in Poland

The aim of the study was to estimate copper (Cu) accumulation efficiency in whole-fruiting bodies of 18 edible and non-edible wild growing mushrooms collected from 27 places in the Wielkopolska Voivodeship. Mushrooms were collected each time from the same places to estimate the diversity in Cu accumulation between tested mushroom species within 3 consecutive years of study (2011–2013). The study results revealed various accumulation of Cu in the whole-tested mushroom fruiting bodies. The highest mean accumulation of Cu was observed in Macrolepiota procera (119.4 ± 20.0 mg kg^?1 dm), while the lowest was in Suillus luteus and Russula fellea fruiting bodies (16.1 ± 3.0 and 18.8 ± 4.6 mg kg^?1 dm, respectively). Significant differences in Cu accumulation between mushroom species collected in 2011 and in the two following years (2012 and 2013) were observed. The results indicated that sporadic consumption of these mushrooms was not related to excessive intake of Cu for the human body (no toxic influence on health).     

Trends in summer sulphate in Europe

A trend analysis of the sulphate concentration in Europe in the summer half-year was performed. Data from various measuring networks were analysed, but only stations with quality assured sampling methods and a record of more than 10 years were included in the study. 1978 served as the reference year for the trend, because in that year most stations started operation. The relatively dense network in Belgium provided the most valuable data, as evidenced by the fact that two sites at a distance of only 10 km apart correlated better than 95% over a month. The two sites also show a correlation of better than 90% over a season with two other stations at distances of 45 and 95 km. The relative decrease in summer-sulphate at the four stations in Belgium, as analysed by linear regression, was 3.3% per year which corresponds to an absolute decrease of 0.42 μgm⁻³ per year. In the Netherlands the average yearly decrease in summer-sulphate at two stations was 3.5% (−0.34 μgm⁻³). In other countries stations were further apart or only a single site wits in use, which limits the representativeness of the data. In northwestern Germany, a region with several monitoring stations, a yearly averaged decrease of 3.0% occurred. The lower absolute decrease (0.25 μgm⁻³) per year compared to that in the two neighbouring countries reflects the lower summer-time sulphate concentrations. In the remainder of Germany the average decrease was 1.6%. In South-Scandinavia the yearly relative decrease at two sites was 2.6% (0.13 μgm⁻³ absolute). There was no significant trend in the U.K. Al the Polish station the levels increased, it decreased at the Hungarian and Austrian station and remained constant at the Czechoslovakian site. Reasons for omission of the data from France from the trend analysis are discussed.     

Pesticides in rainfall in Europe

Papers and published reports investigating the presence of pesticides in rainfall in Europe were reviewed. Approximately half of the compounds that were analysed for were detected. For those detected, most concentrations were below about 100 ng/l, but larger concentrations, up to a few thousand nanograms per litre, were detected occasionally at most monitoring sites. The most frequently detected compounds were lindane (gamma-HCH) and its isomer (alpha-HCH), which were detected on 90-100% of sampling occasions at most of the sites where they were monitored. For compounds developed more recently, detection was usually limited to the spraying season. A classification of pesticides according to their deposition pattern is proposed.