皱纹盘鲍自污染及其对幼鲍生长及成活率的影响

在水温12～14℃条件下,进行了不同自污染程度对皱纹盘鲍HaliotisdiscushannaiIno幼鲍生长和成活率影响的生产规模试验。结果表明,随着换水频率或水交换量的减小,总氨(TNH+4-N)、活性磷(PO4-P)、亚硝态氮(NO-2-N)和化学耗氧量(CODMn)的含量增加(单位体重鲍所对应的平均污染速率依次为0 176、0 050、0 184、0 294mg/(g·d)),pH下降。自污染对成活率影响较小,对生长影响较大。总氨和pH是自污染水中影响幼鲍生长的主要因子。天然水(pH=8 11±0 06)条件下,总氨对幼鲍相对增长率的EC5(使相对增长率下降5%的总氨浓度)为0 18mg/L(非离子氨为0 004mg/L),EC10(使相对增长率下降10%的总氨浓度)为0 307mg/L(非离子氨为0 007mg/L);总氨在0 75mg/L(非离子氨0 02mg/L)以下时对幼鲍成活率无明显影响。pH的下降对幼鲍的相对增长率有影响,pH的频繁波动对幼鲍相对增重率影响明显。加入Na2CO3适当提高pH,对幼鲍生长有促进作用。作者建议用总氨作为监控鲍养殖闭路循环体系的水质指标,推荐总氨警戒线为0 30mg/L,危险线为0 8mg/L。pH为辅助指标。

养鲍自污染水净化处理的初步研究

用孔石莼变异株Ulvapertusa、活性炭纤维（ACF）和二氯异氰尿酸钠（NaDDT）对养殖皱纹盘鲍HaliotisdiscushannaiIno产生的自污染水进行净化，并用于饲养幼鲍。结果表明，孔石莼变异株能有效地吸收对幼鲍生长产生影响的水化因子──氨氮、亚硝酸盐，而活性炭纤维对污水中的COD_Mn和细菌的吸附率分别达82％和99．98％，经孔石莼变异株处理后的养鲍污水与未处理的养鲍污水对幼鲍生长影响明显不同。文中同时提出了用活性炭纤维、孔石莼变异株和二氯异氰尿酸钠净化养鲍污水的循环反馈投饵养殖模式。

航天器的防污染技术

简单介绍了航天器污染的概念,污染对航天器的损害,航天器污染研究的重要性,以及国内外航天器防污染研究概况。着重介绍真空热试验中的污染控制方法。引入航天器自污染的概念,介绍消除航天器自污染的有效办法是真空烘烤。

解读“养殖业”对环境的污染与防范对策

2007年中国内陆湖泊蓝藻肆虐，发生蓝藻的直接原因是水体的富营养化。水体的富营养则源自污染，人们往往把目光聚焦在工业污染源上，而忽视了农业，特别是养殖业对环境的污染。集约化畜牧业是现代人类赖以生存和发展的基础产业，近20年来我国集约化养殖业突飞猛进的发展为农村经济的振兴和农民收入的增加做出了巨大的贡献。一些北方农业大省畜牧业产值已经达到或超过农业总产值的50％，占领了农村经济的半壁江山。发展畜牧业已成为农民发家致富的首选项目。

主要污染因子对虾蟹健康影响的研究进展

氨氮、亚硝氮、硫化物是水产动物养殖水环境中最常见、最重要的自污染因子,是虾蟹胁迫因素。文章从3种污染因子对虾蟹健康及生长的损害表现、损害机理、安全浓度等方面进行综述,以期为养殖虾蟹的科学研究和实际生产中维持良好水生态环境、提高免疫抗病能力、促进健康生长提供参考。

总氨、亚硝酸氮及养鲍污水对皱纹盘鲍生长的影响

单因子总氨氮(TNH3-N)、亚硝酸氮(NO-2-N)试验表明,当养鲍用水中非离子氨氮(NH3-N)为0 035mg/L以下或NO-2-N为0 8mg/L以下时,对皱纹盘鲍HaliotisdiscushannaiIno幼鲍的生长不产生明显影响;NH3-N对幼鲍生长产生影响的EC5(引起幼鲍生长速度减慢5%的浓度)为0 103mg/L,不产生影响的最大浓度为0 045mg/L。双因素试验结果表明,水中TNH3-N、NO-2-N对幼鲍生长的影响没有交互作用,只是简单的相加作用。经回归表明,养鲍自污染水中,NH3-N是影响幼鲍生长的主要因子,它对幼鲍生长产生影响的EC5为0 022mg/L,不产生影响的最大浓度为0 01mg/L,均比单因子试验结果显著降低。

释“(污)”

释“■（污）”杨宝忠《孟子·梁惠王上》：“数罟不入池，鱼鳖不可胜食也。”“”字，前人注释多不能得其确解。符定一《联绵字典》收“池”条，释“”为“浊水不流”；王力主编的《古代汉语》亦如此释。杨伯峻的《孟子译注》释之曰：“，音乌，大也。《广雅·释诂》云：...

养殖密度和换水量及频率对凡纳滨对虾生长的影响

在26℃下,将体长(2.089±0.021)cm的凡纳滨对虾(Litopenaeus vannamei)饲养在15 L聚乙烯圆形水桶中,设置400尾/m^3和800尾/m^32个密度和5个换水条件(不换水、日换水量20%、日换水量50%、3 d全量换水、5 d全量换水)双因素处理,研究不同养殖密度和日换水条件对水质和凡纳滨对虾幼虾生长的影响,并根据养殖密度、日换水量及养殖天数对自污染因子的影响,建立了各污染指标与养殖密度、日换水量及养殖天数的回归关系模型。结果显示:养殖密度和日换水量对水体p H无显著性影响(P>0.05);水中NO_2^--N、NH_4^+-N及COD浓度均随换水量增大而降低,其中日换水量50%组累积量最低,显著低于其他组(P<0.05);3 d全量换水和5 d全量换水试验组中,NO_2^--N、NH_4^+-N及COD浓度在换水前达峰值,在换水次日骤降至最低值,然后逐渐升高,如此循环,但仍低于对照组;相同换水条件下,密度400尾/m^3时自污染因子浓度均低于800尾/m^3组;NO_2^--N(Y_1)、NH_4^+-N(Y_2)和COD(Y_3)浓度指标与养殖密度(X_1)、日换水量(X_2)及养殖天数(X_3)的回归关系模型分别为:Y_1=0.048-0.002X_2-0.001X_3;Y_2=0.163+0.04X_1-0.018X_2+0.01X_3;Y_3=4.85+0.429X_1-0.199X_2。研究表明:在养殖密度400尾/m^3、换水率50%的养殖条件下,可以保证水体自污染程度最低,凡纳滨对虾生长良好。

Structure Design of Large-scale Fattening Pig House with Fermentation Bed

The fattening pig house with fermentation bed had an area of 2 100 m2, and the area of fermentation bed was 1 900 m2 with a utilization rate of 91.4%, which was 45% higher than that of conventional pig house with surrounding barrier. There was feeding trough around the house. The water troughs were set in the middle of the fermentation bed and of the feeding trough on the short sides of the house, separating feed and water. There were electric aluminum alloy shutters in both long sides of the house for ventilation, cooling and heat preservation. On both short sides, there were fans and wet curtains. The spray cooling devices were in- stalled outside the roof for cooling. The environmental control in the piggery, includ- ing light, temperature, water, humidity, carbon dioxide and ammonia, was realized to run by computer automatically. The coconut chaff and chaff configuration were used as mattress material, realizing the advantages of fermentation bed, such as no smell, zero emission, high-quality meat, saving labor, controlling disease, no drug residue, producing fertilizer, intelligent control, mechanized operation, etc.

Enhanced electrokinetic remediation of cadmium-contaminated natural clay using organophosphonates in comparison with EDTA

Soil contamination by metals is a worldwide environmental problem. Electrokinetic extraction is a promising technology for in-situ remediation of contaminated soils of low hydraulic permeability. However, the extraction of metals is usually hindered by the high buffer capacity of natural soils. Organophosphonates are strong metal chelates as ethylenediaminetetraacetic acid(EDTA) which has been widely studied in the enhancement of electrokinetic remediation. In this study, batch desorption experiments and bench-scale electrokinetic extraction experiments were carried out to study the effect of two organophosphonates, i.e.,(nitrilotrimethylene)triphosphonate(NTMP) &(ethylenedinitrilo)-tetramethylenephosphonate(EDTMP), on the extraction of cadmium from a natural clay in comparison with EDTA. Results of the batch desorption experiments showed that more than 75% of the sorbed cadmium could be dissolved into solution using 0.1 mol·L^(-1) organophosphonates or EDTA in the wide p H range of 1–11. Results of the electrokinetic extraction experiments showed that the cadmium spiked in the specimen migrated towards the anode with the enhancement of NTMP,EDTMP, and EDTA under a constant voltage gradient of approximately 1.0 V·cm-1. Although cadmium mobilization enhanced by EDTA was more efficient than that by the organophosphonates, accumulation of cadmium was observed in the vicinity of the anode. The average removal efficiencies of cadmium from the soil after approximately 5 days of electrokinetic extraction enhanced by 0.1 mol·L-1 NTMP(22.8%) and EDTMP(22.4%) were higher than that by 0.1 mol·L^(-1) EDTA(15.1%).

Dynamic imaging of metallic contamination plume based on self-potential data

A dynamic imaging method for monitoring self-potential data was proposed.Based on the Darcy’s law and Archie’sformulas,a dynamic model was built as a state model to simulate the transportation of metallic ions in porous medium,and theNernst equation was used to calculate the redox potential of metallic ions for observation modeling.Then,the state model andobservation model form an extended Kalman filter cycle to perform dynamic imaging.The noise added synthetic data imaging testshows that the extended Kalman filter can effectively fuse the model evolution and observed self-potential data.The further sandboxmonitoring experiment also demonstrates that the self-potential can be used to monitor the activities of metallic ions and exactlyretrieve the dynamic process of metallic contamination.

Petrochemical wastewater treatment with a pilot-scale bioaugmented biological treatment system

In solving the deterioration of biological treatment system treating petrochemical wastewater under low temperatures, bioaugmentation technology was adopted by delivering engineering bacteria into a pilot-scale two-stage anoxic-oxic (A/O) process based on previous lab-scale study. Experimental results showed that when the concentrations of COD and NH4+-N of the influent were 370~910 mg/L and 10~70 mg/L, the corresponding average concentrations of those of effluent were about 80 mg/L and 8 mg/L respectively, which was better than the Level I criteria of the Integrated Wastewater Discharge Standard (GB8978-1996). According to GC-MS analysis of the effluents from both the wastewater treatment plant (WWTP) and the pilot system, there were 68 kinds of persistent organic pollutants in the WWTP effluent, while there were only 32 in that of the pilot system. In addition, the amount of the organics in the effluent of the pilot system reduced by almost 50% compared to that of the WWTP. As a whole, after bioaugmentation, the organic removal efficiency of the wastewater treatment system obviously in- creased.

Model for seawater fouling and effects of temperature,flow velocity and surface free energy on seawater fouling

A kinetic model was proposed to predict the seawater fouling process in the seawater heat exchangers.The new model adopted an expression combining depositional and removal behaviors for seawater fouling based on the Kern–Seaton model.The present model parameters include the integrated kinetic rate of deposition(k d)and the integrated kinetic rate of removal(k r),which have clear physical signi ficance.A seawater-fouling monitoring device was established to validate the model.The experimental data were well fitted to the model,and the parameters were obtained in different conditions.SEM and EDX analyses were performed after the experiments,and the results show that the main components of seawater fouling are magnesium hydroxide and aluminum hydroxide.The effects of surface temperature,flow velocity and surface free energy were assessed by the model and the experimental data.The results indicate that the seawater fouling becomes aggravated as the surface temperature increased in a certain range,and the seawater fouling resistance reduced as the flow velocity of seawater increased.Furthermore,the effect of the surface free energy of metals was analyzed,showing that the lower surface free energy mitigates the seawater fouling accumulation.

Study of CNG／diesel dual fuel engine＇s emissions by means of RBF neural network

Great efforts have been made to resolve the serious environmental pollution and inevitable declining of energy resources. A review of Chinese fuel reserves and engine technology showed that compressed natural gas (CNG)/diesel dual fuel engine (DFE) was one of the best solutions for the above problems at present. In order to study and improve the emission performance of CNG/diesel DFE, an emission model for DFE based on radial basis function (RBF) neural network was developed which was a black-box input-output training data model not require priori knowledge. The RBF centers and the connected weights could be selected automatically according to the distribution of the training data in input-output space and the given approximating error. Studies showed that the predicted results accorded well with the experimental data over a large range of operating conditions from low load to high load. The developed emissions model based on the RBF neural network could be used to successfully predict and optimize the emissions performance of DFE. And the effect of the DFE main performance parameters, such as rotation speed, load, pilot quantity and injection timing, were also predicted by means of this model. In resumé, an emission prediction model for CNG/diesel DFE based on RBF neural network was built for analyzing the effect of the main performance parameters on the CO, NOx emissions of DFE. The predicted results agreed quite well with the traditional emissions model, which indicated that the model had certain application value, although it still has some limitations, because of its high dependence on the quantity of the experimental sample data.

Treatment of Phenol-Contaminated Soil by Potassium Ferrate Based on pH Control

This study aims to optimize the treatment of phenol-contaminated soil by potassium ferrate. Variations in pH value can accurately reflect the state and reaction status of the entire treatment process. Therefore, the pH value could be an important variable for optimizing the reaction conditions and achieving the automatic control of the process. About 99.89% of phenol was removed after 10 min of the pH-contxolled reaction at a rotational speed of 40-70 r/min, with the initial phenol concentration equating to 10.0 g/kg and the total water consumption reaching 2.72 L （at a soil/water ratio of 1：0.68）. The test results could provide a basis for practical application of automatic reaction control by pH value.

Can Cadmium Uptake by Chinese Cabbage be Reduced After Growing Cd-Accumulating Rapeseed?

Rapeseed （Brassica campestris L.）, a Cd-accumulating crop, is effective in reducing plant-available Cd from soil. A pot experiment was conducted to test the hypothesis that the Cd uptake by Chinese cabbage （Brassica pekinensis Rupr.） grown in rotation with rapeseed would be reduced due to the efficient removal of bioavailable Cd from soil solution by the rapeseed crops. The Cd removal by shoot for the rapeseed cultivar Zhucang Huazi ranged from 0.24% to 0.99% in natural Cd-contaminated soil （soil A） and from 0.63% to 1.23% in artificial Cd-contaminated soil （soil B） during the growth period of 4 7 weeks; whereas that for the rapeseed cultivar Chuanyou Ⅱ-93 ranged from 0.25% to 0.66% and from 0.38% to 1.02%, respectively. Chinese cabbage grown in the pots with soil A for five weeks after harvesting rapeseed exhibited a significantly lower Cd concentration compared to that grown in the control pots （uncropped with rapeseed）. However, the rotation of rapeseed did not lower the Cd concentration of Chinese cabbage on soil B. Although an increase of Cd uptake was observed in the rapeseed cultivars with growth time, and the decrease of soil NH4OAc-extractable Cd was found only in the natural rather than artificial Cd-contaminated soil.

Coastal Water Quality Assessment by Self-Organizing Map

A new approach to coastal water quality assessment was put forward through study on self-organizing map （ SOM ）. Firstly, the water quality data of Bohai Bay from 1999 to 2002 were prepared. Then, a set of software for coastal water quality assessment was developed based on the batch version algorithm of SOM and SOM toolbox in MATLAB environment. Furthermore. the training results of SOM could be analyzed with single water quality indexes, the value of N ： PC atomic ratio） and the eutrophication index E so that the data were clustered into five different pollution types using k-means clustering method. Finally, it was realized that the monitoring data serial trajectory could be tracked and the new data be classified and assessed automatically. Through application it is found that this study helps to analyze and assess the coastal water quality by several kinds of graphics, which offers an easy decision support for recognizing pollution status and taking corresponding measures.

Impending Pollution of Betare Oya Opencast Mining Environment （Eastern Cameroon）

Mining resources are offered by the natural milieu and liable to exploitation. Raw materials extracted are essential for jewellery and economy. But in most cases, the environmental impact assessment is disappointing. In this study conducted at Betare Oya, mining residues are directly disposed in the immediate environment without passing through the tailing ponds for treatment, despite environmental laws and standards. Soluble components of matter are slowly dissolved, drained by meteoric water and flowed into tail bay vicinity. Soil and mining residues were sampled in Mari, Mbigala, Mboufa and Bedobo, respectively, four sub-watershed of Lom, the main river of the region. Concentration of nine MTE （metallic trace elements）： As, Cd, Cr, Cu, Co, Ni, Pb, Zn and Hg were determined by ICP-MS （inductively coupled plasma-mass spectrometry）. Highest concentrations of trace and toxic metals in soil and mining residues are： Cr （210 mg·kg-1） 〉 Zn （136 mg·kg-1） 〉 Ni （64 mg·kg-1） 〉 As （34 mg·kg-1） 〉 Cu （30 mg·kg-1） 〉 Pb （25 mg·kg-1） 〉 Co （17 mg·kg-1） 〉 Cd （0.5 mg·kg-1） 〉 Hg （0.1 mg·kg-l）, respectively. These results let assume that it is a risk of environmental pollution and poisoning relative to these elements around Betare Oya opencast mining area, with impact on human health.

Co-benefits of Local Air Pollutants and Greenhouse Gas Reduction Achieved by Hydropower Development in Xizang(Tibet) Autonomous Region, China

Hydropower development in Xizang(Tibet) Autonomous Region plays a vital role in co-control of local air pollutants and greenhouse gas(GHG) in China. According to emission factors of local air pollutants and GHG of coal-fired power industry in different hydropower service regions, we estimate the effect and synergy of local air pollutants and GHG reduction achieved by hydropower development in Tibet, examine the main factors constraining the effect and synergy, using correlation analysis and multiple regression analysis. The results show that: 1) During the period from 2006 to 2012, the effect of local air pollutants and GHG reduction achieved by hydropower development in Tibet decreased as a whole, while the synergy increased first and decreased afterwards. 2) The effect and synergy of local air pollutants and GHG reduction achieved by hydropower development in Tibet vary significantly across different hydropower service regions. The effect based on emission levels of Central China power grid(CCPG) and Northwest China power grid(NCPG) was more significant than that based on emission level of national power grid(NPG) from 2006 to 2012, and the synergy based on emission levels of CCPG and NCPG was also more significant than that based on emission level of NPG from 2010 to 2012. 3) The main factors constraining the effect and synergy based on emission levels of NCPG and CCPG included SO2 removal rate and NOx removal rate, the effect and synergy based on emission level of NPG was mainly influenced by net coal consumption rate. 4) Transferring hydropower from Tibet to NCPG and CCPG, and substituting local coal-fired power with hydropower can greatly help to co-control local air pollutants and GHG, transform the emission reduction pattern of the power industry and optimize energy structure.