中国湖泊水资源问题与优化调控战略

湖泊水资源在国民经济和社会可持续发展中占有重要的位置,实施优化调控战略是中国湖泊水资源可持续开发利用的重要途径。文中扼要综述了中国湖泊水资源特点和开发利用中存在水资源短缺、湖泊水资源污染和相关问题,指出湖泊资源优化调控的思路是进行湖泊流域系统的综合调控,目前针对中国湖泊水资源问题的优化战略措施包括:实施湖泊水资源流域管理战略、建立流域节约型国民经济体系、增加科技投入并因地制宜实施环境整治、流域污染的全过程与全方位控制、实施环境教育战略。     

Biologically effective radiation of solar ultraviolet radiation and the depletion of stratospheric ozone

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A primary study of nitrous oxide emission in agriculture region of Northern China

Significance of nitrous oxide in atmospheric chemistry is reviewed briefly. Background concentration of N2O at Wudaoliang in Qinghai Province of Western China has been measured by collecting gas samples and analysing them with electron capture-gas chromatography. The atmospheric concentration fluctuates in the range of 303-315 ppb with the mean value of 308 ppb. The emission rate of N2O in agriculture region of Northern China has been studied primarily. Fertilization, rain and temperature of soil appear conductible to N2O emission. The interactions between greenhouse effect and N2O emission have been discussed. The catalytic action of N2O in stratospheric ozone depletion processes and the effect of high N2O concentration on ozone depletion in stratosphere have been considered and discussed.     

三级以上海况海面油膜厚度测定装置的研制

本文描述了３级以上海况（３￣５级）海面油膜厚度测定的非光学装置，该装置由敝开一封闭式油膜采样器和降集增厚器组成。为适应恶劣海况情况下采集油膜，保证数据的可靠性，该装置增加了防止油膜外溢的机构及原始平行样采样管，海上现场试验分别以零号轻柴油、海军燃料油、混合油为对象，测定厚度为１００￣１０００μｍ的油膜。并对多次采样的测定值进行了数理统计。该装置现场测定的相对误差≤±２４．５％。     

浙江经验：“三生统筹”理念下的农村环境综合整治

浙江是我国农村现代化进展较快的省，也是农村环境问题较为突出的省。浙江省按照“三生统筹”理念，政府和市场各尽所能，重点推进了乡镇企业污染集中治理，实施了以农村聚居点环境综合整治为主题的”万村整治，千村示范“工程以及生态农业促进计划，在解决农村三类环境污染问题上积累了若干经验：对于乡镇企业以及集约化畜禽养殖场的污染问题，通过产业布局调整和进园、市场化、集中治理机制解决；对于农村聚居点的环境污染问题，采取资源、能源、环境问题统筹，政府投资和民曹资金介入统筹的办法解决；对于农业面源污染问题，通过提高化肥、农药利用率及推行绿色食品管理体系等前置手段解决。在我国农村现代化进程迅速的今天，“浙江经验“对其他省市的借鉴意义明显。     

辽河流域面源污染负荷定量试验研究

本文通过对辽河流域面源污染物来源途径分析及系统采样进行试验测定，获得了不同面源污染类型的流失物中可进入水体的COD、总氮和总磷负荷，通过试验核算首次对辽河流域面源污染负荷进行了定量化研究。     

聚硅酸氯化铁絮凝剂

介绍以水玻璃和ＦｅＣｌ３等为原料合成的一种新型无机复合絮凝剂－聚硅酸氯化铁。该絮凝剂对去除某些废水中的ＳＳ和重金属效果良好，价格低廉，很有实用价值。     

高梁种子萌发成苗过程中水分需求的量化研究

用渗透势不同的聚乙二醇（ＰＥＧ）６０００模拟外界环境水分条件，对高梁不同品种的种子在萌动、萌发及成苗３个阶段水分需求的量化研究表明：种子的抗旱性随吸水进程的推进而减弱，种子在萌动、萌发及出士成苗的时间（ｔ）与外界环境水势（ｗ）之间存在着１／ｔ＝ａ＋ｂｗ的关系，据此推算不同品种在不同成苗阶段的需水阈值，发现不同品种在同一成苗过程中对环境水分条件的反应不同，抗旱性也不同．     

Chemical fixation of toxic metals in stainless steel pickling residue by Na2S∙xH2O, FeSO4∙6H2O and phosphoric acid for beneficial uses

The leaching concentrations of different metals in stainless steel pickling residue(SSPR)were determined and the toxic metals were treated using Na_2 S·xH_2 O,FeSO_4·6 H_2 O,and phosphoric acid.A modified European Community Bureau of Reference(BCR) sequential extraction was used to identify the speciation of the concerned metals.Results showed that SSPR contains a large amount of Ca(58.41%),Fe(29.44%),Cr(3.83%),Ni(2.94%),Mn(2.82%) and some of Al,Cu,Mg,Zn.Among them,Cr and Ni were the most toxic metals in SSPR,thus the raw SSPR falls into hazardous waste category due to the leaching amount of Cr.In addition,the leached Cr was identified as Cr6+(MgCr04) in the waste.BCR test revealed that risk assessment code(RAC) of Cr and Ni were 33.29% and 61.7%,indicating they posed "high" and "very high" risk to the environment,respectively.After fixing by Na_2 S·xH_2 O and FeSO_4·6 H_2 O,the leaching concentrations of Cr and Ni were less than 1.5 and 0.5 mg/L,respectively.After fixing by Na_2 S·xH_2 O and FeSO_4·6 H_2 O the tre ated SSPR can be safely reused as roadbed materials,concrete and cement aggregates.This study provides a useful implication in treatment and beneficial reuse of heavy metal-containing hazardous wastes.     

Environmental fate and behavior of silver nanoparticles in natural estuarine systems

Silver nanoparticles (AgNPs) are widely used in many consumer products, whereas their environmental behaviors in natural aquatic systems remain unknown, especially in natural brackish media. Therefore, it is urgent to investigate the environmental fate of AgNPs in natural brackish waters. Here, we investigated the stability of citrate-coated AgNPs in natural brackish water collected from 6 different sites with distinct salinities in the Xinglinwan Reservoir, located in Xiamen City, southeast China. The obtained results showed that AgNP colloids remained stable in low-salinity waters, which was mainly determined by the effects of dissolved organic matter (DOM) promoting the stability of the nanoparticles. However, the environmental fate of AgNPs in high-salinity waters was dominated by the salinity or ionic strength, especially the free ion concentrations of Cl^?, SO₄^2?, or S^2?, resulting in rapid sedimentation and dissolution. In addition, both DOM and salinity contributed to the environmental behavior of AgNPs in moderate-salinity waters, ultimately resulting in either colloidal stability or sedimentation. Overall, these results may reveal that AgNPs remain relatively stable for a long period in low-salinity natural waters, and that the stability might gradually decrease as AgNPs are transferred from freshwaters through brackish waters and eventually end up in seawater along the bay. Our findings also further indicate that the toxicity and potential risks of AgNPs may present more serious threats to the environment and organisms in natural freshwaters than in natural estuarine systems or seawater.