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.     

Cause of PM2.5 pollution during the 2016-2017 heating season in Beijing, Tianjin, and Langfang, China

To investigate the cause of fine particulate matter (particles with an aerodynamic diameter less than 2.5 µm, PM_2.5) pollution in the heating season in the North China Plain (specifically Beijing, Tianjin, and Langfang), water-soluble ions and carbonaceous components in PM_2.5 were simultaneously measured by online instruments with 1-hr resolution, from November 15, 2016 to March 15, 2017. The results showed extreme severity of PM_2.5 pollution on a regional scale. Secondary inorganic ions (SNA, i.e., NO₃^?+SO₄²+ NH₄⁺) dominated the water-soluble ions, accounting for 30%-40% of PM_2.5, while the total carbon (TC, i.e., OC + EC) contributed to 26.5%-30.1% of PM_2.5 in the three cities. SNA were mainly responsible for the increasing PM_2.5 pollution compared with organic matter (OM). NO₃^? was the most abundant species among water-soluble ions, but SO₄^2- played a much more important role in driving the elevated PM_2.5 concentrations. The relative humidity (RH) and its precursor SO₂ were the key factors affecting the formation of sulfate. Homogeneous reactions dominated the formation of nitrate which was mainly limited by HNO₃ in ammonia-rich conditions. Secondary formation and regional transport from the heavily polluted region promoted the growth of PM_2.5 concentrations in the formation stage of PM_2.5 pollution in Beijing and Langfang. Regional transport or local emissions, along with secondary formation, made great contributions to the PM_2.5 pollution in the evolution stage of PM_2.5 pollution in Beijing and Langfang. The favourable meteorological conditions and regional transport from a relatively clean region both favored the diffusion of pollutants in all three cities.     

基于物联网的智能化安全仿真实训研究

结合物联网技术,介绍一种智能化安全仿真实训技术,通过对培训关键控制指标的筛选以及感知元件的应用,研发了安全仿真实训项目的感知层设计方案,以及多项目间的培训状态数据匹配技术,形成了系统的智能化安全仿真实训技术方案。通过与当前普遍应用的安全仿真实训技术进行对比,该技术方案能够有效提升培训考核的客观性,提高安全仿真实训实施效率,更好满足企业需求。     

基于生态型城市圈的西安大城市圈一体化交通运输体系发展研究

生态型城市圈应是按照生态学原理构建的,人居与自然和谐的新型城市圈发展模式。城市圈一体化交通运输体系通过综合方式解决城市圈交通运输问题,促进城市圈规划目标的实现。以生态型城市圈的内涵作为研究的出发点。对生态型城市圈的基本内容进行了分析,同时基于生态型城市圈的西安大城市圈发展目标,提出与之相契合的西安大城市圈一体化交通运输体系发展构架。。