碳基吸附剂对典型有机防晒剂二苯甲酮-3的吸附性能及热力学研究

针对环境水体中药物及个人护理用品(PPCPs)的污染问题,选择在环境水体中存在的有机紫外防晒剂二苯甲酮-3(BP-3)作为典型污染物,以颗粒活性炭(GAC)、粉末活性炭(PAC)和碳纳米管(CNT)作为吸附剂,考察吸附剂对BP-3的吸附性能、吸附特性和吸附热力学.结果表明:吸附性碳材料对BP-3具有良好的吸附性能,3种碳材料的最大吸附容量排列为:PACGACCNT,其中,PAC的单层最大吸附容量为450.36mg·g-1.Freundlich、Redlich-Peterson和Temkin吸附等温线方程能够较好地拟合吸附数据,Langmuir吸附等温线方程对PAC的吸附拟合效果较好,而对粒径较大的吸附剂(GAC、CNT)的拟合效果不理想.PAC、GAC的吸附过程可以采用一级动力学或者二级动力学模型拟合,而CNT适合采用一级动力学模型来描述.吸附热力学分析表明,PAC、GAC和CNT对BP-3的吸附过程都是自发进行的,其中,PAC和GAC的吸附过程是吸热的,升高温度有利于吸附反应的进行;而CNT的吸附过程是放热的.     

生态水利研究的理论基础与重点领域

生态水利是近些年来涌现出的新兴学科研究领域.论文结合国内外相关研究进展和国家重大需求,总结了生态水利的概念内涵和学科发展特点,从系统理论、二元结构和安全边界角度阐释了生态水利研究的理论基础.在此基础上,进一步从水与生态系统的相互作用、水利工程的长期生态效应、河湖连通与湿地水系网络构建、受损生态系统的恢复、生态需水与生态...     

基于三级电压控制的宁夏电网AVC系统的建设

为进一步提高宁夏电网电压运行水平,基于传统三级电压控制和时空解耦特性,研发了宁夏电网自动电压控制(Automatic Voltage Control,AVC)系统,并成功地实现了与电厂的闭环联调,联调结果表明:宁夏电网自动电压控制系统能够充分适应宁夏电网特征,为提高宁夏电网电压运行水平提供了关键技术支撑。     

Particulate matter assessment of a wetland in Beijing

To increase the knowledge on the particulate matter of a wetland in Beijing, an experimental study on the concentration and composition of PM₁₀ and PM_2.5 was implemented in Beijing Olympic Forest Park from 2013 to 2014. This study analyzed the meteorological factors and deposition fluxes at different heights and in different periods in the wetlands. The results showed that the mean mass concentrations of PM₁₀ and PM_2.5 were the highest at 06:00–09:00 and the lowest at 15:00–18:00. And the annual concentration of PM₁₀ and PM_2.5 in the wetland followed the order of dry period (winter) > normal water period (spring and autumn) > wet period (summer), with the concentration in the dry period significantly higher than that in the normal water and wet periods. The chemical composition of PM_2.5 in the wetlands included NH₄⁺, K⁺, Na⁺, Mg^2 +, SO₄^2 −, NO₃⁻, and Cl⁻, which respectively accounted for 12.7%, 1.0%, 0.8%, 0.7%, 46.6%, 33.2%, and 5.1% of the average annual composition. The concentration of PM₁₀ and PM_2.5 in the wetlands had a significant positive correlation with relative humidity, a negative correlation with wind speed, and an insignificant negative correlation with temperature and radiation. The daily average dry deposition amount of PM₁₀ in the different periods followed the order of dry period > normal water period > wet period, and the daily average dry deposition amount of PM_2.5 in the different periods was dry period > wet period > normal water period.     

施肥量对福州平原稻田CO2排放及其温度敏感性的影响

为了阐明施肥量对稻田CO_2排放及其温度敏感性的影响,采用静态箱-气相色谱法,对福州平原稻田对照(CK)、常规施肥组(CG)和倍增施肥组(BZ)的CO_2排放及其温度敏感性进行了测定和分析.结果表明,CK、CG和BZ的CO_2排放通量变化范围分别为32.33~3181.97、30.68~3701.05和32.81~3206.29 mg·m~(-2)·h~(-1),CG的CO_2排放通量比较CK增加了14.16%,BZ的CO_2排放通量较CK增加了8.04%,CK、CG和BZ之间CO_2排放通量差异不显著(p0.05);稻田CO_2排放与土温(r=0.683,p0.01)、株高(r=0.820,p0.01)及含水量(r=0.309,p0.05)具有显著的正相关关系;CK、CG和BZ的CO_2排放通量与土温和气温均具有显著的正相关关系(n=42,p0.01);CK、CG、BZ的Q_(s10)值和Q_(a10)值分别为28.13、18.88、13.24和9.86、7.64、6.35,CK的温度敏感性显著高于CG和BZ(p0.05),施肥显著降低了稻田CO_2排放的温度敏感性(p0.05).     

Magnetically recoverable Fe3O4@polydopamine nanocomposite as an excellent co-catalyst for Fe3+ reduction in advanced oxidation processes

Advanced oxidation processes are widely applied to removal of persistent toxic substances from wastewater by hydroxyl radicals(·OH),which is generated from hydrogen peroxide(H_2O_2) decomposition.However,their practical applications have been hampered by many strict conditions,such as iron sludge,rigid pH condition,large doses of hydrogen peroxide and Fe~(2+),etc.Herein,a magnetically recyclable Fe_3O_4@polydopamine(Fe_3O_4@PDA) coreshell nanocomposite was fabricated.As an excellent reducing agent,it can convert Fe~(3+)to Fe~(2+).Combined with the coordination of polydopamine and ferric ions,the production of iron sludge is inhibited.The minimum concentration of hydrogen peroxide(0.2 mmol/L and Fe~(2+)(0.18 mmol/L)) is 150-fold and 100-fold lower than that of previous reports,respectively.It also exhibits excellent degradation performance over a wide pH range from 3.0 to 9.0.Even after the tenth recycling,it still achieves over 99% degradation efficiency with the total organic carbon degradation rate of 80%,which is environmentally benign and has a large economic advantage.This discovery paves a way for extensive practical application of advanced oxidation processes,especially in environmental remediation.     

环境违法行为举报原因、特点及解决途径初探

徐州市是一座资源型城市,环境违法行为举报的上升趋势和构成特点有一定的代表性。据统计,2003年-2007年,环境违法行为举报件数平均每年上升20％,其中噪声和废气污染举报分别占40％和35％,这两类举报80％集中于市区。废水污染举报占15％,85％集中于农村地区。在分析了上升、构成特点原因的基础上,提出通过加大环保部门的执法力度、建立监督机制和环境绩效考核体系、强化个案查处等手段,逐步完善环境违法行为举报制度。     

SCR脱硝超低排放工程改造流场优化

采用CFD数值模拟方法对某电厂400 MW机组烟气脱硝装置流场进行了诊断,分析了导致效率低、烟道积灰以及空预器磨损等问题的具体原因,之后对此脱硝装置流场进行优化。优化结果表明：在省煤器出口水平扩张段烟道增设导流板,消除了该区域的大范围涡流,有利于减轻烟道积灰,并使喷氨区域烟气速度分布均匀;将喷氨混合装置改成喷氨格栅+圆盘混合器型式,强化了氨氮混合,使首层催化剂入口氨浓度分布均匀性得到显著改善,有利于提高脱硝效率、降低氨逃逸率;在空预器上游烟道增设导流装置,提高了空预器烟气速度分布均匀性,有利于解决空预器磨损问题。通过流场优化后,提高了此脱硝装置脱硝效率,减轻和消除了烟道积灰及空预器磨损。     

无机、有机添加剂对磷矿浆脱硫强化的影响

为了对磷矿浆湿法脱硫技术进行强化,研究了添加剂种类、添加剂的比例、SO2进口浓度对磷矿浆脱硫的影响。结果表明：在矿浆固液比为5%、反应温度为25 ℃、气体流量为0.3 L·min-1、添加剂比例为2%、O2含量为5%的实验条件下,处理SO2浓度为3 000 mg·m-3,反应120 min时,可得出最佳硝酸盐添加剂为硝酸铁、最佳金属氧化物添加剂为二氧化锰,最佳有机添加剂为己二酸,硝酸铁、二氧化锰、己二酸的最佳添加比例分别为4%、6%、2%。在以上3种添加剂的最佳添加比例条件下,选取不同浓度的SO2进行实验,反应120 min时,二氧化锰对磷矿浆的强化脱硫效果最好,硝酸铁对磷矿浆的强化脱硫效果次之,而己二酸对磷矿浆的强化脱硫效果最差,它的波动较大。     

2种分步浸提方法对土壤中Cr形态提取效果的比较

实验模拟了受铬渣污染的土壤环境,比较在不同活性炭加入量下2种典型分步浸提方法:Tessier 5步法和改进的7步分离方法得到的不同结果,探究适合于铬渣污染对土壤环境的铬形态浸提方法。实验结果表明,2种方法的浸提数据虽有较大差异,但能得到相对一致的变化趋势;七步法形态分类更为细致,99%以上的铬都分布在2~3个结合形态,Tessier五步法的物料衡算结果更为准确(96%~103%),相比七步法形态分类更具包容性,数据更具重现性;随着活性炭的加入,土壤环境中游离铬离子明显减少,转化为有机结合态等更稳定的结合形态,说明活性炭能有效固定土壤环境中游离的铬离子,增加其迁移稳定性。