活性焦对水中汞的吸附性能

采用活性焦作为吸附剂,通过静态吸附实验,研究了活性焦对水中汞的吸附特性,并初步探讨了其吸附机理。活性焦对汞的吸附可用拟二级动力学模型描述;在pH为5时能达到对Hg(Ⅱ)的最大吸附容量,在不同离子强度下均能保证对Hg(Ⅱ)有较高的去除率;据Langmuir吸附等温线模型计算出活性焦对Hg(Ⅱ)的饱和吸附容量可达412.1 mg/g。结合红外光谱、Zeta电位测试的结果,可推测活性焦对Hg的吸附过程是物理吸附和化学吸附综合作用的结果。活性焦是一种成本低、效果显著且稳定的吸附剂,有望在含汞废水处理中发挥重要作用。     

高铁酸钾预处理垃圾渗滤液

采用自制高纯度高铁酸钾预处理危废填埋场和垃圾焚烧厂的垃圾渗滤液,探讨和分析了处理效果。正交实验表明,高铁酸钾预处理危废填埋场渗滤液COD的最佳条件为:高铁酸钾与COD的初始质量浓度比为0.5、渗滤液初始pH值4.00、反应温度30℃、反应时间40 min,此时COD去除率达71.51%。此最佳条件下高铁酸钾对不同类型垃圾渗滤液的色度、SS、COD、BOD5、氨氮、总磷、重金属离子等污染因子都具有良好的去除效果,危废填埋场渗滤液经高铁酸钾预处理后可以直接进入后续生化处理系统;垃圾焚烧厂渗滤液预处理后其COD为2 861.0 mg/L,经二次预处理也可进入生化处理系统。实验结果表明,高铁酸钾对不同类型垃圾渗滤液都具有良好的预处理效果。     

不同生物营养物处理工艺剩余污泥中温水解特性

为了解不同生物营养物处理（BNR）工艺剩余污泥性质差异及其中温水解特性,采用序批式实验研究了来源于Orbal氧化沟（OD）和倒置A2／O工艺剩余污泥在中温水解过程中污泥浓度、营养物释放、污泥粒径、污泥絮凝性、污泥比阻及污泥胞外聚合物（EPS）的历时变化。结果表明,相同泥龄（约18d）条件下,OrbalOD剩余污泥氮含量较高,倒置A2／O剩余污泥磷含量较高,两者VSS／SS均低于0．6,导致中温水解过程污泥减量空间有限、氮磷释放速率不同。此外,尽管倒置A2／O工艺剩余污泥絮体尺寸及絮凝能力明显大于OrbalOD工艺剩余污泥的对应值,但两污泥比阻相近。中温水解过程中,两污泥絮体的尺寸均变小、絮凝能力均降低、比阻均增高;两者的胞外聚合物均呈现增高再降低趋势,且蛋白质均占EPS质量的75％以上,为主要的胞外物质。     

玻璃减薄蚀刻液中氟硅酸的选择性脱除方法

光电玻璃减薄蚀刻液中氟硅酸(H2SiF6)的累积,是导致蚀刻液无法连续使用而转化为废液的主要原因。尝试对蚀刻废液中氟硅酸进行选择性脱除工艺,探索刻蚀液循环利用的有效处理方法。鉴于氟硅酸的碱金属盐具有溶解度较低的特点,研究考察了利用钠盐或钾盐为沉淀剂,将废液中的H2SiF6以氟硅酸盐的形式沉淀去除,为实现蚀刻液的循环利用提供可能。结果表明,KCl相比NaCl对H2SiF6处理效果更好,但生成的K2SiF6的结晶颗粒过细,难以自然沉降,过滤效果较差;而Na2SiF6结晶沉降特性较好,且使用NaCl为沉淀剂具有价廉易得等特点,可作为氟硅酸的理想沉淀剂。H2SiF6去除率与碱金属盐H2SiF6摩尔计量比正相关,当摩尔计量比NaCl/H2SiF6=2,H2SiF6含量10%的模拟废液,其H2SiF6去除率可达到90%以上。     

古运河(镇江段)沉积物酶活性及其与氮磷阴离子的相关性

以古运河镇江段为研究对象,研究了表层沉积物中碱性磷酸酶活性、硝酸还原酶活性和亚硝酸还原酶活性的时空变化以及3种酶活性与河流表层沉积物中氮磷阴离子浓度及上覆水水质的相关性。结果表明,镇江古运河表层沉积物中碱性磷酸酶活性、硝酸还原酶活性和亚硝酸还原酶活性具有显著的时间和区域性差异,枯水期(12月)各酶活性较高,分别介于0.29~0.32 mg/(g·24 h)、0.13~0.19 mg/(g·24 h)、3.05~5.21 mg/(g·24 h);丰水期(5月)各酶活性较低,变化范围分别为0.18~0.29 mg/(g·24 h)、0.08~0.14 mg/(g·24 h)、2.95~3.64 mg/(g·24 h)。冗余分析结果显示,古运河表层沉积物酶活性在枯水期差异较大,丰水期差异较小,各酶活性与其相关离子浓度呈显著正相关(P0.05),硝酸还原酶和亚硝酸还原酶与上覆水的水质呈正相关。3种酶活性可被作为判断古运河镇江段沉积物富营养化负荷的参考性指标,硝酸还原酶和亚硝酸还原酶还可作为评价古运河镇江段水质的参考性指标。     

富含活性氯与Al_(13)水处理药剂对铜氰络合物去除效能

含重金属铜离子与氰离子(CN)的络合物广泛存在于电镀、冶金等工业废水中,是一种较难处理的污染物。富含活性氯和Al13聚合体的水处理药剂(PACC)兼具氧化和絮凝效能,在处理含重金属氰络合物([Cu(CN)3]2-)废水方面具有良好的应用前景。研究PACC与[Cu(CN)3]2-的反应计量学、动力学,考察了pH、反应时间和投药量等影响因素,确定PACC的最佳工作参数。结果表明,PACC可同时实现对CN的氧化和对Cu2+的絮凝,有效去除水中[Cu(CN)3]2-。使用PACC对[Cu(CN)3]2-的无害化处置过程分为2个阶段:CN-首先被氧化成氰酸根(OCN-);然后OCN-被进一步氧化并生成碳酸氢根和氮气,同时所释放的游离态铜离子被絮凝去除。这2个阶段反应的最佳pH分别为11和8,去除1 mol[Cu(CN)3]2-的最佳投药量为9.35 mol Cl2的PACC;在此条件下反应43 min后,其出水中CN-和Cu2+的浓度均达到排放标准(GB21900-2008)要求。     

Pros and cons of climate change in China

Climate change strongly affected the structure and functions of natural ecosystems,e.g.the vegetation productivity decreased in the Northeast permafrost region due to the higher temperature and less precipitation,whereas in the Tibetan Plateau,the vegetation productivity increased,owing to the improved thermal resource.Climate change led to reduced precipitation in North and Northeast China and thus the reduced surface runoff.The public needs for energy were changed because of climate change,e.g.the shorter heating period in winter.Climate change profoundly influenced human health,pathophoresis and major projects by increasing extreme events,including frequency and magnitude,and causing more serious water shortage.Under the background of climate change,although the improved thermal resources can be helpful for extending the crop growth period,more extreme events may resulted in more instability in agricultural productivity.Not only did climate change indirectly affect the secondary and tertiary industries through the impacts on agriculture and natural resources,but also climate change mitigation measures,such as carbon tax,tariff and trading,had extensive and profound influences on the socioeconomic system.Further analysis indicated that the impact of climate change presented significant regional differences.The impact had its pros and cons,while the advantages outweighed the disadvantages.Based on the above analysis on the impacts of climate change,we put forward suggestions on coping with climate change.First,scientifically dealing with climate change will need to seek advantages while avoiding the disadvantages of climate change in order to achieve the orderly adaptation to climate change,which is characterized with"Overall best,long-term benefit."Second,quantitative adaptation should be given more attention,e.g.proposing operational schemes and predictable goals and using uncertainty analysis on adaptation measures.Third,more active coping strategy should be adopted to enhance China's future comprehensive competitiveness.The strategies include but are not limited to gradually adjusting the industrial structure,intensifying the research and development(RD)of emission reduction technology and actively responding to the influence of carbon tax,tariff and trading on socioeconomic development in China.     

一种缺氧型生物滴滤塔对硫化氢去除的最佳反应条件

取自污水处理厂二沉池活性污泥载入生物滴滤塔中,与传统生物滴滤塔对比,考察了在缺氧条件下微生物对H2S的去除效率,最适工艺运行条件及影响因素,实验结果表明,最佳工艺运行条件:温度为30℃,pH 6.0,H2S入口浓度C1=1 000 mg/m3、C2=2 000 mg/m3、C3=3 000 mg/m3,对应的最适气体流量和循环液喷淋量分别为35～55 L/h、45 L/h、55L/h和20 L/h、40 L/h、50 L/h,该生物滴滤塔最高H2S负荷率可达6.9 g/(m3.h),具有较高的H2S去除效率,最适工艺运行条件的确定对实际大中型沼气发酵池净化配套系统具有一定的指导意义。     

Control strategies of atmospheric mercury emissions from coal-fired power plants in China

Atmospheric mercury (Hg) emission from coal is one of the primary sources of anthropogenic discharge and pollution. China is one of the few countries in the world whose coal consumption constitutes about 70% of total primary energy, and over half of coals are burned directly for electricity generation. Atmospheric emissions of Hg and its speciation from coal-fired power plants are of great concern owing to their negative impacts on regional human health and ecosystem risks, as well as long-distance transport. In this paper, recent trends of atmospheric Hg emissions and its species split from coal-fired power plants in China during the period of 2000-2007 are evaluated, by integrating each plant's coal consumption and emission factors, which are classified by different subcategories of boilers, particulate matter (PM) and sulfur dioxide (SO2) control devices. Our results show that the total Hg emissions from coal-fired power plants have begun to decrease from the peak value of 139.19 t in 2005 to 134.55 t in 2007, though coal consumption growing steadily from 1213.8 to 1532.4 Mt, which can be mainly attributed to the co-benefit Hg reduction by electrostatic precipitators/fabric filters (ESPs/FFs) and wet flue gas desulfurization (WFGD), especially the sharp growth in installation of WFGD both in the new and existing power plants since 2005. In the coming 12th five-year-plan, more and more plants will be mandated to install De-NO(x) (nitrogen oxides) systems (mainly selective catalytic reduction [SCR] and selective noncatalytic reduction [SNCR]) for minimizing NO(x) emission, thus the specific Hg emission rate per ton of coal will decline further owing to the much higher co-benefit removal efficiency by the combination of SCR + ESPs/FFs + WFGD systems. Consequently, SCR + ESPs/FFs + WFGD configuration will be the main path to abate Hg discharge from coal-fired power plants in China in the near future. However advanced specific Hg removal technologies are necessary for further reduction of elemental Hg discharge in the long-term.     

磁性介孔锰铁复合氧化物对Cr(Ⅵ)的吸附性能研究

以复合金属草酸盐为前驱体制备了纳米晶构筑的介孔锰铁氧化物材料,采用透射电镜、X射线衍射仪和固体比表面测定仪等对产物进行了表征.并研究了其对水体Cr(Ⅵ)的吸附性能,考察了pH及离子强度对吸附容量的影响、吸附动力学、吸附等温线以及碱液对Cr(Ⅵ)的洗脱率。结果表明,获得的锰铁氧化物为纳米晶构筑的介孔材料,比表面达277.4 m2/g,对Cr(Ⅵ)在酸性条件下有较强的吸附性能。在初始Cr(Ⅵ)质量浓度为100 mg/L,pH值在2时,10 min内能使溶液中的Cr(Ⅵ)去除率达96.8%,最大Cr(Ⅵ)吸附容量Qm为40 mg/g。