中国华北地区冬季大气污染物航空测量(II)—空中大气气溶胶污染特征研究

大气气溶胶在酸性降水中的作用非常重要。在“八五”期间酸性降水的研究中,进行了华北地区冬季空中大气气溶胶污染特征的分析和研究,填补了国内外相关研究领域的空白。结果表明,华北地区冬季空中大气气溶胶污染比较严重,形成了浓度与地面相近的空中污染区域,大气气溶胶主要来源于煤炭燃烧等人为过程。同时大气气溶胶具有较强的酸性,有利于酸性降水的形成。      

生态系统对酸沉降敏感性评价方法与进展

评述水体、土壤和整个生态系统对酸沉降敏感性评价的各种方法,这些方法用系统 的不同物理化学性质表征它们缓冲酸输入的能力。     

甲醇装置酸性尾气工业处理试验

进行了甲醇装置酸性尾气工业处理试验,用体积分数为25％～30％的N-甲基二乙醇胺(MDEA)水溶液提浓该酸性尾气,提浓后的酸性尾气送至克劳斯硫磺回收装置回收硫磺。在再生塔底温度为124℃、气液比为80、吸收塔塔板为11层的条件下脱除H2S,净化气中H2S体积分数小于0．25％,去除率为97．3％。该项目的实施消除了HCN、CH30H、H2S等有毒气体对大气环境的污染,同时可回收硫磺736t／a,具有较大的社会效益和一定的经济效益。     

CuO/CSAC催化剂的制备及酸性大红GR废水的处理

以椰壳活性炭(CSAC)为载体负载CuO制备了CuO/CSAC催化剂。采用正交实验优化了CuO/CSAC催化剂的制备工艺条件,采用单因素实验和响应面实验优化了CuO/CSAC催化剂处理模拟酸性大红GR废水的工艺参数。结果表明:在CSAC加入量5 g、煅烧时间2.5 h、煅烧温度300 ℃、0.5 mol/L的硝酸铜溶液用量15 mL的最佳工艺条件下,CuO/CSAC催化剂微孔结构丰富,CuO特征峰明显;CuO/CSAC催化剂处理酸性大红GR废水的最佳工艺参数为pH 5.0,曝气时间4.10 h,催化剂加入量0.57 g,可将100 mL初始COD 962 mg/L、初始色度32 700倍的废水分别处理至残余COD 41.5 mg/L,残余色度28.4倍。建立了以残余COD和残余色度为响应值的工艺模型,计算值与实验值的相对误差均在±10%以内。     

Effects of leachant temperature and pH on leachability of metals from fly ash. A case study: Can thermal power plant, province of Canakkale, Turkey

Lignite powered electric generation plants result in increasing environmental problems associated with gaseous emissions and the disposal of ash residues. Especially, low quality coals with high ash content cause enormous quantities of both gaseous and solid fly ash emissions. The main problem is related to the disposal of fly ash, which, in many cases, contains heavy metals. It is known that toxic trace metals may leach when fly ash is in contact with water. In this study, fly ash samples obtained from the thermal power plant in the town of Can in Turkey were investigated for leachability of metals under different acidic and temperature conditions. The experimental results show that a decrease in pH of the leachant favors the extraction of metal ions from fly ash. A significant increase in the extraction of arsenic, cadmium, chromium, zinc, lead, mercury, and selenium ions from the ash is attributed to the instability of the mineral phases. These heavy metals concentrations increase with respect to increasing acidic conditions and temperature. Peak concentrations, in general, were found at around 30°C.     

中酸性土壤无机磷形态及生物有效性

在黄棕壤和棕红壤上施用磷肥,经三年室内湿润条件下培养,用石灰性土壤无机磷分级方法测定各形态磷含量.各形态用增量的分配比例表明,Fe-P居首位,其次为Al-P和O-P.三级Ca-P之和在20％以下.经培养的土壤种植黑麦草,其生物量和吸磷量与各形态磷量的相关系数除Ca10-P外,均达到极显著水准.土壤有效磷与各形态磷的相关性表明,Ca2-P是土壤有效磷的直接给源（r=0.992）,Fe-P、Al-P是有效磷的重要潜在性给源（r分别为0.982和0.914）,O-P、Ca10-P为无效态磷（r=-0.168）.     

Watershed Nitrogen and Mercury Geochemical Fluxes Integrate Landscape Factors in Long-term Research Watersheds at Acadia National Park, Maine, USA

This paper is an overview of this special issue devoted to watershed research in Acadia National Park (Acadia NP). The papers address components of an integrated research program on two upland watersheds at Acadia NP, USA (44° 20′ N latitude; 68° 15′ E longitude). These watersheds were instrumented in 1998 to provide a long-term foundation for regional ecological and watershed research. The research was initiated as part of EPA/NPS PRIMENet (Park Research and Intensive Monitoring of Ecosystems Network), a system of UV-monitoring stations and long-term watershed research sites located in US national parks. The initial goals at Acadia NP were to address research questions about mercury, acid rain, and nitrogen saturation developed from prior research. The project design was based on natural differences in forests and soils induced by an intense wildfire in one watershed in 1947. There is no evidence of fire in the reference watershed for several hundred years. We are testing hypotheses about controls on surface water chemistry, and bioavailability of contaminants in the contrasting watersheds. The unburned 47-ha Hadlock Brook watershed is 70% spruce-fir mature conifer forest. In contrast, burned 32-ha Cadillac Brook watershed, 4 km northeast of the Hadlock watershed, is 20% regenerating mixed northern hardwoods and 60% shrub/rocky balds. Differences in atmospheric deposition are controlled primarily by forest stand composition and age. The watersheds are gauged and have water chemistry stations at 122 m (Cadillac) and 137 m (Hadlock); watershed maximum elevations are 468 and 380 m, respectively. The stream water chemistry patterns reflect, in part, the legacy of the intense fire, which, in turn, controls differences in forest vegetation and soil characteristics. These factors result in higher nitrogen and mercury flux from the unburned watershed, reflecting differences in atmospheric deposition, contrasting ecosystem pools of nitrogen and mercury, and inferred differences in internal cycling and bioavailabilty.     

浅析高酸性污水处理方法在川西北净化厂的应用

概述川西北气矿天然气净化厂高酸性污水的处理现状及改造措施,通过对几处工艺管线及设备的改造,实现了高酸性污水的安全处理与零排放,保证了川西北气矿天然气净化厂生产的安全平稳运行。     

交流杂散电流对X80管线钢的腐蚀行为影响

目的 研究交流杂散电流干扰下管线钢的腐蚀机理.方法 采用电化学阻抗谱(EIS)、动电位极化扫描(Tafel)等电化学测试技术和表面分析技术研究不同交流电流密度干扰下(0～80 A/m2)X80管线钢在酸性土壤环境中的腐蚀行为.结果 酸性土壤环境中,即使是10 A/m2的交流电流密度,也会引起X80的交流腐蚀,且钢的腐蚀...     

河底沉积物培养耐酸产甲烷颗粒污泥的试验研究

利用河底沉积物作为接种污泥,在一个3.1L的EGSB反应器中进行培养耐酸产甲烷颗粒污泥的试验研究.结果表明,EGSB反应器在pH6.0,出水碱度低于400mg CaCO3/L,容积负荷5.3kg COD/(m³d)的条件下培养出具有良好沉降性能和产甲烷活性的耐酸颗粒污泥.形成耐酸颗粒污泥后,EGSB反应器在pH5.8～6.0,进水COD 3000mg/L,容积负荷5.2kg COD/(m³d)的条件下稳定运行29d, COD去除率平均为89.2%,出水总碱度仅为264.4mg CaCO₃/L,沼气中甲烷的含量约为56.9%.扫描电镜观察发现颗粒污泥内部存在成簇生长的索氏甲烷丝菌