Nitric oxide and nitrous oxide emission from Hungarian forest soils; linked with atmospheric N-deposition

Studies of forest nitrogen (N) budgets generally measure inputs from the atmosphere in wet and dry deposition and outputs via hydrologic export. Although denitrification has been shown to be important in many wetland ecosystems, emission of N oxides from forest soils is an important, and often overlooked, component of an ecosystem N budget. During 1 year (2002–03), emissions of nitric oxide (NO) and nitrous oxide (N₂O) were measured from Sessile oak and Norway spruce forest soils in northeast Hungary. Accumulation in small static chambers followed by gas chromatography-mass spectrometry detection was used for the estimation of N₂O emission flux. Because there are rapid chemical reactions of NO and ozone, small dynamic chambers were used for in situ NO flux measurements. Average soil emissions of NO were 1.2 and 2.1 μg N m⁻² h⁻¹, and for N₂O were 15 and 20 μg N m⁻² h⁻¹, for spruce and oak soils, respectively. Due to the relatively high soil water content, and low C/N ratio in soil, denitrification processes dominate, resulting in an order of magnitude greater N₂O emission rate compared to NO. The previously determined N balance between the atmosphere and the forest ecosystem was re-calculated using these soil emission figures. The total (dry+wet) atmospheric N-deposition to the soil was 1.42 and 1.59 g N m⁻² yr⁻¹ for spruce and oak, respectively, while the soil emissions are 0.14 and 0.20 g N m⁻² yr⁻¹. Thus, about 10–13% of N compounds deposited to the soil, mostly as and , were transformed in the soil and emitted back to the atmosphere, mostly as greenhouse gas (N₂O).     

长江口及其邻近海域表层沉积物分布特征

根据长江口和杭州湾北部沉积物粒度分析数据，研究表层沉积物类型、分布以及分区特征。结果表明：沉积物的分布特征受水动力条件、地貌类型以及泥沙来源等因素的综合影响，长江口表层沉积物在纵向分布上，自西向东粒径从粗到细、分选程度从好至差，在横向上自北港－北槽－南槽，沉积物粒度逐渐变细；水流动力作用强的河槽和波浪作用强的口门浅滩沉积物粒度较粗，水动力较弱的河口边滩及口外海滨区沉积物则较细。根据沉积物分布特征可将长江口及其邻近海域分为河口分汊河段沉积区、河口拦门沙沉积区、口外海滨沉积区和杭州湾北部沉积区等4个沉积区。     

粪尿分集全方位负压排臭生态卫生旱厕应用实例

介绍了粪尿分集生态卫生旱厕的特点及应用效果，该厕能节约和保护水资源，排泄物可再次利用，能形成可持续的完整的生态系统。具有较好的发展前景。     

A Comparison of the Precipitation Chemistry Measurements Obtained by the CAPMoN and NADP/NTN Networks

Precipitation chemistry measurementsobtained by the Canadian Air and PrecipitationMonitoring Network (CAPMoN) and the U.S. NationalAtmospheric Deposition Program/National Trends Network(NADP/NTN) have been examined using more than 7 yrof collocated data from two sites, namely, Sutton,Quebec, Canada and State College, Pennsylvania, U.S.A.In the case of the CAPMoN data, weeklyprecipitation-weighted mean concentrations, totalsample depths and total standard gauge depths werecomputed from daily data and compared to thecorresponding weekly sampling data of the NADP/NTNnetwork. Seasonal and annual precipitation-weightedmean concentrations and deposition values were alsocomputed for both networks and compared. Statisticallysignificant between-network biases were found to existin the weekly results for most of the measuredvariables, particularly standard gauge depth, sampledepth, pH, H⁺, NO₃ ^-,NH₄ ⁺,Na⁺; the NADP/NTN values were consistently lowerthan those of CAPMoN with the exception of pH andNa⁺. The magnitude of the biases was less than35% of the median CAPMoN weekly value for the 7 yr. For most of the measured parameters, thevariability of the between-network differencesrepresented less than 20% of the median CAPMoN weeklyvalue. Both the between-network biases andvariabilities were functions of several physicalparameters, the most dominant being the sample depthand the ionic concentration. For seasonal and annualdeposition values, statistically significantbetween-network biases were found for H⁺,SO₄ ^2-, NO₃ ^-,Ca²⁺,NH₄ ⁺ for both periods; for Mg²⁺ andK⁺ for seasonal data; and Cl^- for yearlydata, with the NADP/NTN deposition values being lowerthan those of CAPMoN. The relative biases ranged from7 to 37%. Part of the between-network bias in thedeposition estimates was directly attributable to astrong bias in the standard gauge depths of the two networks.     

梅家洲形成、演化及其对鄱阳湖的影响

根据鄱阳湖口梅家洲东南缘钻孔 (ZK2 )沉积物环境指标特征 ,结合历史资料对梅家洲的形成与发展及其在历史时期对鄱阳湖的影响进行了探讨。随着古长江不断南迁 ,在长江与古赣江的共同作用下 ,2 .3kaBP前后 ,在长江南岸湖口地区形成天然堤 ,即梅家洲。它的出现对古赣江来水产生阻水 ,导致了鄱阳湖形成并向南扩张。对比 1970年和 1980年湖口地区水下地形图 ,发现梅家洲仍在不断加积 ,其对鄱阳湖的阻水作用更加明显 ,将引起鄱阳湖湖区沉积环境的改变 ,给鄱阳湖带来生态环境等多方面的影响。     

纤维布袋除尘器高温下干法脱硫研究

论述了高温条件下布袋除尘器中喷入碱性固体物质（Ca(OH)2)脱硫的反应机理。分析了喷射阶段、过滤阶段烟温对脱硫过程发生的各种反应的影响；总结了在布袋除尘器应用不同脱硫剂的脱硫效果。     

干式硫酸雾净化法在环境工程中的应用

介绍干式吸附法净化硫酸雾的特点、工艺流程及产生的环境效益。该法净化效率高，无二次污染，操作简单、方便。     

川东北地区元素大气沉降通量及其季节变化

从2011年8月~2012年7月在川东北地区共收集12个月的大气沉降样品.采用电感耦合等离子体质谱仪(ICP-MS)分析了样品在弱酸性环境下(pH值在2左右)溶解态组分中Na、Mg、Ca、K、Si、Sr、Ba、Zn等元素的含量,计算了这些元素的沉降通量.结果表明:①各元素的沉降通量存在显著的季节变化.Na的沉降通量随着降水增加而显著增加,显示它主要以大气湿沉降为主;Ca、Si、Ba、Sr、Mg的沉降通量在冬季或春季显著上升,显示这些元素的沉降可能主要与大气粉尘活动有关.②不同的元素之间年沉降通量存在显著差异,Na的沉降通量最大,达到30 497μg·(102cm2·a)-1,比最小的Ba沉降通量[27.4μg·(102cm2·a)-1]高出3个数量级.     

Fe/Zn-TMS体系吸收去除催化裂化干气中H2S的性能

本研究采用FeCl3·6H2O、ZnCl2和环丁砜(TMS)复配形成的Fe/Zn-TMS体系脱除催化裂化(FCC)干气中的H2S,并用30%H2O2氧化再生Fe/Zn-TMS体系.同时,研究了各活性成分比例、吸收液体积浓度、吸收液pH值等对脱硫效率的影响,以及H2O2用量、吸收富液pH值对Fe2+氧化率的影响.结果表明,n(FeCl3·6H2O)∶n(ZnCl2)∶n(TMS)为0.45∶0.55∶1,吸收液pH为0.75,体积浓度(W)为50%的条件下能长时间高效脱硫,最高脱硫率达99.9%;在n(Fe2+)∶n(H2O2)为2∶1,吸收富液pH为0.65的条件下,Fe2+氧化率达96.7%.体系可循环使用3次,且能耗低、操作简单.