大气传输路径对上甸子本底站气溶胶光学特性的影响

利用2005~2010年北京上甸子本底站的PM2.5浓度、气溶胶散射系数(σsp)的连续观测资料,结合后向轨迹分析方法,探讨了不同季节、不同气团传输路径对本底地区气溶胶光学特性的影响.结果表明,污染物水平不仅与气团来向有关,也与气团的运动状态有关.偏南气团路径下的PM2.5浓度和σsp整体高于偏北气团路径,同时运动速度较慢、高度较低的气团路径多对应较高的PM2.5浓度和σsp.春、夏、秋季来自华北平原地区以及冬季来自华北区域北部的慢速、低气团对上甸子的污染水平有重要贡献.沙尘气溶胶多出现在春季,平均气溶胶质量散射效率(αsp)为0.78 m2·g-1.四季平均人为污染气溶胶的αsp为4.00 m2·g-1,其中冬季最高,春季最低.对于人为污染气溶胶来说,春、夏、秋三季的西北偏西路径、偏南路径以及偏北路径中速度较慢的轨迹组均具有较高的αsp(4.0 m2·g-1),表明这些气团路径受人为排放活动影响较大,而冬季各路径的αsp均较高,说明冬季区域内人为排放的影响比较一致.春、夏、秋三季中其他偏北的气团路径主要受到人为污染与沙尘气溶胶的共同影响.     

LAKE CHAMPLAIN BASIN NONPOINT SOURCE PHOSPHORUS ASSESSMENT1

ABSTRACT: Existing land use data were used to estimate nonpoint source phosphorus loads to Lake Champlain (Vermont/New York/Quebec) in a loading function model that combined P concentration coefficients with regional hydrologic data. The estimates were verified against monitored loading data, then used to assess the relative magnitudes of contributions from major land uses and regions of the Lake Champlain Basin. The Basin is comprised of 62 percent forest, 28 percent agricultural land, 3 percent urban land, and 7 percent water. The best-fit model estimated an annual total P load of 457 mt/year, which did not differ significantly from the 458 metric tons/year measured for an average hydrologic year, and accurately predicted loads from major tributaries. Agriculture contributes 66 percent of the annual nonpoint source P load to Lake Champlain; urban and forest land contribute 18 percent and 16 percent, respectively. Because agricultural land contributes most nonpoint source P to Lake Champlain, load reduction effort must deal with agricultural sources. However, because the urban 3 percent of the basin contributes 18 percent of the estimated load, high load reduction efficiencies might be achieved by addressing urban sources. This assessment clearly demonstrated the relationship between land use and P loads in the Lake Champlain Basin, a prerequisite for policy-makers to endorse a P management strategy requiring changes in land use and management.     

神经网络法预测分子总表面积的研究

本文用误差反向传播人工神经网络（ＡＮＮ）预测有机分子的总表面积，提出一组分子描述码（描述分子的分支性、不饱和性和成环性）作为输入的特征参数，预测结果：对于烷烃、烯烃、炔烃、脂环烃、芳烃、卤代烃、醇、醛、酮、酸、酯、胺、硫醇、杂环等１４类有机物平均误差为２．５８％，对于多环芬烃平均误差为２．８８％。根据ＡＮＮ法提供的信息，用统计分析的方法，得到分子总表面积与分子描述码之间的关联式，用它估算分子总表面     

粉煤灰固结技术及应用研究

为防治火电厂贮灰扬尘污染对粉煤灰固结技术进行了试验研究，目前已研制出２个系列的粉煤灰固结剂，固结后的抗压强度都在１６ｋｇ／ｃｍ＾２以上，最高达７０ｋｇ／ｃｍ＾２，水稳系数和冻稳系数都在０．９０－１．００，该项技术具有抑尘效果好，保持时间长，治理成本低，原料来源广泛，施工工艺简单和易于推广等特点，它可用于正在使用的灰场（包括中转灰场，碾压灰场）和贮满灰的灰场治理扬尘，还可用于灰场防渗和灰坝加固。     

芳香烃化合物的酸碱性与五种溶剂／水分配系数的相关性

本文以化合物的丁醚/水分配系数与环已烷/水分配系数的对数差作为酸性的量度,以氯仿/水分配系数与四氯化碳/水分配系数的对数差作为碱性的量度,测定芳香烃化合物的酸碱性,在此基础上,研究了40种各类芳烃化合物的五种溶剂/水分配系数与摩尔折射率、酸性和碱性参数的关系,得到了良好的相关关系。     

COMPARISON OF TWO PESTICIDE LEACHING INDICES1

ABSTRACT: Agriculture is the leading cause of regional‐scale non‐point source (NPS) pollution in the world today. Indices of pesticide leaching in the vadose zone are well suited for estimating the spatial accumulation and distribution of NPS pollutants in the near surface. In this study the Attenuation Factor (AF) and the Leaching index (Li) are used to assess the near‐surface leaching potential for 32 important agrochemicals for world average agricultural soil properties and recharge rates. The AF and Li indices both require the same input data and appear to work well for nonpolar chemicals. In the effort reported here the AF and Li indices produced similar results for the 32 agrochemicals. Pesticides with high and moderate leaching potential are identified. The AF estimates were more constant than the Li estimates for changes in the compliance depth and recharge rate. The AF index is simpler to use than the Li index and, therefore, is more likely to be employed in the future for screening/ranking agrochemicals relative to regional‐scale NPS ground water vulnerability.     

日用化学产品制造业产排污量核算系数手册的修订

通过分析日用化学产品制造业5个小类行业污染物产排情况,采集样本企业污染物指标数据模拟计算得出相应污染物指标的产排污量核算系数.系数涵盖了12个主要污染物指标,并按照16种产品类别组合编制系数手册,为第二次全国污染源普查统计提供参考.该核算系数手册是对第一次全国污染源普查中系数手册的修订与增补,以期更为系统、科学地量化日...     

Soil attenuation of As(III,V) and Se(IV,VI) seepage potential at ash disposal facilities

Leachate from ash landfills is frequently enriched with As and Se but their off-site movement is not well understood. The attenuation potential of As and Se by soils surrounding selected landfills during leachate seepage was investigated in laboratory column studies using simulated ash leachate. As(III, V) and Se(IV, VI) concentrations as well as pH, flow rate, and a tracer were monitored in influent and effluent for up to 800 pore volumes followed by sequential desorption, extraction, and digestion of column segments. Column breakthrough curves (BTCs) were compared to predictions based on previously measured sorption isotherms. Early As(V) breakthrough and retarded As(III) breakthrough relative to predicted BTCs are indicative of oxidative transformation during seepage. For Se(VI), which exhibits linear sorption and the lowest sorption propensity, measured BTCs were predicted fairly well by equilibrium sorption isotherms, except for the early arrival of Se(IV) in one site soil, which in part, may be due to higher column pH values compared to batch isotherms. Most of the As and Se retained by soils during leaching was found to be strongly sorbed (60–90%) or irreversibly bound (10–40%) with <5% readily desorbable. Redox potential favoring transformation to the more sorptive valence states of As(V) and Se(IV) will invoke additional attenuation beyond equilibrium sorption-based predictions. With the exception of Se(IV) on one site soil, results indicate that attenuation by down-gradient soils of As and Se in ash landfill seepage will often be no less than what is predicted by equilibrium sorption capacity with further attenuation expected due to favorable redox transformation processes, thus mitigating contaminant plumes and associated risks.     

呼吸计量法对甲醇和葡萄糖为基质的ASM1参数测定

污水水质和污泥特性不同,活性污泥1号模型(ASM 1)参数的测定结果也不相同。研究以甲醇和葡萄糖为基质,对分别经过甲醇和葡萄糖驯化的活性污泥,通过呼吸计量法测定高食微比、中食微比和零食微比下的氧利用速率(OUR)随时间变化的曲线。确定了异养菌产率系数(YH)、异养菌最大比增长速率(μ^H)和衰减系数(bH),并根据YH、μ^H和bH的测定结果和对中食微比下OUR曲线的数值拟合确定了异养菌半饱和常数(ks)、最大比水解速率(kh)和慢速可生物降解底物水解的半饱和常数(KX)。研究结果表明,在20℃下,采用甲醇和葡萄糖为基质测得的YH、bH、μ^H、ks、KX和kh分别为0.53、0.48、5.75、0.9、0.03、3.0和0.87、1.03、2.27、4.45、0.01、7.0。YH、bH、μ^H和ks的值与ASM1中城市污水的推荐值0.67、0.62、6.0、20.0不同,反映了不同基质对参数测定结果的影响。对于慢速可生物降解有机物(Xs)含量低的水质来说,KX和kh对生化反应过程影响不大,可采用ASM1模型的推荐值。