Characterization of peroxyacetyl nitrate (PAN) under different PM2.5 concentration in wintertime at a North China rural site

As a secondary pollutant of photochemical pollution, peroxyacetyl nitrate(PAN) has attracted a close attention. A four-month campaign was conducted at a rural site in North China Plain(NCP) including the measurement of PAN, O₃, NO_x, PM_2.5, oxygenated volatile organic compounds(OVOCs), photolysis rate constants of NO₂ and O₃ and meteorological parameters to investigate the wintertime characterization of photochemistry from November 2018 to Fe...     

科学家首次在大洋中脊发现新海底热液活动区

中国大洋第19航次科学考察队的“大洋一号”科学考察船在西南印度洋脊发现了新的海底热液活动区．确定了热液喷口位置．并在东南印度洋中脊发现新的海底热液异常区。这是我国科学家第一次也是世界上首次在西南印度洋中脊和超慢速扩张洋中脊发现正在活动     

郫县灰潮田有效硅含量和小麦施硅效应初探

通过同田对比试验，本文对郫县水稻土小麦施用硅肥进行了初步研究．结果表明，小麦施硅获得了增产效果；施硅对小麦穗粒数、株高和基部节间体积等具有生长效应；郫县水稻土有效硅含量为１２７±３９ｍｇ·ｋｇ－１（ｎ＝１２），变异较大，与土壤粘粒（＜０．００１ｍｍ）呈极显著正相关（ｒ＝０．７９）；发育于第四系岷江灰色冲积母质的郫县水稻上，粘粘含量普遍较低，因此，郫县小麦施硅具有较大增产潜力．     

Water Supply Planning Considering Uncertainties in Future Water Demand and Climate: A Case Study in an Illinois Watershed

Ensuring an adequate, reliable, clean, and affordable water supply for citizens and industries requires informed, long-range water supply planning, which is critically important for water security. A balance between water supply and demand must be considered for a long-term plan. However, water demand projections are often highly uncertain. Climate change could impact the hydrologic processes, and consequently, threaten water supply. Thus, understanding the uncertainties in future water demand and climate is critical for developing a sound water supply plan. In Illinois, regional water supply planning attempts to explore the impacts of future water demand and climate on water supply using scenario analyses and hydrologic modeling. This study is aimed at developing a water supply planning framework that considers both future water demand and climate change impacts. This framework is based on the Soil and Water Assessment Tool to simulate the watershed hydrology and conduct scenario analyses that consider the uncertainties in both future water demand and climate as well as their impacts on water supply. The framework was applied to water supply planning efforts in the Kankakee River watershed. The Kankakee River watershed model was calibrated and validated to observed streamflow records at four long-term United States Geological Survey streamflow gages. Because of the many model parameters involved, the calibration process was automated and was followed by a manual refinement, resulting in good model performance. Long-range water demand projections were prepared by the Illinois State Water Survey. Six future water demand scenarios were established based on a suite of assumptions. Climate scenarios were obtained from the Coupled Model Intercomparison Projection Phase 5 datasets. Three representative concentration pathways (RCPs), RCP2.6, RCP4.5, and RCP8.5, are used in the study. The scenario simulation results demonstrated that climate change appears to have a greater impact on water availability in the study area than water demand. The framework developed in this study can also be used to explore the impacts of uncertainties of water demand and climate on water supply and can be extended to other regions and watersheds.     

Towards zero discharge of chromium-containing leather waste through improved alkali hydrolysis

The treatment of chromium-containing leather waste (CCLW), the major solid waste generated at the post-tanning operations of leather processing, has the potential to generate value-added leather chemicals. Various alkali and enzymatic hydrolysis were compared, and calcium oxide was found to be important for effective (but still incomplete) hydrolysis. Three possible reasons are given for the incomplete hydrolysis under alkaline conditions. Data for 19 amino acids are presented for four different treatment products. On the basis of the results, a novel three-step CCLW treatment process is proposed. The gelatin extracted in the first step is chemically modified to produce leather finishing agents. The collagen hydrolysates isolated in the second step are used as proteinic retanning agents by chemical modification. The remaining chrome cake is further hydrolyzed with acids in the third step, and the obtained chromium-containing protein hydrolysates could be used for the preparation of chromium-containing retanning agents for leather industry. The proposed three-step process provides a feasible zero discharge process for the treatment of CCLW.     

高效生物处理技术在炼油厂碱渣废水处理中的应用

结合大港石化实际情况,在详细介绍柴油碱渣应用QBR高效生物处理技术取得成功的基础上,提出酸化回收粗酚或环烷酸并配套QBR、QBF等高效生物处理技术处理各种碱渣的新型工艺路线。经QBR处理后,出水COD去除率可达97%以上,石油类和挥发酚的去除率可达98%以上,硫化物去除率在99%以上。该技术的成功应用解决了困扰石化公司多年的碱渣废水处理的老大难问题,为炼厂碱渣废水乃至高浓度有机废水的处理开辟了一条新的途径。     

煤矿突发事件应急救援的群决策方法

提出了基于直觉模糊集的煤矿突发事件应急救援TOPSIS群决策模型。其中决策者权重采用偏好值与群体平均偏好值的相似度计算,属性指标权重采用直觉模糊熵权法确定。通过直觉模糊加权集成运算将各决策矩阵进行合成得到综合决策矩阵,利用改进后的直觉模糊距离公式计算出全部备选救援方案到正负理想解的距离,根据TOPSIS运算结果可以确定最佳事故救援决策方案。最后通过黑龙江省鸡西某矿的实例分析,验证了该模型的有效性及合理性。     

Serious BTEX pollution in rural area of the North China Plain during winter season

Atmospheric BTEX compounds(benzene, toluene, ethylbenzene and xylenes) in a rural site of the North China Plain(NCP) were preliminarily investigated in winter, and the outdoor concentrations(25.8–236.0 μg/m3) were found to be much higher than those reported in urban regions. The pollution of BTEX inside a farmer's house was even more serious, with combined concentrations of 254.5–1552.9 μg/m3. Based on the ratio of benzene to toluene(1.17 ± 0.34) measured, the serious BTEX pollution in the rural site was mainly ascribed to domestic coal combustion for heating during the winter season. With the enhancement of farmers' incomes in recent years, coal consumption by farmers in the NCP is rapidly increasing to keep their houses warm, and hence the serious air pollution in rural areas of the NCP during winter, including BTEX, should be paid great attention.