泥石流灾情评估指标体系

泥石流灾情评估指标体系的建立应满足适用性、完备性、可比性、综合性和系统性原则，而指标的选取还应在一定的要求下确定。依据上述原则，在泥石流灾情网络分析结果的基础上，建立了评估指标体系的结构层次模型，进而对各类灾情评估指标进行了分析，确定出评估泥石流灾情的具体指标和因子。最后建立了以成灾度为目标层，经济损失，社会影响，环境损害为准则层。评估指标和评估因子为指标层的泥石流灾情评估指标体系。     

Modeling the atmospheric transport and deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans in North America

The atmospheric fate of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was simulated for the year 2000 in North America using a SMOKE/CMAQ-based chemical transport model that was modified for this purpose. The 1999 USEPA emission inventories of PCDD/Fs and criteria pollutants were used. The 1995 Canadian emission inventory of criteria pollutants and the 1995 Canadian area source emissions for PCDD/Fs were used with the 2000 Canadian point source emissions. Modifications to CMAQ involved coupling it with dual organic matter (OM) absorption and black carbon (BC) adsorption models to calculate PCDD/F gas–particle partitioning. The model satisfactorily reproduced the particle bound fractions at all rural sites for which there were measured data and across the whole domain, the modeled vs. measured differences in particle bound fractions were less than 20% for nearly all congeners. The model predicted ambient air PCDD/F concentrations were also consistent with measurements. Simulated deposition fluxes were within 58% of direct measurements. PCDD/F atmospheric depositions to each of the Great Lakes were estimated for the year 2000. The results indicate that approximately 76% of the total deposition of PCDD/Fs to the Great Lakes (in W-TEQ, or toxic equivalent units as defined by the World Health Organization) is attributed to PCDD/Fs absorbed into OM in aerosol. For all of the lakes, more than 92% of all deposition is particle phase wet deposition and only 5–8% is particle phase dry deposition. Wet deposition from the gas phase is negligible. Of the 17 toxic PCDD/F congeners, the Cl_4–5DD/F compounds contribute approximately 70% to the total atmospheric deposition to the Great Lakes. The seasonal changes in the PCDD/F deposition flux track variations in ambient temperature.     

次氯酸钠催化氧化法处理十二碳硫醇恶臭污水

采用活性炭和次氯酸钠催化氧化处理含有十二碳硫醇的恶臭污水，进行了小试并取得了良好的效果。在活性炭作催化剂，反应温度为100℃，反映时间为2-3min的实验条件下，1mL1%(m/v)NaClO即可处理100mL污水，处理后的废水无色无臭，可直接排放。     

Distribution and sources of mercury in soils from former industrialized urban areas of Beijing, China

Fifty-seven typical surface soils and 108 deeper soils were collected from five former industrial sites in Beijing and concentrations of total Hg (SigmaHg) as well as pH, total carbon (TC), total nitrogen (TN), total sulfur, and dissolved organic carbon concentrations determined. The mean concentration of SigmaHg in surface soils was significantly greater than background concentrations in the vicinity of Beijing. Forty-eight percent of the samples exceeded the "critical" concentration of 1.0 mg Hg/kg, dry weight in soils, which has been established by the Chinese government. At depths of 0-80 cm in the soil, profile concentrations of SigmaHg also exceeded the background value. There were significant correlations between concentrations of SigmaHg, TC, and TN in the industrial soils. The greater concentration of SigmaHg in most soils could have been due in part to combustion of coal and leakage from industrial processes.     

秸秆覆盖对旱地红壤水分动态变化的影响

在中国科学院红壤生态实验站的猕猴桃园上进行秸秆覆盖改进方法的试验．结果表明，旱地红壤覆盖秸秆后再覆±5-10cm，与原来单纯覆盖秸秆相比，在干旱季节表层土壤水分含量可增加1．5％，凋萎含水量出现几率减少8％，抗旱效果大大增强，是一种值得推广的防旱措施．另外，与对照相比，深翻0．8m对改善土壤水分状况也有明显效果．不同覆盖物的试验结果表明，覆盖草本植物残体，在改善表层土壤水分状况、提高作物产量上的效果优于覆盖秸秆植物残体，建议在应用诸如玉米等稿秆作物的秸秆进行覆盖时应进行切碎处理并适当配施无机肥料．     

V型排导槽横纵比降对泥石流流速的差异影响研究

V型排导槽是一种有利于泥石流固体物质排泄的速流结构形式,可解决泥石流在槽内发生淤积堵塞的难题,因而被广泛应用。但是,因V型排导槽流速计算中水力坡度采用相同权重横纵坡矢量合成的综合比降,导致排导槽流速计算结果不准确而仍发生泥石流淤积的现象,不能充分发挥V型排导槽的速流优势。为了揭示V型排导槽横纵比降对泥石流流速的差异影响,设计完成了25组室内模型实验,分析了不同横纵比降组合条件下泥石流流速的差异及原因,查明横纵比降均与泥石流流速呈正相关关系,其中横比降对泥石流流速的影响低于纵比降;根据实验数据建立了泥石流流速关系式,得到横比降和纵比降在V型排导槽泥石流流速中的权重分别为0.75和1.30,验证了横比降在V型排导槽综合比降中的权重影响低于纵比降,为V型排导槽过流能力计算的优化研究提供思路和参考。     

Kinetic study of the removal of dimethyl phthalate from an aqueous solution using an anion exchange resin

Phthalate acid esters are becoming an important class of pollutants in wastewaters. This study addresses the kinetics of removal of dimethyl phthalate (DMP) using the anion exchange resin D201-OH from an aqueous solution. The effects of various factors on the removal rate and efficiency were investigated. An overall initial removal rate (OIRR) law and a pseudo first-order kinetic (PFOK) model were also developed. The internal diffusion of DMP within the resin phase of D201-OH is the rate-controlling step. Optimization of the particle size and pore structure of the resin D201-OH, the DMP concentration, and the reaction temperature can improve the DMP removal rate. The hydrolysis reaction of DMP catalyzed by D201-OH indicates an overall reaction order of 1.76, a value that is between the first order and the second order. The apparent activation energy of the reaction is 34.6 kJ/mol, which is below the homogeneous alkaline hydrolysis activation energy of 44.3 kJ/mol. The OIRR law can quantify the initial removal rate under different conditions. The results also show that the theoretical DMP removal efficiency predicted by the PFOK model agrees well with the experimentally determined values. Our research provides valuable insights into the primary parameters influencing the kinetic process, which enables a focused improvement in the removal or hydrolysis rate for similar processes.     

S-K型管式混合器-微絮凝高速过滤的实验研究

基于2种传统管式混合器的特点，研究了苏尔士-凯尼斯（S-K）新型组合管式混合器在预氧化-微絮凝高速过滤技术中的应用，对苏尔士（Sulzer）管式混合器、凯尼斯（Kenics）管式混合器及s-K型管式混合器高速过滤出水水质进行了对比分析，结果表明，S-K型微絮凝方式对浊度、COD及TP的平均去除率比其他2种混合器混合方式的去除效果提高了5％～10％，分别为80．3％、64．76％和51．15％。S-K型混合器过滤形成的絮体能够充分利用深层滤料，延长过滤周期。     

改进钒基SCR脱硝催化剂的抗碱金属中毒性能

以锐钛矿型二氧化钛和钛钨粉(5%WO3-TiO2)为载体,制备了系列钒和钨负载量不同的钒钛催化剂,考察碱金属和碱土金属(钾、钠和钙)对催化剂在氨选择性催化还原(NH3-SCR)氮氧化物反应中催化活性的影响。钾、钠和钙对钒钛催化剂的中毒影响大小顺序为钾钠钙。提高钒钛催化剂中钒的含量可显著提高催化剂的SCR活性和抗碱金属中毒性能,但高钒负载量(4.5%V2O5)造成催化剂氮气选择性明显下降,氧化亚氮生成显著增加。钨的添加有利于提高钒钛催化剂的低温活性和抗碱金属中毒性能,对氮气选择性无明显影响。     

Occurrence of free estrogens,conjugated estrogens,and bisphenol A in fresh livestock excreta and their removal by composting in North China

An efficient pretreatment and analytical method was developed to investigate the occurrence and fate of four free estrogens (estrone (E1), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinylestradiol (EE2)), four conjugated estrogens (estrone-3-sulfate sodium salt (E1-3S), 17β-estradiol-3-sulfate sodium salt (E2-3S), estrone-3-glucuronide sodium salt (E1-3G), and 17β-estradiol-3-glucuronide sodium salt (E2-3G)), and bisphenol A (BPA) in three livestock farms raising beef cattle, cows, sheep, swine, and chickens in Qi County, which is located in North China. The results demonstrated that one cow and one beef cattle excreted 956.25–1,270.41 and 244.38–319.99 μg/day of total (free and conjugated) estrogen, respectively, primarily through feces (greater than 91 %), while swine excreted 260.09–289.99 μg/day of estrogens, primarily through urine (98–99 %). The total estrogen excreted in sheep and broiler chicken feces was calculated to be 21.64–28.67 and 4.62–5.40 μg/day, respectively. It was determined that conjugated estrogens contributed to 21.1–21.9 % of the total estrogen excreted in cow feces and more than 98 % of the total estrogen excreted in swine urine. After composting, the concentration of total estrogen decreased by 18.7–59.6 %; however, increased levels of BPA were measured. In treated compost samples, estrogens were detected at concentrations up to 74.0 ng/g, which indicates a potential risk of estrogens entering the surrounding environment.