Optimal Treatment Zone Moves During Enhanced Reductive Dechlorination in Fractured Bedrock

An enhanced bioremediation pilot test was implemented to study the efficacy of enhancing in situ reductive dechlorination of tetrachloroethene (PCE) in shallow bedrock where some intrinsic degradation to cis‐1,2‐dichloroethene (cis‐1,2‐DCE) was observed without further degradation to vinyl chloride or nontoxic ethene. Limited Dehalococcoides spp. cell concentrations were present within the study area prior to the gravity‐fed injection of an injectate of fermentable carbon substrates in native anaerobic groundwater. Direct connectivity between the injection well screen and performance monitoring well was evidenced and resulted in the degradation of nearly all PCE to cis‐1,2‐DCE, significant decrease in pH, and apparent inhibited Dehalococcoides spp. growth in the study area groundwater in the first six months. After 24 months, nearly all cis‐1,2‐DCE had degraded to nontoxic ethene, pH rebounded to more optimal levels, and abundant growth of Dehalococcoides spp. (6.8E05 cells/mL) and its functional gene expressions responsible for complete dechlorination were evident. The observations indicated initial poor dechlorination within the injection zone did not preclude effective treatment, allowing sufficient monitoring time showed the effective treatment zone (or more‐optimal fringe) first moved outward from the injection zone beyond the monitoring point and then receded back toward the point of injection over a period of two years. ©2015 Wiley Periodicals, Inc.     

γ-Al2O3负载多金属复合催化剂选择性催化还原烟气脱硝

以γ-Al₂O₃作为载体，先后负载CeO₂，MnC₂O₄，Fe（NO₃）₃，CrO₃，Ni（NO₃）₂，NH₄VO₃等多种金属组分制备γ-Al₂O₃负载多金属复合催化剂，并用于模拟烟气的选择性催化还原脱硝。通过SEM和XRD技术对催化剂进行了表征。表征结果显示：Fe，Mn，Cr的添加能增加催化剂的低温催化活性、提高催化剂的N₂选择性;γ-Al₂O₃对活性金属氧化物的负载效果良好。实验结果表明：各金属化合物的最佳加入量为 w（MnC₂O₄·2H₂O）=20%，w（Fe（NO₃）₃·9H₂O）=15%，w（CrO₃）=10%，w（Ni（NO₃）₂·6H₂O）=5%，w（NH₄VO₃）=10%，w（CeO₂）=5%，w（γ-Al₂O₃）=35%;以在最佳正交实验条件下制得的γ-Al₂O₃负载多金属复合物为催化剂，在脱硝反应温度为205 ℃的条件下，NO转化率为96.7%;γ-Al₂O₃负载多金属复合催化剂经5次重复使用，NO转化率仍可稳定在94%左右。     

臭氧氧化处理页岩气钻井废水的机理与动力学

采用臭氧氧化法处理页岩气钻井废水经混凝沉淀后的出水(COD=759.63 mg/L),重点研究了废水中有机污染物的去除机理与反应动力学。实验结果表明:在废水pH为11.2、臭氧通入量为8 mg/min、反应时间为50 min的最佳工艺条件下,废水的COD去除率为42.51%;羟基自由基抑制剂CO_3~(2-)、HCO_3~-和叔丁醇的引入抑制了废水COD的臭氧氧化去除,尤其是叔丁醇的加入使COD去除率显著下降,说明废水中有机物的臭氧氧化去除过程遵循羟基自由基机理;臭氧氧化法对钻井废水中有机物的氧化去除过程符合表观二级反应动力学规律。     

PW_(12)/g-C_3N_4光催化降解甲基橙

采用浸渍法制备了磷钨酸(PW12)/g-C3N4复合光催化剂,并将其用于溶液中甲基橙的光催化降解,运用IR技术对使用前后的光催化剂进行了表征。表征结果显示,PW12和g-C3N4的结构未在浸渍负载中发生改变,且PW12和g-C3N4结合牢固。实验结果表明:最佳的PW12负载量(光催化剂中PW12的质量分数)为50%;光催化降解甲基橙的优化反应条件为初始甲基橙质量浓度5 mg/L、光催化剂加入量0.6 g/L、初始溶液p H=7;在优化条件下,分别采用紫外光、模拟太阳光、可见光照射120 min后,甲基橙的降解率分别为96.59%,82.23%,42.78%;该光催化剂固载良好,使用中不易发生溶脱,稳定性好,可重复使用。     

Associations between ambient high temperatures and suicide mortality: a multi-city time-series study in China

Environmental Science and Pollution Research - Suicide prevention has become a public health issue of great concern. Previous studies proved that ambient temperature had an impact on suicide death,...     

Simultaneous adsorption and immobilization of As and Cd by birnessite-loaded biochar in water and soil

Environmental Science and Pollution Research - A novel biochar was prepared by loading birnessite to improve its capability to simultaneously adsorb As(III), As(V), and Cd(II) in water and soil....     

Estimating resource utilization demands in implementing statewide screening,brief intervention,and referral to treatment for alcohol-impaired drivers

Objectives: The Alcohol Use Disorders Identification Test (AUDIT) is used to assess the level of alcohol use/misuse and to inform the intensity of intervention delivered within screening, brief intervention, and referral to treatment (SBIRT) programs. Policy initiatives are recommending delivery of SBIRT within health care settings to reduce alcohol misuse and prevent alcohol-impaired driving. Recent reports are considering extending delivery of SBIRT to criminal justice settings. One consideration in implementing SBIRT delivery is the question of resource utilization; the amount of effort required in delivering the 4 different intensities of intervention in SBIRT: Alcohol education, simple advice, brief counseling and continued monitoring, and brief counseling and referral to specialist (from least to most intense in terms of delivery time, the skill level of the provider, and personnel resources).

Methods: In order to inform expectations about intervention intensity, this article describes the AUDIT scores from 982 adults recently arrested for alcohol-impaired driving. The distribution of scores is extrapolated to state rates for individuals arrested for alcohol-impaired driving by intervention level.

Results: Though alcohol education was the most common intervention category, about one quarter of the sample scored in a range corresponding with the more intensive interventions using the brief counseling, continued monitoring for ongoing alcohol use, and/or referral to specialist for diagnostic evaluation and treatment.

Conclusions: This article provides local distribution of AUDIT scores and state estimates for the number of individuals scoring in each level of risk (AUDIT risk zone) and corresponding intervention type. Routine criminal justice practice is well positioned to deliver alcohol screening, education, simple advice, and continued alcohol monitoring, making delivery of SBIRT feasible for the majority of alcohol-impaired drivers. Challenges to implementing the full range of SBIRT services include resource demands of brief counseling, identifying the appropriate providers within a criminal justice context, and availability of community providers for referral to diagnostic and specialty care. Solutions may vary by state due to differences in population density and incidence rates of alcohol-impaired driving.     

Study of the adsorption of endocrine disruptor compounds on typical filter materials using a quartz crystal microbalance

Environmental Science and Pollution Research - Drinking water containing environmental endocrine disruptor compounds (EDCs) endangers human health, and researching the purification process of...