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141.
KOH活化花生壳生物质炭对亚甲基蓝吸附性能研究   总被引:2,自引:0,他引:2  
以花生壳生物质炭(P-BC)为原料,KOH为活化剂,采用化学活化法制得活化生物质炭(K-BC),通过考察对亚甲基蓝的吸附性能,研究了花生壳生物质炭的最佳活化条件,并利用N2吸附-脱附实验、SEM等对最佳活化条件下的生物质炭进行表征.结果表明,K-BC活化的最佳条件为碱炭比为1.5:1,活化温度为800℃,活化时间为90 min,此时K-BC的比表面积达到597.93 m2/g,总孔容达到0.76 cm3/g.并考察了亚甲基蓝初始浓度、pH等对K-BC吸附亚甲基蓝的影响,随着初始浓度的增加,吸附平衡时间显著延长,亚甲基蓝去除率显著降低;当pH=6时,K-BC对亚甲基蓝的吸附量最大;K-BC对亚甲基蓝的吸附动力学曲线符合伪二阶动力学模型,吸附平衡时K-BC对亚甲基蓝的吸附能力为80~149.95 mg/g.  相似文献   
142.
As indoor smoking bans have become widely adopted, some U.S. communities are considering restricting smoking outdoors, creating a need for measurements of air pollution near smokers outdoors. Personal exposure experiments were conducted with four to five participants at six sidewalk bus stops located 1.5–3.3 m from the curb of two heavily traveled California arterial highways with 3300–5100 vehicles per hour. At each bus stop, a smoker in the group smoked a cigarette. Gravimetrically calibrated continuous monitors were used to measure fine particle concentrations (aerodynamic diameter ≤2.5 µm; PM2.5) in the breathing zones (within 0.2 m from the nose and mouth) of each participant. At each bus stop, ultrafine particles (UFP), wind speed, temperature, relative humidity, and traffic counts were also measured. For 13 cigarette experiments, the mean PM2.5 personal exposure of the nonsmoker seated 0.5 m from the smoker during a 5-min cigarette ranged from 15 to 153 µg/m3. Of four persons seated on the bench, the smoker received the highest PM2.5 breathing-zone exposure of 192 µg/m3. There was a strong proximity effect: nonsmokers at distances 0.5, 1.0, and 1.5 m from the smoker received mean PM2.5 personal exposures of 59, 40, and 28 µg/m3, respectively, compared with a background level of 1.7 µg/m3. Like the PM2.5 concentrations, UFP concentrations measured 0.5 m from the smoker increased abruptly when a cigarette started and decreased when the cigarette ended, averaging 44,500 particles/cm3 compared with the background level of 7200 particles/cm3. During nonsmoking periods, the UFP background concentrations showed occasional peaks due to traffic, whereas PM2.5 background concentrations were extremely low. The results indicate that a single cigarette smoked outdoors at a bus stop can cause PM2.5 and UFP concentrations near the smoker that are 16–35 and 6.2 times, respectively, higher than the background concentrations due to cars and trucks on an adjacent arterial highway.

Implications: Rules banning smoking indoors have been widely adopted in the United States and in many countries. Some communities are considering smoking bans that would apply to outdoor locations. Although many measurements are available of pollutant concentrations from secondhand smoke at indoor locations, few measurements are available of exposure to secondhand smoke outdoors. This study provides new data on exposure to fine and ultrafine particles from secondhand smoke near a smoker outdoors. The levels are compared with the exposure measured next to a highway. The findings are important for policies that might be developed for reducing exposure to secondhand smoke outdoors.  相似文献   

143.
生物接触氧化法处理煤矿生活污水的工艺探讨   总被引:2,自引:0,他引:2  
根据煤矿生活污水的特点,结合几年来工作和学习的经验及体会,论述生物接触氧化法的工艺流程,讨论设计中遇到的问题,探讨设计参数,使用填料和选取方法,为今后的污水处理站设计提供参考。  相似文献   
144.
我国环境信息技术应用回顾与展望   总被引:9,自引:0,他引:9  
21世纪人类将全面进入知识经济时代。专家预测 ,到21世纪中叶主导知识经济社会的仍是信息。在此期间 ,信息系统是资金投入的重点 ,数据转化为信息、信息转化为知识、知识转化为智慧、智慧转化为科学决策 ,信息与知识管理、存储、传递和应用将对决策起着重要的指导作用。面对新世纪知识经济的挑战 ,必须从战略高度来认识并建设我国环境信息系统。1我国环境信息发展历程1 1我国环境信息基础设施建设“七五”期间 ,我国开始环境信息标准化和环境数据库的开发研究。经过十几年的努力 ,国家环境信息化进展较快 ,取得了一定成效。《国家环…  相似文献   
145.
The transport behaviors of a suite of contaminants released from electronic waste (e-waste) recycling operations, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and heavy metals, were evaluated by analyzing the contaminant residues in surface soils sampled in the surrounding area of an e-waste recycling site in South China. Concentrations of PBDEs and PCBs in the soil samples ranged from 0.565 to 2908 ng g(-1) dw and from 0.267 to 1891 ng g(-1) dw, respectively, while soil residues were 0.082-2.56, 3.22-287, and 16.3-162 μg g(-1) dw for Cd, Cu, and Pb, respectively. Concentrations of PBDEs and PCBs in soil decreased with increasing distance from the source of pollution, indicating possible PBDE and PCB contamination in the surrounding areas due to the short-range transport of these compounds from the e-waste recycling site. Although no significant difference in the short-range transport potential among PBDE and PCB congeners was observed, reductions in concentrations of the highly-brominated-BDEs and highly-chlorinated-CBs were slightly quicker than those of their less-halogen-substituted counterparts. Conversely, heavy metals showed the lowest transport potential due to their low vapor pressure, and results showed metals would remain near the pollution source instead of diffusing into the surrounding areas. Finally, mass inventories in areas near the e-waste site were 0.920, 0.134, 0.860, 4.68, 757, and 673 tons for BDE209, PBDEs (excluding BDE209), PCBs, Cd, Cu, and Pb, respectively.  相似文献   
146.
本文用统计能量分析的方法对一个放在扩散声场内的矩形隔声罩的声衰减进行了预测,计算了隔声罩声衰减随壁厚改变的变化,并讨论了罩内声吸收对声衰减的影响。  相似文献   
147.
战略环境评价及其应用初探   总被引:1,自引:0,他引:1  
概述了战略环境价的概念、产生原因、研究现状及其工作程序,结合川南矿肥工程项目对它进行了应用初探,提出了计划、规划层次SEA的方法和指标,并对我国环评工作提出了建议。  相似文献   
148.
秦皇岛作为著名的沿海旅游城市,外语语言环境作为旅游软环境的一个重要因素直接影响着整个旅游产业的综合竞争力。鉴于此,对秦皇岛市外语语言软环境进行调查摸底。调查结果表明,旅游景区标示语及城市公示语的翻译存在不同程度的问题,旅游从业人员总体素质不高,市民的外语能力普遍偏低。以调查结果为依托,从政府导向、行业把关、全民参与三方面提出了优化秦皇岛市旅游业外语语言软环境的建议。  相似文献   
149.
关于肥满度指数的讨论   总被引:19,自引:0,他引:19  
肥满度指数,也称身体状况指数,广泛应用于各个动物类群和生态学、生理、生化、遗传学以及养殖业.至今已有多种肥满度指数提出,从计算公式结构上,肥满度指数可以划分为比值法和残差法两大类.通过对各种肥满度指数的分析,Le Cren相对状态指数Kn、log10(体重)与log10(身体大小指数)线性回归的(标准化)残差这两种肥满度指数系统误差相对较小.实际应用中最好根据所考察的问题分别计算不同年龄段、性别的个体的肥满度指数来分析肥满度指数.由于定义的模糊性及其前提假设缺乏广泛验证,因此,肥满度指数在实际应用中需要谨慎考察其前提假设是否满足.参33  相似文献   
150.
Biomass is one of the renewable energy sources on which policy makers are greatly dependent on since it is a flexible feedstock capable of conversion into electricity, transport liquid fuels and heat by chemical and biological processes on demand. Though numerous publications have examined the relationship of economic growth with renewable energy and other parameters, biomass energy has never been included in these studies. Then, this study examines the causal relationship within a multivariate panel cointegration/error correction framework which combines the cross-section and time series data while allowing for heterogeneity across different provinces. After employing panel data regression model ranging from 2003 through 2012 to examine the relationships of biofuels production with sustainable development in China, the paper concludes that the development of biofuel energy production integrated with the consideration of the improvement of income per capita, and the attraction of more capital investment, does make a significant contribution to economic growth. However, some negative side effects including the increase of greenhouse emissions and the decrease of marginal land still coexist with the economic development. Of course, the importance of these findings lies on their implications and their adoption on strategic policies.  相似文献   
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