Adsorptive removal of basic dyes from aqueous solutions by surfactant modified bentonite clay (organoclay): Kinetic and competitive adsorption isotherm

Cationic surfactant (Hexadecyltrimenthylammonium chloride) modified bentonite clay was prepared and systematically studied for its adsorption behavior as an efficient adsorbent for the removal of basic dyes such as methylene blue (MB), crystal violet (CV) and Rhodamine B (RB) from aqueous phase. Organo modified clay shows better capacity for the removal of three dyes. The adsorption process was found to be dependent on pH and initial dye concentration. The maximum dye sorption was found to be at a pH of 9.0 (99.99% for MB, 95.0% for CV and 83.0% for RB). The adsorption capacity for the dyes was found to be 399.74, 365.11 and 324.36 μmol/g for MB, CV and RB, respectively at 30 °C. The equilibrium uptake was attained within 240 min. The kinetic studies were revealed that sorption follows a pseudo-second-order kinetic model which indicates chemisorption between adsorbent and adsorbate molecules. Adsorption isotherm indicates non-energetically adsorption sites which fit with Freundlich isotherm model. The fitness of kinetics and isotherm models was evaluated by using HYBRID error analysis function. Competitive adsorptions of dyes were studied by using binary component systems.     

区域自然灾害系统基本单元研究-Ⅱ:应用部分——湖南省综合农业灾情区域分异规律

本文应用灾害系统基本单元理论,以湖南省农业自然灾害为例,在地理信息系统支持下,将湖南省农业自然灾害系统划分为３２５２４个基本单元。进而,以民政部１９７８～１９９３年农业灾情统计数据为标准,通过多因子逐步回归的方法,建立了反映湖南省多年平均状况的五种主要农业灾害灾情模型。最后,以灾害基本单元为最小空间分异单位,对综合农业灾情分异规律进行了探讨,并首次提出了基于自然单元的湖南省综合农业灾情的分异规律首先是受地势控制的东西分异的主要结论。     

CSSTLP1000标准制定几个主要问题的研究思考

针对职业安全卫生管理体系（ＯＨＳＭＳ）的国际发展趋势,中国劳动保护科学技术学会（ＣＳＳＴＬＰ）开展了ＯＨＳＭＳ的研究与学会ＯＨＳＭＳ标准（ＣＳＳＴＬＰ１０００）的制定工作。既与国际惯例接轨,又能结合国内实际情况,是制定我国ＯＨＳＭＳ标准的基本原则。在ＣＳＳＴＬＰ１０００标准制定工作中,围绕标准的运行模式、内容等问题,进行了深入的研究思考。在分析国际上现有的ＯＨＳＭＳ标准的共同特点及我国现行有效职业安全卫生管理制度的基础上,确立了ＣＳＳＴＬＰ１０００标准运行模式、内容及标准系列     

四级站环境监测工作量化管理

根据四级环境监测站的特点，提出了一种新的环境监测定量化管理工作，即单元工作只计分法，通过对单元工作累积计法的论述和实例应用介绍，阐述了单元工作累积计分法用于四级站量化管理的先进性，实用性和科学性。     

碱性固硫剂的固硫效果分析

本文描述了各种碱性氧化物固硫效果选择实验结果,论述了煤种,燃烧温度、钙/硫比、Fe_2O_3对固硫效果的影响。     

Visual Basic在数字林业系统中二次开发地理信息系统

在当今信息时代，林业安全管理要实现数字林业系统必须由3S技术作为支持。本文主要介绍用VisualBasic二次开发地理信息系统（GIS）管理软件ArcInfo，实现林业各地理要素的显示漫游和查询等功能。     

论生态环境建设的基本法律制度

中国现有的生态环境建设的立法,缺乏对生态环境建设基本法律制度系统而明确的规定,无法满足生态环境建设的实际需要.针对现状,就中国生态环境建设的基本法律制度加以探讨,以期完善生态环境建设的立法规定.     

Estimating the Unknown Components of Nutrient Mass Balances for Forestry Plantations in Mine Rehabilitation, Upper Hunter Valley, New South Wales, Australia

Commercial forestry plantations as a postmining land use in the Upper Hunter Valley of New South Wales, Australia are restricted by both the poor nutrient availability of mining substrates and low regional rainfall. An experiment was conducted to investigate whether municipal waste products and saline groundwater from coal mining operations could improve early tree growth without impacting on the environment through salt accumulation and/or nutrient enrichment and changes in groundwater quality. Potential impacts were investigated by quantifying the nutrient cycling dynamics within the plantation using an input–output mass balance approach for exchangeable calcium (Ca²⁺), exchangeable magnesium (Mg²⁺), exchangeable potassium (K⁺), exchangeable sodium (Na⁺), nitrogen (N), and phosphorus (P). Measured inputs to and outputs from the available nutrient pool in the 0–30 cm of the overburden subsystem were used to estimate the net effect of unmeasured inputs and outputs (termed “residuals”). Residual values in the mass balance of the irrigated treatments demonstrated large leaching losses of exchangeable Ca, Mg, K, and Na. Between 96% and 103% of Na applied in saline mine-water irrigation was leached below the 0–30-cm soil profile zone. The fate of these salts beyond 30 cm is unknown, but results suggest that irrigation with saline mine water had minimal impact on the substrate to 30 cm over the first 2 years since plantation establishment. Accumulations of N and P were detected for the substrate amendments, suggesting that organic amendments (particularly compost) retained the applied nutrients with very little associated losses, particularly through leaching.     

Ultrasound enhancement of the reduction of the Basic Green dye in wastewater by cast iron

Dyes in wastewater are of particular environmental concern since they give an undesirable color to the waters, dye and their derivatives are harmful to human health and the environment （ Annadurai et al., 2002）. Due to their biological persistency, conventional biological treat-ment processes such as activated sludge process are ineffective for their removal（Shaul et al., 1991）. There is a need to develop effective methods for the degradation of such persistent organic pollutants, either to less harmful compounds or, more desirable, to their complete mineralization.     

企业环境监测工作的现状及发展初探

剖析了企业环境监测工作的现状,明确了企业环境监测工作的工基本立足点,在面临大中型国有企业主业副业剥离的情况下,对企业环境监测机构在市场经济条件下如何面对自己的生存进行了探讨,并提出企业环境监测工作的发展设想。