中国石灰生产和能源消耗分析

基于全国涉及石灰生产的企业全口径统计数据,分析中国2007年石灰生产的基本特征,探讨了石灰产量统计的不确定性和来源。2007年,中国石灰生产的企业共6 154家,涉及9 327座石灰窑。总产能为2.27亿t,共生产石灰1.06亿t,企业平均产量为4 000 t/a,企业生产每吨石灰平均能耗水平为163 kg标准煤。中国约有两千八百多万吨的石灰生产很难通过正规渠道统计上来,也意味着这些产量很可能是基于非常简易和高能耗的石灰土窑生产的。     

湖北省湖泊水环境化学特征及其与人类活动的关系

通过对湖北省近３０个湖泊水环境化学的分析，探讨了湖北省湖泊水质状况和湖水的化学稳定性，指出远离工业区和居民生活区的湖泊水质一般较好，城区或城效型湖泊在不同程度上受到了工业废水和生活污水的影响。控制，消除湖泊污染是今后经济、社会和环境建设不可忽视的重要工作。     

锌对增强玉米耐涝抗渍的作用及其机理初探

在缺锌的砂姜黑土上研究锌对玉米增产效应的田间试验中发现，在严重渍涝高温时，锌有显著的增强玉米耐涝抗渍的作用。其机理与锌能明显降低植株体内氮磷含量，提高钾素含量，从而增强玉米的抗渍涝与高温的能力有关。统计结果表明，玉米秸杆中氮磷含量占整株氮磷含量的百分数与死亡率呈显著的正相关，而秸杆中的含钾量与死亡率呈一定的负相关。     

Determination of gas phase adsorption isotherms--a simple constant volume method

Single and ternary solute gas phase adsorption isotherms were conducted in this study to evaluate the effectiveness of a simple constant volume method, which was utilized by using Tedlar gas sampling bags as a constant volume batch reactor. For this purpose, gas phase adsorption of toluene, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) on two types of activated carbons, BPL-bituminous base and OVC--coconut base, were investigated. For the single solute adsorption, the experimental adsorption data were found to be well correlated with Freundlich and Myers adsorption equations. The pore size distribution of adsorbents was found to affect their adsorption capacities; its effect was dependant on the solute concentration. The ternary adsorption experimental isotherms were accurately predicted by using the well-known model, i.e., ideal adsorbed solution theory (IAST).     

Photocatalytic oxidation of triclosan

In the spring of 2003, there was an outbreak of the severe respiratory syndrome (SARS) in Hong Kong. Health concerns have thus triggered an increased and predominant use of various types of household cleansing agents such as triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol). However, it has been reported recently that triclosan could be photochemically converted to toxic 2,8-dichlorodibenzo-p-dioxin (2,8-Cl(2)DD) in the environment. It is therefore necessary to develop environmentally friendly methods for the treatment of triclosan. To this end, photocatalytic degradation of triclosan in aqueous solution was conducted using TiO(2) (Degussa P25) under irradiation of UV light (lambda < 365 nm). It was found that triclosan could be degraded by this approach. Hydrogen peroxide was added to enhance the degradation process, and the optimal initial hydrogen peroxide concentration for triclosan degradation was 0.005% (w/v). Product identification indicated that triclosan oxidation occurred at its phenol moiety and yielded quinone and hydroquinone intermediates. The formation of a dichlorophenol intermediate in triclosan degradation suggested bond-breaking of the ether linkage occurred during the process. Moreover, no chlorinated dibenzo-p-dioxin congener was detected. These findings confirm that the photocatalytic degradation of triclosan is an environmentally friendly process.     

Methods for the preparation of a biodesulfurization biocatalyst using Rhodococcus sp

Several methods to prepare a biodesulfurization (BDS) biocatalyst were investigated in this study using a strain of Rhodococcus sp. 1awq. This bacterium could selectively remove sulfur from dibenzothiophene (DBT) via the "4S" pathway. DBT, dimethylsulfoxide (DMSO), sodium sulphate and mixed sulfur sources were used to study their influence on cell density, desulfurization activity, desulfurization ability, and the cost of biocatalyst production. In contrast to that observed from bacteria cultured in DBT, only partial desulfurization activity of strain 1awq was induced by DBT after cultivation in a medium containing inorganic sulfur as the sole sulfur source. The biocatalyst, prepared from culture with mixed sulfur sources, was found to possess desulfurization activity. With DMSO as the sole sulfur source, the desulfurization activity was shown to be similar to that of bacteria incubated in medium with DBT as the sole sulfur source. The biocatalyst prepared by this method with the least cost could remove sulfur from hydrodesulfurization (HDS)-treated diesel oil efficiently, providing a total desulfurization percent of 78% and suggesting its cost-effective advantage.     

Extraction of arsenate and arsenite species from soils and sediments

The primary objective of this study was to develop a simple method that can be used to extract the more readily mobilizable and bioavailable arsenic species from soil and sediment while at the same time minimizing the transformation between (AsIII) and (AsV), the two most commonly found arsenic species in the environment. Several extraction strategies were evaluated using phosphate as extractant in combination with either ethylenediaminetetraacetic acid (EDTA), hydroxylamine hydrochloride (NH2OH.HCl), or sodium diethyldithiocarbamate trihydrate (NaDDC). The addition of EDTA in the phosphate solution did not prevent AsIII from oxidation. While promising results were shown when 1% NH2OH.HCl was added, conversion of AsIII began to occur with extended extraction time (> 12 h). Good results were achieved using 10 mM phosphate and 0.5% NaDDC where AsIII oxidation was clearly minimized. The combined phosphate and NaDDC solution was applied to several soil and sediment samples. AsIII spiked was quantitatively recovered in all soil types tested.     

三丁基氯化锡对红鳍笛鲷的急性毒性及不同组织生化指标的影响

为研究有机锡化合物对海洋生物抗氧化防御系统和神经系统的影响,以我国东南沿海常见的中下层增养殖鱼类红鳍笛鲷(Lutjanus erythopterus)幼鱼为实验生物,采用半静态毒性实验方法,分别研究了三丁基氯化锡(tributyltin chloride,TBTCl)的急性毒性和96 h暴露时间内对红鳍笛鲷幼鱼鳃、脑和...     

基于高通量分析方法的长江干流重庆段抗生素种类特征及来源初探

采用高通量分析方法对长江干流重庆段11个流域断面、2个市政污水处理厂进水和6个养殖场废水的潜在抗生素进行筛查,并结合抗生素使用调查探讨其来源。结果表明,(1)共检出83种抗生素,其中流域内检出36种,污水处理厂和养殖场废水中检出70种;磺胺间甲氧嘧啶检出率最高,在流域水体和废水的检出率分别为91%和55%,喹诺酮类是检出抗生素的主要类型;(2)长江干流重庆段下游检出抗生素数量高于上游检出抗生素;(3)有20种抗生素可能由上游携带和重庆市内排放2种方式进入流域,7种抗生素可能由上游携带入境,9种抗生素可能由重庆市内排放引入长江。     

Capacity estimation and preliminary strategy for reducing the release of dioxins in China

As a party of the Stockholm Convention on Persistent Organic Pollutants, China must submit its national implementation plan (NIP) for this convention. The strategy and action plan for reducing the release of dioxins in China are the most important components of the NIP. Three problems are key points for developing such strategy and action plan—what are the key sources for applying the best available technology/best environmental practice (BAT/BEP) to reduce the release of dioxins? How about the capacity for reducing the dioxins release from the key sources? Where are the areas of priority for applying BAT/BEP? This paper shows the efforts towards the solution of these problems. The list of key sources covering about half of the total dioxins release was determined considering four criteria. The capacity of key sources were estimated based on the difference between the emission factor corresponding to the actual situation in 2004 and that corresponding to the scenario that all key sources have been applied BAT/BEP to reduce the dioxins release. The priority analysis using the geographical information system (GIS) tool has revealed that castern provinces should be of high priority in the future reduction activities of dioxins release in China.