涡凹气浮(CAF)/SBR法在高寒地区屠宰废水中的应用

采用涡凹气浮(CAF)和序批式活性污泥(SBR)法处理高寒地区屠宰废水,在冬季室温15℃以上培养的活性污泥完全适应该工艺的要求.经该工艺处理后,出水水质可达到国家《污水综合排放标准》(GB 8978-1996)一级标准,COD、BOD5、SS、氨氮和TN去除率分别达到95.3%、96.7%、87.1%、63.3%和60.9%.     

Modeling of a combined ultraviolet-biofilter system to treat gaseous chlorobenzene I: model development and parametric sensitivity

A new type of a combined ultraviolet (UV)-biofilter system for air pollution control is developed. In this paper, two conceptual mathematical submodels of the UV reactor and standalone biofilter are developed. All model parameters have been determined by independent experiments or have been taken from literature. Results from UV and the standalone biofilter submodels are in a good agreement with experimental data. However, the performance of the combined system has significantly deviated from those of the UV or standalone submodels because of the stimulating effects of UV irradiation products on the subsequent biofilter performance. A modified model that considers the stimulating effects has agreed well with experimental data over a wide range of operating conditions. Further analysis of the primary parametric sensitivity of the model has shown that inlet chlorobenzene concentrations, gas empty-bed residence time in the UV reactor, and light intensity are important operating conditions.     

重金属元素在冻土与融土中迁移的对比试验

随着寒区经济的发展,冻土地区的矿山开采活动不断加剧,随之产生的重金属污染问题也越来越严重.冻土地区生态环境脆弱,一旦受到破坏就很难恢复.针对此问题,室内模拟了尾矿矿渣在冻土与融土中的填埋及其对填埋场周边土体的影响,通过检测填埋场各处土壤的温度、含水量以及重金属元素的含量,发现温度和水分对重金属元素的迁移影响很大.土壤温度越低,重金属元素的迁移越慢;在温度梯度的作用下,重金属元素均随着水分从土体的暖端向冷端迁徙并聚集于冻结锋面.重金属元素在冻土中的迁移比融土中慢,表明冻土环境不利于重金属元素的迁移.在土壤质地、温度和含水量等相同的情况下,Zn的迁移性较强,Pb和Cu的迁移性相对较弱.     

In vitro activity of antimicrobial agents against Legionella isolated from environmental water systems: first results from Turkey

We evaluated the in vitro activity of antimicrobial agents against Legionella obtained from hotel and hospital water systems in three different regions of Turkey. Sixty-five Legionella strains (Legionella pneumophila serogroup 6 [n?=?32], L. pneumophila serogroup 1 [n?=?27], L. pneumophila serogroup 3 [n?=?2], and Legionella spp. [n?=?4]) were tested against levofloxacin, ciprofloxacin, clarithromycin, azithromycin, and rifampicin. The minimum inhibitory concentration (MIC) values of each antimicrobial agent for these strains was determined by the microdilution method using buffered yeast extract medium supplemented with 0.1% ketoglutarate broth. L. pneumophila ATCC 33152, Staphylococcus aureus ATCC 29213, and Escherichia coli ATCC 25922 were used as controls. Minimum inhibitory concentration values were in the following ranges: clarithromycin 0.001–0.5 mg/L, azithromycin 0.001–0.5 mg/L, levofloxacin 0.001–0.5 mg/L, ciprofloxacin 0.001–0.125 mg/L, and rifampicin 0.001– 0.5 mg/L. The MIC₉₀ for rifampicin, levofloxacin, ciprofloxacin, azithromycin, and clarithromycin were 0.015, 0.125, 0.06, 0.125, and 0.06 mg/L, respectively. To the best of our knowledge, this is the first study to determine in vitro activities of antimicrobial agents against Legionella species in Turkey. Rifampicin had the lowest MIC₉₀ value. It would seem that azithromycin and clarithromycin exhibit good activity as well as levofloxacin and ciprofloxacin against Legionella isolated from environmental water systems in Turkey.     

学龄儿童肺功能水平影响因素的研究

用逐步回归分析方法对与室内、外空气污染和机体状况等有关的因素对广州市学龄儿童肺功能 (FVC、FEV1 、PEFR和 FEF2 5～ 75 )水平的影响进行研究。结果提示 ,影响肺功能水平的主要因素是内因 ,身高的影响最明显 ,呼吸系统疾病或症状发生与肺功能水平下降有关 ;室外空气污染使肺功能水平下降 ,SO2 、NOx 和 PM2 .5 的影响明显 ,PM2 .5 的影响明显大于 PM1 0 和 TSP;居室或厨房通风不良、家庭烹饪用不洁燃料对儿童肺功能的生长不利 ;被动吸烟对女性儿童肺功能有不利影响。对各种影响因素 ,PEFR和 FEF2 5～ 75 比 FVC和 FEV1 更为敏感     

The impact of economic complexity on carbon emissions: evidence from France

Environmental Science and Pollution Research - This paper reanalyzes the determinants of the CO2 emissions in France. For this purpose, it considers the unit root test with two structural breaks...     

孤岛油区外排采油污水生化处理技术的研究

针对孤岛污水矿化度高,Cl-含量高,油含量和COD含量严重超标的现象,采取微生物接触氧化工艺进行外排采油污水治理的工艺研究。在处理过程中首先对菌种进行了严格的筛选和培养,然后在室内进行了模拟试验,最后在现场进行了中试。目前已根据中试结果,对孤岛污水原有的污水池进行了改造,设置了隔油池、气浮池、接触氧化池和沉淀池四个部分,经过一年的运行,成功地实现了污水的达标排放。     

高压输电系统对通信局(站)危险影响中地电流系数的确定

高压输电系统发生接地短路故障时,会产生一个地电位升,对通信局(站)会危险影响,为了计算这个危险影响的大小,首先能够准确的计算出高压输电系统的地电流系数。本文论述了高压输电系统对通信局(站)危险影响中地电流系数的确定,介绍了地电流系数的定义,并分析了不同危险情况下地电流系数的计算。     

外绝缘用液体硅橡胶的自然老化因素研究

近年来,液体硅橡胶(Liquid Silicone Rubber,LSR)已经在外绝缘领域得到了较为广泛的应用,但是目前对其耐老化性能的研究还不够深入。尤其是在中国南方地区使用时,高温、高湿环境更容易导致液体硅橡胶的老化。在许多地区都观察到了电流、电压互感器的液体硅橡胶绝缘外套的龟裂、老化现象,对设备的安全运行产生了影响。本文设计并实施了在光照、高温、高湿、电晕等老化因素作用下的液体硅橡胶人工老化试验,并对老化试验后的样品进行了硬度、力学性能、憎水性、光泽度以及SEM、FTIR等微观性能试验和分析。认为在光照作用下,高温、高湿环境对液体硅橡胶具有加速老化作用,表现为硬度上升、憎水性下降、光泽度下降,并且在表面出现细微裂纹。     

An Estimation of the Effects of China’s Priority Forestry Programs on Farmers’ Income

In the late 1990s, the Chinese government initiated some new programs and consolidated other existing ones of ecological restoration and resource development in its forest sector, and renamed them as “Priority Forestry Programs,” or PFPs. They include the Natural Forest Protection Program (NFPP), the Sloping Land Conversion Program (SLCP), the Desertification Combating Program around Beijing and Tianjin (DCBT), the Shelterbelt Development Program (SBDP), and the Wildlife Conservation and Nature Reserve Development Program (WCNR). In addition to improving the environmental and resource conditions, a frequently reiterated goal of these PFPs is to increase rural households’ income, therefore discussing why looking at rural household income impacts might be an important part of forest program evaluation. Thus, an interesting and important question is: How has implementing the PFPs affected the farmers’ income and poverty status? This article addresses this question using a fixed-effects model and a panel dataset that covers 1968 households in four provinces for ten consecutive years (1995–2004). The empirical evidence indicates that their effects are mixed. The SLCP, the SBDP, and the NFPP have made positive impact and, by far, the SLCP has the largest effect. But the WCNR and the DCBT still have not had a pronounced overall effect due to their short time span of execution, even though they may have exerted certain influence at the margin. Notably, the impact of the WCNR, if any, is negative.