西藏自治区的土地、粮食和人口

本文讨论了西藏自治区土地系统、农业发展、人口增长和它们之间的相互关系。指出西藏土地类型复杂多样,极少土地能用于种植业,单位产量亦不高。人均占有粮食不足300kg,若干牧区不足50kg。粮食生产不能满足人口增长的需求。这种趋势在今后30年内仍将继续下去。 为了解决土地—粮食—人口三者之间关系的不协调,需采取若干切实措施。文中亦强调人口控制的必要。     

Combined toxic impacts of thiamethoxam and four pesticides on the rare minnow (Gobiocypris rarus)

To examine pesticide mixture toxicity to aqueous organisms, we assessed the single and combined toxicities of thiamethoxam and other four pesticides (chlorpyrifos, beta-cypermethrin, tetraconazole, and azoxystrobin) to the rare minnow (Gobiocypris rarus). Data from 96-h semi-static toxicity assays of various developmental phases (embryonic, larval, juvenile, and adult phases) showed that beta-cypermethrin, chlorpyrifos, and azoxystrobin had the highest toxicities to G. rarus, and their LC₅₀ values ranged from 0.0031 to 0.86 mg a.i. L^?1, from 0.016 to 6.38 mg a.i. L^?1, and from 0.39 to 1.08 mg a.i. L^?1, respectively. Tetraconazole displayed a comparatively high toxicity, and its LC₅₀ values ranged from 3.48 to 16.73 mg a.i. L^?1. By contrast, thiamethoxam exhibited the lowest toxic effect with LC₅₀ values ranging from 37.85 to 351.9 mg a.i. L^?1. Rare minnow larvae were more sensitive than embryos to all the pesticides tested. Our data showed that a pesticide mixture of thiamethoxam–tetraconazole elicited synergetic toxicity to G. rarus. Moreover, pesticide mixtures containing beta-cypermethrin in combination with chlorpyrifos or tetraconazole also had synergetic toxicities to fish. The majority of pesticides are presumed to have additive toxicity, while our data emphasized that the concurrent existence of some chemicals in the aqueous circumstance could cause synergetic toxic effect, leading to severe loss to the aqueous environments in comparison with their single toxicities. Thence, the synergetic impacts of chemical mixtures should be considered when assessing the ecological risk of chemicals.

     

萃取法分离回收不锈钢酸洗污泥硫酸浸出液中的重金属

采用非皂化P204和皂化P204萃取剂对不锈钢酸洗污泥的硫酸浸出液进行萃取。在浸出液pH为0.80、非皂化P204体积分数为25%、萃取剂与浸出液体积比为1∶2、萃取时间为5 min的条件下,Fe~(3+)萃取率达99.64%,Cr~(3+)和Ni~(2+)萃取率为3.98%和6.99%,一次萃余液pH为0.64。采用皂化P204对除Fe~(3+)后的一次萃余液进行萃取,在P204体积分数为25%、萃取剂与浸出液体积比为1∶2、萃取剂皂化率为60%、一次萃余液pH为1.50、萃取时间为5 min的条件下,Ni~(2+)萃取率为93.12%,Cr~(3+)萃取率为20.69%,二次萃余液pH为2.63。     

钙钛矿型催化剂催化湿式氧化处理煤气化废水纳滤浓缩液

采用溶胶-凝胶法制备了Mn掺杂钙钛矿型催化剂LaFexMn1-xO3,并以其为催化剂催化湿式双氧水氧化处理煤气化废水纳滤浓缩液。采用XRD,SEM,FTIR技术对催化剂进行了表征。表征结果显示：制备的催化剂均具有标准的钙钛矿型结构,其中,LaFe0.9Mn0.1O3的结构稳定,比表面积大。实验结果表明：制备的催化剂中LaFe0.9Mn0.1O3的催化活性最高,且稳定性好,连续使用5次后催化活性未见明显减弱;在H2O2投加量3.0 g/L、n（H2O2）∶n（LaFe0.9Mn0.1O3）=12∶1、反应温度160 ℃、反应压力1 MPa、浓缩液pH 3、反应时间60 min的最优条件下,COD、UV254和TOC的去除率分别达到80.9%、95.2%和68.0%,BOD5/COD由0.02提升至0.40,可生化性大幅提高。     

Global trends and development of energy services industry in China

Energy service is an effective way to promote energy conservation by market mechanisms, including energy saving services, energy procurement, supply of many varieties of energy, supply of renewable energy technologies, energy-related consulting services, risk management, etc. China is a major energy consumer but energy is in short supply, and the efficiency of energy use is low. China’s energy service industry has expanded rapidly, in terms of both the number of new Energy Service Companies entering the market and amount of capital invested in Energy Performance Contracting projects, but the energy service sector in China is still at an early stage of development. Developed countries began early in developing the energy service sector and their energy service market is mature, and the experience of developed countries shows that energy services play a significant role in advancing energy saving and emission reduction. Under the new situation, China needs combine energy services experience of developed countries, and take following measures to accelerate China’s energy services rapid and healthy development, including the long-term aspects of policy planning, energy-saving core technology, finance and capital investment, public sector reductions, personnel training, and so on.     

TiO2催化高压脉冲放电等离子体降解2，4-二硝基苯酚

采用TiO2催化高压脉冲放电等离子体降解废水中的2,4-二硝基苯酚,对反应进行了动力学研究.研究结果表明,在高压脉冲放电等离子体及TiO2催化高压脉冲放电等离子体反应中,2,4-二硝基苯酚的降解过程均符合表观一级反应动力学方程.加入TiO2催化剂、提高放电电压均可提高2,4-二硝基苯酚的降解反应速率常数.在TiO2加入量为0.15%、放电电压为16 kV时,2,4-二硝基苯酚的降解率为87.4%,TiO2的催化效应增强因子为1.55.     

Role of illumination intensity in microcystin development using Microcystis aeruginosa as the model algae

Environmental Science and Pollution Research - Microcystis aeruginosa (M. aeruginosa) is one of the most common genera of cyanobacteria in algal blooms. In the present work, the impact of the...     

Characteristics and management of domestic waste in a rural area of the Tibetan Plateau

In the rural area of the Tibetan Plateau (RATP), the characteristics of domestic waste, people’s environmental awareness, people’s willingness to pay and their influence factors were firstly studied by questionnaires, field samplings and laboratory tests. The results showed that, in the RATP, the generation of domestic waste was 85 g?d-1 per capita and it was mainly composed of plastics, inert waste, kitchen waste, glass and paper. The waste bulk density, moisture content, ash, combustible and low calorific value were 65 kg?m-3, 19.25%, 44.90%, 35.85% and 10,520 kJ?kg-1 respectively. These characteristics are influenced by income sources and geographical position to some extent. Classified collection should be promoted widely on the household and the village basis. Compost, fermentation, landfill, bioreactor landfill and semi-aerobic landfill have been approved as effective techniques to treat domestic waste, except incineration. The distance of 50–800 m between each collection facility and the disposal fee of around $0.8 per month per household are suggested. For suburbs or large population villages, it’s better to treat domestic waste by the centralized way. But for the remote rural areas, a decentralized way is proposed. Significantly, the educational and economic influence should be considered into an effective domestic waste management program.

Implications:?The current situatio n of the environment in the rural areas of the Tibetan Plateau (RATP) was surveyed. There, the generation of organics and moisture of domestic waste were low but ash, recyclables, and combustibles were high. People’s knowledge of domestic waste was absent but their participation in management was strong. Based on the current situation, compost, fermentation, and landfill were effective but incineration was inappropriate. Also, a localized mini landfill for a cluster of villages and or settlements was the best method there.