Spatial systems approach to sustainable development: A conceptual framework

Even though “sustainable development” seems to have emerged as the development paradigm of the 1990s, a great deal of vagueness still surrounds the meaning, definition, and theoretical underpinnings of the concept. There is also a general lack of emphasis on the spatial dimension of sustainable development when developing relevant conceptual or environmental accounting frameworks. In clarifying the concept, this article proposes a definition that explicitly incorporates the temporal as well as the spatial dimension of sustainability. It also develops a logically consistent conceptual framework for the analysis and evaluation of sustainable development, following a spatial systems approach. Five interconnected aspatial subsystems or subsets of a spatial system are identified and their respective operational dimensions discussed. A proposed composite index calleddegree of stainable development (DSD) and its five component indicators are also outlined. The difficulties involved in operationalizing the DSD measure and the conceptual framework are noted, and the various tasks that need to be undertaken in this regard are specified. It is concluded that future research utilizing the proposed conceptual framework should not only foster the development of appropriate methodologies for the comparative evaluation of sustainable development at global, national, or regional scales, but also offer insights to appropriate decision makers at various levels regarding available options and alternative actions for the healthy development of their respective societies.     

高碘酸钾氧化中性红测定间苯二酚

在酸性和75℃条件下,微量的间苯二酚对高碘酸钾氧化中性红褪色反应具有显著的抑制作用,据此建立了测定间苯二酚的新的动力学光度法。该方法灵敏、快速、操作简便,此法的线性范围为0．1～3．0μg／mL,检出限为0．082μg／mL,对1．0μg／mL的间苯二酚测定11次的相对标准偏差为2．26％。     

Experimental study on biomass advanced reburning for nitrogen oxides reduction

Advanced reburning (AR) is effective for nitrogen oxides (NO_x) reduction, which integrates the basic reburning (BR) with the injection of nitrogen agents and additive compounds. The basic reburning of poplar, cornstalk, wheat-straw and peanut shell, is studied on a boiler simulator facility (BSF). The influence of operating parameters and the synergistic effect of the injection of ammonia, urea or/and sodium carbonate on NO_x reduction are investigated. The results show that an efficiency of 54–67% NO_x reduction could be achieved during the basic reburning process under the optimum operating conditions and the efficiency would be increased if nitrogen agent is injected with the over-fire air or into the burnout zone. Further, co-injection of sodium carbonate with the nitrogen agent could make the NO_x reduction process more thorough. On the whole, 85–92% NO_x reduction could be achieved during the advanced reburning process with a reburning fuel heat input of 15–20%.     

等离子体与光催化复合技术净化污水处理泵站臭气

用一种等离子体-光催化复合技术净化污水处理泵站臭气,研究表明该复合技术具有较显著的协同促进效应,通过改变等离子体发生单元与光催化单元的距离以及在两者之间放置去静电网,可消除等离子体单元产生的负电荷对光催化单元的不利影响,进一步提高其复合效应.同时还对这一复合技术产生协同效应的机理进行了分析,并在污水处理泵站实地考查了这种复合技术对臭气的净化效果.该技术对臭气中NH3的降解率可达46.1%,对H2S的降解率可达67.3%.     

双酚A替代品与双酚A对非洲爪蛙急性毒性及其应激响应的比较

双酚F(bisphenol F, BPF)和双酚AF(bisphenol AF, BPAF)作为双酚A(bisphenol A, BPA)的替代品已被投入生产和使用,然而目前有关BPA替代品毒性的数据还很缺乏。本文从急性毒性和应激响应2个方面比较了BPF、BPAF与BPA对非洲爪蛙蝌蚪的毒性。结果表明,48 h的半致死浓度(LC_(50))顺序为BPF(11.01 mg·L~(-1))>BPA(7.54 mg·L~(-1))>BPAF(2.87 mg·L~(-1));对氧化应激水平的影响BPAF强于BPA,BPF与BPA相近;BPA和BPAF对热休克蛋白基因表达水平有影响,BPF没有影响。本研究提示,BPAF作为BPA的替代品,其毒性强于BPA,而BPF与BPA类似。     

Utilizing transparent and conductive SnO2 as electron mediator to enhance the photocatalytic performance of Z-scheme Si-SnO2-TiOx

• A novel Z-scheme Si-SnO₂-TiO_x with SnO₂ as electron mediator is first constructed. • Transparent and conductive SnO₂ can pass light through and promote charge transport. • V_O from SnO₂ and TiO_x improve photoelectrochemical performances. • Efficient photocatalytic degradations originate from the Z scheme construction. Z-scheme photocatalysts, with strong redox ability, have a great potential for pollutants degradation. However, it is challenging to construct efficient Z-scheme photocatalysts because of their poor interfacial charge separation. Herein, by employing transparent and conductive SnO₂ as electron mediator to pass light through and promote interfacial charge transportation, a novel Z-scheme photocatalyst Si-SnO₂-TiO_{x (1<x<2)} was constructed. The Z-scheme photocatalyst displayed an order of magnitude higher photocurrent density and a 4-fold increase in open-circuit potential compared to those of Si. Moreover, the onset potential shifted negatively for approximately 2.2 V. Benefiting from these advantages, this Z-scheme Si-SnO₂-TiO_x exhibited efficient photocatalytic performance toward phenol degradation and mineralization. 75% of the phenol was degraded without bias potential and 70% of the TOC was removed during phenol degradation. Other typical pollutants such as bisphenol A and atrazine could also be degraded without bias potential. Introducing a transparent and conductive electron mediator to construct Z-scheme photocatalyst gives a new sight to the improvement of photocatalytic performance in Z scheme.     

麻质活性炭的制备及其对Cu2＋的吸附研究

以废麻为原料,KOH为活化剂制备粉状活性炭,通过静态吸附实验研究了活性炭对Cu2＋的吸附性能,探讨了溶液起始pH值、活性炭投加量、吸附时间、起始Cu2＋质量浓度等对Cu2＋吸附效果的影响。结果表明,溶液pH和活性炭投加量对吸附效果有较大影响,活性炭对Cu2＋的吸附率在60 min内超过50%,初始浓度在10~50 mg/L时,活性炭对Cu2＋的吸附量与起始浓度近似成正比。采用Langmuir、Freundlich吸附等温式对吸附平衡数据进行了拟合,结果表明吸附等温线符合Frenudlich模型。采用傅立叶红外光谱法（FT-IR）分析了活性炭的表面官能团,分析表明活性炭表面酸性官能团可能是吸附Cu2＋的活性中心。     

不同混合比牛粪玉米秸中温干发酵产沼性能

设置5组牛粪和玉米秸的混合物(干物质比为0∶1、1∶0、1∶1、1∶2、2∶1),研究其在中温35℃下干发酵产沼性能,以产沼性能最好实验组的实验数据为基础,对比研究了两类产气模型。研究结果显示:玉米秸与牛粪的混合干发酵运行效果较好;其中,牛粪和玉米秸干物质比为2∶1时产沼效果最好,产气量最高为81 209 mL,干物质产气率为0.312 m3/kg,整个发酵过程中产气量和甲烷的含量比较稳定,CH4含量最高达56.59%,总固体、挥发性固体的去除率相对较高,分别为26.11%和34.27%。一级动力学模型与多项式函数方程2个产气模型拟合检验结果显示,应用简单的多项式函数即可对产气情况进行相对准确的预测。     

微污染水源水生物处理工艺中IAL-CHS与三相流化床的初步比较

初步比较气升式内循环蜂窝陶瓷反应器(IAL-CHS)和内循环三相流化床反应器(ITFB)对微污染水源水进行生物预处理的效果。IAL-CHS反应器比ITFB反应器挂膜启动速度快,但是在挂膜期承受冲击负荷能力较ITFB反应器差。在进水相同条件下,两者所能达到的最小水力停留时间、最大体积负荷和容积负荷相差不大,但是ITFB反应器的曝气强度却为IAL-CHS反应器的3.33倍,并且比IAL-CHS反应器出水SS高,浊度去除率低,单位载体的生物量及活性生物量小。     

氮磷钾和乙二胺四乙酸对镉污染三叶鬼针草的吸收特征研究

超富集植物的筛选是植物修复重金属污染土壤技术的核心内容.采用盆栽试验的方法,研究了Cd胁迫下添加营养元素N、P、K和螯合剂乙二胺四乙酸(EDTA)对三叶鬼针草(Bidens pilosa L.)的生长反应和生理生化特性以及对Cd的吸收积累特征.盆栽试验结果显示,在Cd为10 mg/kg时,添加营养元素N、P、K和EDT...