Beyond barriers: examining root causes behind commonly cited Cleaner Production barriers in Vietnam

Despite the promotion of Cleaner Production (CP) by government, academia and research institutions in the past few years, only a small number of Vietnamese industries have adopted it. This paper explores why CP has not been widely adopted by industry through an examination of the root causes preventing effective CP implementation in Vietnam. The paper concludes with possible directions for improving the effectiveness and sustainability of CP programs in Vietnam through training and education.     

清洁生产的可操作性

剖析清洁生产的基本内涵、词义及实施方案 ,讨论了清洁生产的可操作性 ,表明企业可以根据实际情况推行清洁生产 ,选择余地很大。     

中国有色金属行业绿色发展和技术转型

我国有色金属行业发展迅速,铜、铝、铅、锌等10种有色金属产量占世界的40%以上。我国有色金属行业在资源节约、环境友好型产业的方针指导下,不断推动主体工艺技术进步,技术装备水平进入世界先进行列,重金属污染物防治、废物综合利用取得新进展,清洁生产取得显著成果,末端技术取得新突破。目前有色金属行业环境污染压力依然很大,需切实转变发展方式,继续走绿色发展之路。     

Energy indicators and sustainable development: The International Energy Agency approach

The International Energy Agency (IEA), together with the International Atomic Energy Agency (IAEA), UN‐DESA, Eurostat and the European Environmental Agency, has recently published a comprehensive joint‐agency overview of energy indicators for sustainable development. The IEA's contribution to this publication is based on the IEA energy indicator approach. This approach has been developed and used by the IEA over a number of years. The indicators advocated by the IEA are relatively disaggregated to allow for meaningful analysis of sustainability issues in the energy sector. Using a decomposition approach helps reveal the causal links between human/economic driving forces, energy use and emissions. This article presents examples of IEA's work with indicators and an overview of the methodology used, including an explanation of the link to sustainable development. It also provides an example of a simplified indicator analysis of India, to illustrate the importance of improved data systems in developing indicators that can provide meaningful policy analysis.     

Energy economy of salmon aquaculture in the Baltic sea

Resource utilization in Atlantic salmon aquaculture in the Baltic Sea was investigated by means of an energy analysis. A comparison was made between cage farming and sea ranching enterprises each with yearly yields of 40 t of Atlantic salmon. A variety of sea ranching options were evaluated, including (a) conventional ranching, (b) ranching employing a delayed release to the sea of young smolts, (c) harvesting salmon both by offshore fishing fleets and as they return to coastal areas, and (d) when offshore fishing is banned, harvesting salmon only as they return to coastal areas where released. Inputs both from natural ecosystems (i.e., fish consumed by ranched salmon while in the sea and raw materials used for producing dry food pellets) and from the economy (i.e., fossil fuels and energy embodied in economic goods and services) were quantified in tonnes for food energy and as direct plus indirect energy cost (embodied energy). The fixed solar energy (estimated as primary production) and the direct and indirect auxiliary energy requirements per unit of fish output were expressed in similar units. Similar quantities of living resources in tonnes per unit of salmon biomass output are required whether the salmon are feeding in the sea or are caged farmed. Cage farming is about 10 times more dependent on auxiliary energies than sea ranching. Sea ranching applying delayed release of smolts is 35–45% more efficient in the use of auxiliary energies than conventional sea ranching and cage farming. Restriction of offshore fishing would make sea ranching 3 to 6.5 times more efficient than cage farming. The fixed solar energy input to Atlantic salmon aquaculture is 4 to 63 times larger than the inputs of auxiliary energy. Thus, cage farming and sea ranching are both heavily dependent on the productivity of natural ecosystems. It is concluded that sustainable development of the aquaculture industry must be founded on ecologically integrated technologies which utilize the free production in marine ecosystems without exhausting or damaging the marine environment.     

Emergy analysis of municipal wastewater treatment and generation of electricity by digestion of sewage sludge

This study examines and evaluates, by using emergy analysis, the use of environmental resources for wastewater treatment in a Swedish town. Emergy analysis was applied, while it facilitates the comparison of resource use of substantially different kind. In the emergy analysis, all resources are assessed on the basis of the amount of direct and indirect solar energy required in their generation. The study also includes an evaluation of the amount of emergy associated with the production of wastewater. On the basis of our analysis, we suggest that the large amount of emergy that wastewater contains are in proportion to the amount of resources employed for wastewater treatment and the extensive effects on surrounding ecosystems of discharge of untreated wastewater. The use of local renewable natural resources in Swedish municipal wastewater treatment systems is negligible compared with the use of purchased inputs, processed largely with the support of fossil energy. A drastic shift of this order would demand that extensive land areas surrounding human settlements be (indirectly or directly) devoted to wastewater treatment. These areas are not accessible today. Our analysis also indicates that resource requirements from the economy in the production of electricity by the digestion of sewage sludge is about two times the total resource use for generation of the average mix of electricity used in the town. We, therefore, conclude that if the only reason to digest the sludge were to produce electricity, it would be more resource-efficient to purchase the electricity on the Swedish distribution net. Accordingly, there is no resource economy in producing biomass to digest just to increase the energy production at the wastewater treatment plant.     

建设项目清洁生产能力评估方法

清洁生产能力评估将清洁生产概念引入建设项目环境影响评价，对实现经济与环境可持续发展具有重要意义。探讨清洁生产能力评估的必要性，可能性及方法，并对前景进行展望。     

Recyling of plastic wastes via pyrolysis

Pyrolysis for the simultaneous generation of oils and gases can be convenient to obtain hydrocarbons and even to recover crude petrochemicals or to generate energy from waste plastics. A Gray–King apparatus has been used to pyrolyze waste polyethylene (PE), polystyrene (PS), both separately and with different compositions. Thermogravimetric analysis of waste plastics indicated the critical temperatures, which should be effective for pyrolysis. The chosen heating rate was low in order to achieve higher liquid yields. The results showed that waste PS yielded higher liquid, and waste PE yielded higher gaseous products. The dominant liquid product of PS waste was styrene whereas for waste PE, prophenylbenzene was the dominant pyrolysis product.