华北地区某污水处理厂升级改造工程实例

华北地区某城市污水处理厂升级改造工程处理规模为50万t/d,原设计为A/O脱氮工艺,执行《城镇污水处理厂污染物排放标准》(GB 18918-2002)二级排放标准。由于近年来进水水质严重恶化以及对污水排放标准的提高,需对原污水处理系统进行改造,通过技术方案对比,在原生物处理段增加厌氧池,使之变为A2/O脱氮除磷,新增深度处理工艺为反硝化生物滤池-加砂沉淀池-滤布滤池-紫外消毒,使出水水质达到一级A排放标准。     

Strategic environmental policy and the accumulation of knowledge

In dealing with a transnational pollutant-emitting duopoly welfare-maximising policy makers face two negative externalities: imperfect competition and unpriced emissions. Strategic environmental policy models show that these externalities involve a trade-off between reducing pollution and allowing for rent-seeking of the respective firm. This dilemma usually results in a suboptimal internalisation of the negative externality emerging from emissions. Indeed, the conventional model setup includes an R&D stage that enables the firms to mitigate regulation costs. But the typical one period configuration ignores that R&D expenditures create knowledge capital which is, due to its inherent cumulativeness, also effective in following periods. Our model analyses the established trade-off in a two period setting and therefore allows for an investigation of intertemporal knowledge accumulation. We find that the intertemporal effects provide an incentive for a policy maker to set a higher tax rate compared to a one-period setup which lessens the magnitude of the suboptimal internalisation of emissions. Under certain conditions even a tax rate above the Pigouvian level is possible in period 1.     

The non-linear effects of life expectancy on economic growth

This paper shows that improvements in life expectancy (LE) had a non-linear effect on income per capita over the 1940-1980 period as this effect was conditional on each country’s initial level of LE. Whereas higher LE had an initial statistically significant negative impact on income per capita in countries with LE under 43 years in 1940, the opposite is true in countries with initial LE over 53 years.     

Influencia de los sistemas de información en los resultados organizacionales

Over the last years, information systems (IS) have constituted the main focus of research in the business organization literature. This has created the need to identify their entrepreneurial value. The paper presents a theory-based model that was developed to assess the degree of IS success in SMEs. The aim of the proposed model is to determine the influence of IS on organizational performance. To achieve this aim, the Partial Least Square statistical technique is used to analyze data from 133 questionnaires administered to businesses across the state of Tamaulipas, Mexico. The results show that those enterprises that are more concerned with the improvement of the systems’ quality, information quality and the informatics service enhance the organizational outcomes. The present study contributes to the body of literature on the assessment of IS success in the context of an emerging country. In particular, the study provides a thorough assessment of the IS effectiveness and their impact on organizational performance.