An ecological perspective on a river’s rights: a recipe for more effective water quality governance?

ABSTRACT

In several countries, the transfer of legal rights to rivers is being discussed as an approach for more effective water resources management. But what could this transfer mean in terms of a healthy river? We address this question by identifying the ecological requirements for naturally functioning rivers and then explore the demands which these requirements impose on society, the current policy responses to these requirements and whether the transfer of rights to the river could facilitate the preservation of healthy freshwater ecosystems.     

Techno-economic feasibility of power to gas–oxy-fuel boiler hybrid system under uncertainty

One of the main challenges associated with utilisation of the renewable energy is the need for energy storage to handle its intermittent nature. Power-to-Gas (PtG) represents a promising option to foster the conversion of renewable electricity into energy carriers that may attend electrical, thermal, or mechanical needs on-demand. This work aimed to incorporate a stochastic approach (Artificial Neural Network combined with Monte Carlo simulations) into the thermodynamic and economic analysis of the PtG process hybridized with an oxy-fuel boiler (modelled in Aspen Plus^®). Such approach generated probability density curves for the key techno-economic performance indicators of the PtG process. Results showed that the mean utilisation of electricity from RES, accounting for the chemical energy in SNG and heat from methanators, reached 62.6%. Besides, the probability that the discounted cash flow is positive was estimated to be only 13.4%, under the set of conditions considered in the work. This work also showed that in order to make the mean net present value positive, subsidies of 68 €/MW_elh are required (with respect to the electricity consumed by PtG process from RES). This figure is similar to the financial aids received by other technologies in the current economic environment.     

RoHS指令与阻燃塑料的发展

综述和分析了下述几方面的问题及有关进展:1)RoHS指令的主要内容及其对十溴二苯醚的豁免;2)正在进行危害性评估的阻燃剂;3)RoHS指令及WEEE指令对阻燃塑料的影响;4)中国电子电气行业用阻燃塑料面临的挑战。     

加速中国阻燃剂及阻燃塑料的环保化进程

叙述和讨论了RoHS指令对十溴二苯醚(DBDPO)的豁免被欧洲法院否决的情况和欧盟阻燃剂危害性评估的最新结果。从环保的观点分析了中国阻燃剂的结构及市场,提出了加速中国阻燃剂及阻燃塑料环保化进程的见解。     

法兰制造厂申请PED/AD2000-W0认证的关键技术要求

国内法兰锻造厂在申请承压设备指令PED 97/23/EC/AD2000-W0认证的过程中,普遍存在技术储备不足,对规范要求不够了解等情况。本文依据PED指令及AD规范对法兰用典型材料如S235JRG2(碳钢)、1.4301和1.4401(不锈钢)的认证技术要求,从执行标准、检验组别、试验要求、化学成分含量以及力学性能要求等方面进行了归纳总结。为企业顺利通过认证,编制相关的程序文件和作业指导书提供了指南和索引,对提高企业产品质量、增强竞争力,从而提高开拓欧盟产品市场的竞争力。     

Surahammar: a case study of the impacts of installing food waste disposers in 50% of households

This paper reviews 15 years of sewage works' monitoring data to assess the effect of installing in-sink food waste disposers (FWD) and how these effects compare with the published scientific literature. For the first time, it has been possible to assess at full scale the load/cost transfer from solid-waste to wastewater management. Within a period of 10 years, 50% of households in the town of Surahammar in Sweden chose to have FWD installed as their means of managing their kitchen food waste. The drainage from the households feeds a single wastewater treatment works (WwTW) that comprises primary settlement, activated sludge, followed by chemical phosphate precipitation and mesophilic anaerobic digestion. The sewer system is separate but with overflow between foul and surface water in times of surcharge; the diameters and gradients of the sewers are unexceptional. This paper reviews the influent and biogas monitoring data for the years before installation started and the 10 years after the first peak of installations (by which time they had been installed in 30% of households). This provides a unique opportunity to verify the published research on FWD. The operational monitoring data are consistent with the already published research that FWD have little or no impact on water use, sewer blockages, vermin or wastewater treatment. The data are consistent with a hypothesis that in-sewer biological process acclimated to the change in wastewater composition and treated the dissolved and fine particulate load before it reached the WwTW. The digesters produced 46% more biogas than before FWD were installed (P=0.01). There was no significant increase in hydraulic load, or in the loading of BOD₇, COD, N or NH₄. As a result of Surahammar's overall waste strategy, not just the FWD, but the tonnage of waste to landfill from the municipality has also decreased from 3600 tonnes/year in 1996 to 1400 tonnes/year in 2007.