UK allotments and urban food initiatives: (limited?) potential for reducing inequalities

The number of urban food initiatives in many regions of the world, notably Europe and the USA, has burgeoned in recent years, and analyses of the impacts of these activities on people and environments are the focus of an increasing academic literature. The impacts documented include enhanced food security, cohesive neighbourhoods, sustainability, and food justice. Yet, another literature presents opposing analyses and focuses on exclusionary aspects of projects and their enabling of a continued neo-liberal reduction in state welfare provision. As a result, there has been an impasse in debates over the potential of urban food projects to reduce inequalities. This paper proposes that the benchmark of the UK allotment system provides a means to examine these opposing positions. It uses the conceptual frameworks of diverse economies and the capital assets framework to attain clarity in the analysis of the many kinds of food-related activities seen in (peri-)urban areas. Drawing on empirical work in Plymouth, UK, it focuses on the potential of the different food ventures to reduce inequalities, given certain contingent economic and political factors. It also presents evidence that the allotment movement despite its initially radical roots can be seen as largely apolitical in the present day and has no leverage over allocation of land to allotment sites. Even so, evidence is growing that both allotments and the newer forms of urban food activities contribute to meeting national and city-level policy objectives, with the potential to enhance food justice and reduce inequalities.     

城镇污水处理厂污水资源化调查与分析研究

根据渭河流域关中段污染状况及《(渭河流域水污染防治三年行动方案(2012-2014年)》实际需求,采用资料搜集、实地调查、问卷发放、数理统计等方式对该流域城镇污水处理厂污水资源化企业(工程)进行了调查与分析。同时,提出了污水资源化企业(工程)存在的若干问题,并结合该流域实际情况提出了若干措施,期望能对该流域中水回用事业的健康发展提供帮助并对其隶属课题(2011KTZB 03-03-03)的基础性内容提供直接技术支持。     

油漆废渣处理技术综述

探讨了油漆废渣的成分与特性,分析了油漆废渣的危害,对比了油漆废渣的处理方式,综述了油漆废渣循环再生、回收利用、制备功能材料、堆肥等综合利用方法,并就当前油漆废渣处理中存在的问题提出了合理化建议。     

The bumpy road to better risk control: A Tour d'Horizon of new concepts and ideas

How can we be sure that sufficient safeguards are in place and safety level is acceptable? As we heard Prof. Nancy Leveson stating at last year's MKOPSC symposium, even with all components functioning, dysfunctional component interaction can still be a cause of mishap. Human factor expert, Prof. Erik Hollnagel, asserts it in even stronger terms: the Efficiency-Thoroughness Trade-off principle, or rather dilemma, contends that one can hardly do it perfectly well. Perfect thoroughness, certainly in complex situations, requires an amount of time with which efficiency will be in conflict. For improved situational awareness, sufficient resilience, and adequate risk control, we must adopt a top-down system approach. Hazard scenarios possible in the system, with all its entangled interactions of hardware, procedures, and humans shall be identified bottom-up and causal relations made clear. Fortunately, in recent years two potentially helpful tools have become available: Blended Hazid, a vastly improved, heavily computerized system approach making use of HazOp and FMEA, and Bayesian networks, a tool to model cause–effect structures allowing inclusion of uncertainty information. Bayesian networks as an infrastructure enable also the use of indicator values to relate the result of safety management effectiveness, which expresses itself as safety attitude of employees, competence, workload, and motivation, with their effects on error and failure probability. This paper will explain the directions these developments are advancing and the openings they provide for further process safety research and risk assessment, which when applied will result in improved process risk control.     

Airborne PCDD/Fs in two e-waste recycling regions after stricter environmental regulations

Since the 2010 s, the authorities of Guangdong province and local governments have enhanced law enforcement and environmental regulations to abolish open burning, acid washing, and other uncontrolled e-waste recycling activities. In this study, ambient air and indoor dust near different kinds of e-waste recycling processes were collected in Guiyu and Qingyuan to investigate the pollution status of particles and polychlorinated dibenzo-pdioxins and furans(PCDD/Fs) after stricter environmental regulations. PM_(2.5) and PCDD/Fs both showed significantly reduced levels in the two regions compared with the documented data. The congener distribution and principal component analysis results also confirmed the significant differences between the current PCDD/Fs pollution characterizations and the historical ones. The estimated total intake doses via air inhalation and dust ingestion of children in the recycling region of Guiyu ranged from 10 to 32 pg TEQ/(kg·day), which far exceeded the tolerable daily intake(TDI) limit(1–4 pg TEQ/(kg·day). Although the measurements showed a significant reduction of the release of PCDD/Fs, the pollution status was still considered severe in Guiyu town after stricter regulations were implemented.     

硝化液回流比对ABR-MBR工艺反硝化除磷效能的影响

基于ABR工艺与MBR工艺的耦合联动,以低C/N比生活污水为研究对象,构建生物相分离、液相循环和功能联动的ABR-MBR新型组合工艺,以实现稳定、高效、节能的多功能生物除污(去碳-脱氮-除磷)为目标,通过优化水力停留时间(HRT)以获得ABR优质碳源提供与MBR短程硝化实现的最佳组合,并进行了硝化液回流比为100%、200%、300%和400%时对反硝化除磷的影响研究.ABR-MBR耦合工艺在不同条件下的运行研究结果表明,将溶解氧(DO)维持在低浓度(0.3~1.0 mg·L-1)下及HRT维持在较短(HRTMBR=3 h)情况下在MBR中实现了短程硝化,亚硝酸盐积累率达到60%以上;随着硝化液回流比的增大,ABR中反硝化除磷效能先升高后下降,以300%时反硝化除磷效果为最佳,此时亦处于MBR短程硝化阶段,实现了短程反硝化除磷(主要以NO-2作为电子受体的反硝化除磷),且短程反硝化除磷在系统除磷中占据了主导作用.     

Technical specifications for mechanical recycling of agricultural plastic waste

Technical specifications appropriate for the recycling of agricultural plastic wastes (APWs), widely accepted by the recycling industry were developed. The specifications establish quality standards to be met by the agricultural plastics producers, users and the agricultural plastic waste management chain. They constitute the base for the best economical and environmental valorisation of the APW.The analysis of the APW streams conducted across Europe in the framework of the European project “LabelAgriWaste” revealed the inherent characteristics of the APW streams and the inherent constraints (technical or economical) of the APW. The APW stream properties related to its recycling potential and measured during pilot trials are presented and a subsequent universally accepted simplified and expanded list of APW recycling technical specifications is proposed and justified. The list includes two sets of specifications, applied to two different quality categories of recyclable APW: one for pellet production process (“Quality I”) and another one for plastic profile production process (“Quality II”). Parameters that are taken into consideration in the specifications include the APW physical characteristics, contamination, composition and degradation. The proposed specifications are focused on polyethylene based APW that represents the vast majority of the APW stream. However, the specifications can be adjusted to cover also APW of different materials (e.g. PP or PVC) that are found in very small quantities in protected cultivations in Europe. The adoption of the proposed specifications could transform this waste stream into a labelled commodity traded freely in the market and will constitute the base for the best economical and environmental valorisation of the APW.     

电解锰企业生产废水循环模式优化

通过对贵州省电解锰行业生产废水循环模式的调查,针对水质、水量特征进行改造:电解锰生产冷却循环水的强制排污水可降级作为电解产品和阴极板的冲洗水使用,处理后的含铬锰废水可作为制液氨水和电解清槽用水。进行以上优化后,电解锰生产废水闭路循环是可以实现的。     

Waste scavenging in Third World cities: A case study in Ilorin, Nigeria

Solid waste poses a serious problem to government agencies and people in third world cities. Recycling as a way of managing waste has received relatively little attention. This paper examines the role of waste scavengers in the waste recycling process. The preliminary findings reported here indicate that the waste scavenger could be incorporated formally into the recycling process. Using plastic waste as an example, it is demonstrated that such recycling is economically viable.     

Reactions of model compounds of phenol resin in sub- and supercritical water under an argon atmosphere

Model compounds of phenol resin were reacted in sub- and supercritical water to clarify the mechanism of the decomposition reaction of plastics in water. Cleavage reaction of methylene bonds was confirmed in the reactions of model compounds of phenol resin such as bis(hydroxyphenyl)methanes in sub- and supercritical water under an Ar atmosphere, although the methylene bond was stable in thermal reactions. It was also confirmed that sub- and supercritical water played important roles not only as a stable solvent thermally, but also as a chemical reagent. Received: July 19, 2000 / Accepted: September 14, 2000