Production of activated carbons from waste tire--process design and economical analysis

The process design and economic analysis of process plants to produce activated carbons from waste tires and coal have been performed. The potential range of products from each process has been considered, namely for waste tire--pyro-gas, active carbon, carbon black and pyro-oil; for coal--pyro-gas and active carbons. Sensitivity analyses have been carried out on the main process factors; these are product price, production capacity, total production cost, capital investment and the tipping fee. Net present values for the two plants at various discount factors have been determined and the internal rates of return have been determined as 27.4% and 18.9% for the waste tire plant and the coal plant, respectively.     

Use of inert C&D materials for seawall foundation: A field-scale pilot test

The generation rate of construction and demolition (C&D) materials in Hong Kong has well exceeded the demand rate. An innovative solution has been developed by the Hong Kong Special Administrative Region Government to use the inert portion of C&D materials, denoted as public fill, for seawall foundation construction. A field-scale pilot test has been conducted to evaluate the constructability and engineering performance of the foundation so as to establish the viability of the solution. Details of the pilot test and results of the performance evaluation are presented in this paper. More importantly, the viability of an innovation solution to achieve effective allocation of sand fill resources, and conservation and recycling of inert C&D materials has been established.     

Industrial pollution and social deprivation: Evidence and complexity in evaluating and responding to environmental inequality

The local impacts of industrial pollution can take many forms and—whilst uncertain in their scale, severity and distribution—are widely recognised. The question of who in society potentially experiences these impacts through living near to emission sources has been little explored, at least in the UK. This paper reports on a study carried out for the Environment Agency, which examined the distribution of sites coming within the Industrial Pollution Control (IPC) regime against patterns of deprivation. Our analysis provides evidence of a socially unequal distribution of IPC sites in England, with sites disproportionately located and clustered together in deprived areas and near to deprived populations. In discussing these results we emphasise the methodological limitations of this form of environmental justice analysis and the crucial differences between proximity, risk and impact. We also consider the distinction between inequality and injustice and the difficult policy questions which arise when evaluating evidence of environmental inequality, including potential grounds for policy intervention.     

Influence of Targets and Assessment Region Size on Perceived Conservation Priorities

We used an existing conservation opportunity area (OA) data layer for four contiguous ecological subsections within the Ozark Highlands to quantitatively evaluate the influence of conservation targets and assessment region size on conservation priorities. OAs are natural and seminatural land-cover patches that are away from roads and away from patch edges. To evaluate the influence of targets, we assigned a priority score to each OA polygon for each of five different conservation targets, including land-cover patch size, landform representation, target vertebrate richness, target breeding bird richness, and target land cover. The top-scoring OAs for each target were added to an OA selection set for that target until 50% of the study area was chosen. These five OA selection sets were overlain to quantify overlap in priorities. Only 1.6% of the study area, or 2.1% of all OA polygons, was selected by all five targets. To evaluate the influence of assessment region size, we compared results of priority ranking of OAs relative to the entire study area against a merged set of priority rankings established separately relative to each of the four subsections within the study area. When high-priority OAs were added until 25% of the region was within the selection set for each of the five targets, the sets based on the whole study area versus each subsection evaluated separately overlapped from 45.4% to 81.9%. Thus, perceived priorities of conservation assessments are strongly influenced both by the targets that are evaluated and by the size of the assessment region.     

The effects of three oils on marine phytoplankton photosynthesis

The effects of 3 oils (Venezuelan crude, No. 2 fuel, and No. 6 fuel) on the photosynthesis of natural phytoplankton communities from Bedford Basin, Nova Scotia (Canada), and the northwest Atlantic Ocean between Halifax and Bermuda were examined using a radiocarbon method. The 3 oils can inhibit photosynthesis, and the degree of inhibition depends upon oil type and concentration. The No. 2 fuel oil was the most toxic. Under certain conditions, low concentrations of Venezuelan crude oil can stimulate photosynthesis. On the basis of these results, it is concluded that present levels of oil contamination in Bedford Basin could be inhibiting photosynthesis by a few percent, while present levels in open ocean water have no apparent deleterious effect on photosynthesis.Bedford Institute of Oceanography Contribution.     

Characterization of Biodegradable Composite Films Prepared from Blends of Poly(Vinyl Alcohol), Cornstarch,and Lignocellulosic Fiber

Several composite blends of poly(vinyl alcohol) (PVA) and lignocellulosic fibers were prepared and characterized. Cohesive and flexible cast films were obtained by blending lignocellulosic fibers derived from orange waste and PVA with or without cornstarch. Films were evaluated for their thermal stability, water permeability and biodegradation properties. Thermogravimetric analysis (TGA) indicated the suitability of formulations for melt processing, and for application as mulch films in fields at much higher temperatures. Composite films were permeable to water, but at the same time able to maintain consistency and composition upon drying. Chemical crosslinking of starch, fiber and PVA, all hydroxyl functionalized polymers, by hexamethoxymethylmelamine (HMMM) improved water resistance in films. Films generally biodegraded within 30 days in soil, achieving between 50–80% mineralization. Both starch and lignocellulosic fiber degraded much more rapidly than PVA. Interestingly, addition of fiber to formulations enhanced the PVA degradation.     

二阶模糊安全评估方法及其在油库安全评价中的应用

通过分析油库安全因素的层次关系,将影响油库安全的因素划分为人员、装备、管理以及环境因素等不同的层次,并对油库安全指标、各层次间的评估方法以及模糊运算方法进行研究,建立针对油库安全的二阶综合模糊评估模型,给出评估的整体流程。评估过程中以改进的层次分析法确定不同层次和因素的重要度,以加权平均方法为模糊运算准则。利用建立的评估体系对某油库的安全状况进行评估,并根据总体评估结果和各层次评估结果中的不足,提出了油库安全整改意见。评估实施过程表明:该二阶综合模糊评估模型避免了评估中的主观因素,并且可操作性好,评估过程易于实现。     

Pollution budgeting: A concept whose time has come

Summary The paper provides a discussion of the pollution budgeting concept and the use of emissions trading as an implementation strategy. The paper is divided into three sections. Section 1 discusses the use of emissions trading to implement the pollution budget concept. Section 2 provides a discussion of the policy problems that have arisen in the implementation of emissions trading as a transitional system. Section 3 provides concluding comments. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the author and do not necessarily reflect the views of the President's Council on Environmental Quality. Dr Gordon L. Brady Jr. holds a Ph.D. degree in Economics and a Masters in the Study of Law. His present appointment is Senior Economic Policy Advisor at the President's Council on Environmental Quality. Prior to this appointment he was Special Consultant on Regulatory Reform at the National Science Foundation.     

Transformation of [14C] trichloroethylene by poplar suspension cells

Trichloroethylene (TCE) is one of the most prevalent environmental contaminants, and it poses an expensive remediation problem. Phytoremediation has been investigated as a potential tool for the removal of TCE from ground water and soil, and has shown promise in preliminary trials. However, the fate of TCE in plants is largely unknown. Radiolabel studies showed that once taken up and transformed, most of the TCE is incorporated into plant tissue as a non-volatile, un-extractable residue. We describe here an assay for TCE transformation by poplar suspension cells. Using this assay, it was shown that two different activities contribute to the fixation of TCE by poplar cells, one associated with cell walls and insoluble residues, the other associated with a high molecular weight, heat labile fraction of the cell extract. It appears that plant enzymes catalyze some of the transformations.