Assessing nutrient flows in septic tanks by eliciting expert judgement: a promising method in the context of developing countries

Simple models based on the physical and biochemical processes occurring in septic tanks, pit and urine diversion latrines were developed to determine the nutrient flows in these systems. Nitrogen and phosphorus separation in different output materials from these on-site sanitation installations were thus determined. Moreover, nutrient separation in septic tanks was also assessed through literature values and by eliciting expert judgement. Use of formal expert elicitation technique proved to be effective, particularly in the context of developing countries where data is often scarce but expert judgement readily available. In Vietnam, only 5-14% and 11-27% of the nitrogen and phosphorus input, respectively, are removed from septic tanks with the faecal sludge. The remaining fraction leaves the tank via the liquid effluent. Unlike septic tanks, urine diversion latrines allow to immobilize most of the nutrients either in form of stored urine or dehydrated faecal matter. These latrines thus contribute to reducing the nutrient load in the environment and lowering consumption of energy and non-renewable resources for fertiliser production.     

Declines in phosphorus concentration in the upper River Thames (UK): Links to sewage effluent cleanup and extended end-member mixing analysis

Phosphorus concentrations in the upper River Thames Basin (southeastern England) are described and linked to sewage effluent sources. Weekly surveys between 1997 and 2007 of the Thames and two of its major tributaries, the Thame and the Kennet indicated that phosphorus was mainly in soluble reactive (SRP) form. Baseflow concentrations in the Thames reduced from 1584 μg/l in 1998 to 376 μg/l in 2006 and from 2655 to 715 μg/l for the Thame. Flow response, flux and endmember mixing analysis indicated that these declines resulted from SRP reductions in sewage treatment works (STW) effluent following phosphorus stripping for the major STWs in the region. This was confirmed by comparing our analysis with direct measurements of SRP in the effluents based on Environment Agency data. A within-river loss under baseflow of ~ 64% (range 56-78%) of the SRP-effluent input was estimated for the Thames, with a near balance for the Thame. SRP concentrations in the Kennet were an order of magnitude lower than the Thames/Thame: non-point sources dominated and were important for all the rivers at high flows. It was concluded that removal of SRP from effluents would be insufficient SRP in the Thames and Thame to meet annual average environmental targets of 50 to 120 μg/l.The paper flags the value of combining hydrological/chemical tracing and concentration/flux approaches to data interrogation and the bonus of having actual measurements of the effluent. It highlights the need for fuller assessment of water storage/sediment/biota interactions for phosphorus and for caution in using boron as a long-term tracer for effluent inputs, its concentrations having declined markedly in response to reduced usage in washing powders: the value of using sodium as a tracer for examining SRP changes is shown.     

Receptor modeling of PM2.5, PM10 and TSP in different seasons and long-range transport analysis at a coastal site of Tianjin, China

Atmospheric particulate matter (PM_2.5, PM₁₀ and TSP) were sampled synchronously during three monitoring campaigns from June 2007 to February 2008 at a coastal site in TEDA of Tianjin, China. Chemical compositions including 19 elements, 6 water-solubility ions, organic and elemental carbon were determined. principle components analysis (PCA) and chemical mass balance modeling (CMB) were applied to determine the PM sources and their contributions with the assistance of NSS SO₄²⁻, the mass ratios of NO₃⁻ to SO₄²⁻ and OC to EC. Air mass backward trajectory model was compared with source apportionment results to evaluate the origin of PM. Results showed that NSS SO₄²⁻ values for PM_2.5 were 2147.38, 1701.26 and 239.80 ng/m³ in summer, autumn and winter, reflecting the influence of sources from local emissions. Most of it was below zero in summer for PM₁₀ indicating the influence of sea salt. The ratios of NO₃⁻ to SO₄²⁻ was 0.19 for PM_2.5, 0.18 for PM₁₀ and 0.19 for TSP in winter indicating high amounts of coal consumed for heating purpose. Higher OC/EC values (mostly larger than 2.5) demonstrated that secondary organic aerosol was abundant at this site. The major sources were construction activities, road dust, vehicle emissions, marine aerosol, metal manufacturing, secondary sulfate aerosols, soil dust, biomass burning, some pharmaceutics industries and fuel-oil combustion according to PCA. Coal combustion, marine aerosol, vehicular emission and soil dust explained 5-31%, 1-13%, 13-44% and 3-46% for PM_2.5, PM₁₀ and TSP, respectively. Backward trajectory analysis showed air parcels originating from sea accounted for 39% in summer, while in autumn and winter the air parcels were mainly related to continental origin.     

A decision making tool providing aid in choosing a storm drainage network solution: description and analysis

Software packages developed for the design of urban storm drainage networks allow several solutions to be proposed for the same problem. It subsequently falls to the decision maker to choose which solution to adopt. The question is to compare the propositions according to economic, ecological, functionality and maintenance criteria. A tool which can be applied to this problem is presented in this article. This tool integrates multicriteria, fuzzy sets and the base of rules concepts. One of the principal difficulties stems from the fact that the evaluation of some of the criteria needed is not straightforward. Thus, a method which helps to evaluate one of the criteria (the global functioning of a storm drainage network) was defined. This method was first tested and validated on imaginary cases and subsequently applied to a real case: the restructuring of the urban storm drainage network of the city of Annequin. Then, on the basis of this experiment, the knowledge about the use of such a tool in an environment more complex than a laboratory was improved.     

Risk analysis and protection measures in a carbon nanofiber manufacturing enterprise: An exploratory investigation

The emerging US carbon nano-manufacturing sector accounts for 40% of nanotechnology product marketplace, thus, there is a significant potential for increased risks arising from workers' exposure to carbon nanofibers (CNF). This research aims at developing a low-cost/evidence-based tool, thereby, increasing the sustainability of CNF manufacturing firms. The following specific aims achieve the study objective: Aim 1 — To present a technical discussion of the proposed concept for risk analysis and protection measures; Aim 2 — To describe the manufacturing process utilized for the CNF production; Aim 3 — To describe the hazards typically encountered in a CNF manufacturing facility; and, Aim 4 — To document the application of the proposed tool for risk analysis and intervention strategy development.In this study, a four-step methodology was developed to protect worker health in the nano-manufacturing enterprise through the generation of improvement actions (i.e., suggested changes in the hazard/work environment characteristics and individual capabilities without specifying how changes are made) followed by interventions (i.e., workplace solutions which specify how changes are being implemented). The methodology was implemented in a CNF manufacturing enterprise in the Midwest of the US. The data collected were based on detailed observations and interviews with worker and management personnel.A detailed flow process analysis was conducted for the nano-manufacturing operation. Eleven hazards were identified at the facility. Analysis indicated that the computed risk scores ranged from moderate (i.e., requiring one to start with incremental changes, then, explore substantial changes, if needed) to very high (i.e., substantial changes should be planned in the short term, followed by incremental changes). A detailed intervention plan was presented for the identified hazards on the basis of criteria of applicability, cost, benefit and feasibility. Management personnel were in agreement with the findings of the study.In conclusion, a low-cost/evidence-based tool was developed and implemented to assess and manage the risks associated with exposure to CNF production in a manufacturing enterprise. Preliminary validation of the tool suggests that management personnel were in agreement with the study findings. Further application of the systematic methodology is warranted.     

An embodied carbon and energy analysis of modern methods of construction in housing: A case study using a lifecycle assessment framework

There is a growing interest in comparing the energy and consequential carbon embodied in buildings using different methods of construction and alternative materials. This paper compares the embodied carbon in a low energy, affordable house constructed using a novel offsite panellised modular timber frame system, in Norfolk UK with two traditional alternative scenarios. A lifecycle assessment (LCA) framework is used to conduct a partial LCA, from cradle to site, of the construction. An inventory of the materials and fossil fuel energy utilised in the construction was used to calculate the primary energy consumed and the associated embodied carbon. The embodied carbon was found to be 34.6 tonnes CO₂ for a 3 bedroom semi-detached house, 405 kgCO₂ per m² of useable floor area. When compared with traditional methods of construction the modern methods of construction (MMC) house resulted in a 34% reduction in embodied carbon. Despite timber being the predominant structural and cladding material, concrete is the most significant material (by proportion) in embodied carbon terms, responsible for 36% of materials related embodied carbon.     

Coupled HM effects in a crystalline rock mass due to glaciation: indicative results from groundwater flow regimes and stresses from an FEM study

This paper highlights certain aspects of glacial impact on groundwater flow and rock mechanics, of particular interest in future scenarios for the geological disposal of nuclear waste. The investigation took the form of a generic exercise based on conditions at the underground research facility in Whiteshell, Canada. The site scale model domain boundaries were set up based on a number of major deformation zones. The surface boundary conditions comprised a transient ice sheet load and related hydraulic heads, generated by meltwater. It has thus been possible to compare glacial impact in relation to present-day climatological conditions. The main issues in the investigation were to evaluate the groundwater flow regime and the pre-requisites for underground jacking as well as shearing according to the prescribed geoscientific properties of a benchmark protocol. Special attention has been devoted to a solution to the hydromechanical (HM) problem (1) with or without process coupling, (2) with or without a transient approach, and (3) considering a two- or three-dimensional mode. The study underlines the need for transient analyses in 3D of these coupled phenomena.      

15分钟生活圈公共服务设施绩效评估方法构建——基于供需平衡视角的长沙市实证研究

结合长沙市“一圈两场三道”两年行动计划的实践经验，从供需平衡的视角切入15分钟生活圈的公服设施绩效评估，围绕日常生活、长者照料、教育培养、文体娱乐、医疗护理、社区就业、公共空间、慢行环境等8个维度建立了28分项的指标评价体系，并通过手机信令数据测度居民小区的设施需求度、通过开源数据与调研数据测度设施供给情况，采用先评估居民小区、再均值降维至生活圈单元的方法展开分析，结果发现：（1）强政府导向型、弱市场导向型、景观导向型设施在空间分布存在不同偏好特征，并浅析了差异产生的原因；（2）不同年龄群体对公服设施的需求偏好不同，引入设施需求紧迫度的概念，可辅助判断设施缺项生活圈单元的建设时序，为其他城市的生活圈规划研究与实践提供一定参考。     

Explaining new firm creation in Europe from a spatial and time perspective: A multilevel analysis based upon data of individuals,regions and countries

This paper seeks to better understand the significance of spatial context conditions and personal attributes for early‐stage entrepreneurship. We combine individual with regional and national level data using multilevel analysis to test our hypotheses. We differentiate between two phases in the entrepreneurial process as well as between general and ambitious entrepreneurship. First, we show that both the national and the regional context significantly impact individual entrepreneurial activities. Second, individual level characteristics exert the greatest overall influence, but the direction of this influence is not stable. Third, the impact of the three levels varies across the different phases in the entrepreneurial process as well as between different types of start‐ups. Fourth, we demonstrate that cross‐level interactions between individual characteristics and spatial context factors are important in explaining entrepreneurial activities.