Biopotentiality as an index of environmental compensation for composting plants

The Biopotentiality Index is a landscape ecology indicator, which can be used to estimate the latent energy of a given land and to assess the environmental impacts due to the loss of naturalness on a landscape scale. This indicator has been applied to estimate the effectiveness of the measures put in place to provide an environmental compensation for the revamping of a composting plant. These compensation measures are represented by a green belt with a minimum width of 25 m all around the plant, representing both a windbreak and a buffer zone, and by two wide wooded zones acting as core natural areas.This case-study shows that the compensation index could be used as a key tool in order to negotiate the acceptance of waste treatment plant with the population.     

Application of Biobarriers for Groundwater Containment at Fractured Bedrock Sites

Biological barriers are a beneficial application of biofilms that aim at reducing the hydraulic conductivity (K) in geological formations. Several studies have shown the potential benefits of creating such barriers either by stimulating the indigenous microbial community (biostimulation) or injecting bacteria (bioaugmentation). For example, laboratory experiments show that groundwater microorganisms attached to a ceramic surface and generated a biofilm as thick as 1,100 μm. In a limestone fracture, this bacterial community clogged a single fracture up to 99.2 percent within 22 days. At the field scale, applications in porous aquifers led to a five‐fold decrease in K after 2.5 days of biostimulation, and a bioaugmentation with a starved, adapted bacterial culture decreased K by 99.4 percent. One promising development of the biobarrier concept is a field application at a fractured bedrock site. Using a multidisciplinary approach and focusing on a well‐characterized fracture system, a field trial was undertaken in Southern Ontario to measure the extent of bioclogging and the stability over time. This article focuses on the literature pertinent to the preparation of this field trial and presents the innovative approach selected to monitor the bioclogging in such a challenging environment.     

Experimental research on emission and removal of dioxins in flue gas from a co-combustion of MSW and coal incinerator

This paper describes the experimental study of dioxins removal from flue gas from a co-combustion municipal solid waste and coal incinerator by means of a fluidized absorption tower and a fabric filter. A test rig has been set up. The flow rate of flue gas of the test rig is 150-2000 m3/h. The system was composed of a humidification and cooling system, an absorption tower, a demister, a slurry make-up tank, a desilter, a fabric filter and a measurement system. The total height of the absorption tower was 6.5m, and the diameter of the reactor pool was 1.2 m. When the absorbent was 1% limestone slurry, the recirculation ratio was 3, the jet rate was 5-15 m/s and the submerged depth of the bubbling pipe under the slurry was 0.14 m, the removal efficiency for dioxins was 99.35%. The concentration of dioxins in the treated flue gas was 0.1573 x 10(-13)kg/Nm3 and the concentration of oxygen was 11%. This concentration is comparable to the emission standards of other developed countries.     

The circular economy in China

This article makes an attempt to answer the three questions of why China is devoting its full effort to promoting a circular economy, what a circular economy is, and how to implement a circular economy in China. The evolutionary process of a circular economy in China, from introduction of the concept and the relevant actions of national decision making to demonstration of the system nationwide, has taken only around 6 years, with strong encouragement from politicians and the urgent need to cope with environmental pollution and a severe shortage of natural resources. The circular economy in China is now being actively implemented at three levels: enterprises, eco-industrial parks, and regions. The consolidated theoretical bases of ecology and economics have helped the circular economy to define its position as a new economic model to effectively resolve the problems of resources and the environment. In this regard, material flow management is naturally a unique planning and management method for implementation of a circular economy, and eco-efficiency is a good indicator to measure circular economic activities. Of particular significance has been initiation of the legislative process for the Circular Economy Law, which is among a number of initiatives developing core policies for a circular economy in China. Stringent enforcement of a set of policies for energy saving and pollution abatement nowadays in China will certainly create an enabling environment for the development of a circular economy.     

In situ hypochlorous acid generation for the treatment of syntan wastewater

A new treatment process was employed to treat wastewater generated from a factory manufacturing syntan (synthetic tannin). In this treatment process, in-situ production of hypochlorous acid was achieved by the use of an aqueous sodium chloride solution for chlorine production. As the graphite anode and stainless steel cathode zones were kept unseparated, the hypochlorous acid was produced by electrolysis. The hypochlorous acid was utilized for the oxidation of organic matter present in the wastewater. The results showed that for an initial COD concentration of 10,000 mg/l, a turbidity of 277 NTU, a tannin concentration of 4000 mg/l, a temperature of 27±1°C, a current density of 42.5 mA/cm², a sodium chloride content of 3% and an electrolysis period of 210 min showed an effluent COD concentration of 230 mg/l, a turbidity of 9 NTU, a tannin concentration below the detection limit and a temperature of 37±2°C.     

Liability and Compensation for Oil Pollution Damage: Some Current Threats to the International Convention System

The carriage of oil is indispensable to the industrialized nations. In this respect, the carriage of oil is undertaken as a service to society as a whole with its individual members deriving benefits from its carriage to varying degrees. Consequently, after examining the four Conventions in the international system of compensation for oil pollution from ships, it is argued that the general citizenship of those nations pay, in exceptional cases, for a small share of the risk, which is created in part by the citizens, as users of oil. The paper proposes the creation of a fund of last resort that could be conceived either at a regional level or a national level and financed through (indirect) taxation on the population as a whole. This type of fund could have a wider use in the field of marine pollution and protection of marine resources.     

烟气脱硫喷淋塔的容积负荷与本体设计

提出了以喷淋塔的容积负荷——平均容积吸收率为控制指标的本体设计路线。在目前已有的设计、运行经验基础上，根据烟气的SO2进口浓度、要求的吸收效率等来确定喷淋塔容积。讨论了容积吸收率不同角度的定义，给出了采用容积吸收率进行喷淋塔本体设计的步骤。     

The financial and economic feasibility of rural household biodigesters for poor communities in South Africa

Given the persistence of systemic poverty in, most notably, the rural parts of South Africa, the question is whether the use of biodigesters as a source of energy offers potential solutions to some of the difficulties and development needs faced by people in these areas. At the core, this translates into whether this technology would be financially and economically feasible for installation and use by rural households. Here we conduct both a financial and an economic cost-benefit analysis in one such community based on survey data from 120 households. Analysis of these data and supporting literature reveals that a biodigester is not a financially feasible investment for a rural household. Substantial economic benefits are, however, found to make a biodigester a worthwhile investment from a broader societal perspective. This is a compelling argument for further study and the consideration of government support in the light of broader economy-wide benefits.     

How to negotiate remediation projects with regulatory agencies

The news that a company has been identified as a potentially responsible party (PRP) at a federal or state Superfund site usually sends a current of fear through the company's management. Even executives with experience in Superfund projects foresee a lengthy, complicated process that involves enormous expenditures and a possible public relations disaster. The author argues, however, that the Superfund process can be managed in a cost-effective way, prevent reactive responses, inaction, and ineffective action, and applying the business acumen that enabled the company to prosper in the first place. This article explores a critical aspect of the remediation process—negotiation of settlements with regulatory agencies (EPA or a state department of environmental protection)—and details the practical steps needed to conduct those negotiations. It also describes common mistakes that can be avoided. For brevity and clarity, it is assumed that the company in question is the only PRP that has received a notice letter from the regulatory agency.     

Adsorption removal of pollutants by active cokes produced from sludge in the energy recycle process of wastes

This study proposes a recycling system of sludge into active cokes and the fundamental examinations for the application were carried out. In the system, active cokes were produced by carbonizing pellets of sludge in a steam stream. Pyrolysis gas yielded by carbonization can be available to a fuel for a steam generation boiler. The exhaust heat from the boiler is used sequentially for drying of sludge. The active cokes are applied to the adsorbent for dioxin removal in exhaust gas from incinerators of wastes, or for purification of gas obtained in a gasification process of wastes, particularly removal of H2S. The used adsorbent is not recycled, but incinerated in the furnace without a desorption process to decompose adsorbed dioxin or to oxidize H2S for a sequential desulfurization process of SO2. Dry pellets of sludge were carbonized in a quartz tube reactor under various atmospheres. The micro pore structure and the adsorption performance of the cokes produced without activation process were examined. The micro pore structure was influenced by the temperature, the sort of flow gas (N2, CO2 and steam) and carbonization time, and the active cokes produced under the condition of the temperature 823 K for 60 min in the steam atmosphere had a largest specific surface area in the diameter less than 5 nm. The amount of benzene adsorption as an alternative substance of dioxin into the active cokes had a similar quality to a commercial active char produced from coal if it was evaluated by adsorption per a unit specific surface area. This fundamental knowledge must be reflected to an optimum design for development of a simple continuous process to produce the active cokes by a fluidized bed type of the carbonization furnace.     

Mathematical modeling of biomass fuels formation process

The increasing demand for thermal and electric energy in many branches of industry and municipal management accounts for a drastic diminishing of natural resources (fossil fuels). Meanwhile, in numerous technical processes, a huge mass of wastes is produced. A segregated and converted combustible fraction of the wastes, with relatively high calorific value, may be used as a component of formed fuels. The utilization of the formed fuel components from segregated groups of waste in associated processes of co-combustion with conventional fuels causes significant savings resulting from partial replacement of fossil fuels, and reduction of environmental pollution resulting directly from the limitation of waste migration to the environment (soil, atmospheric air, surface and underground water). The realization of technological processes with the utilization of formed fuel in associated thermal systems should be qualified by technical criteria, which means that elementary processes as well as factors of sustainable development, from a global viewpoint, must not be disturbed. The utilization of post-process waste should be preceded by detailed technical, ecological and economic analyses. In order to optimize the mixing process of fuel components, a mathematical model of the forming process was created. The model is defined as a group of data structures which uniquely identify a real process and conversion of this data in algorithms based on a problem of linear programming. The paper also presents the optimization of parameters in the process of forming fuels using a modified simplex algorithm with a polynomial worktime. This model is a datum-point in the numerical modeling of real processes, allowing a precise determination of the optimal elementary composition of formed fuels components, with assumed constraints and decision variables of the task.     

Results from Three Field Tracer Experiments on the Neighbourhood Scale in the City of Birmingham UK

The physical processes governing flow and pollutantdispersion at the neighbourhood scale, a spatial scaleintermediate between the street scale and the city scale, is notwell understood. Furthermore, it is not clear whether a traditional approach using averaged characteristics such as theaerodynamic roughness length is sufficient to predict the concentration field at this scale. To investigate pollutant dispersion in a real urban area, three field experiments were designed within the UK-URGENT programme sponsored by NERC. Theexperiments were performed in the City of Birmingham using a finite duration release of inert, non-toxic and non-depositingtracers, vis. perfluoromethylcyclohexane (PMCH) and perfluoromethylcyclopentane (PMCP). Measurements were taken using air bag samplers placedin an arc at 3.5 km (first experiment) and 1 km (second andthird experiments) from the source; some trap samplers wereplaced outside the main arc in the outskirts of the city. Measurements were analysed in the laboratory using anovel gas-chromatography technique. Data so obtained werecompared with predictions from a simple steady-state modeland a time-dependent model. The concentration-time serieswere very asymmetrical with a sharp rise, a plateau followedby a relatively slow decrease and finally a long-livedplateau above (or possibly very slow decrease to) thebackground level.     

Resolving public conflict in site selection process-a risk communication approach

In Japan, conflicts regarding the siting of waste disposal facilities occur frequently. In particular, siting of incinerators and landfills has become increasingly difficult because the public is highly concerned about the dioxin issues. Inefficient siting of waste disposal facilities causes several social problems, such as the shortage of waste treatment and disposal facilities, the rising of waste management costs and an increase in the consumption of resources. While dealing with a similar situation, the Chemical Society of Japan adopted a risk communication technique successfully. Hence, the pragmatic use of a risk communication technique is proposed to avoid conflicts and for a smooth information exchange to seek cooperation in waste management. In order to achieve this, a study was conducted to resolve conflicts between residents and the municipality for the selection of site for a solid waste treatment and disposal facility. This study aims to discuss the subject of risk communication for the waste disposal system in Japan. This study is performed through personal interviews and a questionnaire covering opposing parties in the town. As a result of the survey, a risk communication approach for a waste treatment and disposal system is presented in the paper addressing issues such as building of social trust, pragmatic use of the communication process, installation of credible information sources, and environmental education and awareness.     

Batch and column tests of metal mobilization in soil impacted by landfill leachate

The percolation of landfill leachate, even in the absence of a high concentration of specific pollutant, may induce a strong modification of soil chemical and physical characteristics, due to the alteration of the natural equilibrium between the aqueous phase and the soil matrix. As a result, a huge amount of cations can be solubilized, thus inducing groundwater pollution.In this work batch and column experiments of metal mobilization from a soil sampled down gradient of a municipal waste landfill in Northern Italy are presented. The experiments were initially performed in batch scale on soil slurries at different pH and Eh. Distilled water was used first and then a groundwater sampled down-gradient in the same site. Subsequently, to better simulate the aquifer conditions, 50 d column tests were performed on 15 kg of saturated soil. The concentrations of Fe, Mn, and Ni were evaluated when these selected environmental parameters were altered. Results indicated a greater release when acidic conditions were achieved, a positive effect in this case of the addition of an oxidant and a great Mn mobilization when negative redox potentials were established.     

Multi-criteria GIS-based siting of an incineration plant for municipal solid waste

Siting a municipal solid waste (MSW) incineration plant requires a comprehensive evaluation to identify the best available location(s) that can simultaneously meet the requirements of regulations and minimise economic, environmental, health, and social costs. A spatial multi-criteria evaluation methodology is presented to assess land suitability for a plant siting and applied to Santiago Island of Cape Verde. It combines the analytical hierarchy process (AHP) to estimate the selected evaluation criteria weights with Geographic Information Systems (GIS) for spatial data analysis that avoids the subjectivity of the judgements of decision makers in establishing the influences between some criteria or clusters of criteria. An innovative feature of the method lies in incorporating the environmental impact assessment of the plant operation as a criterion in the decision-making process itself rather than as an a posteriori assessment. Moreover, a two-scale approach is considered. At a global scale an initial screening identifies inter-municipal zones satisfying the decisive requirements (socio-economic, technical and environmental issues, with weights respectively, of 48%, 41% and 11%). A detailed suitability ranking inside the previously identified zones is then performed at a local scale in two phases and includes environmental assessment of the plant operation. Those zones are ranked by combining the non-environmental feasibility of Phase 1 (with a weight of 75%) with the environmental assessment of the plant operation impact of Phase 2 (with a weight of 25%). The reliability and robustness of the presented methodology as a decision supporting tool is assessed through a sensitivity analysis. The results proved the system effectiveness in the ranking process.     

Assessment of plasma gasification of high caloric waste streams

Plasma gasification is an innovative technology for transforming high calorific waste streams into a valuable synthesis gas and a vitrified slag by means of a thermal plasma. A test program has been set up to evaluate the feasibility of plasma gasification and the impact of this process on the environment. RDF (refuse derived fuel) from carpet and textile waste was selected as feed material for semi-pilot gasification tests. The aim of the tests was: (1) to evaluate the technical feasibility of making a stable synthesis gas; (2) to characterize the composition of this synthesis gas; (3) to define a suitable after-treatment configuration for purification of the syngas and (4) to characterize the stability of the slag, i.e., its resistance to leaching for use as a secondary building material. The tests illustrate that plasma gasification can result in a suitable syngas quality and a slag, characterized by an acceptable leachability. Based on the test results, a further scale-up of this technology will be prepared and validation tests run.     

Integrating multi-criteria decision analysis for a GIS-based hazardous waste landfill sitting in Kurdistan Province, western Iran

The evaluation of a hazardous waste disposal site is a complicated process because it requires data from diverse social and environmental fields. These data often involve processing of a significant amount of spatial information which can be used by GIS as an important tool for land use suitability analysis. This paper presents a multi-criteria decision analysis alongside with a geospatial analysis for the selection of hazardous waste landfill sites in Kurdistan Province, western Iran. The study employs a two-stage analysis to provide a spatial decision support system for hazardous waste management in a typically under developed region. The purpose of GIS was to perform an initial screening process to eliminate unsuitable land followed by utilization of a multi-criteria decision analysis (MCDA) to identify the most suitable sites using the information provided by the regional experts with reference to new chosen criteria. Using 21 exclusionary criteria, as input layers, masked maps were prepared. Creating various intermediate or analysis map layers a final overlay map was obtained representing areas for hazardous waste landfill sites. In order to evaluate different landfill sites produced by the overlaying a landfill suitability index system was developed representing cumulative effects of relative importance (weights) and suitability values of 14 non-exclusionary criteria including several criteria resulting from field observation. Using this suitability index 15 different sites were visited and based on the numerical evaluation provided by MCDA most suitable sites were determined.     

Public opinion and awareness towards MSW and separate collection programmes: A sociological procedure for selecting areas and citizens with a low level of knowledge

The principal aim of this study was to define and apply a procedure based on a structured questionnaire survey useful to analyze the people’s environmental knowledge in order to select the areas and age groups with a low level of knowledge in a municipality (in Southern Italy) and, therefore, suggest a specific educational campaign for each. The detailed sampling procedure made it possible to carry out a meticulous statistical analysis of the results. The youngest and oldest people showed the lowest level of awareness for each district. A high level of education did not necessarily imply a high level of environmental awareness as well as a greater acceptance of MSW facilities. The satisfaction level of the recycling program was higher amongst the oldest age group. All the citizens in the several areas were unanimous in pointing out the presence of dirt in the street as the main shortcoming of the bring separate collection program. Only the youngest age group self-criticised, considering that they revealed a low level of participation to the separate collection program. While, the oldest people retaining them less influential, claimed that the citizens were not responsible for the failure of the separate collection program. The prevailing opinion of the sample was that people protested against the construction of waste facilities because they were not well-informed, with the most significant opinion of all the age subdivisions being that incineration is a hazardous treatment. The presence of criminal organizations was indicated as the main reason why the Campania Region suffers a serious solid waste emergency. While, the percentage of people pointing their finger at politicians increases with the average age of the respondents with there being a very strong correlation (r² = 0.9903).     

System performance assessment of final repository for radioactive wastes using first-order reliability method

When a final option for radioactive waste is determined, it is necessary to demonstrate compliance of disposal system chosen with relevant regulations. Considering the large number of physical and chemical factors involved, the complexity of their interrelationships, and long time periods, a system approach is required. A stochastic analysis is also needed to ensure that these regulatory criteria can be met with confidence. Among a variety of models developed to treat the effect of uncertainty on system performance, the first-order reliability method is suggested as an attractive tool to stochastic problems incorporating any amount of probabilistic information. Based on the first-order approximation, the method can give a probability of failure against a preselected target value, and information concerning the sensitivity of the outcome to variations in the input random variables and their statistical moments. In this paper, for reliable prediction of the performance of repository for radioactive wastes, first-order reliability method is applied in treating the parameter uncertainties of predictive models. First, a thickness of canister corrosion and breach time of canister is calculated using a uniform corrosion model, combined with the diffusional transport modeling of radionuclides in the backfill material. Second, a fractional release rate for each radionuclide is derived from the evaluation of the performance of a waste package which consists of canister and backfill material. Third, a cumulative release rate at the accessible environment is obtained by geosphere transport modeling with the source term given as a fractional release rate. The proposed first-order reliability method can be applicable to a full range of problems occurring in radioactive waste management and beyond.     

Evaluating a Protocol for Testing a Fire-Resistant Oil-Spill Containment Boom

Most response plans for in situ burning of oil at sea call for the use of a fire-resistant boom to contain the oil during a burn. Presently, there is no standard method for the user of a fire-resistant boom to evaluate the anticipated performance of different booms. The ASTM F-20 committee has developed a draft standard, “Standard Guide for in situ Burning of Oil Spills on Water: Fire-Resistant Containment Boom”; however, the draft provides only general guidelines and does not specify the details of the test procedure. Utilizing the guidelines in the draft standard, a series of experiments were conducted to evaluate a protocol for testing the ability of fire-resistant booms to withstand both fire and waves.