Using a Set of Strategic Indicator Systems as a Decision-making Support Implement for Establishing a Recycling-oriented Society - A Taiwanese Case Study (16 pp)

Background Scope and Aims. To realize the vision of sustainable development (SD) originating from the ‘only one earth’ philosophy, and to integrate the conceptions of ecology and sustainability into the planning and decision-making criteria of urban growth management, the establishment of a recycling-oriented society (ROS) is essential. However, before the above intention can be achieved, it is indispensable to develop a system of strategic indicators for supporting a radical reformation of the urban development plan. Therefore, this study, based on the conception of the new urban development pattern ROS, attempted to carefully choose a sample city in Taiwan for launching a preliminary case study, and furthermore designed and proposed a concise and strategy-oriented assessment indicator system termed ROSAIS. ROSAIS, on the one hand, can act as a compass for understanding resource using efficiency and recycling status during city development and, on the other hand, can serve as an implement supporting decision-making for ROS construction.Methods According to the definition and spirit of ROS, the structure of ROSAIS should clearly represent the relationship between resources and environment in human activities. The eco-efficiency indicator system (EEIS) and environmental symbiosis indicator system (ESIS) can be considered two key sub-indicator systems, and are the necessary components of ROSAIS. EEIS chooses the dominant production sectors in urban economic activities to calculate their eco-efficiency (EE). Separately, for obtaining a consensus regarding the framework of ESIS, the questionnaire approaches and expert consultation, together with the research experience and foundation of current relevant studies and indicator systems, are applied when crucial resource and environmental issues and respective indicators are selected.Results and Discussion The calculation results of EEIS in this case study indicated that among the three dominant production activities (agricultural, fishery, and animal husbandry sector) the fishery sector has the highest EE, which indicates that the fishery activities and resources significantly influence the sustainability of the economic-environmental system of the sample city. Furthermore, according to a consensus achieved in ESIS, local green spaces, resource recovery, energy consumption pattern change, freshwater conservation and greenhouse effect abatement were considered as the five crucial issues influencing how the case study city can develop into an ES-city. The rate of local green spaces, resource recycling, freshwater conservation and the rate of reduction of nonrenewable energy use as well as carbon dioxide (CO2) emissions were used to evaluate the above five issues.Conclusion This case study is unparalleled in Taiwan. Even in Japan, where ROS legislation has been implemented, this kind of study remains in the preliminary stages. Furthermore, when communicating the indicator results, it is essential to provide the context and countermeasures of the crucial issues that are faced. The two sub-indicator systems proposed in this case study could comply completely with the above-mentioned requirements. For example, the EEIS provides information for achieving a balance between environmental burden and economic benefits among dominant production sectors; the ESIS provides information for setting strategies for overcoming the crucial issues faced. Recommendation and Outlook This study recommends that urban planers should consider the construction of the corresponding strategic indicator system to be indispensable, and makes further use of the indicator results related to the environmental education of residents for identifying and promoting participation with ROS, and turning them into implements for supporting urban SD decision-making. Furthermore, a successful indicator system depends on data availability and quality. This study recommends that urban planers should pay considerable attention to constructing relevant data collection channels, databases and the data quality.     

Towards sets of hazardous waste indicators. Essential tools for modern industrial management

Decision-makers require useful tools, such as indicators, to help them make environmentally sound decisions leading to effective management of hazardous wastes. Four hazardous waste indicators are being tested for such a purpose by several countries within the Sustainable Development Indicator Programme of the United Nations Commission for Sustainable Development. However, these indicators only address the 'down-stream' end-of-pipe industrial situation. More creative thinking is clearly needed to develop a wider range of indicators that not only reflects all aspects of industrial production that generates hazardous waste but considers socio-economic implications of the waste as well. Sets of useful and innovative indicators are proposed that could be applied to the emerging paradigm shift away from conventional end-of-pipe management actions and towards preventive strategies that are being increasingly adopted by industry often in association with local and national governments. A methodological and conceptual framework for the development of a core-set of hazardous waste indicators has been developed. Some of the indicator sets outlined quantify preventive waste management strategies (including indicators for cleaner production, hazardous waste reduction/minimization and life cycle analysis), whilst other sets address proactive strategies (including changes in production and consumption patterns, eco-efficiency, eco-intensity and resource productivity). Indicators for quantifying transport of hazardous wastes are also described. It was concluded that a number of the indicators proposed could now be usefully implemented as management tools using existing industrial and economic data. As cleaner production technologies and waste minimization approaches are more widely deployed, and industry integrates environmental concerns at all levels of decision-making, it is expected that the necessary data for construction of the remaining indicators will soon become available.     

Oxidative transformation of polybrominated diphenyl ether congeners (PBDEs) and of hydroxylated PBDEs (OH-PBDEs)

BACKGROUND, AIM, AND SCOPE: The historical and widespread use of polybrominated diphenyl ethers (PBDEs) as flame retardants in consumer products worldwide has caused PBDEs to now be regarded as pervasive environmental contaminants. Most recently, hydroxylated PBDEs (OH-PBDEs) and methoxylated PBDEs (MeO-PBDEs) have emerged as environmentally relevant due to reports of their natural production and metabolism. An important parameter for assessing the environmental impact of a chemical substance is persistence. By formulating the concept that persistence is the result of the substance's physicochemical properties and chemical reactivity, Green and Bergman have proposed a new methodology to determine the inherent persistence of a chemical. If persistence could be predicted by straightforward methods, substances with this quality could be screened out before large-scale production/manufacturing begins. To provide data to implement this concept, we have developed new methodologies to study chemical transformations through photolysis; hydrolysis, substitution, and elimination; and via oxidation. This study has focused on adapting an oxidative reaction method to be applicable to non-water soluble organic pollutants. MATERIALS AND METHODS: PBDEs and one MeO-PBDE were dissolved in tetrahydrofuran/methanol and then diluted in alkaline water. The OH-PBDEs were dissolved in alkaline water prior to reaction. The oxidation degradation reaction was performed at 50 degrees C using potassium permanganate as described elsewhere. The pH was maintained at 7.6 with disodium hydrogen phosphate and barium hydrogen phosphate, the latter also serving as a trapping agent for manganate ions. The oxidation reactions were monitored by high-performance liquid chromatography and reaction rates were calculated. RESULTS: The OH-PBDEs have very fast oxidative transformation rates compared to the PBDEs. The reaction rates seem to be primarily dependent on substitution pattern of the pi-electron-donating bromine substituents and of bromine content. There are indications that further reactions of OH-PBDEs, e.g., methylation to the MeO-PBDEs, decrease the oxidation rates, and thereby generate more persistent substances. DISCUSSION: The resistance of PBDEs to oxidation, a major degradation pathway in air, should be further investigated, since these compounds do undergo long range transport. With slight modifications, the original method has been adapted to include a larger variety of chemical substances, and preliminary data are now available on the oxidative transformation rates for PBDEs and of OH-PBDEs. CONCLUSIONS: The original oxidation degradation method can now include non-water soluble compounds. This modification, using low concentrations of test chemicals, allows us to measure oxidative transformation rates, for some of the lower brominated DEs, data that can be used to assess their persistence in future model calculations. Oxidative transformation rates for PBDEs are slow compared to those for the OH-PBDEs. This suggests that OH-PBDEs, when released into the environment, undergo faster oxidative metabolism and excretion than the PBDEs. RECOMMENDATIONS AND PERSPECTIVES: To evaluate the modified method, more degradation reactions with non-water soluble compounds should be investigated. Recent studies show that OH-PBDEs are present in rats and in humans and, because of their activity as endocrine disruptors, determining their subsequent environmental fate is of importance. The resistance of PBDEs to oxidative degradation should be acknowledged as of possible future concern. Several other compound classes (such as polychlorinated biphenyls (PCBs), hydroxylated polychlorinated biphenyls (OH-PCBs), and pharmaceuticals) need to be subjected to this screening method to increase the database of transformation rates that can be used with this model.     

Extrapolating phosphorus production to estimate resource reserves

Various indicators of resource scarcity and methods for extrapolating resource availability are examined for phosphorus. These include resource lifetime, and trends in resource price, ore grade and discovery rates, and Hubbert curve extrapolation. Several of these indicate increasing scarcity of phosphate resources. Calculated resource lifetime is subject to a number of caveats such as unanticipated future changes in resource discovery, mining and beneficiation technology, population growth or per-capita demand. Thus it should be used only as a rough planning index or as a relative indicator of potential scarcity. This paper examines the uncertainty in one method for estimating available resources from historical production data. The confidence intervals for the parameters and predictions of the Hubbert curves are computed as they relate to the amount of information available. These show that Hubbert-type extrapolations are not robust for predicting the ultimately recoverable reserves or year of peak production of phosphate rock. Previous successes of the Hubbert curve are for cases in which there exist alternative resources, which is not the situation for phosphate. It is suggested that data other than historical production, such as population growth, identified resources and economic factors, should be included in making such forecasts.     

Indicators for Chemicals: Sources,impacts and policy performance (5 pp)

Background Different types of indicators have been developed to describe the impact of chemicals on society and environment. Due to the high number of substances and their different types of use, most of these indicators are directed to specific areas of interest – regarding workplace safety, environmental health or consumer health. They address a specific subset of chemicals and can be used for monitoring enterprise-specific, national or international management measures. Main Features A survey of existing indicators for chemicals has shown that indicators already exist for a remarkable number of problem fields. As soon as the release and the environmental fate of chemicals are taken into account, the complexity of the approaches increases considerably. The distinction between indicators for drivers, pressures, state, impacts and responses, as proposed by the European Environmental Agency, supports the identification of proper indicators for a specific type of problem. Discussion and Conclusions. No single indicator exists which is able to cover the whole range of chemicals and their applications. Several indicator approaches cover at least a subset of the most relevant substances. If they are intended to be used for European monitoring, robust data must be provided by EU Member States. Chemicals in enterprises (ancillary inputs as well as process chemicals) are an important element of in-plant material flow management – in terms of occupational safety and health as well as environmental protection. Existing indicators for hazardous chemicals can be a valuable tool for process and product refinement regarding hazardous chemicals, especially for enterprises. Outlook Indicators for production and impact of chemicals, as well as policy performance indicators, are essential elements in order to monitor the management of chemicals. They have to be established for the national and for the EU level.     

Resource recycling through artificial lightweight aggregates from sewage sludge and derived ash using boric acid flux to lower co-melting temperature

This study focuses on artificial lightweight aggregates (ALWAs) formed from sewage sludge and ash at lowered co-melting temperatures using boric acid as the fluxing agent. The weight percentages of boric acid in the conditioned mixtures of sludge and ash were 13% and 22%, respectively. The ALWA derived from sewage sludge was synthesized under the following conditions: preheating at 400 °C 0.5 hr and a sintering temperature of 850 °C 1 hr. The analytical results of water adsorption, bulk density, apparent porosity, and compressive strength were 3.88%, 1.05 g/cm³, 3.93%, and 29.7 MPa, respectively. Scanning electron microscope (SEM) images of the ALWA show that the trends in water adsorption and apparent porosity were opposite to those of bulk density. This was due to the inner pores being sealed off by lower-melting-point material at the aggregates' surface. In the case of ash-derived aggregates, water adsorption, bulk density, apparent porosity, and compressive strength were 0.82%, 0.91 g/cm³, 0.82%, and 28.0 MPa, respectively. Both the sludge- and ash-derived aggregates meet the legal standards for ignition loss and soundness in Taiwan for construction or heat insulation materials.

Implications Artificial lightweight aggregates (ALWAs) could be synthesized from sewage sludge and derived ash. In this study, co-melting technology of low temperature was applied with boric acid as a fluxing agent and the formation temperature of glass phase was decreased to 900 °C. Both aggregates derived from sludge and ash meet regulatory standards of ignition loss and soundness in Taiwan for construction or heat insulation material.     

A Call for Urgent Monitoring of Food and Water Security Based on Relevant Indicators for the Arctic

This perspective paper argues for an urgent need to monitor a set of 12 concrete, measurable indicators of food and water security in the Arctic over time. Such a quantitative indicator approach may be viewed as representing a reductionist rather than a holistic perspective, but is nevertheless necessary for actually knowing what reality aspects to monitor in order to accurately understand, quantify, and be able to project critical changes to food and water security of both indigenous and non-indigenous people in the Arctic. More relevant indicators may be developed in the future, taking us further toward reconciliation between reductionist and holistic approaches to change assessment and understanding. However, the potential of such further development to improved holistic change assessment is not an argument not to urgently start to monitor and quantify the changes in food and water security indicators that are immediately available and adequate for the Arctic context.     

The measurement of water scarcity: Defining a meaningful indicator

Metrics of water scarcity and stress have evolved over the last three decades from simple threshold indicators to holistic measures characterising human environments and freshwater sustainability. Metrics commonly estimate renewable freshwater resources using mean annual river runoff, which masks hydrological variability, and quantify subjectively socio-economic conditions characterising adaptive capacity. There is a marked absence of research evaluating whether these metrics of water scarcity are meaningful. We argue that measurement of water scarcity (1) be redefined physically in terms of the freshwater storage required to address imbalances in intra- and inter-annual fluxes of freshwater supply and demand; (2) abandons subjective quantifications of human environments and (3) be used to inform participatory decision-making processes that explore a wide range of options for addressing freshwater storage requirements beyond dams that include use of renewable groundwater, soil water and trading in virtual water. Further, we outline a conceptual framework redefining water scarcity in terms of freshwater storage.     

The identification of readily bioavailable pollutants in lake shkodra/skadar using semipermeable membrane devices (SPMDs), bioassays and chemical analysis

GOAL, SCOPE AND BACKGROUND: Lake Shkodra/Skadar is the largest lake in the Balkans region and located on the border between Albania to the south and Montenegro to the north. Because of the wide range of endemic, rare or endangered plant and animal species it supports, Lake Shkodra/Skadar and its extensive associated wetlands are internationally recognised as a site of significance and importance (Ramsar site). In recent years, social and economic changes in both Albania and Montenegro have lead to unprecedented levels of urban and industrial effluent entering the lake. Of particular concern is the increasing input of toxic hydrophobic organic pollutants (HOPs) into the lake and the degree to which these compounds are available for uptake by aquatic biota. Semipermeable membrane devices (SPMDs) have been shown to sample the readily bioavailable fraction (dissolved phase) of waterborne HOPs and in doing so provide relevant data for exposure assessment. The aim of the current study was to use SPMD-based sampling in conjunction with appropriate bioassays and chemical analysis to identify readily bioavailable HOPs in the lake. METHODS: SPMDs were constructed and deployed at three sites in the Albanian sector and three sites in the Montenegrin sector of Lake Skadar/Shkodra for 21 days. Following the dialytic recovery of target analytes and size exclusion chromatographic clean-up, aliquots of SPMD samples were subjected to GC-MS scan analysis for major components, GC-MS SIM analysis for 16 priority pollutant polycyclic aromatic hydrocarbons (PP-PAHs) and assayed for EROD-inducing, estrogenic and mutagenic potential using rainbow trout liver cells (RTL-W1), the yeast estrogen screen (YES) and the Ames Test, respectively. RESULTS AND DISCUSSION: A total of 39 compounds were tentatively identified in SPMD samples from the six sampling sites. Alkylated PAHs were the most abundant and ubiquitous compounds present along with various sterols and sterol derivatives. Numerous other compounds remain unidentified. 15 of the 16 targeted PP-PAHs were present in samples from one or more of the sampling sites indicating these compounds are both readily bioavailable and widely distributed in Lake Shkodra/Skadar. Total PP-PAH concentrations ranged between 3991 ng/SPMD and 10695 ng/SPMD. Bioassays carried out on SPMD samples revealed significant EROD-inducing and estrogenic potential at five of the six sampling sites indicating toxicologically relevant compounds are readily available for uptake by resident aquatic biota. EROD-inducing potential was positively correlated with targeted PP-PAH concentration (r2 = 0.74). However, comparison of bioassay- and analytically-derived toxicity equivalents revealed targeted PP-PAHs were responsible for less than 0.06% of the total EROD-inducing potential. CONCLUSIONS AND OUTLOOK: The combination of SPMD-based sampling with appropriate bioassays and chemical analysis provided an effective tool for the identification of environmentally relevant waterborne pollutants in Lake Shkodra/Skadar. Our results show that toxicologically relevant HOPs including EROD-inducing and potentially estrogenic compounds are widely distributed in the lake and readily available for uptake by aquatic biota. Our results also suggest that alkylated PAHs rather than parent compounds may be of greater toxicological relevance in the lake. As anthropogenic influences continue to increase, SPMD-based sampling is expected to play a central role in future research concerned with the identification, monitoring and assessment of the risk posed by HOPs to Lake Shkodra/Skadar's aquatic biota.     

工业循环经济发展区域分异研究--以江苏省为例

依据工业循环经济发展的基本原则,构建了包括产业及社会发展、资源减量、循环利用、污染减排、资源与环境安全五类指标在内的区域工业循环经济发展评价指标体系.运用AHP(层次分析法)方法,测算了指标权重,并以江苏省13个地级市为例进行了研究.用2003年的数据,对13个地级市的工业循环经济发展状况进行了评价.研究结果表明,江苏省13个地级市的工业循环经济发展水平可以分为四个层次,第一层次(水平良好)的城市为无锡、苏州、常州;第二层次(水平中上)的城市为盐城、南通、泰州;第三层次(水平中等)的城市为扬州、镇江、徐州、南京、连云港;第四层次(水平较差)的城市为淮安、宿迁.从总体上看,南部好于北部,东部好于西部,沿江沿海地区要好于内陆地区,靠近工业产业带的地区好于远离工业产业带的地区.     

Identification of Pollution Source of Cadmium in Soil. Application of Material Flow Analysis and A Case Study in Taiwan (11 pp)

Background Since the 1970s, at least 200 hectares (ha) of farmland has been polluted by the heavy metal cadmium (Cd).Consequently, the Cd pollution has led to contaminate the rice production and caused acute social panic. According to the recent investigation results performed by the Taiwan Environmental Protection Administration (TEPA), it is indicated that most of the Cd pollution incidents in Taiwan resulted from the wastewater discharge of stearate Cd factories. To prevent the Cd pollution incidents from spreading, the TEPA has either forced these factories to close down or assisted them in improving their production processes since the 1980s. Unfortunately, accidental incidents of Cd pollution still emerge in an endless stream, despite the strict governmental controls placed on these questionable factories. Whether this pollution has resulted from undetected or hidden pollution sources stemming from two decades ago or comes from some new source, will be an outstanding issue. Therefore, this study attempts to identify the pollution sources of Cd in soil in Taiwan as well as to find the solution to the above-mentioned, outstanding issue by way of a methodology termed Material Flow Analysis (MFA). Method logy. The MFA has proved to be a useful tool on providing quantitative information of the flow of substances through an economic to an environmental system. Based upon the supply-and-demand theory of MFA, researchers have successfully conducted an overview of the use of materials in many industries, the construction industry being one of these. Therefore, this study tries to establish a set of analytical processes by way of MFA for identifying the pollution source of Cd in soil in Taiwan. In addition, the spirit of Life Cycle Analysis (LCA) technique was also employed to identify the materials, and products should be ignored as a crucial pollution source in this study. Results and Discussion According to the MFA methodology applied in this study and on the basis of related studies performed by Taiwanese governmental authorities, we arrive at the following analysis results: (1) the total amount of Cd from the economic perspective of material and product flow was approximately 441.2 tons; (2) the wastewater directly discharged into irrigation water can be concluded to be the major pollution route of Cd in farmland soil in Taiwan; (3) material plastic stabilizer (cadmium oxide, CdO), Zn-Pd compounds and Cu compounds should be the crucial pollution sources to contaminate environment through the route of wastewater in Cd flow analysis; (4) the crucial pollution sources to contaminate environment through the route of wastewater in Cd flow analysis were five factories, Coin, Jili, Taiwan Dye, Guangzheng and Mingguan, and they were all categorized as stearate Cd industries; (5) the typical source of the Cd pollution in soil in Changhua County through the pollution route of wastewater should be the metal surfacing process industries. Conclusions This study proved that MFA can be a good tool for identifying Cd flow as well as for recognizing the crux of the problem concerning incidents of Cd pollution. This study led to the conclusion that the causal relationship between farmland pollution caused by Cd and stearate Cd factories in Taiwan seemed quite close by way of MFA methodology. In addition, this study also found that the wastewater discharged from a single metal surfacing process factory will not cause remarkable farmland pollution. However, the wastewater simultaneously discharged from a group of pollution factories can result in a significant pollution incident. Recommendations and Outlook This case study is only a small contribution to the understanding of the toxic material flow related to Cd in the environment. This study recommends that Taiwanese governmental authorities should not deal with problems on an ad hoc basis, but should instead deal with Cd pollution problems overall employing control measures. Finally, the more accurate information or data we can collect, the more reliable results we can identify. Therefore, the quality and quantity of related data used in this MFA model should be closely scrutinized in order to ensure the most correct and comprehensive investigation on the toxic material flow.     

Development and field validation of an indicator to assess the relative mobility and risk of pesticides in the Lourens River catchment,South Africa

A GIS based pesticide risk indicator that integrates exposure variables (i.e. pesticide application, geographic, physicochemical and crop data) and toxicity endpoints (using species sensitivity distributions) was developed to estimate the Predicted Relative Exposure (PREX) and Predicted Relative Risk (PRRI) of applied pesticides to aquatic ecosystem health in the Lourens River catchment, Western Cape, South Africa. Samples were collected weekly at five sites from the beginning of the spraying season (October) till the beginning of the rainy season (April) and were semi quantitatively analysed for relevant pesticides applied according to the local farmers spraying programme. Monitoring data indicate that physicochemical data obtained from international databases are reliable indicators of pesticide behaviour in the Western Cape of South Africa. Sensitivity analysis identified K_OC as the most important parameter influencing predictions of pesticide loading derived from runoff. A comparison to monitoring data showed that the PREX successfully identified hotspot sites, gave a reasonable estimation of the relative contamination potential of different pesticides at a site and identified important routes of exposure (i.e. runoff or spray drift) of different pesticides at different sites. All pesticides detected during a monitored runoff event, were indicated as being more associated with runoff than spray drift by the PREX. The PRRI identified azinphos-methyl and chlorpyrifos as high risk pesticides towards the aquatic ecosystem. These results contribute to providing increased confidence in the use of risk indicator applications and, in particular, could lead to improved utilisation of limited resources for monitoring and management in resource constrained countries.     

Impacts of Meteorological Factors on PM10: Artificial Neural Networks (ANN) and Multiple Linear Regression (MLR) Approaches

In this study, prediction capacities of multi-linear regression (MLR) and artificial neural networks (ANN) onto coarse particulate matter (PM₁₀) concentrations were investigated. Different meteorological factors on particulate pollution were chosen for operating variables in the model analyses. Two different regions (urban and industrial) were identified in the region of Kocaeli, Turkey. All data sets were obtained from air quality monitoring network of the Ministry of Environment and Urban Planning, and 120 data sets were used in the MLR and ANN models. Regression equations explained the effects of the meteorological factors in MLR analyses. In the ANN model, backpropagation network with two hidden layers has achieved the best prediction efficiency. Determination coefficients and error values were examined for each model. ANN models displayed more accurate results compared to MLR.     

Applying the three R’s: Reduce,reuse, and recycle in the chemical industry

Pollution prevention (P2) assessment was conducted by applying the three R’s, reduce, reuse, and recycle, in a chemical industry for the purpose of reducing the amount of wastewater generated, reusing paint wastewater in the manufacture of cement bricks, recycling cooling water, and improving water usage efficiency. The results of this study showed that the annual wastewater flow generated from the paint manufacturing can be reduced from 1,100 m³ to 488.4 m³ (44.4% reduction) when a high-pressure hose is used. Two mixtures were prepared. The first mixture (A) contains cement, coarse aggregate, fine aggregate, Addicrete BVF, and clean water. The second mixture (B) contains the same components used in the first mixture, except that paint wastewater was used instead of the clean water. The prepared samples were tested for water absorption, toxicity, reactivity, compressive strength, ignitability, and corrosion. The tests results indicated that using paint wastewater in the manufacture of the cement bricks improved the mechanical properties of the bricks. The toxicity test results showed that the metals concentration in the bricks did not exceed the U.S. EPA limits. This company achieved the goal of zero liquid discharge (ZLD), especially after recycling 2,800 m³ of cooling water. The total annual saving could reach $42,570 with a payback period of 41 days.

Implications: This research focused on improving the water usage efficiency, reducing the quantity of wastewater generated, and potentially reusing wastewater in the manufacture of cement bricks. Reusing paint wastewater in the manufacture of the bricks prevents the hazardous pollutants in the wastewater (calcium carbonate, styrene acrylic resins, colored pigments, and titanium dioxide) from entering and polluting the surface water and the environment. We think that this paper will help to find the most efficient and cost-effective way to manage paint wastewater and conserve fresh water resources. We also believe that this paper provides a rich agenda for future research in water conservation and industrial wastewater reuse subjects.     

Resource recycling through artificial lightweight aggregates from sewage sludge and derived ash using boric acid flux to lower co-melting temperature

This study focuses on artificial lightweight aggregates (ALWAs) formed from sewage sludge and ash at lowered co-melting temperatures using boric acid as the fluxing agent. The weight percentages of boric acid in the conditioned mixtures of sludge and ash were 13% and 22%, respectively. The ALWA derived from sewage sludge was synthesized under the following conditions: preheating at 400 degrees C 0.5 hr and a sintering temperature of 850 degrees C 1 hr. The analytical results of water adsorption, bulk density, apparent porosity, and compressive strength were 3.88%, 1.05 g/cm3, 3.93%, and 29.7 MPa, respectively. Scanning electron microscope (SEM) images of the ALWA show that the trends in water adsorption and apparent porosity were opposite to those of bulk density. This was due to the inner pores being sealed off by lower-melting-point material at the aggregates'surface. In the case of ash-derived aggregates, water adsorption, bulk density, apparent porosity, and compressive strength were 0.82%, 0.91 g/cm3, 0.82%, and 28.0 MPa, respectively. Both the sludge- and ash-derived aggregates meet the legal standards for ignition loss and soundness in Taiwan for construction or heat insulation materials.     

Characterising the hydrological regime of an ungauged temporary river system: a case study

Temporary streams are characterised by specific hydrological regimes, which influence ecosystem processes, groundwater and surface water interactions, sediment regime, nutrient delivery, water quality and ecological status. This paper presents a methodology to characterise and classify the regime of a temporary river in Southern Italy based on hydrological indicators (HIs) computed with long-term daily flow records. By using a principal component analysis (PCA), a set of non-redundant indices were identified describing the main characteristics of the hydrological regime in the study area. The indicators identified were the annual maximum 30- and 90-day mean (DH4 and DH5), the number of zero flow days (DL6), flow permanence (MF) and the 6-month seasonal predictability of dry periods (SD6). A methodology was also tested to estimate selected HIs in ungauged river reaches. Watershed characteristics such as catchment area, gauging station elevation, mean watershed slope, mean annual rainfall, land use, soil hydraulic conductivity and available water content were derived for each site. Selected indicators were then linked to the catchment characteristics using a regression analysis. Finally, MF and SD6 were used to classify the river reaches on the basis of their degree of intermittency. The methodology presented in this paper constitutes a useful tool for ecologists and water resource managers in the Water Framework Directive implementation process, which requires a characterisation of the hydrological regime and a ‘river type’ classification for all water bodies.     

The impact of recycled coarse aggregates obtained from waste concretes on lightweight pervious concrete properties

Environmental Science and Pollution Research - Significant environmental damage can result from the use of natural resources such as cement, aggregate, and water in concrete production. Thus, more...     

Environmental sustainability and the integration of different methods for its assessment

The aim of this paper is to propose a research framework, based on the joint use of three widely used methods: EMergy Evaluation (EME), Ecological Footprint Analysis (EFA) and Greenhouse Gas Inventory (GHGI), that are applied to assess the environmental sustainability of a region. The results of application of these methods to several Italian Provinces enabled us to compare their sustainability, and to test the methods with respect to sustainability requirements at local and global level. The outcomes suggest that the proposed framework provides an organic evaluation of regional systems based on key aspects, such as resources depletion, consumption patterns, waste production and absorption.     

Breakthrough Curves Characterization and Identification of an Unknown Pollution Source in Groundwater System Using an Artificial Neural Network (ANN)

Contamination of groundwater constrains its uses and poses a serious threat to the environment. Once groundwater is contaminated, the cleanup may be difficult and expensive. Identification of unknown pollution sources is the first step toward adopting any remediation strategy. The proposed methodology exploits the capability of a universal function approximation by a feed-forward multilayer artificial neural network (ANN) to identify the sources in terms of its location, magnitudes, and duration of activity. The back-propagation algorithm is utilized for training the ANN to identify the source characteristics based on simulated concentration data at specified observation locations in the aquifer. Uniform random generation and the Latin hypercube sampling method of random generation are used to generate temporal varying source fluxes. These source fluxes are used in groundwater flow and the transport simulation model to generate necessary data for the ANN model-building processes. Breakthrough curves obtained for the specified pollution scenario are characterized by different methods. The characterized breakthrough curves parameters serve as inputs to ANN model. Unknown pollution source characteristics are outputs for ANN model. Experimentation is also performed with different number of training and testing patterns. In addition, the effects of measurement errors in concentration measurements values are used to show the robustness of ANN based methodology for source identification in case of erroneous data.     

Possible reuse of Egyptian controlled cement dust

Possibilities for the reuse of controlled cement dust, collected from the hopper of the electrostatic precipitators installed on the different cement kilns of two of the three biggest companies for Portland cement production located to the south of Cairo, have been investigated. Twenty-one factors representing the physical properties and mineral and chemical composition of the cement dust were estimated and discussed. The results have been compared with the corresponding figures of three Portland cement companies in the United Arab Emirates and also with the British Standard Requirements of ordinary Portland cement. The study found that the cement dust can be reused after some feasible treatments, such as increasing the fineness and tricalcium silicate ratio and decreasing its alkalinity. Consequently, in this circumstance, pollution prevention at source is proving to be a boon as it can not only bring down pollution levels but also add to the companies' profits through efficient use of resources.