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A PROPOSED ACCOUNTING FRAMEWORK FOR REDUCING WATER POLLUTION AND WASTE MANAGEMENT: AN APPLIED STUDY ON A SAMPLE OF THE CEMENT SECTOR IN EGYPT
Latest (Most Recent: March 2024 - 20 March 2025) Citations to Some of Hilmi S. Salem’s Publications (PhD, MSc, BSc – Prof. Dr.)
Cited by academicians, research scientists, researchers, and postgraduate students at universities, research institutions, and companies in the following countries:
Iran, Pakistan, Saudi Arabia, United States of America (USA), Japan, Vietnam, Taiwan, China, Palestine, Turkey, Qatar, United Arab Emirates (UAE), India, Australia, Maldives, Mozambique, Philippines, Croatia, Oman, Malaysia, Ethiopia, Sudan, Iraq, Mexico, Nigeria, Brazil, Algeria, Egypt, Czech Republic, Jordan, Portugal, Norway, Ghana, United Kingdom (UK), Germany, Austria, Thailand, Indonesia, Italy, Botswana, South Africa, Canada, Russia
A few Examples of Hilmi S. Salem’s Published Research in: Civil, Environmental, and Petroleum Engineering; Aquifer and Reservoir Characterization; Renewable (Solar and Wind Energies and Technologies); Industrial Air Pollution; Water Strategies and Water-Energy-Food (WEF) Nexus; Agriculture and Irrigation; Sustainable Water Resources’ Management (Fresh Water and wastewater), Energy Efficiency; Women, Water, Agriculture, and Development, Particularly in Rural Areas; Drought, Pest Management, Biology, Biochemistry, and Biotechnology; Climate Change Impacts, and Mitigation and Adaptation Mechanisms; Carbon and Ecological Footprints; Mining; Cancer, Medical, and Health Research; Computer and Machine Learning; Conflicts and International Law; Sustainable Development; and the United Nations’ Sustainable Development Goals (UN SDGs)
Egypt has started constructing its New Administrative Capital since 2015. The new capital was designed to meet smart city standards, which presents a challenge for businesses to make the optimum business decisions given the set budget for such a project. As a result, reaching the optimum solution for allocating the needed materials to each building became important. Many researchers have considered the theory of constraints in their studies to determine the optimum product mix. Frequently, research considers the target of profit maximization to reach the optimum solution with one scenario. In this paper, we aim to solve the problem of product mix in cement production, which organizations face. The problem was formulated based on a case study in Egypt with two linear programming approaches. For this problem, many scenarios were presented under the consideration of two aspects, which are resource utilization and productivity. Data visualization was used in this paper to simplify the procedure of decision-making. Also, a dashboard web application was made for the decision makers to make it easier to create, analyze, and see different business scenarios.
In their recent paper in ERL, ‘Egypt’s water budget deficit and suggested mitigation policies for the Grand Ethiopian Renaissance Dam (GERD) filling scenarios,’ Heggy et al (2021 Environ. Res. Lett. 16 074022) paint an alarming picture of the water deficits and economic impacts for Egypt that will occur as a consequence of the filling of the GERD. Their median estimate is that filling the GERD will result in a water deficit in Egypt of ∼31 billion m ³ yr ⁻¹ . They estimate that under a rapid filling of the GERD over 3 yr, the Egyptian economy would lose US$51 billion and 4.74 million jobs, such that in 2024, Gross Domestic Product (GDP) per capita would be 6% lower than under a counterfactual without the GERD. These and other numbers in Heggy et al (2021 Environ. Res. Lett. 16 074022) article are inconsistent with the best scientific and economic knowledge of the Nile Basin and are not a dependable source of information for policy-makers or the general public. In this response to Heggy et al (2021 Environ. Res. Lett. 16 074022) we draw on high quality peer-reviewed literature and appropriate modeling methods to identify and analyze many flaws in their article, which include (a) not accounting for the current storage level in the High Aswan Dam reservoir (b) inappropriately using a mass-balance approach that does not account for the Nile’s hydrology or how water is managed in Egypt, Sudan and Ethiopia; (c) extreme and unfounded assumptions of reservoir seepage losses from the GERD; and (d) calculations of the economic implications for Egypt during the period of reservoir filling which are based on unfounded assumptions. In contrast to Heggy et al (2021 Environ. Res. Lett. 16 074022), robust scientific analysis has demonstrated that, whilst there is a risk of water shortages in Egypt if a severe drought were to occur at the same time as the GERD reservoir is filling, there is minimal risk of additional water shortages in Egypt during the filling period if flows in the Blue Nile are normal or above average. Moreover, the residual risks could be mitigated by effective and collaborative water management, should a drought occur.
The cement industry though the backbone of modern construction and civilization is associated with the emission of diverse atmospheric pollutants with numerous attendant effects on the balance of ecosystem, human and environmental health, and the global climate in general. Despite the huge advantages derivable from the industry, exploitation and processing of cement must be done in a sustainable manner to prevent irreversible damage to human, animal and vegetation health as well as the environment. Research papers were reviewed from different databases like ScienceDirect, ResearchGate, Google scholar, and Scopus the chief air pollutants are the inorganic gaseous emissions (carbon dioxide (CO2), carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulphur SO2), particulates of various size ranges and elemental emissions. The present study carries out holistic review of the cement production process with a view to identifying the principal air pollutants, sources and associated environmental issues. The study also reviews the pollution control measures currently in use and calls for a concerted effort from researchers, industry operators and regulators at working to reduce emissions with a view to upholding environmental sustainability.
The negative health effects of cement plant exposure are well-known in industrial settings, but they are less well-known among the general public who live near plants. The broad objective of the review was to provide a detailed systematic analysis of the global situation of the cement industry, including generation, pollution, impact on the natural ecosystem, technological and process improvements, sustainable models, the latest laws, challenges, needs, and ways forward. As an initial evaluation, a list of critical keywords was compiled, and a search of all accessible databases was conducted (i.e., Scopus, Web of Knowledge, Google Scholar). The manuscripts published in the journal between 2011 and 2021 were included. According to the findings, India is the second largest cement producer after China, with an installed capacity of 537 million tonnes and around 7.1 percent of the world’s production, up from 337.32 million tonnes in 2019. NOx, SOx, CO, CO2, H2S, VOCs, dioxins, furans, and particulate matter are all common air pollutants from cement manufacturing. Other sources of dust particles include quarrying, blasting, drilling, trucking, cement plants, fuel production, packaging, path cleaning, and slabs. Other methods of reduction play an important part in decreasing industrial emissions, resulting in lower carbon and more sustainable products. The decision-making trial, in conjunction with the DEMATEL evaluation laboratory and the analytical hierarchy process (AHP) technique, will aid in determining the priority of climate alteration and mitigation options. Furthermore, employing sustainable techniques and technology, switching to alternative fuels will save 12% of total CO2 emissions by 2050.
The cement manufacturing industry has played a fundamental role in global economic development, but its production is a major facilitator to anthropogenic CO2 release and solid waste generation. Nigeria has the largest cement industry in West Africa, with an aggregate capacity of 58.9 million metric tonnes (MMT) per year. The Ministry for Mines and Steel Development asserts that the nation possesses total limestone deposits of around 2.3 trillion MT with 568 MMT standing as established reserves and 11 MMT used. Cement industries are largely responsible for releasing air pollutants and effluents into water bodies with apparent water quality deterioration over the years. Air pollution from lime and cement-producing plants is seen as a severe instigator of occupational health hazards and work-related life threats, negatively affecting crop yields, buildings, and persons residing in the vicinity of these industries. World Bank observed in 2015 that 94% of the Nigerian populace is susceptible to air pollutants that surpass WHO guidelines. In 2017, World Bank further reported that 49,100 premature deaths emanated from atmospheric PM2.5, with children beneath age 5 having the greatest vulnerability owing to lower respiratory infections, thereby representing approximately 60% of overall PM2.5-induced deaths. Cement manufacturing involves the significant production of SO2, NOx, and CO connected to adverse health effects on humans. Sensitive populations such as infants, the aged, and persons having underlying respiratory ailments like asthmatics, emphysema, or bronchitis are seen to be most affected. Consequently, in addressing this challenge, growing interests in enacting carbon capture, usage, and storage in the cement industry is expected to alleviate the negative environmental impact of cement production. Still, no carbon capture technology is yet to achieve commercialization in the cement industry. Nonetheless, huge advancement has been made in recent years with the advent of vital research in sorption-enhanced water gas shift, underground gasification combined cycle, ammonium hydroxide solution, and the microbial-induced synthesis of calcite for CO2 capture and storage, all considered sustainable and feasible in cement production.
This research gives a new glimpse on determinants of unemployment in developing countries. Unemployment is not only a burning issue in developing countries but also in developed countries, but in this study, the case is related to developing countries. For this purpose data of ten selected developing countries has been taken for the period of 2000 to 2019 from the World Bank. Stationarity has been checked through the Augmented Dickey-Fuller (ADF) test and the result showed that all variables were stationary at 1st difference except the variable of inflation. The Generalized Method of Moments (GMM) model has been applied and results show that all variables are statistically significant. GDP, inflation, remittances, exchange rate, and expenditure on education has a negative impact on unemployment while population and external debt has a positive impact on unemployment. Policy recommendations are that if developing economies want to reduce unemployment they have to control population, remove deficit in the balance of payment, control the inflation rate, raise their GDP, earn the exchange rate due to increase in exports, and gain the foreign remittance and have to allocate the more budget on expenditure on education. In light of these recommendations, all economies can achieve economic efficiency and economic development.
Air of cities especially in the developing parts of the world is turning into a serious environmental interest. The air pollution is because of a complex interaction of dispersion and emission of toxic pollutants from manufactories. Air pollution caused due to the introduction of dust particles, gases, and smoke into the atmosphere exceeds the air quality levels. Air pollutants are the precursor of photochemical smog and acid rain that causes the asthmatic problems leading into serious illness of lung cancer, depletes the stratospheric ozone, and contributes in global warming. In the present industrial economy era, air pollution is an unavoidable product that cannot be completely removed but stern actions can reduce it. Pollution can be reduced through collective as well as individual contributions. There are multiple sources of air pollution, which are industries, fossil fuels, agro waste, and vehicular emissions. Industrial processes upgradation, energy efficiency, agricultural waste burning control, and fuel conversion are important aspects to reducing pollutants which create the industrial air pollution. Mitigations are necessary to reduce the threat of air pollution using the various applicable technologies like CO2 sequestering, industrial energy efficiency, improving the combustion processes of the vehicular engines, and reducing the gas production from agriculture cultivations.
An up-to-date assessment of environmental emissions in the US health care sector is essential to help policy makers hold the health care industry accountable to protect public health. We update national-level US health-sector emissions. We also estimate state-level emissions for the first time and examine associations with state-level energy systems and health care quality and access metrics. Economywide modeling showed that US health care greenhouse gas emissions rose 6 percent from 2010 to 2018, reaching 1,692 kg per capita in 2018-the highest rate among industrialized nations. In 2018 greenhouse gas and toxic air pollutant emissions resulted in the loss of 388,000 disability-adjusted life-years. There was considerable variation in state-level greenhouse gas emissions per capita, which were not highly correlated with health system quality. These results suggest that the health care sector's outsize environmental footprint can be reduced without compromising quality. To reduce harmful emissions, the health care sector should decrease unnecessary consumption of resources, decarbonize power generation, and invest in preventive care. This will likely require mandatory reporting, benchmarking, and regulated accountability of health care organizations.
The stringent international regulations on marine emission abatement have exerted a huge push on the development of marine desulfurization and denitrification technologies. However, for the traditional vessels driven by large two-stroke diesel engines, simultaneous removal of NO x and SO 2 is still a big challenge at present. Here, a one-stage ozone oxidation combined with in-situ wet scrubbing for simultaneous removal of NO and SO 2 is proposed. A series of experiments were performed based on a bench-scale reaction system. The results showed that in-situ wet scrubbing could effectively decrease flue gas temperature, and then suppress the thermal decomposition of ozone, which was beneficial for improve oxidant utilization. Meanwhile, the in-situ combination of ozone injection and wet scrubbing was in favor of improving the selectivity oxidation of NO over SO 2 by ozone, which was possibly due to the high aqueous solubility of SO 2 in water. Aiming to reduce the electric power consumption by an ozone generating system, O 3 /NO molar ratio was kept as low as possible. A complete removal of SO 2 and a high NO x removal efficiency could be achieved through the introduction of other oxidative additives in scrubbing solution. This integrated system designed for marine application was of great significance.
Utilizing National High-tech Industrial Development Zones (NHIDZs) as a quasi-natural experiment, this study has adopted 285 prefecture and above cities from 2003 to 2018 in China as the research samples and constructed the difference-in-differences (DID) and spatial difference-in-differences (SDID) models to investigate the effects of NHIDZs on economic development and environmental pollution at national, regional, and administrative levels. The results show that NHIDZs have basically achieved a win-win situation in promoting economic development and reducing environmental pollution at the national level. However, spatial heterogeneity is supported at regional and administrative levels. Specifically, “the law of diminishing marginal effect” of NHIDZs is proved in the eastern cities and key cities, which reveals the uneven development pattern of government leading in China, and highlights the importance and necessary of making policy according to local conditions and governing environmental pollution by classification.
This chapter discusses the concepts of CO2 emission, global warming, and climate change with an emphasis on their environmental impacts. Specifically, the chapter reviews different sources of atmospheric CO2 emissions and recent advances in the implementation of carbon capture and storage (CCS) technology to mitigate greenhouse gas emissions. In this chapter, the intricate relationship between CO2 emission, global warming, and climate change was explicitly explained, and CO2 mitigation strategies in selected industrial sectors such as power, cement, iron, and steel as well as the petrochemical industry were presented. An overview of process integration concepts for energy minimization in environmental sustainability studies was highlighted. The current state of research in this field was reviewed, while future prospects in the application of process synthesis techniques to decrease the high energy and material requirement during CO2 capture were suggested. Finally, CO2 emission trend since the beginning of the first industrial revolution was discussed alongside current international treaties, limitations, and forecasts about greenhouse gas emission.
The Chinese cement industry produced 2150 million metric tons of cement in 2014, accounting for 58.1% of the world’s total. This industry has a hugely destructive effect on the environment owing to its pollution. The environmental impact of cement manufacturing is a major concern for China. Although researchers have attempted to estimate impacts using life cycle assessment approaches, it lacks the ability to provide a holistic evaluation of the impacts on the environment. Emergy analysis, through ecological accounting, offers environmental decision making using elaborate book keeping. In spite of the high environmental impact of the cement industry, there has only been a handful of research work done to compute the unit emergy values (UEVs) of cement manufacturing in China. A thorough study of existing UEVs of cement manufacturing in China showed pitfalls that may lead to inaccurate estimations if used in emergy analysis. There is a strong need for a new, updated UEV for cement manufacturing in China, particularly reflecting both the dry and wet raw materials in the manufacturing process. This paper develops a methodology to calculate the nonrenewable resources used in cement manufacturing, particularly using mainstream cement production line. Our systematic approach-based UEV estimates of cement manufacturing in China using the quota method are 2.56 × 1012 sej/kg (wet material) and 2.46 × 1012 sej/kg (dry material). Emergy indicators such as environmental loading ratios which were calculated at 2390 (wet material) and 2300 (dry material); emergy yield ratios at 15.7 and 15.8; and emergy sustainability indices at 0.0066 and 0.0069 for dry and wet materials used in cement manufacturing, respectively; these show the immense impact on the environment in China.
The objective of the study is to examine the dynamic linkages between population growth, price level, poverty headcount ratio, and carbon emissions under investigation of different plausible hypothesis, including “population-induced poverty trap,” “welfare-reducing effects,” “environmental Kuznets curve,” and “pollution haven” hypotheses in the cross-sectional setting of 98 developed and developing countries for the period of 2011. The study used cross-sectional regression and switching regression regime for empirical analysis. The result shows a positive relationship between changes in price level and carbon emissions that verify “welfare-reducing effects,” while there is a negative relationship between population growth and poverty at varying poverty threshold to support the “Gary Becker human capital theory.” Further, there is a positive relationship between poverty rates and carbon emissions across countries. The results verified the “pollution haven” hypothesis in account of increase in pollution through financial liberalization policies. A U-shaped relationship is found between economic growth and carbon emissions in a given time period. The study concludes that globalized world should have to be careful when devising environmental sustainability policies, as it is important to provide social safety nets to the lower income strata group; hence, it would be helpful to achieve global green development agenda.
Numerous mitigation techniques have been incorporated to capture or remove SO2 with flue gas desulfurization (FGD) being the most common method. Regenerative FGD method is advantageous over other methods due to high desulfurization efficiency, sorbent regenerability, and reduction in waste handling. The capital costs of regenerative methods are higher than those of commonly used once-through methods simply due to the inclusion of sorbent regeneration while operational and management costs depend on the operating hours and fuel composition. Regenerable sorbents like ionic liquids, deep eutectic solvents, ammonium halide solutions, alkyl-aniline solutions, amino acid solutions, activated carbons, mesoporous silica, zeolite, and metal-organic frameworks have been reported to successfully achieve high SO2 removal. The presence of other gases in flue gas, e.g., O2, CO2, NOx, and water vapor, and the reaction temperature critically affect the sorption capacity and sorbent regenerability. To obtain optimal SO2 removal performance, other parameters such as pH, inlet SO2 concentration, and additives need to be adequately governed. Due to its high removal capacity, easy preparation, non-toxicity, and low regeneration temperature, the use of deep eutectic solvents is highly feasible for upscale utilization. Metal-organic frameworks demonstrated highest reported SO2 removal capacity; however, it is not yet applicable at industrial level due to its high price, weak stability, and robust formulation.
Hazardous waste output in the world is increasing every year. To achieve higher efficiency and lower pollution, the incineration technology for hazardous waste needs to be studied further. This study mainly reviews the research progress in incineration, slagging, and pollutant emission in the rotary kiln in China and abroad in the last 10 years, and conducts a comprehensive analysis and evaluation of the research. Considering that there are many variables involved in the incineration process, the incineration law cannot be validated in a limited timeframe by experiments. Researchers often use computer simulations to predict and verify the incineration process through experiments and to provide reference opinions for commercial operations. Through the analysis of the research progress in rotary kilns, it is observed that the basic research in rotary kilns is becoming mature. The latest research trend in rotary kilns is interdisciplinary and mixed research. From a new perspective, further research should be focused on a comparative analysis of the rotary kiln and the cement kiln, full life cycle assessment of the impact factors of rotary kiln on the environment, the impact of the factory treatment process on the workers’ health, etc. The research direction of rotary kiln in China and abroad for the future has been predicted reasonably.
The recent intensification of international trade has led to a growing disconnection between consumer demand for goods and services and the water resources that support them. The important role of household demands on the exploitation of distant freshwater resources is widely recognized, yet the different socioeconomic drivers underlying the trends in domestic and foreign water use remain poorly quantified. In this work, the main mechanisms governing the exploitation of domestic and foreign freshwater resources are quantified by undertaking a structural decomposition analysis over the period 1994–2010 in 186 countries. Our results show that growth in affluence has been the main determinant of rising water consumption trends worldwide. There are indications that consumers in developed countries tend to increase their affluence by intensifying the use of foreign water resources. Conversely, affluence growth in developing regions seems to rely on the exploitation of local water resources revealing a significant imbalance among economies. The growth of affluence and population has been only partially offset by improvements in the intensity of blue water use by producers and, to a lesser extent, by changes in the interdependences among sectors.
The cement industry is facing numerous challenges in the 21st century due to depleting natural fuel resources, shortage of raw materials, exponentially increasing cement demand and climate linked environmental concerns. Every tonne of ordinary Portland cement (OPC) produced releases an equivalent amount of carbon dioxide to the atmosphere. In this regard, cement manufactured from locally available minerals and industrial wastes that can be blended with OPC as substitute, or full replacement with novel clinkers to reduce the energy requirements is strongly desirable. Reduction in energy consumption and carbon emissions during cement manufacturing can be achieved by introducing alternative cements. The potential of alternative cements as a replacement of conventional OPC can only be fully realized through detailed investigation of binder properties with modern technologies. Seven prominent alternative cement types are considered in this study and their current position compared to OPC has been discussed. The study provides a comprehensive analysis of options for future cements, and an up-to-date summary of the different alternative fuels and binders that can be used in cement production to mitigate carbon dioxide emissions. In addition, the practicalities and benefits of producing the low-cost materials to meet the increasing cement demand are discussed.
The current study is intended to examine the asymmetric impact
of inflation and unemployment on the poverty of Pakistan over
the period of 1970 to 2016 by applying asymmetric Autoregressive
Distributed Lag (ARDL) cointegration approach. The results
revealed the presence of long-run asymmetries among inflation,
unemployment and poverty. These findings also confirmed the
atypical reaction of poverty to negative and positive shocks in
unemployment and inflation. Furthermore, findings also confirmed
negative and significant association among health expenditures
(HE), population growth and poverty. The findings of the study
have relevant implications for policymakers interested in the asymmetric
relationship among inflation, unemployment and poverty
in Pakistan.
China has experienced considerable economic losses from a severe deterioration in air quality. To solve this, a comprehensive understanding of the impacts and sources of air pollution is necessary. This study aimed to quantify the environmental and human health impacts of PM2.5 and O3 pollution from the six major emission-producing sectors in China. We utilized a chemical transport model to simulate the air quality impacts engendered by sectoral emissions. The consequent impacts on public health and crop production, as well as the corresponding collateral economic costs, were quantified by concentration-response functions. The results show that the sectoral emissions in 2010 caused approximately 1 143 000 (95% confidence interval (CI): 168 000–1 796 000) premature mortalities and a 20 035 (95% CI: 6776–32 166) Gg crop production loss. Of the six sectors, the industrial sector was the largest contributor of air pollution, accounting for 36% of the total impact on health, as well as 41% of crop production loss due to O3 exposure. The impacts attributable to sectoral emissions in China were estimated to cost ~267 (95% CI: 180–360) billion yuan (0.66% of the annual GDP). Our findings suggest an urgent need to reduce anthropogenic emissions in China, particularly those of the industrial sector. The varying characteristics of impact due to emissions of various sectors highlight the importance of evaluating cobenefits when formulating emission control policies.
Of the many problems and challenges facing all arid regions, the shortage of water sources is the most important. Egypt is one such arid region. The total volume of Egypt’s water resources is 72 billion m³/year. The Nile River contributes 55.5 billion m³/year to this total. Recently, the water volume of the Nile River was threatened by the construction of a mega dam by Ethiopia near the border of Sudan. Irrigation consumes 70–80% of Egypt’s water resources. To prevent Egypt suffering from a severe water shortage and due to the increasing population and various external and internal challenges facing Egypt at present, very low per capita water limits have been introduced. To alleviate the suffering resulting from the water limits, all water users must apply all possible techniques to improve water use efficiency in these arid conditions. Examples of sustainable techniques that have been proven to show positive impacts on improving crop yield and water productivity and are also environmentally friendly include: (1) biofertilizers, (2) organic mulching, and (3) compost application. Egypt must apply all possible techniques to improve water use efficiency, starting from the mouth of the El-Rayah, passing through main canals then branch canals until the irrigation water reaches the plant. Examples of engineering techniques that have resulted in improved water productivity include: (1) laser land leveling, (2) new design of drip irrigation system, and (3) pulse irrigation.
Digital concrete construction has recently become the subject of very rapidly growing re-search activities all over the world. Various technologies involving 3D-printing with concrete have been developed, and the number of demonstration projects and practical applications has been increasing exponentially. Most of these approaches are focused on the placement of concrete, while the suggested solutions for incorporation of reinforcement are still rudimentary, and as such they lag behind the concepts for printing concrete. Since the use of (steel) reinforcement is mandatory in most structural applications, there is an urgent need to bring the technology of reinforcing 3D-printed structural elements forward. The article starts with a brief overview of the existing approaches in using reinforcement in digital concrete construction. Then the authors’ own research work is presented, namely a feasibility study on 3D-printing of steel reinforcement using gas-metal arc welding. A description of the newly developed 3D-printing process is followed by a demonstration of its feasibility in producing vertical steel reinforcement bars with and without extra ribs. The mechanical performance of the printed bars was investigated by means of uniaxial tension tests. The samples exhibited com-parable mechanical properties to common steel reinforcement of the same diameter. The investigation of fracture surfaces confirmed a ductile mode of failure of the printed steel bars. Finally, the bond between printed steel bars and printable fine-grained concrete was tested by means of pull-out experiments. Here the overall performance could be rated as satisfactory, even though it could be improved by introducing extra ribs in the process of bar manufacturing.
Acid gas removal is one of the main drivers of operating costs in the flue gas cleaning lines of waste-to-energy (WtE) plants. In the light of updated technical and normative references, such as the revised Best Available Technology reference document for waste incineration in the EU, plants are required to comply with increasingly lower emission limit values (ELV). In the case of existing WtE plants, this requires selecting the appropriate option among three alternatives: intensification of current operations, installation of additional equipment (retrofitting) or substitution of equipment (revamping). The identification of the most cost-effective solution to meet the new ELVs is thus paramount. In the present study, a comparative techno-economic assessment is performed with reference to the relevant options available to WtE plants equipped with a dry acid gas treatment system, explicitly taking into account the influence of several technical and economic variables by a sensitivity analysis. The results show that retrofitting based on furnace sorbent injection is a competitive option especially in the presence of high acid gas loads in the flue gas. Despite the high investment cost, revamping based on conversion to wet scrubbing can also reduce the overall cost of treatment compared to intensification, but only if no constraints are present on flue gas temperature downstream of the acid gas treatment. If flue gas reheating is needed, e.g., for the compatibility with a downstream DeNOx treatment or to avoid plume visibility at stack, the associated costs make revamping not competitive with retrofitting or intensification. Sensitivity analysis confirms that these findings are robust even in presence of relevant variations in cost entries.
At the present time, information and communication technology (ICT) has played a vital role in socioeconomic development such as economic growth, literacy, life expectancy, and employment levels in societies, however, such development has come with various environmental damages perspectives. This study scrutinizes the impact of ICT, economic growth, and foreign direct investment (FDI) on carbon dioxide (CO 2) emissions from 1991 to 2019. This study applied various econometrics approaches such as cross-sectional dependence , second-generation unit root, and Westerlund panel cointegration techniques are executed to analyze the panel data set. The full modified ordinary lease square and dynamic ordinary lease square estimators are applied to investigate the long-term influence of ICT development, GDP (economic growth), and FDI on CO 2 emissions. The empirical analysis was performed at a disaggregated level to assess the possible environmental influences . Overall, the results reported that broadband and mobile development have an adverse effect on CO 2 emissions. The finding further reveals that the broadband indicator negatively affects CO 2 emissions. Similarly, the mobile use indicator protects the environmental quality Moreover, economic growth is responsible to increase pollution levels in all panels. Besides, the results highlight that higher FDI reduces environmental pollution whereby, the pollution halo hypothesis is supported to hold for all panels. Based on the empirical findings, the policymakers and governments of these economies should design policies to grow smarter cities, transportation systems, electrical grids, industrial processes, and energy-saving production through ICT development on a macro level.
Research implies that emphasis frames control preferences. Little is known, however, about how stakeholders frame water. How is water framed in decision-making and shaping rooms? Therefore, we explore the Red Sea–Dead Sea Water Conveyance framing. We compile two data sets: (1) 18 in-depth interviews, archival data; and (2) 10 documents. For data analysis, we use qualitative and quantitative approaches – coding with Atlas.ti and text analysis with Voyant Tools. In the results, we juxtapose dominant and marginal frames, frequencies, and descriptive examples. Findings reveal which actors activate and spread salient frames, concealing pressing issues and sustaining old power structures.
Renewable energy is vital to achieve environmental sustainability, improve public health and address global climate change. However, the transition to renewable energy is impossible without massive public renewable energy research and development budgets (RRDD) along with sustained state and federal policies. RRDD in the US showed significant fluctuations over the last three decades and economic policy uncertainty (EPU) was also highly volatile. Based on this backdrop, this study examined the asymmetric impact of RRDD and EPU on CO2 emissions in the US, accounting for structural breaks in data, and controlling for economic growth and FDI. Keeping in view the overwhelming reliance on linear methods in previous studies, both symmetric and asymmetric ARDL approaches are employed for cointegration and long-run results on quarterly data over the period 1985 to 2017. The outcomes from symmetric and asymmetric cointegration tests unfolded only asymmetric cointegration among variables. The long-run findings unveil that a positive change in EPU mitigates emissions but a dominant reduction in CO2 emissions comes from a negative change in EPU. Therefore, it is highly desirable to reduce EPU to achieve a considerable long-term reduction in CO2 emissions. Surprisingly, positive and negative changes in RRDD do not affect CO2 emissions. Hence, the study could not find any significant reduction in CO2 emissions associated with RRDD, implying that renewable energy technology budgets are not sufficient enough to reduce pollutant emissions. The evidence also confirms that the EKC hypothesis is valid in the US considering RRDD, EPU, and FDI in the model. Finally, the study suggests a significant uplift in RRDD and fiscal policies with more subsidies and tax benefits for the growth of renewable energy sector. Also, stability in the environmental policies, regardless of the economic condition, is necessary to achieve long-term environmental benefits.
Recently, the discharge of flue gas has become a global issue due to the rapid development in industrial and anthropogenic activities. Various dry and wet treatment approaches including conventional and hybrid hybrid wet scrubbing have been employing to combat against these toxic exhaust emissions. However, certain issues i.e., large energy consumption, generation of secondary pollutants, low regeneration of scrubbing liquid and high efficieny are hindering their practical applications on industrial level. Despite this, the hybrid wet scrubbing technique (advanced oxidation, ionic-liquids and solid engineered interface hybrid materials based techniques) is gaining great attention because of its low installation costs, simultaneous removal of multi-air pollutants and low energy requirements. However, the lack of understanding about the basic principles and fundamental requirements are great hurdles for its commercial scale application, which is aim of this review article. This review article highlights the recent developments, minimization of GHG, sustainable improvements for the regeneration of used catalyst via green and electron rich donors. It explains, various hybrid wet scrubbing techniques can perform well under mild condition with possible improvements such as development of stable, heterogeneous catalysts, fast and in-situ regeneration for large scale applications. Finally, it discussed recovery of resources i.e., N2O, NH3 and N2, the key challenges about several competitive side products and loss of catalytic activity over time to treat toxic gases via feasible solutions by hybrid wet scrubbing techniques.
CO 2 emissions CO 2 mitigation Cement industry Challenges of CO 2 reduction a b s t r a c t Cement industry is an intensive source of fuel consumption and greenhouse gases (GHGs) emissions. This industry is responsible for 5% of GHGs emissions and is among the top industrial sources of carbon dioxide (CO 2) emissions. Therefore, CO 2 emissions reduction from cement production process has been always an appealing subject for researches in universities and industry. Various efforts have been carried out to mitigate the huge mass of CO 2 emissions from the cement industry. Although, majority of these strategies are technically viable, due to various barriers, the level of CO 2 mitigation in cement industry is still not satisfactory. Among numerous researches on this topic, only a few have tried to answer why CO 2 abatement strategies are not globally practiced yet. This work aims to highlight the challenges and barriers against widespread and effective implementation of CO 2 mit-igation strategies in the cement industry and to propose practical solutions to overcome such barriers.
From a circular economy perspective, the municipal waste (MW) sector remains a valuable input source for waste recyclable re-industrialization among food, pollution, and energy. In this study, different accounting approaches and scenarios for sustainable MW management are explored to find the most cost efficient and profitable approach. Full Cost Accounting (FCA) method is adopted as the basis of analysis in this study where an integrated sustainable framework for the Pay-As-You-Throw (PAYT) pricing model is developed and designed that can optimize MW management in attaining 'zero waste disposal' at the lowest cost as well as generating economic, environmental and social benefits. Using 27 governorates/council waste management data in Egypt and two different PAYT methods (i.e. weight-based and volume-based) under three case scenarios, this study documents that the prepaid bag system under the volume-based PAYT method leads to the lowest waste costs and creates more incentives for households. These findings have various implications for the policy makers, government councils, waste managers, businesses and communities in the adoption of volume-based PAYT schemes for cost-effective, profitable and socially acceptable reusing and recycling of waste. Such valuable addition in the MW management can contribute to the environmental and social sustainable development in emerging markets and moving towards a circular economy model.
Marine diesel engines, which provide main power source for ships, mainly contribute to air pollution in ports and coastal areas. Thus there is an increasing demand on tightening the emission standards for marine diesel engines, which necessitates the research on various emission reduction strategies. This review covers emission regulations and emission factors (EFs), environmental effects and available emission reduction solutions for marine diesel engines. Not only the establishment of the emission control areas (ECAs) in the regulations but also many experiments show high concerns about the sulfur limits in fuels, sulfur oxides (SOx) and nitrogen oxides (NOx) emissions. Research results reveal that NOx emissions from marine diesel engines account for 50% of total NOx in harbors and coastal regions. Sulfur content in fuel oil is an important parameter index that determines the development direction of emission control technologies. Despites some issues, biodiesel, methanol and liquefied nature gas (LNG) play their important roles in reducing emissions as well as in replacing fossil energy, being promising fuels for marine diesel engines. Fuel-water emulsion (FWE) and exhaust gas recirculation (EGR) are effective treatment option for NOx emissions control. Common rail fuel injection is an effective fuel injection strategy to achieve simultaneous reductions in particulate matter (PM) and NOx. Selective catalytic reduction (SCR) and wet scrubbing are the most mature and effective exhaust aftertreatment methods for marine diesel engines, which show 90% De-NOx efficiency and 95% De-SOx efficiency. It can be concluded that the integrated multi-pollutant treatment for ship emissions holds great promise.
Over the past 4 decades, the increasing amounts of excess sludge from municipal wastewater treatment plants (WWTPs) represent a challenge toward achieving the sustainability of the drinking water and sanitation sector in Egypt, resulting in a serious environmental pollution due to the uncontrolled use of non-stabilized sludge. Here, we report a comprehensive overview on the current situation of excess sludge production, management, and disposal in Egypt. Owing to the technologies used for wastewater treatment in Egypt that mainly consist of activated sludge based-technologies, about 2.1 million tons of dry solids is produced annually. The majority of WWTPs in Egypt lack proper sludge stabilization facilities, except for the WWTPs in high living standards governorates (e.g., Cairo, Alexandria, and Giza). Therefore, about 85% of the non-stabilized sludge is improperly disposed and directly used for agricultural purposes. Despite the importance of managing the use of non- and/or partially-treated sludge, especially for agricultural purposes, the national legislations for sludge disposal/reuse in Egypt are incomplete and, in practice, they are not reinforced. In order to evaluate the most sustainable scenario for sludge management in Egypt, a qualitative decision-support system (DSS) was used. The DSS framework was refined and estimated, based on several evaluating categories, and used to guide the decision process towards achieving sustainable management of municipal wastewater sludge in Egypt. The results reveals that “sludge-to-energy” through anaerobic digestion is the most sustainable scenario for sludge disposal and management in Egypt. The anaerobic digestion-based technology seems to offer advantages of interest at affordable costs, such as the production of renewable energy, stabilized soil conditioners, and fertilizers for agricultural purposes.
Water is the most essential substance for human being and living organisms. Water scarcity in Africa is mainly economic due to the poor management of water resources. The Nile River is the major source of water for different applications, i.e., drinking, industries and agriculture in Egypt; therefore, the development of water resources is inferior, especially under the excessive growth of population. Furthermore, agricultural activities in Egypt consume more than 80% of the available quantity of The Nile water; hence, potential scarcity in water is expected to occur in Egypt; especially, there is a critical argument due to the buildup of the Grand Ethiopian Renaissance Dam (GERD). It is worth mentioning that using the classical irrigation system lead to lose vast amounts of available water. Therefore, attention should be paid to overcome the drought problems of one-third of agricultural soils due to the GERD, which might lead to change in the demographical map in Egypt. Also, efforts should be established to urge the Egyptian farmers to shift their surface irrigation system, which is the common irrigation technology to more advanced technologies, i.e., drip or sprinkler irrigation systems. However, to ensure the success of advanced irrigation systems, the quality of water resources should be taken into consideration. Despite nonconventional water resources are not adequate to compensate for the potential reduction of The Nile water; however, there is an actual need to develop these resources in Egypt.
As emission regulation for marine vessels has become strict since 2016, a new emission control method is required. This paper proposes using the H₂O₂ solution in a wet scrubber for SOx and NOx removal for a conventional large marine vessel that uses a low-speed two-stroke diesel engine and a heavy fuel oil, and aims to evaluate the economic feasibility of this approach compared with other methods. Measurement data for the exhaust gas of the engine are incorporated in a process simulation based on physical properties and kinetics that relate H₂O₂ with emission materials. H₂O₂ consumption rate is determined to be 757.38 and 10.37 kg/h, depending on sailing in an emission control area or not. The parameters for techno-economic analysis are based on capital cost, operating cost, sailing information, and fuel cost in January 2018. The net present value of the proposed method is calculated to be 3.26% higher than other methods, and the proposed method is more economical than other methods when the sailing ratio in the emission control area is less than 75.98%. Based on these results, the proposed method can be utilized as an alternative emission control method for a marine vessel that considers retrofitting to satisfy strict emission regulations.
Environmental issues such as exhaustion of natural resources and generation of enormous amounts of waste and their dumping are currently steering the modern civilization to sustainable construction. Steel fiber reinforced concrete has been in application for many decades because of its capability in arresting crack and introducing ductility to structural concrete. Concerning about natural resources and adverse environmental impact of CO2 emission during the production of industrial steel fibers at a larger scale, significant research efforts have been made towards sustainable, resource conservative and recycled alternatives to replace these high-cost commercially available steel fibers with recycled steel fibers (RSFs). Recycled steel fiber reinforced cement mixtures behaves differently in fresh and hardened states compared to plain and industrial steel fiber reinforced cement mixtures. This review provides a brief overview of the recycled steel fibers from different sources, their characteristics, and application in the production of various cement-based composites. Effect of RSFs on the different properties of concrete in fresh state including workability, porosity, bulk density, and volumetric stability has been addressed. Detail discussion on the mechanical properties of various cementitious systems has been included, comprising compressive and flexural strength, tensile splitting strength, toughness, resistance to impacts and durability of RSFRC. This study aims to critically examine the currently reported literature and to identify research gaps for those who intend to further study of behavior of recycled steel fiber reinforced cementitious systems for various applications.
In the half century since the founding of the US Environmental Protection Agency, public and private US sources have spent nearly 2017) to provide clean rivers, lakes, and drinking water (annual spending of 0.8 percent of US GDP in most years). Yet over half of rivers and substantial shares of drinking water systems violate standards, and polls for decades have listed water pollution as Americans’ number one environmental concern. We assess the history, effectiveness, and efficiency of the Clean Water Act and Safe Drinking Water Act and obtain four main conclusions. First, water pollution has fallen since these laws were passed, in part due to their interventions. Second, investments made under these laws could be more cost effective. Third, most recent studies estimate benefits of cleaning up pollution in rivers and lakes that are less than the costs, though these studies may undercount several potentially important types of benefits. Analysis finds more positive net benefits of drinking water quality investments. Fourth, economic research and teaching on water pollution are relatively uncommon, as measured by samples of publications, conference presentations, and textbooks.
Use of alternative fuels in cement production has three important perspectives: dimension of the industry, its environmental impacts, and the fitness of the process for the purpose of waste management. The global production volume of cement is >4 billion tonnes for the last five years, the energy consumption was about 11 EJ in 2016, and the annual CO2 emission was 2.2 Gt. External to the industry, there is a huge problem of managing waste, which was at a level of about 2 billion tonnes in 2016. All these parameters will enormously aggravate by 2050, affecting sustainability and climate. Co-processing of certain combustible waste in cement kilns has evolved as an important tool for addressing the problems. The paper primarily deals with the sources and types of waste on one hand and effects on clinker process and properties on the other.
The treatment and disposal of industrial waste has become a critical economic and environmental issue with the ever-increasing rates of its generation. Industries in India, as major players in building the economy and GDP, expel about 7.4 million tons of hazardous waste annually, out of which around 3.98 million tons are recyclable for resource or energy recovery. India’s scenario in the usage of alternative fuel and raw material is less than 1%, which reflects a huge quantum of hazardous waste for potential usage in alternative fuel and raw material. The Netherlands, with around 83% of total hazardous waste, is the highest user of hazardous waste as alternative fuel and raw material in cement kilns. Uncontrolled waste management degrades land, ground water and air quality, leading to health risks to humans, animals and the ecosystem. Presently, industrial waste in most cases is disposed to landfills after incineration, without utilizing the full potential of the wastes through recirculation. The present study analyzed the current situation of the treatment facilities for attaining a sustainable management system using waste as alternative fuel and raw material for the disposal of hazardous waste. Through the alternative fuel and raw material concept, hazardous wastes can be used as a substitute for fossil fuels and/or raw material in a few types of industries. This will surely enhance the efficient recirculation of industrial wastes. This paper presents the overall view of Indian hazardous-waste generating industries, their locations, the potential of wastes as alternate sources of fuel to other industries, the use of alternative fuel and raw material by cement industries and applicable regulatory requirements.
Spent Pot lining (SPL) is a carbonaceous material generated during the primary aluminum smelting process. SPL is a hazardous waste but the high energy density (carbon rich fraction) and good environmental impacts (toxic materials such as cyanides are destroyed at temperature well above 1000 °C) of the treated SPL (water washed followed with and NaOH and H2SO4 treatments) makes it a valuable material for use as fuel feedstocks in cement and steel industries. The principal objective of this study is to investigate the combustion performance and emission characteristics of SPL as alternative fuel in cement industry. The goal is to develop sustainable process systems by using solid waste materials such as SPL from Aluminum industry as a fuel in the cement industry. The proximate (moisture, volatile, fixed carbon, and ash contents) and ultimate (C, H, O, N, S) analyses and the heating value (MJ/kg) of the raw and treated SPL materials are determined first. Computational Fluid Dynamics analysis based on gas and discrete phase modeling (DPM) approach and probability density function/mixture fraction turbulent non-premixed combustion model are used to test the combustion performance and pollutants emissions (flame temperature, fuel particle devolatization and burnout rates, and species concentration formations inside and at the exit of the combustor) of the SPL fuel. The results of the SPL or the alternative fuel combustion are compared with conventional fuel (coal) combustion used in cement industry. The final treated SPL fuel (water washed SPL followed with NaOH and H2SO4 treatments) combustion shows lower temperature and NO and CO2 emissions at the exit from the furnace compared to coal. The results show that the final treated fuel can be used as alternative fuel in cement industry to displace coal fuel and reduce the pollutant emissions from the combustor in cement industry.
Assessing global water quality issues requires a multi-pollutant modelling approach. We discuss scientific challenges and future directions for such modeling. Multi-pollutant river models need to integrate information on sources of pollutants such as plastic debris, nutrients, chemicals, pathogens, their effects and possible solutions. In this paper, we first explain what we consider multi-pollutant modelling. Second, we discuss scientific challenges in multi-pollutant modelling relating to consistent model inputs, modelling approaches and model evaluation. Next, we illustrate the potential of global multi-pollutant modelling for hotspot analyses. We show hotspots of river pollution with microplastics, nutrients, triclosan and Cryptosporidium in many sub-basins of Europe, North America and South Asia. Finally, we reflect on future directions for multi-pollutant modelling, and for linking model results to policy-making.
Purpose
Cement industry for both developed and developing countries is important from the economic point of view. It is playing a vital role in economic development of a developing country like Pakistan. However, these industries are posing threat to the environment, human health and plant species. The purpose of this paper is to identify the most critical factors of cement industry that have a negative impact on the environment, human health and plant species in the context of Pakistan.
Design/methodology/approach
The factors are categorized into air pollution, noise pollution, soil pollution, human health and plant species. These factors are categorized on the basis of previous literature and environmental safety reports. Air pollution is caused by iron and sulphur while noise pollution is mainly caused by crusher room and rotatory kiln end. The soil is being polluted by zinc and lead while human health and plant species are being damaged by sulphur dioxide and nitrogen dioxide. For the analysis purpose, a multi-criteria decision-making (MCDM) technique, i.e., decision-making trial and evaluation laboratory (DEMATEL) is used.
Findings
The result shows that the major cause of air pollution is “sulphur” while “crusher room and rotatory kiln end” are responsible for noise pollution. On the other hand, “mercury” is responsible for causing soil pollution while human health and plant species are influenced by the toxic effect of “nitrogen dioxide.”
Research limitations/implications
The results obtained are specific to cement manufacturing industry of Pakistan and cannot be generalized for any other manufacturing sector.
Practical implications
The proposed methodology shows the most critical factors toward which concertation should be given for mitigating their impact. This study will help the government and the cement industry to focus on all those elements that are the most responsible for causing different types of pollution.
Originality/value
No such work is reported in previous research that proposes a framework using DEMATEL technique for analysis of critical factors of cement industries that have a dangerous impact on the environment and human health, especially in a developing country, like Pakistan.
The expansion of reservoirs to cope with droughts and water shortages is hotly debated in many places around the world. We argue that there are two counterintuitive dynamics that should be considered in this debate: supply–demand cycles and reservoir effects. Supply–demand cycles describe instances where increasing water supply enables higher water demand, which can quickly offset the initial benefits of reservoirs. Reservoir effects refer to cases where over-reliance on reservoirs increases vulnerability, and therefore increases the potential damage caused by droughts. Here we illustrate these counterintuitive dynamics with global and local examples, and discuss policy and research implications.
Cement manufacturing contributes to the elevation of air pollutants in the atmosphere and thus impact on the nearby communities. This study assessed air quality in a major Cement Plant in Ibese Ogun State, Nigeria, through an ambient air quality monitoring and air emission dispersion modelling. Particulate Matter (PM) and gaseous pollutants were measured using portable samplers and AERMOD View was used for the emission dispersion modelling. Combustion products including SO2, NO, NO2, CO and VOCs were the gaseous pollutants detected along the complex fenceline and in the receptor environments. Pollutants measurements were undertaken at 23 locations within the fence line and receptor locations. The daily SO2 and NO2 Federal Ministry of Environment - Nigeria (FMEnv) limits were exceeded in ten (10) and five (5) locations along the fenceline, respectively. Particulates were detected in all the locations along the fenceline and in the communities. The cumulative gaseous pollutants resulting from simultaneous operations of all the identified plant air emission point sources are 0.01–276.13% of their respective 24-h limits along the fenceline, with 1-h SO2 within the threshold limit at all fenceline locations, but 1-h NOX exceeds the threshold limit at all locations 16–21 times. The 24-h CO and VOCs are within their limits at all fenceline locations; however the 24-h SO2 and NOX are breaching the limits at some locations 30–34 times (0.34–0.39% of the investigation period) and 44–87 times, respectively. Daily and Annual averaging concentrations of PM10 was 14.32–31.54% and 4.90–52.60% of their respective limits. Process facilities are the major point sources of atmospheric emissions identified in the factory. Several fugitive emission sources were also identified during the field work. Comprehensive evaluation of the fugitive emission sources should be carried out in the cement plant for immediate attention. © 2018 Turkish National Committee for Air Pollution Research and Control
Incineration is well used to treat municipal solid wastes (MSW) but is difficult to treat sewage sludge (SS) because it requires a large amount of heat to remove high content of moisture in SS. Over 50 billion tons of SS are discharged annually in China, and the need for a better waste treatment strategy is urgent. This paper is to introduce a waste disposal technology referring to the integrated treatment of MSW and SS. Four scenarios were analyzed including Mono-incineration of MSW (Case 1) and SS (Case 2), co-incineration of SS and MSW by traditional (Case 3) and integrated ways (Case 4), in terms of environment, energy and economic impact by means of LCA, CED and TEA method. From the environmental perspective, the top four mid-point categories involving the largest effect on four cases are N-C (non-carcinogens), OLD (Ozone layer depletion), TET (Terrestrial eco-toxicity), and GWP (Global warming potential). Case 4 has the most positive effect on climate change and resources (-1.44 kg CO2 eq and -18 MJ, respectively) according to end-point categories. From the view of energy, Case 4 shows the best performance of energy efficiency, and significantly saves the non-renewable energy (0.21 t coal per ton feedstock compared with Case 3). From the economic part, Case 4 is preferentially potential with the best profit, cutting down 79.08% of cost in coal than that in Case 3. These results provide understandings of developing an effective approach for co-treating MSW and SS in the near future.
IoT (Internet of Things) is a new paradigm which provides a set of new services for the next wave of technological innovations. IoT applications are nearly limitless while enabling seamless integration of the cyber-world with the physical world. However, despite the enormous efforts of standardization bodies, alliances, industries, researchers and others, there are still numerous problems to deal with in order to reach the full potential of IoT. These issues should be considered from various aspects such as enabling technologies, applications, business models, social and environmental impacts. In focus of this paper are open issues and challenges considered from the technological perspective. Just for clarification, we put in light different visions that stand behind this paradigm in order to facilitate a better understanding of the IoT's features. Furthermore, this exhaustive survey provides insights into the state-of-the-art of IoT enabling and emerging technologies. The most relevant among them are addressed with some details. The main scope is to deliver a comprehensive overview of open issues and challenges to be tackled by future research. We provide some insights into specific emerging ideas in order to facilitate future research. Also, this paper brings order in the existing literature by classifying contributions according to different research topics.
This paper is about the peculiar particularities of the dual trends towards urban water privatization and commodification. It uses as its analytical entry point the extraordinary emergence of large-scale seawater desalination, delivered through public-private partnerships, as an alternative municipal water supply for the San Diego–Tijuana metropolitan region. The paper engages and extends Karen Bakker’s work on water as an ‘uncooperative commodity’. Interrogating the neoliberalization of water through desalination, it is argued, requires reference to the socio-technical relations drawn together under the ‘desalination assemblage’. Such water treatment technologies –and the social relations that flow through them– are, in other words, efficacious in the market-disciplining of water. The paper presents an understanding of privatization and commodification as diffuse, and as unfolding through multiple and contradictory materially heterogeneous relationships. Drawing on both urban political ecology (UPE) and assemblage thinking, the paper calls for a more constructive dialogue between different concepts of socio-material relationality. The empirical case studies of two large seawater desalination plants (one in Southern California, one in Baja California) and the re-configuring relations of public/private water governance associated with these projects, provides a pertinent imperative for greater attention to be paid to contingency and heterogeneity in our understanding of the ecology of capitalism.
Mounting environmental pressures led China to focus on the effectiveness of the environmental regulation to control pollution. Since the shadow economy, or underground economic activities that are not included in official statistics, accounts for an increasing fraction of China's economy, its impacts on environmental quality should be carefully evaluated. In this study, the main research questions are as follows: 1) What is the extent of the effect of environmental regulation on environmental quality? and 2) What are the factors that influence the impact of environmental regulation on environmental pollution? A theoretical model is developed to explain the relationship among the environmental regulation, shadow economy, and environmental quality in China. An empirical analysis is conducted to test the three propositions of the model, thereby examining the explanatory power of the theoretical model. Concretely, using panel data from 30 provinces for the period of 1998–2012, the generalized method of moments (GMM) method is employed to control for potential endogeneity and introduce dynamic effects. The estimation results indicate that stringent environmental regulation and the level of the shadow economy are both positively related to China's environmental pollution; however, the results also indicate that tighter environmental control would help reduce pollution at a given level of the shadow economy. Moreover, an increase in the proportion of corrupt officials may weaken the environmental regulation, which would consequently lead to the increase in illegal production and total pollutant emissions. Besides, many economic and social factors may also affect the environmental quality. For instance, the development of secondary industry contributes toward an increase in pollutant emissions; however, increased research and development (R&D) spending on eco-friendly industrial operations can help to reduce pollution.