Demonstration of a high field electrostatically enhanced venturi scrubber on a magnesium furnace fume emission

A 566 m³/m (20,000 acfm) permanent installation demonstration system, consisting of the Air Pollution Systems' High Intensity Ionizer and a variable throat venturi scrubber (called the Scrub-E) has been installed on a magnesium recovery furnace. The furnace produces submicron fume particles of MgO, MgCl₂, and ZrCl₄. The system is designed to demonstrate the effectiveness of the High Intensity Ionizer versus high venturi pressure drop on the furnace emissions. The High Intensity Ionizer array operates stably at field strengths of 10–15 kV/cm and at velocities in excess of 18 m/sec (60 fps) while maintaining high charging efficiencies. The report covers the system design, technology, applications, and project developments. An Environmental Protection Agency proposed charged droplet Scrub-E is also discussed covering the design, technology, and proposed demonstration program.     

Taxonomy of groundwater quality using multivariate and spatial analyses in the Tuticorin District,Tamil Nadu,India

A holistic appraisal of the quality of groundwater from the Tuticorin District has been conducted using multivariate statistical and spatial analyses. The objectives of the study were to delineate the spatial and temporal variabilities in groundwater quality and to understand its suitability for human uses. A total of 100 groundwater samples were collected and analyzed for major cations and anions during pre-monsoon and post-monsoon. Water quality index rating was calculated to quantify overall water quality for human consumption. The PRM samples exhibit poor quality in greater percentage when compared with POM due to the dilution after rainfall. Correlation, factor analysis, and plot of the factor scores reflect the seawater intrusion and weathering process. The mineral stability diagrams indicated that the groundwater is in equilibrium with kaolinite and Ca-montmorillonite, whereas Gibbs plot showed that the chemical composition of groundwater in both districts is controlled by the natural weathering processes irrespective of seasons. The major water type identified in this study is the Ca²⁺–Mg²⁺–HCO₃ ^? type, which degrades into predominantly Na⁺–Cl^?–SO₄ ^2? more saline groundwater toward the coast.     

Cancer mortality in towns in the vicinity of incinerators and installations for the recovery or disposal of hazardous waste

BackgroundWaste treatment plants release toxic emissions into the environment which affect neighboring towns.ObjectivesTo investigate whether there might be excess cancer mortality in towns situated in the vicinity of Spanish-based incinerators and installations for the recovery or disposal of hazardous waste, according to the different categories of industrial activity.MethodsAn ecologic study was designed to examine municipal mortality due to 33 types of cancer, across the period 1997–2006. Population exposure to pollution was estimated on the basis of distance from town of residence to pollution source. Using Besag–York–Mollié (BYM) regression models with Integrated Nested Laplace approximations for Bayesian inference, and Mixed Poisson regression models, we assessed the risk of dying from cancer in a 5-kilometer zone around installations, analyzed the effect of category of industrial activity, and conducted individual analyses within a 50-kilometer radius of each installation.ResultsExcess cancer mortality (BYM model: relative risk, 95% credible interval) was detected in the total population residing in the vicinity of these installations as a whole (1.06, 1.04–1.09), and, principally, in the vicinity of incinerators (1.09, 1.01–1.18) and scrap metal/end-of-life vehicle handling facilities, in particular (1.04, 1.00–1.09). Special mention should be made of the results for tumors of the pleura (1.71, 1.34–2.14), stomach (1.18, 1.10–1.27), liver (1.18, 1.06–1.30), kidney (1.14, 1.04–1.23), ovary (1.14, 1.05–1.23), lung (1.10, 1.05–1.15), leukemia (1.10, 1.03–1.17), colon–rectum (1.08, 1.03–1.13) and bladder (1.08, 1.01–1.16) in the vicinity of all such installations.ConclusionsOur results support the hypothesis of a statistically significant increase in the risk of dying from cancer in towns near incinerators and installations for the recovery or disposal of hazardous waste.     

Recovery and recycling of post-consumer waste materials. Part 1. Generalities and target wastes (paper,cardboard and aluminium cans)

Recycling of post-consumer waste materials is gaining increased interest due to public awareness, legislative promotion and imposition, economic benefits and appropriate technologies being available. The present paper does not deal with municipal solid waste as such, but only with the recyclable constituents. The paper does not aim at presenting recycling process details and/or fundamental research results, but reviews the major recyclables with their reuse potential, recycling technologies used, problems, solutions and potential areas of future research and development. These target recyclables include paper and cardboard, aluminium cans, glass beverage bottles, scrap metal and steel cans, scrap tyres, batteries and household hazardous waste. The present paper sets the overall picture and deals with paper, cardboard and aluminium cans only. A second part of the paper assesses the other target recyclables. The assessment of the waste availability, the existing and currently developed recovery and recycling technologies, and the economically rewarding markets while recycling, stress the technical, economic and environmental importance of this waste management sector. The activities associated with the recovery and recycling of post-consumer wastes require a strong sustainable engineering input at all phases of the treatment, from input quality control, to the selection of the most appropriate technology and the delivery of the recyclables as readily reusable feedstock.     

Biodegradation of low-density polyethylene (LDPE) using the mixed culture of Aspergillus carbonarius and A. fumigates

Low-density polyethylene (LDPE) possesses various applications in several industries owing to its durability, low-cost, and many mechano-thermal properties. Unfortunately, LDPE waste creates an environmental threat. The level of biodegradation of black LDPE sheets with fungi isolated from different landfills sites in Sharqiyah Governorate, Egypt, was evaluated. LDPE sheets, the only source of carbon, along with minimal salt medium were incubated on a rotary shaker at 30 °C and 120 rpm for 16 weeks. Aspergillus carbonarius MH 856457.1 and A. fumigatus MF 276893 confirmed to be good candidates for LDPE biodegradation. A mixed culture of two strains showed the excellent weight loss% of sheets as compared to single isolate. Further efforts to improve the degrading capacity through physical and chemical treatments were performed. The biodegradation was significantly stimulated by 39.1% (thermal treatment), 17.76% (HNO₃ treatment), and 5.79% (Gamma-irradiation treatment). Laccases and manganese peroxidases activities were assayed. LDPE biodegradation was analyzed by scanning electronic microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and gas chromatography–mass spectrometry (GC–MS). FTIR spectra showed the appearance of new functional groups assigned to hydrocarbon biodegradation and confirmed the role of manganese peroxidase in process. The changes in the FTIR spectra of the mixed culture biomass before and after the biodegradation (Δ73 cm^?1) and the surface changes in the biodegraded LDPE (as indicated from SEM) confirmed the depolymerization of LDPE. From GC–MS analysis, the plasticizers bis(2-ethylhexyl) phthalate, Diisssctyl phthalate, 1,2-benzenedicarboxylic acid diisooctyl ester, and tributyl acetylcitrate completely biodegraded. Moreover, several antioxidants, antimicrobial, and anticancer compounds, and methyl esters of fatty acids were produced.

     

Health effects from Sahara dust episodes in Europe: Literature review and research gaps

The adverse consequences of particulate matter (PM) on human health have been well documented. Recently, special attention has been given to mineral dust particles, which may be a serious health threat. The main global source of atmospheric mineral dust is the Sahara desert, which produces about half of the annual mineral dust. Sahara dust transport can lead to PM levels that substantially exceed the established limit values. A review was undertaken using the ISI web of knowledge database with the objective to identify all studies presenting results on the potential health impact from Sahara dust particles. The review of the literature shows that the association of fine particles, PM_2.5, with total or cause‐specific daily mortality is not significant during Saharan dust intrusions. However, regarding coarser fractions PM₁₀ and PM_2.5–10 an explicit answer cannot be given. Some of the published studies state that they increase mortality during Sahara dust days while other studies find no association between mortality and PM₁₀ or PM_2.5–10. The main conclusion of this review is that health impact of Saharan dust outbreaks needs to be further explored. Considering the diverse outcomes for PM₁₀ and PM_2.5–10, future studies should focus on the chemical characterization and potential toxicity of coarse particles transported from Sahara desert mixed or not with anthropogenic pollutants. The results of this review may be considered to establish the objectives and strategies of a new European directive on ambient air quality. An implication for public policy in Europe is that to protect public health, anthropogenic sources of particulate pollution need to be more rigorously controlled in areas highly impacted by the Sahara dust.     

Climate change driven plant–metal–microbe interactions

Various biotic and abiotic stress factors affect the growth and productivity of crop plants. Particularly, the climatic and/or heavy metal stress influence various processes including growth, physiology, biochemistry, and yield of crops. Climatic changes particularly the elevated atmospheric CO₂ enhance the biomass production and metal accumulation in plants and help plants to support greater microbial populations and/or protect the microorganisms against the impacts of heavy metals. Besides, the indirect effects of climatic change (e.g., changes in the function and structure of plant roots and diversity and activity of rhizosphere microbes) would lead to altered metal bioavailability in soils and concomitantly affect plant growth. However, the effects of warming, drought or combined climatic stress on plant growth and metal accumulation vary substantially across physico–chemico–biological properties of the environment (e.g., soil pH, heavy metal type and its bio-available concentrations, microbial diversity, and interactive effects of climatic factors) and plant used. Overall, direct and/or indirect effects of climate change on heavy metal mobility in soils may further hinder the ability of plants to adapt and make them more susceptible to stress. Here, we review and discuss how the climatic parameters including atmospheric CO₂, temperature and drought influence the plant–metal interaction in polluted soils. Other aspects including the effects of climate change and heavy metals on plant–microbe interaction, heavy metal phytoremediation and safety of food and feed are also discussed. This review shows that predicting how plant–metal interaction responds to altering climatic change is critical to select suitable crop plants that would be able to produce more yields and tolerate multi-stress conditions without accumulating toxic heavy metals for future food security.     

中国金属矿产的消费强度与回收潜力分析

从中国金属资源安全的角度来看,优化战略性金属矿产的供应结构,降低一次矿产的对外依存度,通过合理的政策导向有效地增加中国城市矿产开发效率,挖掘废旧金属的回收和利用潜力,是实现矿产资源安全保障的重要前提。本文以铁、铜、铝等三种金属矿产为例,采用美国、英国、法国、德国、日本等五个工业化国家及中国1949—2015年的面板数据,通过构建消费强度、回收密度和寿命分布函数分析了工业化五国金属消费和报废金属回收的历史规律,预测了2016—2030年中国三种金属消费和报废回收的变化趋势。结果显示:(1)五个工业化国家铁、铜、铝金属的消费强度经历了快速上升、平台缓降和较快下降的过程,而回收密度则经历了缓慢上升、较快增长和快速增长的三个阶段,在消费强度与回收密度的第三阶段呈现"脱钩"特征;(2)中国铁、铜、铝三种金属的消费强度大幅增加主要是集中在2000年以后,2015年我国铁、铜、铝的消费强度分别为540 kg/人、8 kg/人和23 kg/人,回收密度分别只有100kg/人、0.5 kg/人和3 kg/人,除铁、铝的消费强度进入平台下降期外,铜消费强度和三种金属回收密度仍处于增长的第一阶段;(3)预计2030年,中国铁、铜、铝的消费强度将分别为450 kg/人、9 kg/人和20 kg/人,仍处在平台缓慢下降阶段,回收密度将分别增加到220kg/人、3 kg/人和5 kg/人,回收密度与消费强度比例分别达到49%、33%和25%。通过对比可知,中国未来社会报废金属回收潜力巨大,如果能加以有效政策引导,加快回收利用,可大大缓解中国战略性金属的安全保障压力。     

An interlaboratory comparison of nanosilver characterisation and hazard identification: Harmonising techniques for high quality data

Within the FP7 EU project NanoValid a consortium of six partners jointly investigated the hazard of silver nanoparticles (AgNPs) paying special attention to methodical aspects that are important for providing high-quality ecotoxicity data. Laboratories were supplied with the same original stock dispersion of AgNPs. All partners applied a harmonised procedure for storage and preparation of toxicity test suspensions. Altogether ten different toxicity assays with a range of environmentally relevant test species from different trophic levels were conducted in parallel to AgNP characterisation in the respective test media. The paper presents a comprehensive dataset of toxicity values and AgNP characteristics like hydrodynamic sizes of AgNP agglomerates and the share (%) of Ag⁺-species (the concentration of Ag⁺-species in relation to the total measured concentration of Ag). The studied AgNP preparation (20.4 ± 6.8 nm primary size, mean total Ag concentration 41.14 mg/L, 46–68% of soluble Ag⁺-species in stock, 123.8 ± 12.2 nm mean z-average value in dH₂O) showed extreme toxicity to crustaceans Daphnia magna, algae Pseudokirchneriella subcapitata and zebrafish Danio rerio embryos (EC50 < 0.01 mg total Ag/L), was very toxic in the in vitro assay with rainbow trout Oncorhynchus mykiss gut cells (EC50: 0.01–1 mg total Ag/L); toxic to bacteria Vibrio fischeri, protozoa Tetrahymena thermophila (EC50: 1–10 mg total Ag/L) and harmful to marine crustaceans Artemia franciscana (EC50: 10–100 mg total Ag/L). Along with AgNPs, also the toxicity of AgNO₃ was analyzed. The toxicity data revealed the same hazard ranking for AgNPs and AgNO₃ (i.e. the EC50 values were in the same order of magnitude) proving the importance of soluble Ag⁺-species analysis for predicting the hazard of AgNPs. The study clearly points to the need for harmonised procedures for the characterisation of NMs. Harmonised procedures should consider: (i) measuring the AgNP properties like hydrodynamic size and metal ions species in each toxicity test medium at a range of concentrations, and (ii) including soluble metal salt control both in toxicity testing as well as in Ag⁺-species measurements. The present study is among the first nanomaterial interlaboratory comparison studies with the aim to improve the hazard identification testing protocols.     

Effect of hydrogen addition to CNG in a biodiesel-operated dual-fuel engine

Alternative fuels for diesel engine applications are gaining more prominence as they have numerous advantages compared to fossil fuels. They are renewable, biodegradable; provide food and energy security and foreign exchange savings. They address environmental concerns and socio-economic issues as well. Gaseous fuels such as compressed natural gas and hydrogenated compressed natural gas (HCNG) appear more attractive fuels for diesel engine applications operated in dual-fuel mode. Such dual fuel engines can replace considerable amount of liquid-injected pilot fuels by gaseous fuels besides being friendly to the environment. A small quantity of liquid fuel injected towards the end of the compression stroke initiates combustion of the inducted gas in the dual-fuel engines. The main advantage of dual-fuel engines is their lower nitrogen oxides (NO_x) and particulate emissions. Hence renewable fuels such as biodiesels and gaseous fuels can be used predominantly for transportation and power generation applications. Gaseous fuels are clean burning and are more economical as well. A suitable carburettor was designed to supply a stoichiometric mixture of air and HCNG to the modified diesel engine operated in dual-fuel mode. The biodiesel used in this study is derived from Honge oil called the Honge oil methyl ester (HOME). This paper presents the performance, combustion and exhaust emission characteristics of a single cylinder, four stroke, direct injection, stationary diesel engine operated on HOME and HCNG in dual-fuel mode. From the results it is observed that HOME–HCNG combination gave lower brake thermal efficiency (BTE) and improved emission levels when compared with diesel/HOME in single fuel operation. Lower smoke and particulate matter were obtained with dual-fuel operation. Comparative measures of BTE, peak pressure, pressure–crank angle variation, smoke opacity, hydrocarbon, carbon monoxide and NO_x emissions have been made and analysed.     

Heavy metal contamination by Al-fabrication plants in Hong Kong

Leaf samples of six plant species collected from locations near the Al-fabrication plants in Sai Kung, Hong Kong were found to be heavily contaminated by Al, Cd, Pb, Ni, Cu and Zn, as determined by inductively — coupled plasma emission spectrophotometer (ICP). Studies using scanning electron microscope incorporated with X-ray microanalyzer showed that significant amounts of dust, with elevated concentrations of heavy metals, were deposited on the leaf surface. The stomatal pores were partially plugged and the guard cells were distorted. The amount of dust deposition and metal contamination varied significantly among different species. Lantana camara had the highest concentrations of all metals. Washing with deionized water could remove the surficial dust particles and reduce the metal contamination, with a degree of effectiveness depending on plant species and metal species. About 50% of Al and other metals were removed from leaves of L. camara and Fiscus variegata by washing, whereas only 20% removal was recorded in Bauhina variegata, the species had the least dust deposition. The soil samples and Al wastes collected from the same sites also exhibited higher values of total metal concentrations than the control. However, the contents of extractable metals were extremely low and were almost below the limits of detection. Experimental data further suggested that the source of leaf metals was mainly accumulated from metal-enriched aerosols, either from Al-fabrication plants or from automobile exhausts, and contribution from soil was relatively unimportant.     

Combustion particles emitted during church services: Implications for human respiratory health

Burning candles and incense generate particulate matter (PM) that produces poor indoor air quality and may cause human pulmonary problems. This study physically characterised combustion particles collected in a church during services. In addition, the emissions from five types of candles and two types of incense were investigated using a combustion chamber. The plasmid scission assay was used to determine the oxidative capacities of these church particles. The corresponding risk factor (CRf) was derived from the emission factor (Ef) and the oxidative DNA damage, and used to evaluate the relative respiratory exposure risks. Real-time PM measurements in the church during candle–incense burning services showed that the levels (91.6 μg/m³ for PM₁₀; 38.9 μg/m³ for PM_2.5) exceeded the European Union (EU) air quality guidelines. The combustion chamber testing, using the same environmental conditions, showed that the incense Ef for both PM₁₀ (490.6–587.9 mg/g) and PM_2.5 (290.1–417.2 mg/g) exceeded that of candles; particularly the PM_2.5 emissions. These CRf results suggested that the exposure to significant amounts of incense PM could result in a higher risk of oxidative DNA adducts (27.4–32.8 times) than tobacco PM. The generation and subsequent inhalation of PM during church activities may therefore pose significant risks in terms of respiratory health effects.     

Decoupling of nonferrous metal consumption from economic growth in China

Nonferrous metal is an important basis material for the development of the national economy, and its consumption directly affects economic development. It has great significance in the effective utilization of nonferrous metals, development of an environment-friendly society, and investigation of the decoupling of nonferrous metal consumption and GDP growth. The decoupling indicators for nonferrous metal consumption and GDP growth (D _r) in China from 1995 to 2010 were calculated in this study, and the results were analyzed. A productive model based on BP neural network was established. Then, the decoupling indicators for nonferrous metal consumption and GDP growth in China for the period of 2011–2020 were predicted. For the period of 1995–2010, the annual average decoupling indicators were <1 for copper, aluminum, zinc, lead, and nickel, except for tin, which was 0.21. The analysis showed that the decoupling of nonferrous metal consumption and GDP growth is in a less optimistic situation to copper, aluminum, zinc, lead, and nickel in China from 1995 to 2010. The annual average decoupling indicator for tin was 0.21, which indicates relative decoupling. For the period of 2011–2020, the predicted decoupling indicators for copper, aluminum, zinc, lead, nickel, and tin were between 0 and 1. This finding indicates the implementation of relative decoupling. However, the total consumption of nonferrous metals did not decouple from GDP growth.     

Effect of bioethanol and thermal barrier coating on the performance of dual fuel engine operating on Honge oil methyl ester (HOME) and producer gas induction

Alternative fuels have numerous advantages compared to fossil fuels as they are renewable, biodegradable; provide energy security and foreign exchange saving besides addressing environmental concerns and socio-economic issues as well. Renewable fuels can be used predominantly as fuel for both transportation and power generation applications. Improved engine performance with reduced engine exhaust emissions is a major research objective in engine development. Today, the use of biomass derived producer gas is more relevant for addressing rural power generation and is a promising technique for controlling both nitric oxide (NO_x) and soot emission levels. In view of this, exhaustive experiments on the use of Honge oil methyl ester (HOME)–Producer gas in a dual fuel engine have been carried out with an intension of improving its fuel efficiency. This paper mainly presents results on a single cylinder four stroke direct injection diesel engine operated in dual fuel mode using HOME–Producer gas combination with and without bio-ethanol addition and thermal barrier coating (TBC). Further, the results were compared with diesel–producer gas mode of operation. Experimental investigation on dual fuel operation using HOME+5% bioethanol (BE5)–Producer gas operation with TBC showed 12.35% increased brake thermal efficiency with decreased hydrocarbon and carbon monoxide emissions and increased NO_x emission levels compared to HOME–Producer gas mode of operation.     

Assessment of the radiological impact of oil refining industry

The field of radiation protection and corresponding national and international regulations has evolved to ensure safety in the use of radioactive materials. Oil and gas production processing operations have been known to cause naturally occurring radioactive materials (NORMs) to accumulate at elevated concentrations as by-product waste streams. A comprehensive radiological study on the oil refining industry in Egypt was carried out to assess the radiological impact of this industry on the workers. Scales, sludge, water and crude oil samples were collected at each stage of the refining process. The activity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K were determined using high-resolution gamma spectrometry. The average activity concentrations of the determined isotopes are lower than the IAEA exempt activity levels for NORM isotopes. Different exposure scenarios were studied. The average annual effective dose for workers due to direct exposure to gamma radiation and dust inhalation found to be 0.6 μSv and 3.2 mSv, respectively. Based on the ALARA principle, the results indicate that special care must be taken during cleaning operations in order to reduce the personnel's exposure due to maintenance as well as to avoid contamination of the environment.     

Experimental investigation of energy properties for Stigonematales sp. microalgae as potential biofuel feedstock

Microalgae has been considered potential biofuel source from the last decade owing to its versatile perspectives such as excellent capability of CO₂ capture and sequestration, water treatment, prolific growth rate and enormous energy content. Thus, energy research on microalgae is being harnessed to mitigate CO₂ and meet future energy demands. This study investigated the bioenergy potential of native blue-green microalgae consortium as initial energy research on microalgae in Brunei Darussalam. The local species of microalgae were assembled from rainwater drains, the species were identified as Stigonematales sp. and physical properties were characterised. Sundried biomass with moisture content ranging from 6.5% to 7.37% was measured to be used to determine the net and gross calorific value and they were 7.98 MJ/kg-8.57 MJ/kg and 8.70 MJ/kg-9.45 MJ/kg, respectively. Besides that, the hydrogen content, ash content, volatile matter, and bulk density were also experimented and they were 2.56%-3.15%, 43.6%-36.71%, 57–38%-63.29% and 661.2 kg/m³-673.07 kg/m³, respectively. Apart from experimental values, other physical bioenergy parameters were simulated and they were biomass characteristic index 61,822.29 kg/m³-62,341.3 kg/m³, energy density 5.27 GJ/m³-5.76G J/m³ and fuel value index 86.19–88.54. With these experimental results, microalgae manifested itself a potential source of biofuel feedstock for heat and electricity generation, a key tool to bring down the escalated atmospheric greenhouse gases and an alternation for fossil fuel.     

Using air quality modeling to study source–receptor relationships between nitrogen oxides emissions and ozone exposures over the United States

Human exposure to ambient ozone (O₃) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source–receptor relationships between nitrogen oxides (NO_x) emissions and population exposure to ambient O₃ in 48 states over the continental United States. By removing NO_x emissions from each state one at a time, we calculate the change in O₃ exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source–receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO_x emissions from upwind states contribute more to O₃ exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O₃ exposures in 90% of U.S. states. A state's NO_x emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O₃ exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O₃ exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO_x is equal. In this study, the average O₃ exposures caused by one ton of NO_x emissions ranges from ? 2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO_x emissions varies considerably over space.     

Housing interventions and health: Quantifying the impact of indoor particles on mortality and morbidity with disease recovery

Housing interventions for energy efficiency and greenhouse gas emission reduction have the potential to reduce exposure to indoor air pollution if they are implemented correctly. This work assessed the health impacts of home energy efficiency measures in England and Wales resulting in a reduction in average indoor PM_2.5 exposures of 3 μg m^− 3. The assessment was performed using a new multistate life table model which allows transition into and between multiple morbid states, including recovery to disease-free status and relapse, with transition rates informed by age- and cause-specific disease prevalence, incidence and mortality data. Such models have not previously included disease recovery. The results demonstrate that incorporation of recovery in the model is necessary for conditions such as asthma which have high incidence in early life but likelihood of recovery in adulthood. The impact assessment of the home energy efficiency intervention showed that the reduction in PM_2.5 exposure would be associated with substantial benefits for mortality and morbidity from asthma, coronary heart disease and lung cancer. The overall impact would be an increase in life expectancy of two to three months and approximately 13 million QALYs gained over the 90 year follow-up period. Substantial quality-of-life benefits were also observed, with a decrease in asthma over all age groups and larger benefits due to reduced coronary heart disease and lung cancer, particularly in older age groups. The multistate model with recovery provides important additional information for assessing the impact on health of environmental policies and interventions compared with mortality-only life tables, allowing more realistic representation of diseases with substantial non-mortality burdens.     

The removal of metals and ammonium by natural glauconite

Glauconite deposits, naturally occurring aluminosilicates rich in iron and potassium, are abundant in New Jersey, Delaware, and Maryland. The presence of these deposits has been shown to be responsible for a high content of sodium in ground water for certain region of Maryland. The ammonium and metal (Pb, Zn, and Cd) removal capability was investigated in both batch and column reactors using natural, NaCl- and NaOH-treated glauconite-bearing sand. Ammonium removal by glauconite is a typical ion exchange process. Both ion exchange and adsorption are responsible for matal removal. Important factors such as pH, sample source, and method of pretreatment were studied. The metal removal follows the order of Pb(II) > Zn(II) > Cd(II). The surface acidity of the glauconite is characterized by an acidmetric-alkalimetric titration. The acidity constants, pK₁ⁱ, and pK₂ⁱ, and 3.6 and 6.0, respectively.