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This paper aims to develop a construction and operation cost model of wastewater treatment for the paper industry in China and explores the main factors that determine these costs. Previous models mainly involved factors relating to the treatment scale and efficiency of treatment facilities for deriving the cost function. We considered the factors more comprehensively by adding a regional variable to represent the economic development level, a corporate ownership factor to represent the plant characteristics, a subsector variable to capture pollutant characteristics, and a detailed-classification technology variable. We applied a unique data set from a national pollution source census for the model simulation. The major findings include the following: (l) Wastewater treatment costs in the paper industry are determined by scale, technology, degree of treatment, ownership, and regional factors; (2) Wastewater treatment costs show a large decreasing scale effect; (3) The current level of pollutant discharge fees is far lower than the marginal treatment costs for meeting the wastewater discharge standard. Key implications are as follows: (l) Cost characteristics and impact factors should be fully recognized when planning or making policies relating to wastewater treatment projects or technology development; (2) There is potential to reduce treatment costs by centralizing wastewater treatment via industrial parks; (3) Wastewater discharge fee rates should be increased; (4) Energy efficient technology should become the future focus of wastewater treatment. [ABSTRACT FROM AUTHOR]

This study provides a systematic approach for assessment of contaminants in materials for recycling. Paper recycling is used as an illustrative example. Three selected chemicals, bisphenol A (BPA), diethylhexyl phthalate (DEHP) and mineral oil hydrocarbons (MOHs), are evaluated within the paper cycle. The approach combines static material flow analysis (MFA) with dynamic material and substance flow modeling. The results indicate that phasing out of chemicals is the most effective measure for reducing chemical contamination. However, this scenario was also associated with a considerable lag phase (between approximately one and three decades) before the presence of chemicals in paper products could be considered insignificant. While improved decontamination may appear to be an effective way of minimizing chemicals in products, this may also result in lower production yields. Optimized waste material source-segregation and collection was the least effective strategy for reducing chemical contamination, if the overall recycling rates should be maintained at the current level (approximately 70% for Europe). The study provides a consistent approach for evaluating contaminant levels in material cycles. The results clearly indicate that mass-based recycling targets are not sufficient to ensure high quality material recycling. [ABSTRACT FROM AUTHOR]

Significant amounts of paper deinking residue (DIR) has been and is still being generated from paper deinking processes, representing both an economic and environmental burden for recycled paper mills. Our research on low-temperature (<200 °C) microwave-assisted (MW-assisted) pyrolysis of DIR allows for simultaneously efficient fast separation and recovery of the organic and inorganic content of DIR at relatively low temperature and within 15 min. Our study is the first highly detailed account of the use low-temperature MW-assisted pyrolysis to effect this change. The obtained liquid and solid products were characterized by a variety of analytical techniques (e.g., attenuated total reflection infrared, gas chromatography-mass spectrometry, liquid-state nuclear magnetic resonance (NMR), X-ray diffraction, solid-state cross-polarization/magic-angle spinning 13C NMR, and Bloch-decay 13C NMR). The results reveal that the process efficiently separates the inorganic minerals as microwave residue (mainly calcite and kaolinite) from organic matter, and hence the microwave residue could be reused to produce new paper/cardboard products. The organic fraction bio-oil generated is energy-densified and rich in carbohydrates and is a potential source for valuable aromatic compounds. [ABSTRACT FROM AUTHOR]

Simulated experiments indicated that chlorinated volatile methylsiloxanes, detected by Q-TOF GC/MS, could be generated in a pulpbleaching process, where poly(dimethylsiloxane)s fluids with volatile methylsiloxanes as impurities and molecular chlorine were used as a defoamer and bleaching agent, respectively. In the producing processes of one papermaking factory, the mean total concentrations of monochlorinated D4, D5, and D6, i.e., D3D(CH2Cl), D4D(CH2Cl), and D5D(CH2Cl), were 0.0430−287 μg/L in aqueous samples, while they were 0.0329−270 μg/g in solid samples. In the coupled papermaking-wastewater treatment processes, D3D(CH2Cl), D4D(CH2Cl), and D5D(CH2Cl) were detected in all water (0.113−8.68 μg/L) and solid samples (0.888−26.2 μg/g), with solid−water partition values (468−3982 L/kg) 1.08−4.82 times higher than those of their corresponding nonchlorinated analogs. The removing efficiencies of D3D- (CH2Cl)−D5D(CH2Cl) in the whole wastewater treatment processes were 77.1−81.6%, and sorption to sludge (35.7−74.1%) and removal in the primary clarifier (7.19−32.5%) had major contributions to their total removal. Elimination experiments showed that 1) hydrolysis half-lives of D3D(CH2Cl)−D5D(CH2Cl) (0.9−346 h) in the primary clarifier (pH = 7.8−9.2) were 2.16−3.60 times shorter than those of their nonchlorinated analogs; 2) D3D(CH2Cl)−D5D(CH2Cl) were hardly degraded in oxic sludge treatment process, and their volatilization half-lives (7.38− 21.1 h) in oxic sludge were 1.21−1.50 times longer than those of their nonchlorinated analogs. [ABSTRACT FROM AUTHOR]

Toxicokinetic-toxicodynamic (TKTD) models, as the General Unified Threshold model of Survival (GUTS), provide a consistent process-based framework compared to classical dose-response models to analyze both time and concentration-dependent data sets. However, the extent to which GUTS models (Stochastic Death (SD) and Individual Tolerance (IT)) lead to a better fitting than classical dose-response model at a given target time (TT) has poorly been investigated. Our paper highlights that GUTS estimates are generally more conservative and have a reduced uncertainty through smaller credible intervals for the studied data sets than classical TT approaches. Also, GUTS models enable estimating any x% lethal concentration at any time (LCx,t), and provide biological information on the internal processes occurring during the experiments. While both GUTS-SD and GUTS-IT models outcompete classical TT approaches, choosing one preferentially to the other is still challenging. Indeed, the estimates of survival rate over time and LCx,t are very close between both models, but our study also points out that the joint posterior distributions of SD model parameters are sometimes bimodal, while two parameters of the IT model seems strongly correlated. Therefore, the selection between these two models has to be supported by the experimental design and the biological objectives, and this paper provides some insights to drive this choice. [ABSTRACT FROM AUTHOR]

Sorption-enhanced steam reforming (SESR) is an energy and cost efficient approach to produce hydrogen with high purity. SESR makes it economically feasible to use a wide range of feedstocks for hydrogen production such as methane, ethanol, and biomass. Selection of catalysts and sorbents plays a vital role in SESR. This article reviews the recent research aimed at process intensification by the integration of catalysis and chemisorption functions into a single material. Alkali metal ceramic powders, including Li2ZrO3, Li4SiO4 and Na2ZrO3 display characteristics suitable for capturing CO2 at low concentrations (<15% CO2) and high temperatures (>500 °C), and thus are applicable to precombustion technologies such as SESR, as well as postcombustion capture of CO2 from flue gases. This paper reviews the progress made in improving the operational performance of alkali metal ceramics under conditions that simulate power plant and SESR operation, by adopting new methods of sorbent synthesis and doping with additional elements. The paper also discusses the role of carbonates formed after in situ CO2 chemisorption during a steam reforming process in respect of catalysts for tar cracking. [ABSTRACT FROM AUTHOR]

Biologically Inspired Design (biomimicry) and Industrial Ecology both look to natural systems to enhance the sustainability and performance of engineered products, systems and industries. Bioinspired design (BID) traditionally has focused on a unit operation and single product level. In contrast, this paper describes how principles of network organization derived from analysis of ecosystem properties can be applied to industrial system networks. Specifically, this paper examines the applicability of particular food web matrix properties as design rules for economically and biologically sustainable industrial networks, using an optimization model developed for a carpet recycling network. Carpet recycling network designs based on traditional cost and emissions based optimization are compared to designs obtained using optimizations based solely on ecological food web metrics. The analysis suggests that networks optimized using food web metrics also were superior from a traditional cost and emissions perspective; correlations between optimization using ecological metrics and traditional optimization ranged generally from 0.70 to 0.96, with flow-based metrics being superior to structural parameters. Four structural food parameters provided correlations nearly the same as that obtained using all structural parameters, but individual structural parameters provided much less satisfactory correlations. The analysis indicates that bioinspired design principles from ecosystems can lead to both environmentally and economically sustainable industrial resource networks, and represent guidelines for designing sustainable industry networks. [ABSTRACT FROM AUTHOR]

The organic foulants and bacteria in secondary wastewater treatment can seriously impair the membrane performance in a water treatment plant. The embedded electrode approach using an externally applied potential to repel organic foulants and inhibit bacterial adhesion can effectively reduce the frequency of membrane replacement. Electrode embedment in membranes is often carried out by dispensing a conductor (e.g., carbon nanotubes, or CNTs) in the membrane substrate, which gives rise to two problems: the leaching-out of the conductor and a percolation-limited membrane conductivity that results in an added energy cost. This study presents a facile method for the embedment of a continuous electrode in thin-film composite (TFC) forward osmosis (FO) membranes. Specifically, a conducting porous carbon paper is used as the understructure for the formation of a membrane substrate by the classical phase inversion process. The carbon paper and the membrane substrate polymer form an interpenetrating structure with good stability and low electrical resistance (only about 1O/?). The membrane-electrode assembly was deployed as the cathode of an electrochemical cell, and showed good resistance to organic and microbial fouling with the imposition of a 2.0 V DC voltage. The carbon paper-based FO TFC membranes also possess good mechanical stability for practical use. [ABSTRACT FROM AUTHOR]

Due to the complexity of power systems, tracking emissions attributable to a specific electrical load is a daunting challenge but essential for many environmental impact studies. Currently, no consensus exists on appropriate methods for quantifying emissions from particular electricity loads. This paper reviews a wide range of the existing methods, detailing their functionality, tractability, and appropriate use. We identified and reviewed 32 methods and models and classified them into two distinct categories: empirical data and relationship models and power system optimization models. To illustrate the impact of method selection, we calculate the CO2 combustion emissions factors associated with electric-vehicle charging using 10 methods at nine charging station locations around the United States. Across the methods, we found an up to 68% difference from the mean CO2 emissions factor for a given charging site among both marginal and average emissions factors and up to a 63% difference from the average across average emissions factors. Our results underscore the importance of method selection and the need for a consensus on approaches appropriate for particular loads and research questions being addressed in order to achieve results that are more consistent across studies and allow for soundly supported policy decisions. The paper addresses this issue by offering a set of recommendations for determining an appropriate model type on the basis of the load characteristics and study objectives. [ABSTRACT FROM AUTHOR]

Managing freshwater allocation for a highly populated and growing economy like India can benefit from knowledge about the effect of economic activities. This study transforms the 2003-2004 economic input-output (IO) table of India into a water withdrawal input-output model to quantify direct and indirect flows. This unique model is based on a comprehensive database compiled from diverse public sources, and estimates direct and indirect water withdrawal of all economic sectors. It distinguishes between green (rainfall), blue (surface and ground), and scarce groundwater. Results indicate that the total direct water withdrawal is nearly 3052 billion cubic meter (BCM) and 96% of this is used in agriculture sectors with the contribution of direct green water being about 1145 BCM, excluding forestry. Apart from 727 BCM direct blue water withdrawal for agricultural, other significant users include "Electricity" with 64 BCM, "Water supply" with 44 BCM and other industrial sectors with nearly 14 BCM. "Construction", "miscellaneous food products"; "Hotels and restaurants"; "Paper, paper products, and newsprint" are other significant indirect withdrawers. The net virtual water import is found to be insignificant compared to direct water used in agriculture nationally, while scarce ground water associated with crops is largely contributed by northern states. [ABSTRACT FROM AUTHOR]

This paper has changed the vague understanding that "the short-lived buildings have huge environmental footprints (EF)" into a concrete one. By estimating the annual floor space of buildings demolished and calibrating the average building lifetime in China, this paper compared the EF under various assumptive extended buildings' lifetime scenarios based on time-series environmental-extended input-output model. Results show that if the average buildings' lifetime in China can be extended from the current 23.2 years to their designed life expectancy, 50 years, in 2011, China can reduce 5.8 Gt of water withdrawal, 127.1 Mtce of energy consumption, and 426.0 Mt of carbon emissions, each of which is equivalent to the corresponding annual EF of Belgium, Mexico, and Italy. These findings will urge China to extend the lifetime of existing and new buildings, in order to reduce the EF from further urbanization. This paper also verifies that the lifetime of a product or the replacement rate of a sector is a very important factor that influences the cumulative EF. When making policies to reduce the EF, adjusting people's behaviors to extend the lifetime of products or reduce the replacement rate of sectors may be a very simple and cost-effective option. [ABSTRACT FROM AUTHOR]

Risk assessment (RA) and life cycle assessment (LCA) are two analytical tools used to support decision making in environmental management. This study reviewed 30 environmental assessment case studies that claimed an integration, combination, hybridization, or complementary use of RA and LCA. The focus of the analysis was on how the respective case studies evaluated emissions of chemical pollutants and pathogens. The analysis revealed three clusters of similar case studies. Yet, there seemed to be little consensus as to what should be referred to as RA and LCA, and when to speak of combination, integration, hybridization, or complementary use of RA and LCA. This paper provides clear recommendations toward a more stringent and consistent use of terminology. Blending elements of RA and LCA offers multifaceted opportunities to adapt a given environmental assessment case study to a specific decision making context, but also requires awareness of several implications and potential pitfalls, of which six are discussed in this paper. To facilitate a better understanding and more transparent communication of the nature of a given case study, this paper proposes a "design space" (i.e., identification framework) for environmental assessment case studies blending elements of RA and LCA. Thinking in terms of a common design space, we postulate, can increase clarity and transparency when communicating the design and results of a given assessment together with its potential strengths and weaknesses. [ABSTRACT FROM AUTHOR]

The freight infrastructure network (e.g., roads, railways, waterways, etc.) is the backbone of nearly all trade partnerships in the United States and abroad. The manner in which the individual portions of its constituent parts are interrelated or arranged plays an important role for determining the environmental footprint of goods moved within the network. Herein, we compare the spatial distribution of potential consumer-producer exchanges (i.e., accessibility) under varying greenhouse gas (GHG) budgets or preferences for minimal transportation-related GHG emissions. We conduct case studies using two freight modes (truck and intermodal rail) for two representative commodities: meat/seafood and paper articles. Results across all counties in the United States indicate that the geographic area in which trade is possible, given a GHG budget, varies by transportation mode, location, and commodity. Our results suggest that intermodal terminal availability is an important determinant of low-GHG accessibility. Since only a fraction of road-to-rail terminals accommodate meat/seafood (4.9%) and paper (0.7%), the United States could increase its expected GHG savings associated with truck-to-rail mode-switching policies by 70% (+20 kg CO2,e/ton for meat/seafood) and 310% (+30 kg CO2,e/ton for paper) by upgrading current terminals to allow the exchange of all types of goods. [ABSTRACT FROM AUTHOR]

According to Lim et al., based on World Health Organization (WHO) data, hazardous chemicals in the workplace are responsible for over 370 000 premature deaths annually. Despite these high figures, life cycle impact assessment (LCIA) does not yet include a fully operational method to consider occupational impacts in its scope over the entire supply chain. This paper describes a novel approach to account for occupational exposure to chemicals by inhalation in LCA. It combines labor statistics and measured occupational concentrations of chemicals from the OSHA database to calculate operational LCIA characterization factors (i.e., intakes per hour worked and impact intensities for 19 069 organic chemical/sector combinations with confidence intervals across the entire U.S. manufacturing industry). For the seven chemicals that most contribute to the global impact, measured workplace concentrations range between 5 × 10-4 and 3 × 10³ mg/m³. Carcinogenic impacts range over 4 orders of magnitude, from 1.3 × 10-8 and up to 3.4 × 10-4 DALY per blue-collar worker labor hour. The innovative approach set out in this paper assesses health impacts from occupational exposure to chemicals with population exposure to outdoor emissions, making it possible to integrate occupational exposure within LCIA. It broadens the LCIA scope to analyze hotspots and avoid impact shifting. [ABSTRACT FROM AUTHOR]

The 46 cytochrome P450 (CYP) gene superfamily was identified in the marine copepod Paracyclopina nana after searching an RNA-seq database and comparing it with other copepod CYP gene families. To annotate the 46 Pn- CYP genes, a phylogenetic analysis of CYP genes was performed using a Bayesian method. Pn-CYP genes were separated intofive different clans: CYP2, CYP3, CYP20, CYP26, and mitochondrial. Among these, the principal Pn- CYP genes involved in detoxification were identified by comparing them with those of the copepod Tigriopus japonicus and were examined with respect to their responses to exposure to a water-accommodated fraction (WAF) of crude oil and to the alkylated forms of two polycyclic aromatic hydrocarbons (PAHs; phenanthrene and fluorene). The expression of two Pn- CYP3027 genes (CYP3027F1 and CYP3027F2) was increased in response to WAF exposure and also was upregulated in response to the two alkylated PAHs. In particular, Pn-CYP3027F2 showed tire most notable increase in response to 80% WAF exposure. These two responsive CYP genes (Pn-CYP3027F1 and CYP3027F2) were also phylogenetically clustered into the same clade of the WAF- and alkylated PAH-specific CYP genes of the copepod T. japonicus, suggesting that these CYP genes would be those chiefly involved in detoxification in response to WAF exposure in copepods. In this paper, we provide information on the copepod P. nana CYP gene superfamily and also speculate on its potential role in the detoxification of PAHs in marine copepods. Despite the nonlethality of WAF, Pn-CYP3027F2 was rapidly and significantly upregulated in response to WAF that may serve as a useful biomarker of 40% or higher concentration of WAF exposure. This paper will be helpful to better understand the molecular mechanistic events underlying the metabolism of environmental toxicants in copepods. [ABSTRACT FROM AUTHOR]

We develop an ozone transport and reaction model to determine reaction probabilities and assess the importance of physical properties such as porosity, pore diameter, and material thickness on reactive uptake of ozone to five materials. The one-dimensional model accounts for molecular diffusion from bulk air to the air-material interface, reaction at the interface, and diffusive transport and reaction through material pore volumes. Material-ozone reaction probabilities that account for internal transport and internal pore area, γipa, are determined by a minimization of residuals between predicted and experimentally derived ozone concentrations. Values of γipa are generally less than effective reaction probabilities (?eff) determined previously, likely because of the inclusion of diffusion into substrates and reaction with internal surface area (rather than the use of the horizontally projected external material areas). Estimates of γipa average 1 × 10-7, 2 × 10-7, 4 × 10-5, 2 × 10-5, and 4 × 10-7 for two types of cellulose paper, pervious pavement, Portland cement concrete, and an activated carbon cloth, respectively. The transport and reaction model developed here accounts for observed differences in ozone removal to varying thicknesses of the cellulose paper, and estimates a near constant γipa as material thickness increases from 0.02 to 0.16 cm. [ABSTRACT FROM AUTHOR]

Agricultural land use is a main driver of global biodiversity loss. The assessment of land use impacts in decision-support tools such as life cycle assessment (LCA) requires spatially explicit models, but existing approaches are either not spatially differentiated or modeled at very coarse scales (e.g., biomes or ecoregions). In this paper, we develop a high-resolution (900 m) assessment method for land use impacts on biodiversity based on habitat suitability models (HSM) of mammal species. This method considers potential land use effects on individual species, and impacts are weighted by the species' conservation status and global rarity. We illustrate the method using a case study of crop production in East Africa, but the underlying HSMs developed by the Global Mammals Assessment are available globally. We calculate impacts of three major export crops and compare the results to two previously developed methods (focusing on local and regional impacts, respectively) to assess the relevance of the methodological innovations proposed in this paper. The results highlight hotspots of product-related biodiversity impacts that help characterize the links among agricultural production, consumption, and biodiversity loss. [ABSTRACT FROM AUTHOR]

China is a country with significant but unevenly distributed water resources. The water stressed North stays in contrast to the water abundant and polluted South defining China's current water environment. In this paper we use the latest available data sets and adopt structural decomposition analysis for the years 1992 to 2007 to investigate the driving forces behind the emerging water crisis in China. We employ four water indicators in China, that is, freshwater consumption, discharge of COD (chemical oxygen demand) in effluent water, cumulative COD and dilution water requirements for cumulative pollution, to investigate the driving forces behind the emerging crisis. The paper finds water intensity improvements can effectively offset annual freshwater consumption and COD discharge driven by per capita GDP growth, but that it had failed to eliminate cumulative pollution in water bodies. Between 1992 and 2007, 225 million tonnes of COD accumulated in Chinese water bodies, which would require 3.2-8.5 trillion m3 freshwater, depending on the water quality of the recipient water bodies to dilute pollution to a minimum reusable standard. Cumulative water pollution is a key driver to pollution induced water scarcity across China. In addition, urban household consumption, export of goods and services, and infrastructure investment are the main factors contributing to accumulated water pollution since 2000. [ABSTRACT FROM AUTHOR]

Energy, water, and waste systems analyzed at a nexus level are important to move toward more sustainable cities. In this paper, the "resilience.io" platform is developed and applied to emphasize on waste-to-energy pathways, along with the water and energy sectors, aiming to develop waste treatment capacity and energy recovery with the lowest economic and environmental cost. Three categories of waste including wastewater (WW), municipal solid waste (MSW), and agriculture waste are tested as the feedstock for thermochemical treatment via incineration, gasification, or pyrolysis for combined heat and power generation, or biological treatment such as anaerobic digestion (AD) and aerobic treatment. A case study is presented for Ghana in sub-Saharan Africa, considering a combination of waste treatment technologies and infrastructure, depending on local characteristics for supply and demand. The results indicate that the biogas generated from waste treatment turns out to be a promising renewable energy source in the analyzed region, while more distributed energy resources can be integrated. A series of scenarios including the business-as-usual, base case, naturally constrained, policy interventions, and environmental and climate change impacts demonstrate how simulation with optimization models can provide new insights in the design of sustainable value chains, with particular emphasis on whole-system analysis and integration. [ABSTRACT FROM AUTHOR]

The discarding of plastic products has led to the ubiquitous occurrence of microplastic particles in the marine environment. The uptake and depuration kinetics of ingested microplastics for many marine species still remain unknown despite its importance for understanding bioaccumulation potential to higher trophic level consumers. In this study, Antarctic krill (Euphausia superba) were exposed to polyethylene microplastics to quantify acute toxicity and ingestion kinetics, providing insight into the bioaccumulation potential of microplastics at the first-order consumer level. In the 10 day acute toxicity assay, no mortality or dose-dependent weight loss occurred in exposed krill, at any of the exposure concentrations (0, 10, 20, 40, or 80% plastic diet). Krill exposed to a 20% plastic diet for 24 h displayed fast uptake (22 ng mg-1 h-1) and depuration (0.22 h-1) rates, but plastic uptake did not reach steady state. Efficient elimination also resulted in no bioaccumulation over an extended 25 day assay, with most individuals completely eliminating their microplastic burden in less than 5 days post exposure. Our results support recent findings of limited acute toxicity of ingested microplastics at this trophic level, and suggest sublethal chronic end points should be the focus of further ecotoxicological investigation. [ABSTRACT FROM AUTHOR]

The production of photochemical atmospheres under controlled conditions in an irradiation chamber permits the manipulation of parameters that influence the resulting air-pollutant chemistry and potential biological effects. To date, no studies have examined how contrasting atmospheres with a similar Air Quality Health Index (AQHI), but with differing ratios of criteria air pollutants, might differentially affect health end points. Here, we produced two atmospheres with similar AQHIs based on the final concentrations of ozone, nitrogen dioxide, and particulate matter (PM2.5). One simulated atmosphere (SA-PM) generated from irradiation of ∼23 ppmC gasoline, 5 ppmC α-pinene, 529 ppb NO, and 3 μg m-3 (NH4)2SO4 as a seed resulted in an average of 976 μg m-3 PM2.5, 326 ppb NO2, and 141 ppb O3 (AQHI 97.7). The other atmosphere (SA-O3) generated from 8 ppmC gasoline, 5 ppmC isoprene, 874 ppb NO, and 2 μg m-3 (NH4)2SO4 resulted in an average of 55 μg m–3 PM2.5, 643 ppb NO2, and 430 ppb O3 (AQHI of 99.8). Chemical speciation by gas chromatography showed that photo-oxidation degraded the organic precursors and promoted the de novo formation of secondary reaction products such as formaldehyde and acrolein. Further work in accompanying papers describe toxicological outcomes from the two distinct photochemical atmospheres. [ABSTRACT FROM AUTHOR]

This paper discussed the field test results of mercury oxidation activities over vanadium and cerium based catalysts in both coal-fired circulating fluidized bed boiler (CFBB) and chain grate boiler (CGB) flue gases. The characterizations of the catalysts and effects of flue gas components, specifically the particulate matter (PM) species, were also discussed. The catalytic performance results indicated that both catalysts exhibited mercury oxidation preference in CGB flue gas rather than in CFBB flue gas. Flue gas component studies before and after dust removal equipment implied that the mercury oxidation was well related to PM, together with gaseous components such as NO, SO2, and NH3. Further investigations demonstrated a negative PM concentration-induced effect on the mercury oxidation activity in the flue gases before the dust removal, which was attributed to the surface coverage by the large amount of PM. In addition, the PM concentrations in the flue gases after the dust removal failed in determining the mercury oxidation efficiency, wherein the presence of different chemical species in PM, such as elemental carbon (EC), organic carbon (OC) and alkali (earth) metals (Na, Mg, K, and Ca) in the flue gases dominated the catalytic oxidation of mercury. [ABSTRACT FROM AUTHOR]

Increasing hydropower electricity production constitutes a unique opportunity to mitigate climate change impacts. However, hydropower electricity production also impacts aquatic and terrestrial biodiversity through freshwater habitat alteration, water quality degradation, and land use and land use change (LULUC). Today, no operational model exists that covers any of these cause-effect pathways within life cycle assessment (LCA). This paper contributes to the assessment of LULUC impacts of hydropower electricity production in Norway in LCA. We quantified the inundated land area associated with 107 hydropower reservoirs with remote sensing data and related it to yearly electricity production. Therewith, we calculated an average net land occupation of 0.027 m²⋅yr/kWh of Norwegian storage hydropower plants for the life cycle inventory. Further, we calculated an adjusted average land occupation of 0.007 m²⋅yr/kWh, accounting for an underestimation of water area in the performed maximum likelihood classification. The calculated land occupation values are the basis to support the development of methods for assessing the land occupation impacts of hydropower on biodiversity in LCA at a damage level. [ABSTRACT FROM AUTHOR]

The compound 4-hydroxyphenyl 4-isoprooxyphenylsulfone (BPSIP), a derivative of bisphenol S (BPS), has been detected in thermal paper and human urine samples; however, its potential effects on the endocrine system are largely unknown. The present study was conducted to determine the adverse effects of BPSIP on egg production, relative organ weights, plasma levels of sex hormones, and transcription of genes related to the hypothalamus-pituitary-gonad (HPG) axis in zebrafish (Danio rerio). In male fish, the gonadosomatic index was significantly decreased at concentrations of 5 and 50 μg/L BPSIP. The estrogenic (increase in the 17β-estradiol/testosterone [E2/T] ratio) and antiandrogenic (decrease in T) effects were observed in fish exposed to BPSIP and males were more sensitive to the adverse effects than females. The changes in sex hormones were supported by the regulation of genes along the HPG axis, such as cyp19, 17βhsd, and cyp17 transcripts. Although the effective concentration for endocrine disruption was greater than that of BPS, the actions of BPSIP on the steroidogenic pathway were similar to the effects of BPS exposure. [ABSTRACT FROM AUTHOR]

A novel method for the exhaustive conversion of inorganic nitrogen to nitrogen gas is proposed in this paper. The key properties of the system design included an exhaustive photoelectrochemical cycle reaction in the presence of Cl-, in which Cl· generated from oxidation of Cl- by photoholes selectively converted NH4+ to nitrogen gas and some NO3- or NO2-;. The NO3- or NO2- was finally reduced to nitrogen gas on a highly selective Pd-Cu-modified Ni foam (Pd-Cu/NF) cathode to achieve exhaustive conversion of inorganic nitrogen to nitrogen gas. The results indicated total nitrogen removal efficiencies of 30 mg L-1 inorganic nitrogen (NO3-, NH4+, NO3-/NH4+ = 1:1 and NO2–/NO3-/NH4+ = 1:1:1) in 90 min were 98.2%, 97.4%, 93.1%, and 98.4%, respectively, and the remaining nitrogen was completely removed by prolonging the reaction time. The rapid reduction of nitrate was ascribed to the capacitor characteristics of Pd–Cu/NF that promoted nitrate adsorption in the presence of an electric double layer, eliminating repulsion between the cathode and the anion. Nitrate was effectively removed with a rate constant of 0.050 min–1, which was 33 times larger than that of Pt cathode. This system shows great potential for inorganic nitrogen treatment due to the high rate, low cost, and clean energy source. [ABSTRACT FROM AUTHOR]

We conducted a mobile sampling campaign in a historically industrialized terrain (Pittsburgh, PA) targeting spatial heterogeneity o f organic aerosol. Thirty-six sampling sites were chosen based on stratification of traffic, industrial source density, and elevation. We collected organic carbon (O C ) on quartz filters, quantified different OC components with thermal-optical analysis, and grouped them based on volatility in decreasing order (O C l, OC2, OC3, OC4, and pyrolyzed carbon (PC )). We compared our ambient OC concentrations (both gas and particle phase) to similar measurements from vehicle dynamometer tests, cooking emissions, biomass burning emissions, and a highway traffic tunnel. OC2 and OC3 loading on ambient filters showed a strong correlation with primary emissions while OC4 and PC were more spatially homogeneous. While we tested our hypothesis o f OC2 and OC3 as markers o f fresh source exposure for Pittsburgh, the relationship seemed to hold at a national level. Land use regression (LUR) models were developed for the OC fractions, and models had an average R2 o f 0.64 (SD = 0.09). The paper demonstrates that OC2 and OC3 can be useful markers for fresh emissions, OC4 is a secondary OC indicator, and PC represents both biomass burning and secondary aerosol. People with higher OC exposure are likely inhaling more fresh OC2 and OC3, secondary OC4 and PC varies much less drastically in space o r with local primary sources. [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) is ubiquitous in aqueous environments and plays a significant role in pollutant mitigation, transformation and organic geochemical circulation. DOM is also capable of forming carcinogenic byproducts in the disinfection treatment processes of drinking water. Thus, efficient methods for DOM quantification are highly desired. In this work, a novel sensor for rapid and selective detection of humic substances (HS), a key component of DOM, based on fluorescence quenching of nitrogen-doped carbon quantum dots was developed. The experimental results show that the HS detection range could be broadened to 100 mg/L with a detection limit of 0.2 mg/L. Moreover, the detection was effective within a wide pH range of 3.0 to 12.0, and the interferences of ions on the HS measurement were negligible. A good detection result for real surface water samples further validated the feasibility of the developed detection method. Furthermore, a nonradiation electron transfer mechanism for quenching the nitrogen-doped carbon-dots fluorescence by HS was elucidated. In addition, we prepared a test paper and proved its effectiveness. This work provides a new efficient method for the HS quantification than the frequently used modified Lowry method in terms of sensitivity and detection range. [ABSTRACT FROM AUTHOR]

China established ground PM2.5 monitoring network in late 2012 and hence the long-term and large-scale PM2.5 data were lacking before 2013. In this work, we developed a national-scale spatiotemporal linear mixed effects model to estimate the long-term PM2.5 concentrations in China from 1957 to 1964 and from 1973 to 2014 using ground visibility monitoring data as the primary predictor. The overall model-fitting and cross-validation R² is 0.72 and 0.71, suggesting that the model is not overfitted. Validation beyond the model year (2014) indicated that the model could accurately estimate historical PM2.5 concentrations at the monthly (R² = 0.71) level The historical PM2.5 estimates suggest that air pollution is not a new environmental issue that occurs in the recent decades but a problem existing in a longer time before 1980. The PM2.5 concentrations have reached 60-80 µg/m³ in the north part of North China Plain during 1950s-1960s and increased to generally higher than 90 µg/m³ during 1970s. The results also show that the entire China experienced an overall increasing trend (0.19 µg/m³/yr, P < 0.001) in PM2.5 concentrations from 1957 to 2014 with fluctuations among different periods. This paper demonstrated visibility data allow us to understand the spatiotemporal characteristics of PM[sub 2.5] pollution in China in a longterm. [ABSTRACT FROM AUTHOR]