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Emissions of fine particulate matter (PM 2.5) from on-road traffic and their influence on air quality and human health are of major concern in urban areas. Exposure to traffic-related PM 2.5 indoors has received considerable attention as people spend about 80% of their time in indoor environments, but little information is currently available on the assessment and mitigation of this exposure. A systematic field study was conducted with the key objective to assess and mitigate indoor human exposure to traffic-related PM 2.5 in a typical naturally ventilated residential apartment. Results indicated that traffic-related PM 2.5 levels indoors exceeded the air quality guidelines (12 μg/m3), and the PM 2.5 levels decreased significantly (74%) while using an indoor air cleaner. The human health risk assessment based on the bioavailable fraction of toxic trace elements revealed a substantial reduction in potential health risk while using the air cleaner. Overall, the major outcomes of this study would help develop effective air pollution control strategies to reduce indoor human exposure to PM 2.5 and potential human health risk caused by vehicular pollution in urban areas. Image 1 • Assessment and mitigation of traffic-related indoor PM 2.5 was studied. • The lowest levels of PM 2.5 indoors were observed while using the air cleaner. • Potential carcinogenic health risk was reduced while using the air cleaner. • Keeping windows closed only provided partial protection to PM 2.5 exposure indoors. • More effective mitigation of exposure to PM 2.5 indoors is needed in Singapore. [ABSTRACT FROM AUTHOR]

Graphene aerogels (GAs) are increasingly being recognized as high performance multifunctional materials to tackle our current and emerging environmental concerns. In order to extend the application potential of GAs, herein we have successfully synthesized nitrogen (N) and sulfur (S) codoped GAs (NSGAs) via a simple, scalable, and inexpensive approach. Owing to their large specific surface area (up to 132 m2 g−1), profound porosity, superior mechanical properties, and coexistence of N and S atoms with tunable atomic content and bonding configurations, the as-prepared NSGAs demonstrated exceptional absorption capacity toward a broad spectrum of oils and organic solvents, with an average absorption rate many folds higher than conventional absorbents. Further, the NSGAs exhibited excellent photocatalytic activity for the decomposition of recalcitrant organic compounds under visible light illumination due to pronounced synergistic coupling effect between the heteroatoms. Specifically, after 5 h of exposure to visible light, a degradation efficiency of over 99% was observed and more than 84% of the total organic carbon was eliminated. Radical trapping experiments revealed that superoxide anion radicals are the predominant oxygen reactive species driving the photocatalytic reactions. More importantly, the mineralization byproducts did not pose any significant antibacterial activity, illustrating the environmentally benign nature of these macroscale photocatalysts. Image 1 • N/S codoped graphene aerogels (NSGAs) are prepared by facile hydrothermal method. • NSGAs can rapidly absorb oils and different types of organic solvents. • NSGAs induce near complete mineralization of a recalcitrant dye under visible light. • More than 80% of the total organic carbon is eliminated by NSGAs. • Coupling of N and S dopants synergistically enhance the application potential of GAs. Versatile nitrogen and sulfur codoped graphene aerogels were synthesized with unique geometrical configurations that show potential for a wide range of environmental applications. [ABSTRACT FROM AUTHOR]

In recent years, the removal of heavy metals from water and wastewater systems remains a challenging issue globally. Adsorption technology is widely used for the removal of heavy metals from aquatic systems due to several advantages including its simple operation, low cost and high efficiency. Biochar, which is an environmental benign and low-cost adsorbent, is increasingly used for remediation of heavy metal pollution in aquatic systems. This review critically analyzes recent developments on the biochar-based adsorptive removal of heavy metals from water and wastewater. Biochar is effective for the removal of several toxic metals (As, Cr and Mn) from groundwater and drinking water. Biochar also shows promising performance for the removal of various heavy metals (Cr, Pb, Cu, Cd and Zn) from wastewater. The heavy metal adsorption capacity of the biochar largely depends on the water/wastewater chemistry (pH, competing ions and initial concentrations of adsorbates), contact time between adsorbates and the adsorbent, adsorbent dose and environmental parameters (temperature). The adsorption isotherms and kinetics can be well explained by the Langmuir and pseudo-second order models, respectively. The key mechanisms which drive the heavy metal adsorption onto biochar include precipitation and ion exchange. Biochar-based adsorptive decontamination of heavy metal pollution is sustainable due to low environmental impacts, low energy consumption and low-costs. The key knowledge gaps and future research directions for improvement of biochar-based sorption capacities are highlighted. This review would help for the development of effective biochar-based adsorption technology for the removal of heavy metals from aquatic environments. [Display omitted] • Recent progress on biochar-based removal of heavy metals is critically analyzed. • Biochar is a low-cost, low-energy demand and environmentally friendly adsorbent. • Biochar is effective for heavy metal removal from water and wastewater systems. • Langmuir isotherm and pseudo-second order kinetic well explain the adsorption data. • Key mechanisms for heavy metal removal include surface precipitation and ion exchange. [ABSTRACT FROM AUTHOR]

Reformulation of petroleum diesel through its blending with various oxygenated fuels has been explored for reducing emissions of diesel particulate matter (DPM). Such oxygenated fuel blends tend to alter the physico-chemical characteristics of DPM and its toxicity due to changes in the combustion chemistry, caused by the thermo-chemical properties of the oxygenated fuels. However, there is a lack of in-depth investigations on the changes in the chemical composition of size-segregated DPM and its related toxicity, especially for smaller particles, when the blended fuels are combusted in diesel engines. To fill this knowledge gap, we examined the effects of blending ultralow sulfur diesel (ULSD) with five different oxygenated fuels (diglyme (DGM), palm oil methyl ester (PME), dimethyl carbonate (DMC), diethyl adipate (DEA), and butanol (Bu)) at 2% and 4% oxygen levels on the carbonaceous composition of size-segregated engine-out DPM and the toxicity of quasi-ultrafine particles (quasi-UFPs, aerodynamic diameter <0.2 μm). The oxygenated fuel blends are effective in promoting soot oxidation in all size ranges and in reducing the total engine-out DPM mass concentrations, but lead to a significant increase in organic carbon (OC) fractions. Smaller particles had higher fractions of OC, particle-bound PAHs and n-alkanes, which varied with the type and content of oxygenates used. The blended fuels significantly affected the surface areas of both soot and volatile particles in the quasi-ultrafine size range, the cytotoxicity of the quasi-UFPs, and altered the global gene expression with a broad range of biochemical pathways due to the changes in the engine-out particle composition caused by the blended fuels. [ABSTRACT FROM AUTHOR]

The importance of three-dimensional (3D) graphene-based macrostructures (GBMs) is increasingly being recognized over the last five years for diverse clean energy-related applications and global climate change mitigation. With exceptionally large specific surface area and highly interconnected pore networks, 3D graphene scaffolds manifest extraordinary nanoscale effects that result in materials with unusual electrical, mechanical, and electrochemical properties. A global multidisciplinary research effort focusing on the development of innovative 3D GBMs with hierarchical microstructures and novel functionalities has therefore recently emerged. This review provides a comprehensive account of the key design principles in preparing high performance 3D GBMs and discusses their application as advanced electrode materials in a range of energy storage and conversion devices, including lithium-ion batteries, supercapacitors, fuel cells, dye-sensitized solar cells, and photoelectrochemical water splitting units. In addition, the review provides insights into newer and emerging sustainable energy applications of 3D GBMs, such as adsorbents for high-density hydrogen storage and selective capture of CO 2 from flue gases, as well as catalysts for photoconversion of CO 2 into clean fuels and value-added chemicals. The current state of knowledge is highlighted for each of the applications, followed by a discussion of our own perspectives on each topic. Finally, the future outlook on practical deployment of 3D GBMs is suggested as concluding remarks. [ABSTRACT FROM AUTHOR]

• Reduction in the exposure to BC and UFPs was assessed with three types of vegetation barriers (VBs). • All three configurations of VBs reduced the exposure of pedestrians to BC and UFPs. • Three-layered hedges of varying heights showed higher BC and UFPs reductions. • PM with diverse morphology and elemental composition was found on leaves of VBs. • This is the first study of its kind conducted in a tropical Asian city. This study investigated the effectiveness of vegetation barriers (VBs) planted along roadsides in a highly urbanized tropical Asian city-state to mitigate pedestrians' exposure to airborne particles (PM) of traffic origin for the first time. Mobile and fixed-site measurements of black carbon (BC) and ultrafine particles (UFPs) were conducted with three types of VBs (green walkway covered with creepers; hedgerow; and three-layer hedges with varying heights) using portable PM devices. The three-layered hedges showed higher BC and UFPs reductions (the average reduction of about 60%) than the other two configurations (20–40%). Deposition of PM with diverse size, morphology and elemental composition onto VBs leaves plays an important role in reducing PM exposure concentration, providing health benefits to pedestrians involved in active mobility on roads. Our findings provide a scientific basis for formulating appropriate guidelines for selecting and installing VBs to reduce the inhalation exposure of pedestrians to PM of traffic origin. [Display omitted] [ABSTRACT FROM AUTHOR]

Atmospheric particulate mercury (PHg) is recognized as a global pollutant that requires regulation because of its significant impacts on both human health and wildlife. The haze episodes that occur frequently in China could influence the transport and fate of PHg. To examine the characteristics of PHg during haze and non-haze days, size-fractioned particles were collected using thirteen-stage Nano-MOUDI samplers (10 nm–18 μm) during a severe haze episode (from December 2013 to January 2014) in Shanghai. The PHg concentration on haze days (4.11 ± 0.53 ng m −3 ) was three times higher than on non-haze days (1.34 ± 0.15 ng m −3 ). The ratio of the PHg concentration to total gaseous mercury (TGM) ranged from 0.42 during haze days to 0.21 during non-haze days, which was possibly due to the elevated concentration of particles for gaseous elemental mercury (GEM) adsorption, elevated sulfate and nitrate contributing to GEM oxidation, and the catalytic effect of elevated water-soluble inorganic metal ions. PHg/PM10 during haze days (0.019 ± 0.004 ng/μg) was lower than during non-haze days (0.024 ± 0.002 ng/μg), and PHg/PM10 was significantly reduced with an increasing concentration of PM10, which implied a relatively lower growth velocity of mercury than other compositions on particles during haze days, especially in the diameter range of 0.018–0.032 μm. During haze days, each size-fractioned PHg concentration was higher than the corresponding fraction on non-haze days, and the dominant particle size was in the accumulation mode, with constant accumulation to a particle size of 0.56–1.0 μm. The mass size distribution of PHg was bimodal with peaks at 0.32–0.56 μm and 3.1–6.2 μm on non-haze days, and 0.56–1.0 μm and 3.1–6.2 μm on haze days. There was a clear trend that the dominant size for PHg in the fine modes shifted from 0.32–0.56 μm during non-haze days to 0.56–1.0 μm on haze days, which revealed the higher growth velocity of PHg on haze days due to the condensation and accumulation of Hg in particles. Traffic emissions and coal combustion may contribute to the high concentrations of Hg, because PHg of every size was found to correlate positively with SO 2 , NO 2 , and CO. A correlation was found between every mode of PHg and relative humidity, which affected the gas-particle partitioning of semi-volatile organic compounds, resulting in effective partitioning into aerosols. The strong correlations between Hg and water-soluble ions implied the oxidation of elemental Hg was the main gas-to-particle chemical transformation process. [ABSTRACT FROM AUTHOR]

Graphene, by virtue of its unique molecular structure and many interesting properties, is receiving considerable attention as an adsorbent for separation and purification of gases. In this study, graphene nanosheets were subjected to heat treatment in the temperature range of 200–800 °C under flowing N 2 to improve their textural characteristics (surface area, pores size, and total pore volume) for efficient removal of CO 2 from flue gases. The resulting graphene materials showed highly ordered structure, large surface area (up to 484 m 2 g −1 ) and interconnected hierarchical pore networks with narrow pore size distribution in the large-micropore/small-mesopore range. As a consequence, the heat-treated graphene samples demonstrated significantly greater CO 2 uptake capabilities (up to 2.89 mmol g −1 ) compared to pristine graphene (0.81 mmol g −1 ) at 0 °C and 1 bar. More importantly, the materials displayed rapid adsorption kinetics with ultrahigh selectivity for CO 2 over N 2 , as well as stable and readily reversible adsorption/desorption cycling behavior. The isosteric heat of adsorption had an unusual dependence on surface loading because of the presence of attractive intermolecular forces between the adsorbed quadrupolar CO 2 molecules. These findings demonstrate for the first time that thermal treatment at high-temperatures can have a positive influence on the single component CO 2 adsorption characteristics of graphene sheets and should be explored further as an effective strategy in the design and development of graphene-based porous solid adsorbents for CO 2 abatement. [ABSTRACT FROM AUTHOR]

A systematic study was conducted to make a comparative evaluation of the effects of blending n-butanol and n-pentanol with biodiesel at 10% and 20% by volume on engine performance and on the physico-chemical characteristics of particulate emissions from a single cylinder, direct injection diesel engine. The engine was operated at a constant engine speed and at three engine loads. Compared to biodiesel, butanol–biodiesel blends lead to a maximum of 1.6% increase in the brake thermal efficiency (BTE) and an increase in the brake specific fuel consumption (BSFC) by 1.9–3.9% at low and medium engine loads. Pentanol–biodiesel blends result in an improvement in the BTE and a maximum of 2% increase in the BSFC. Compared to biodiesel, both the blended fuels can reduce the particulate mass and elemental carbon (EC) emissions, with butanol being more effective than pentanol. The blended fuels also show a lower emission of total particle-phase polycyclic aromatic hydrocarbons (PAHs) and also a lower carcinogenic potential. However, the proportion of particulate-bound organic carbon (OC) and water-soluble organic carbon (WSOC) are increased for the both blended fuels, especially for 20% butanol in blends. The emissions of volatile and solid particles are reduced significantly in terms of their counts for both kinds of blended fuels at medium and high engine loads, whereas the total particle counts for both 10% and 20% butanol in blended fuels are increased at low engine load due to a significant increase in particles with diameter less than 15 nm. [ABSTRACT FROM AUTHOR]

Metal-based fuel-borne catalysts (FBCs) have been used with diesel fuels to effectively reduce soot and diesel particulate matter (DPM) emissions from both on-road and off-road applications. However, there is a lack of detailed investigations on the potential changes in the properties of particulates, when FBCs-doped fuels are combusted in diesel engines. This study fully evaluates the potential impacts of ferrocene-doped ultralow sulfur diesel (ULSD) fuels on physical, chemical and toxicological characteristics of the particulates emitted by a single cylinder, direct-injection diesel engine working at a constant speed and at three engine loads. The results indicated that ferrocene-doped fuels could effectively reduce the particulate mass and elemental carbon (EC) emissions, while increasing the proportion of both organic carbon (OC) and water-soluble organic carbon (WSOC) in particles. Particle-phase PAHs and n-alkanes emissions increased with an increase of Fe in the fuels. Ferrocene addition also led to lower soot ignition temperature and activation energy. However, the total number emissions of particles from ferrocene-doped fuels dramatically increased due to the formation of Fe-rich nuclei mode particles. Compared to pure ULSD, the particles emitted from ferrocene-doped fuels showed a slight decline in cell viability. The Fe in the particles and the changes in chemical composition of particulates are thought to be responsible for the variation of cell viability. [ABSTRACT FROM AUTHOR]

A systematic study was conducted to evaluate and compare the effects of blending five different oxygenated compounds, diglyme (DGM), palm oil methyl ester (PME), dimethyl carbonate (DMC), diethyl adipate (DEA) and butanol (Bu) with ultralow sulfur diesel (ULSD), on engine performance, particulate mass concentrations, organic (OC) and elemental (EC) carbon fractions of the particles and particle size distributions from a single cylinder, direct injection stationary diesel engine with the engine working at a constant engine speed and at three engine loads. A small increase in the brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) was observed with the use of oxygenates blended with ULSD. All five oxygenates were found to be effective at reducing particulate mass emissions at medium and high engine loads, with butanol being the most effective and DGM being the least effective. Analysis of the relative contribution of changes in the OC and EC emissions to the reduction of particulate matter indicated that under the same oxygen content, EC made a dominant contribution to the reduction of particulate mass. The results also indicated that reduction in both particle mass and number emissions was affected not only by the oxygen content, but also by the chemical structure and thermophysical properties of oxygenates as well as engine operating conditions. [ABSTRACT FROM AUTHOR]

Simple tuning of hydrothermal pre-treatment parameters is shown to result in significant enhancement in the mesopore area of activated carbon obtained from biomass (coconut shell). ZnCl 2 content and temperature were used as parameters to improve the effectiveness of hydrothermal pre-treatment. With progressive increase in the treatment temperature, the enhancement of ZnCl 2 diffusion was tempered by its reduced solubility. By identifying favorable working ranges for ZnCl 2 content and temperature to promote mesopore formation, up to 80% increase in mesopore area is achieved in comparison to the conventional soaking process for formation of mesoporous activated carbon. The enhancement in mesopore area was substantiated by high adsorption capacities for a mixture of phenol red and phenol up to 351 and 264 mg/g, respectively. [ABSTRACT FROM AUTHOR]

Antibiotics are widely used for treatment of diseases caused by bacteria. They reach the aquatic environment through urine and excreta. The dominant antibiotics that are commonly detected in aquatic environments include tetracyclines, sulfonamides and quinolones. This review critically analyzes the effectiveness of carbon-based materials (biochar and hydrochar) for removal of antibiotics from wastewater and water. Both biochar and hydrochar show excellent performance for adsorptive removal of antibiotics from the aqueous medium. However, the adsorption capacity of hydrochar is relatively higher than that of biochar, specifically for the removal of tetracyclines. Insights into removal mechanisms, solution chemistry, adsorption kinetics, isotherms, adsorbent regeneration and cost-analysis are provided. The key mechanisms associated in the adsorption of antibiotics onto biochar/hydrochar surfaces include π-π electron donor-acceptor interactions and H-bonding. Thermodynamics studies indicate the sorption process is mostly spontaneous and endothermic. In most cases, the adsorption data can best fit the pseudo-second-order kinetic and Langmuir isotherm models. Overall, biochar/hydrochar-mediated adsorptive removal of antibiotics from aqueous solution merits serious considerations from both economic and environmental perspectives. The key knowledge gaps and future research directions are highlighted to expand the scope of ongoing research on engineered biochar/hydrochar and modification of their physicochemical characteristics to achieve effective removal of antibiotics and their metabolites. [Display omitted] • This review presents recent advancements on antibiotics removal by bio/hydrochar. • Tetracyclines, sulfonamides and quinolones are included in this review. • Hydrochar shows higher adsorption capacity than biochar for removal of antibiotics. • Adsorption data are best described by pseudo 2nd-order kinetic/Langmuir isotherm models. • Key removal mechanisms include hydrophobic, π - π EDA interactions and H-bonding. [ABSTRACT FROM AUTHOR]

The development of economic growth, population, and rapid urbanization is increasing the pace of energy consumption and waste production. These trends, if left unchecked, will lead to massive environmental degradation. Waste-to-energy (WtE) conversion is one way of alleviating the twin problems of fossil fuel use and solid waste disposal, and their related problems (climate change, pollution etc). Life Cycle Assessment (LCA) is a useful tool for assessing the environmental performances of WtE systems. Over fifty LCA studies on various WtE systems are reviewed, comprising different waste sources, energy products, and including countries from six continents. A variety of waste types, such as agricultural residues, used cooking oil, manure, municipal solid waste, and waste wood were studied. The review found that a large majority of WtE has lower greenhouse gas emissions when compared to fossil fuels. However, some WtE studies showed an increase in environmental impacts such as acidification and eutrophication, compared to fossil fuel extraction and use. This is due to the use of chemicals (fertilizers, pesticides) in agriculture and the allocation of these impacts to the use of the agricultural waste for energy conversion. Other problems with LCA are also highlighted, including allocation issues, definition of reference systems and functional units. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effects of butanol addition to B20 on physicochemical and toxicological characteristics of PM were investigated. [•] The butanol addition slightly increases BSFC and BTE. [•] The PM2.5, EC and particle-phase PAHs emissions decreased, with the increased OC fraction in PM. [•] The total number of particles as well particle geometric mean diameter decreased. [•] Reduction in the cytotoxicity of particle extracts was observed with butanol. [ABSTRACT FROM AUTHOR]

Highlights: [•] Butanol addition to diesel in blends influences particulate emissions. [•] It reduces PM2.5 and elemental carbon emissions while increases the proportion of organic carbon in particles. [•] The total number concentrations of volatile and non-volatile particles decreases significantly. [•] The higher proportion of butanol in blends leads to higher particle-phase PAHs emissions. [•] The cytotoxicity of particle extracts from diesel and blended fuels shows no significant difference. [Copyright &y& Elsevier]

Highlights: [•] The performance of HTC and LTP was compared to produce solid fuel from waste biomass. [•] Fuel qualities of the biochars produced from HTC and LTP were investigated. [•] Ash problem related metal contents in two biochars were analyzed. [•] Combustion characteristics of two biochars were determined. [•] Hydrothermally prepared biochar is suitable for use as a solid fuel. [ABSTRACT FROM AUTHOR]

Highlights: [•] Coconut fiber (CF), its biochar and their blends with lignite were pyrolyzed. [•] CF and its biochar showed different nitrogen partitioning between HCN and NH3. [•] Interactions between CF/biochar and lignite decreased HCN and NH3 yields. [•] Less HCN+NH3 and more N2 were generated from biochar/lignite pyrolysis. [•] Enhanced benefits can be achieved from biochar/lignite co-processing. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a comparative assessment of the effectiveness of ssDNA and chlorine as disinfectants for treating water contaminated with Escherichia coli (E. coli) was investigated on the basis of cytotoxicity and genotoxicity. The gene targets addressed for the ssDNA based inhibition method were marA (multiple antibiotic resistance) and groL (essential gene Hsp60) in E. coli. Based on the maximum log reduction in E. coli cell numbers when compared to no ssDNA control, groL-1 was chosen as the optimized ssDNA for gene silencing-based inactivation. For toxicity assessment, HepG2 cells were exposed to extracts corresponding to concentrations of 0.2, 1, 5, 25 and 50 mL water/mL medium of chlorine doped water and 1, 10, 100, 300 nM of ssDNA. Compared with ssDNA, HepG2 cells exposed to extracts of chlorine doped water for 24 h showed higher cytotoxicity, caspase 3/7 levels, DNA damage, micronuclei frequency, and decreased cell viability. Water doped with chlorine was found to be more toxic than that by ssDNA when exposed to HepG2 cells. The results of this study provide a scientific basis for comparative evaluation of new and conventional disinfection methods by taking into consideration the outcome of cytotoxicity and genotoxicity assessments. [Copyright &y& Elsevier]

One of the key challenges in photocatalysis is the suppression of electron-hole pairs' recombination, which reduces the photocatalytic degradation efficiency of promising materials. In this study, a novel heterostructured photocatalyst (In(OH) 3 /NGAs) was synthesized by coupling indium hydroxide (In(OH) 3) with nitrogen-doped graphene aerogels (NGAs). A comprehensive evaluation of the photocatalytic degradation performance of In(OH) 3 /NGAs was conducted using para -nitrophenol (p -NP) as a model pollutant under visible light. Results show that impressive photocatalytic activities of In(OH) 3 /NGAs are mainly due to their strong synergistic effects of the heterojunction formed between In(OH) 3 and NGAs , and the active nitrogen doping of GAs. The synergistic effects result in a sizable bandgap and thus enhance the visible light absorption capability. The favorable formation of photo-generated holes and hydroxyl radicals is responsible for the efficient photocatalytic degradation of p -NP, leading to 98% removal of total organic carbon. Additionally, a comparative evaluation of the photodegradation performance of In(OH) 3 /NGAs with that of another indium-based heterostructured material (In 2 O 3 /g-C 3 N 4 (graphitic carbon nitride) shows the superior performance of the former photocatalyst which is attributed to its unique molecular configuration and chemical bonds. This work reveals how a rational combination of NGAs with In(OH) 3 can lead to efficient photocatalytic degradation of recalcitrant organic pollutants such as p -NP. [Display omitted] • In-based N-doped graphene aerosols (NGAs) and g-C 3 N 4 composites were synthesized. • Photocatalytic degradation of p-NP by In-NGAs and In g-C 3 N 4 was studied. • In-NGAs demonstrated better photocatalytic performance than In g-C 3 N 4. • The performance of In-NGAs was optimized to maximize their photocatalytic potential. • Insights into the photocatalytic degradation of p-NP by In-NGAs are provided. [ABSTRACT FROM AUTHOR]

Highlights: [•] The biochars were prepared from woody and non-woody biomass by pyrolysis. [•] The biochars had improved fuel qualities than their parent biomass. [•] The addition of biomass (biochar) in lignite increased reactivities of the blends. [•] Significant interactions were observed within all the fuel blends. [•] Limited increase of slagging and fouling for biochar/lignite than biomass/lignite. [Copyright &y& Elsevier]

Abstract: Microcystins (MCs) are algal toxins produced intracellularly within the algal cells, and are subsequently released into the aquatic systems. An increase in the frequency and intensity of occurrence of harmful algal blooms has directed the global attention towards the presence of MCs in aquatic systems. The effects of MCs on fish have been verified in a number of studies including histological, biochemical and behavioral effects. The toxicological effects of MCs on different organs of fish are related to the exposure route (intraperitoneal injection, feeding or immersion), the mode of uptake (passive or active transport) as well as biotransformation and bioaccumulation capabilities by different organs. This paper reviews the rapidly expanding literature on the toxicological evaluation of MCs in fish from both field studies and controlled laboratory experimental investigations, integrates the current knowledge available about the mechanisms involved in MC-induced effects on fish, and points out future research directions from a cross-disciplinary perspective. In addition, the need to carry out systematic fish toxicity studies to account for possible interactions between MCs and other environmental pollutants in aquatic systems is discussed. [Copyright &y& Elsevier]