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Emerging evidences have linked the air pollution particulate matters, especially the fine particulate matter PM2.5, to the disease development of chronic obstructive pulmonary disease (COPD). Our previous studies reported that biofuel PM2.5 can induce devastated damage of human bronchial epithelial cells, this study aims to further investigate the underlying molecular mechanisms how biofuel PM2.5 induces bronchial epithelial cell death and dysfunction. In this study, biofuel PM2.5 extracted from wood smoke (WSPM2.5) was used according to our previous publication. A 16-HBE cell line was used as the cell model. Results showed that: Firstly, WSPM2.5 induced significant pyroptosis in 16-HBE cells, reflected by the typical changes including elevated release of lactate dehydrogenase release (LDH) and activated activity and expression of Caspase-1/IL-1β/IL-18 signaling pathway. Then, specific inhibitors for both Caspases (Z-VAD-FMK) and Caspase-1 (VX-765), as well as specific siRNA knockdown of IL-1β all effectively attenuated the WSPM2.5-induced upregulation of downstream inflammatory cytokines and chemokines (IL-6, IL-8, CXCL-1, CXCL-2, etc), respectively. Notably, WSPM2.5 caused a novel increase of intracellular-to-extracellular ATP secretion, which could also contribute to the WSPM2.5-induced pyroptosis and inflammation by activating the Caspase-1/IL-1β/IL-18 signaling pathway through possible autocrine and/or paracrine mechanisms. Antagonism of ATP (Apyrase) or specific siRNA knockdown against ATP receptors (P2Y2 and P2Y7) both significantly inhibited the WSPM2.5-induced pyroptosis and inflammation. These results add up to the current knowledge and bring up novel insights that WSPM2.5 could induce significant pyroptosis and inflammation of human bronchial epithelial cells, through both a classic NLRP3/Caspase-1/IL-1β-dependent and a novel ATP/P2Y-dependent mechanisms.

The objective of this research was to evaluate the efficacy of cinnamon wood biochar (CWBC) in adsorbing sulfamethoxazole (SUL), which alleviates bioavailability and plant uptake. Batch studies at various pH, contact times, and initial SUL loading were used to study SUL adsorption in CWBC, soil, and 2.5% CWBC amended soil. SUL mitigation from plant uptake were examined using Ipomoea aquatica at different SUL contamination levels in the soil. The kinetic results were described by pseudo-second-order with maximum adsorption capacities (Q

New classes of biosorbents are needed for various environment remediation applications. Thus, a facile and benign approach to synthesize porous biosorbents was developed using acidic or alkaline one-step ball milling of hickory wood biomass (AcBH and AlBH, respectively) without any external heat treatment, and their properties were compared. AcBH and AlBH were richer in O-containing functional groups, had enhanced porous structure and greater ability to remove crystal violet (CV, 476.4 mg g

Various construction materials and interior equipment contain volatile organic compounds (VOCs). Their higher quantities in indoor air are linked to poor health consequences and are controversial regarding health risks, given that people spend so much time indoors. As a result, VOCs in indoor air cause concern regarding sick building syndrome. From a historical perspective, wood and wood-based panels have been frequently employed. Nonetheless, wood appears to be a product and a material of the future in today's world. The emission of VOCs from wood and wood products is essential when assessing the impact of different materials on the indoor environment. The emission rate is affected by both the wood species and the boundary circumstances (drying, storage, etc.). The issue of VOCs emitted from wood, and wood-based panels are addressed in this review paper. The most prevalent VOCs were listed. The advantages and limits of using VOCs for analytical determination from these composites are discussed.

The United Nations estimates the rate of deforestation over 10 million hectares per year, with additional infested wood available due to drought, bark beetle calamity and other damage vectors. Processing the hard-to-reach infested wood into biochar via mobile pyrolysis units seems to be a good option for fire prevention. However, since most biochar is currently produced mainly from biological waste, there is not enough experience with wood biochar on a large scale. Review of current knowledge, followed by techno-economic assessment reveals that following the chemical composition of the feedstock, wood biochar outperforms other types of biochar in terms of high porosity. Therefore, wood biochar shows excellent results in increasing the amount of plant-available water content in soil and appears to be an excellent tool for recycling nutrients (especially into plant-available forms of phosphorus and nitrogen). The overall positive effects of biochar application change from abiotic to biotic over time because as it decays, many of its physical properties disappear, but it can boost soil microbial communities on which soil fertility depends. As global climate change creates a wide range of factors that damage forest cover, wood biochar consequently represents untapped potential in the field of soil, nutrient, and energy management.

The aim of this study was to evaluate the efficacy of biological and chemical remediation of chromated copper arsenate (CCA) treated Corymbia citriodora poles, removed from service after 30 years. The presence of arsenic (As), chromium (Cr) and copper (Cu) was quantified by inductively coupled plasma optical emission spectrometry (ICP–OES). Twelve species of decay fungi were used for the biological remediation assay. For chemical remediation oxalic, citric, maleic and ethylenediamine tetraacetic (EDTA) acids were used for 24 and 48 h. In biological remediation, copper-tolerant brown-rot fungi, Wolfiporia cocos, Antrodia xantha and Fibroporia radiculosa, performed the best results, with the highest removals for As (59–85 %) and Cr (38–61 %). Cu was the most easily extracted, with removals above 60 % among the tested fungi, with the best results (90–98 %) for F. radiculosa, Coniophora puteana, Antrodia vaillantii and Postia placenta. In chemical remediation, the extraction time of 48 h was the most effective, and oxalic acid generally reached the highest removals. The EDTA + oxalic acid combination reached the highest value for Cu extraction (98 %).

Wood-based biochar, as a metal-free heterogeneous activator of peroxydisulfate (PDS), was successfully prepared by pyrolysis of polar sawdust for efficient removal of Acid Orange 7 (AO7). The results demonstrate PDS could be effectively activated by wood-based biochar, and AO7 was rapidly eliminated in a wide range of pH value (3.0–10.0) with AO7 removal achieved ≥ 99.3% after 14 min reaction. The dominant reactive species in the biochar/PDS system were verified via radical quenching tests and electron paramagnetic resonance (EPR) technique. It is speculated that sulfate radicals (SO4•−) and hydroxyl radicals (•OH) were formed on the surface of biochar. Based on the results of X-ray photoelectron spectroscopy (XPS), π-electron density and oxygen-containing functional groups (especially C–OH) on biochar surface were active centers for the catalytic reaction. Recycle experiments of biochar for 4 runs were carried out and the regeneration method of the catalyst was also studied.

Biochar is a promising material for facilitating the reclamation of oil sands process water (OSPW); however, how biochar properties can be optimized for metal removal from OSPW is not well studied. This study was conducted to determine relationships among feedstock type, pyrolysis condition, biochar property, and lead(II) adsorption capacity to demonstrate the potential use of biochar for metal removal from a synthetic OSPW. Sawdust, canola and wheat straw, and manure pellet were pyrolyzed at 300, 500, and 700 °C, with or without steam activation. Increasing pyrolysis temperature increased, with a few exceptions, biochar pH, surface area, and carbon content, but decreased hydrogen and oxygen contents and surface functional groups. Steam activation increased surface area but did not affect other properties. For non-steam-activated biochars, canola and wheat straw biochars produced at 700 °C had the highest lead(II) adsorption capacity (Qmax_Pb), at 108 and 109 mg g−1, respectively. Increasing the pyrolysis temperature increased Qmax_Pb due to increased biochar pH, ash content, and surface area by increasing precipitation, ion exchange, and inner-sphere complexation of lead(II). Steam activation increased lead(II) adsorption capacity for most biochars mainly due to the increased surface area, with the highest Qmax_Pb at 195 mg g−1 for canola straw biochar pyrolyzed at 700 °C with steam activation. The adsorption with time followed a pseudo-second order kinetic model. The results of this study will help select most effective biochars that can be produced from locally available agricultural or forestry byproducts that are optimized for metal removal from synthetic OSPW.

In this study, the influences of feedstock and pyrolysis temperature on carbon fractions of biochar were investigated. Four types of organic wastes (rice straw (RS), pine wood (PW), pig manure (PM) and sewage sludge (SS)) were pyrolyzed at different temperatures (300 °C, 400 °C, 500 °C, 600 °C and 700 °C). Biochar produced at low temperature exhibited high yields, high dissolved organic carbon (DOC) content and unstable organic carbon content. In contrast, biochar formed at high temperature showed high C content and C stability with a low O/C and H/C ratios. In addition, the biochar pyrolyzed from PW contained the lowest DOC of the four biochar types. The properties of DOC fractions (F1, F2 and F3) released from biochar differed depending on feedstock, pyrolysis temperatures, and extraction procedures. The highest specific ultraviolet absorbance at 254 nm of the F1 and F2 fractions were observed for RS biochar, suggesting that more aromatic organic matter was present in sequentially extracted fractions of RS biochar than in extracts from the other biochars. In addition, the hot water extracts (F2) mostly showed higher aromaticity than cold water extracts (F1). The stability of biochars was greatly enhanced at pyrolysis temperatures >500 °C. If the biochars produced in this study were to be used for carbon sequestration in soil, the first priority should be PW, followed in order by RS and PM.

Black carbon such as biochar has been shown to support microbial redox transformation by accepting and/or donating electrons. Electron storage capacity (ESC) is an important property that determines the capacity of a biochar to mediate redox processes in natural and engineered systems. However, it remained unclear whether a biochar's ESC is constant and reversible and if so to what extent, over what redox potential range ESC is distributed, and what fraction of the ESC is microbially accessible. In this study, we developed chemical methods that employed combinations of reductants and oxidants of different potentials – Ti(III) citrate, ferricyanide, dithionite, and dissolved O2 – to measure the ESC of Soil Reef biochar, a wood-derived biochar that can serve as an electron donor or acceptor for Geobacter metallireducens. For a given oxidant–reductant pair, the ESC obtained over multiple redox cycles was constant and fully reversible, though lower than that of the virgin biochar. Pore diffusion within biochar particles was rate-limiting and controlled the timescale for redox equilibrium. Results suggest that redox-facile functional groups in biochar were distributed over a broad range of potentials. The ESC measured using dithionite indicates approximately 22% of the biochar's reversible ESC was accessible to G. metallireducens. We propose that reversible ESC may be regarded as a constant and quantifiable property of black carbon.

This research aims to investigate the effects of irradiation energy and residence time of soft X-ray irradiation in the decomposition of sixteen polycyclic aromatic hydrocarbons (PAHs) in smoke particles emitted from the Para rubber wood burning. The burning process was carried out in a tube furnace and the soft X-ray radiation used had a wave length of 0.13-0.41 nm. The irradiated (IR) and non irradiated (N-IR) smoke particles were collected simultaneously using a 10-stage Andersen sampler equipped with an inertial-filter stage (ANIF), in order to determine the physicochemical characteristic of both IR and N-IR smoke particles, including particle size distribution and concentration, and particle-bound PAHs concentration. Results show that the nano-size smoke particles contained the highest amount of PAHs and of carcinogenic potency equivalent (BaP-TEQ). About 75% of PAH compounds on the total smoke particles were decomposed at the highest irradiation energy. Moreover, 4-6 ring PAHs in nanoparticles (

Biochar has shown a unique electrochemical property being involved in various redox reactions in soil and water. In this study, the electron donating capacities (EDCs) of biochar pyrolyzed at 200–800 °C from pine wood, barley grass and wheat straw were investigated by using the mediated electrochemical oxidation method. The EDC values for all biochar were in the range of 0.18–1.83 mmol e− (g biochar)−1, showing the increase as the temperature increased from 200 °C to 400 °C, the decrease from 400 °C to 650 °C, and then increase from 650 °C until to 800 °C. At low and intermediate temperatures of 200–650 °C, the EDCs were mainly attributed to the phenolic hydroxyl groups, while the conjugated π-electron system associated with aromatic structure dominated the EDCs of biochar at the high temperatures of over 650 °C. The barley grass- and wheat straw-derived biochar had higher EDCs than the pine wood-derived biochar, resulting from the higher phenolic hydroxyl groups in the former samples than the latter one. In conclusion, the reductive property of biochar was mainly attributed to both phenolic hydroxy group and conjugated π-electron system associated with aromatic structure, depending on the pyrolytic temperature and feedstock source. The results will help us to obtain a complete view on the role of biochar in biogeochemical redox reactions and consider developing biochar with controlled redox properties for specific environmental applications such as electron shuttle and catalyst material.

In the present study, a methodology involving hydrophilic interaction liquid chromatography (HILIC) and electrospray (ESI) tandem mass spectrometry (MS/MS) was developed for measurement of anhydrous monosaccharides as markers for wood burning in atmospheric aerosols, PM10. No extensive sample preparation, other than ultrasound-assisted solvent extraction and evaporation, was applied. A pentahydroxysilica column enabled separation of levoglucosan from mannosan and galactosan within 5 min and the quantitative performance was validated using the standard reference materials (SRM) 1649a and 1649b. The experimentally obtained results for SRMs were in agreement with values previously reported in other studies. Achieved instrumental limits of detection (LODs) were below 10 pg injected on column, corresponding to LODs in air lower than 0.10 ng/m3 for all measured isomers for 2–3 day sampling with 1.0 m−3 h−1 sampling rate. The validated method was used for the determination of levoglucosan and its isomers in atmospheric aerosols collected in three different Swedish urban areas during the winter and summer time in 2017. The total measured concentrations for levoglucosan and galactosan + mannosan were determined to be between 78 and 167 ng/m3 in January 2017, which is approximately 10-times higher compared to the levels detected in July, reflecting the higher frequency of wood burning for heating during the cold season. Calculated concentration ratios between levoglucosan and its isomers in the urban area samples indicated mostly mixed softwood/hardwood combustion in winter time; on the other hand, softwood burning was observed as the major emission in summer time.

Household biofuel burning contributes a large proportion of fine particulate matter (PM2.5), black carbon (BC), and organic carbon (OC) emissions in many parts of the world. Dilution sampling has been widely used to characterize PM2.5 emitted from biofuel burning. The residence time in the dilution chamber is a key parameter for accurate sampling. However, residence time has not yet been adequately characterized for biomass combustion. In this work, we investigated the effects of residence time of dilution sampling on PM2.5 emissions from a typical Chinese household stove burning typical biofuels including three major crop wastes and one type of wood. The filter based measurements indicated that the emission factors for PM2.5 and its main chemical components such as OC, EC, Cl−, and K+ did not vary with the residence time over the range of 1–80 s. Theoretical estimation of average time scale for achieving dynamic equilibrium (τs) between the gas and particle phase in the dilution sampling system was less than 1 s. Both the measurement study and theoretical simulations indicated that dilution sampling with a residence time of 1s can provide adequately reliable results for PM2.5 emissions from biofuel burning under the condition of these experiments. A simple way to estimate the equilibration time based on measured average PM2.5 concentration was proposed. Recommendations are provided for the residence time for dilution sampling of accurate measurements of PM2.5 emissions from biofuel burning.

The surface-dependent evaporation behavior of phthalates as semi-volatile organic compounds (SVOCs) on glass, wood, and polyurethane foam (PUF) was investigated. Three phthalates of di-2-ethylhexyl phthalate (DEHP), butyl benzyl phthalate (BBP), and dibutyl phthalate (DBP) were studied to compare the amount of gases vaporized from their surfaces. A 10 mL silicate glass vial was used to compare the gas equilibrium of the phthalates after 2 h. The gases accumulated in the air were transferred to a solid-phase microextraction (SPME) column and analyzed by gas chromatography-mass spectrometry (GC-MS). As correlated with the physicochemical properties of the phthalates, including molecular weights and vapor pressure, the surface-air partition coefficients (Ksa) were found to be in the range of 101–105 m, 106–107 m, and 107–109 m on glass, wood, and PUF, respectively, implying that a significant amount of phthalates are retained on wood and PUF surfaces as compared to glass, and only a trace amount of phthalates can be volatilized into the air, especially the less volatile DEHP. The three-dimensional (3D) morphologies of glass and wood were also examined using a white-light interferometric surface profile microscope and an atomic force microscope (AFM). In contrast to smooth glass surfaces within the sub-micrometer vertical range, the wood surfaces exhibited uneven irregular structures at a height of 5–30 μm. The rough wood surfaces were found to adsorb substantial amounts of gases to prevent the effective volatilization of phthalates into the air, especially the low molecular DBP. Our results imply that wood and PUF surfaces may be superior to glass surfaces in storage and reduction of phthalates in the air, especially DBP.

Green composite processing technology of wood fibers is an inevitable choice for global sustainable development. In this research, waste poplar powder with different particle sizes was used to prepare glue-free biocomposites with good mechanical and waterproof properties by hot-molding. The biocomposites made of larger size wood powder had better tensile strength (40.3 MPa) and the biocomposites made of smaller size wood powder had the greater bending strength (50.5 MPa). The thickness swelling rate of the biocomposites was only 4.26% after soaking in water for 24 h. The cross-section morphology of the biocomposites showed that the cell wall collapses enhanced the interfacial bonding. Chemical analysis showed that lignin repolymerized with cellulose and hemicellulose for the vitrification transition. In addition, the biocomposites with excellent mechanical properties had no formaldehyde release, which can replace the traditional density boards made of adhesives and applied as furniture materials and in line with the concept of cleaner production.

Sustainable materials are urgently desired for treatment of radioactive cesium (Cs) contaminated water to safe-guard the public health. Apart from the synthetic ligand-based materials, the Mangrove charcoal modified adsorbent was fabricated for assessing of Cs removal from waste sample. The raw charcoal was oxidized using nitrification approach and diverse oxygen containing carboxyl, carbonyl and hydroxyl functional groups were introduced. After modification, the adsorbent characteristics were drastically changed as compared to the charcoal during the measurement of FTIR, N2 adsorption-desorption isotherms and SEM micrographs. The data clarified that charcoal modified adsorbent was exhibited high Cs transport through the inner surface of the adsorbent based on bonding ability. The adsorbent was shown comparatively slow kinetics to Cs ion; however, the adsorption capacity was high as 133.54 mg/g, which was higher than the crown ether based conjugate materials. The adsorption data were followed to the Langmuir adsorption isotherms and the monolayer coverage was possible due to the data presentation. The presence of high amount of Na and K were slightly interfered to the Cs adsorption by the charcoal modified adsorbent, however; the Na and K concentration was 350–600 folds higher than the Cs concentration. Then the proposed adsorbent was selective to Cs for the potential real radioactive Cs contaminated water. The volume reduction was established rather than desorption and reuses advantages. More than 99% volume reduction was measured by burning of Cs adsorbed adsorbent at 500 °C for ensuring the safe storage and disposal of used adsorbent. Therefore, the charcoal modified adsorbent may open the new door to treat the Cs containing wastewater.

An on-line analysis system was firstly developed to quantitatively measure the temporal concentrations of selenium in the flue gas directly. Then the selenium release during air combustion, CO2/argon gasification, and argon pyrolysis of sawdust was systematically studied using the on-line analysis system, based on the inductively coupled plasma optical emission spectroscopy. The peak of selenium concentration in the flue gas ranges from 0.38 to 1.76 mg∙Nm−3 with change of reaction temperature and atmosphere. The overall activation energy for selenium release is 75.3 kJ∙mol-1 in air combustion, 102.4 kJ∙mol-1 in CO2/argon gasification, and 81.9 kJ∙mol-1 in argon pyrolysis, respectively. The results show that the combustion atmosphere contributes to the selenium release more than that in gasification and pyrolysis. The promotion effect of chlorine on selenium release under combustion environment was one to three times higher than that under gasification and pyrolysis atmosphere. Thermodynamic equilibrium calculation showed that selenium oxides were the main gaseous selenium species in combustion, while the dominant gaseous selenium species were H2Se (g) and Se (g) under gasification/pyrolysis condition. The selenium release was increased with different degrees by additive chlorine species, mainly because of the formation of SeCl2 (g). The role of chlorine in selenium transformation has been provided in the proposed reaction pathways of selenium release, based on the new findings using on-line analysis system. The selenium species retained in sawdust can be transformed into selenium oxide (SeO2, SeO, corresponding to the combustion condition) and selenium hydride (H2Se, corresponding to the gasification/pyrolysis conditions).

Data for source apportionment estimation was obtained from combustion of 11 types of biomass (rubber wood, palm kernel, palm fiber, sugarcane bagasse, sugarcane leaves, maize residue, rice stubble, rice straw, Xylocarpus moluccensis, Avicennia alba Blume and Rhizophora mucronata) and bituminous coal. Combustion was carried out in a tube furnace and emitted particulate matter (PM) was collected using a nanosampler that segregated particle sizes down to 0.1 μm. Emission factors of PM 0.1 μm were in the range of 0.11-0.28 g kg

The study was conducted to assess the performance of improved and traditional cookstoves using wood as a fuel and three combinations of other fuel mixes – (i) wood and cow dung, (ii) wood and mustard stalks, and (iii) cow dung and mustard stalks). Energy and emission parameters such as specific energy consumption (SEC), emission factors (EFs) of carbon monoxide (CO), particulate matter (PM) and black carbon (BC) were used to compare four different types of cookstoves. These included top-feed forced draft (TF-FD), top-feed natural draft (TF-ND), front-feed natural draft (FF-ND) and front-feed traditional (FF-TR) cookstoves. Controlled cooking test (CCT) was used as the test protocol. The results showed the performance of improved cookstove technologies can vary based on the fuel used for cooking. It was observed that emission factors for PM and CO increased by 67–96% and 45–90% respectively when all three improved cookstoves were tested with three fuel combinations against wood as cooking fuel. Among the tested cookstoves, a marked difference was observed between performance of forced draft and natural draft cookstoves. Forced draft cookstoves emitted higher amount of all pollutant emissions compared to natural draft cookstoves when used with mustard stalks in combination with either wood or cowdung. The results are of critical importance given that forced draft cookstoves have been promoted in geographical regions where fuel mix use is prevalent. Therefore, forced draft cookstove might not be the right choice when the goal is climate mitigation and reduction in impact on human health. It is imperative to study comprehensively the influence of various field variables on performance of cookstoves, which have severe implications on the performance of cookstoves.

In the present study, industrial wood flour waste was selected for the first time as the precursor to produce biochar (WFB). The WFB was then used to prepare WFB/BiOBr visible-light photocatalysts, in which WFB acted as the carbon support to enhance the photocatalytic performance of BiOBr. Specifically, the impact of WFB pyrolysis temperature on the visible-light photo-removal performance of WFB/BiOBr was studied through degrading rhodamine B and reducing Cr(VI). The results indicated that when the pyrolysis temperature was 600 °C, the prepared WFB (600-WFB) had the highest graphitization degree, which afterwards significantly enhanced the visible-light photocatalysis performance of the BiOBr. Having higher graphitization degree, 600-WFB/BiOBr exhibited the highest photocatalytic capability. With a dosage of 0.5 g/L, the 600-WFB/BiOBr could completely remove to 20 mg/L of RhB and 5 mg/L of Cr(VI) within 90 min. Since wood flour is an abundantly existed industrial bioresource waste and easily pyrolyzed to prepare biochar, WFB is a promising alternative to replace traditional carbonaceous materials for the design of green and high-efficient visible-light photocatalysts for environmental remediation.

Elemental defense hypothesis states that metals accumulated in plant tissues may serve as defense against herbivores and pathogens. However, evidences collected so far are inconsistent and studies using woody plants as model species are still lacking. In this study we used a local woody plant species, Populus yunnanensis, to investigate whether cadmium (Cd) accumulation in leaves can protect plants from leaf herbivory and pathogen infection. Plants grown with or without Cd supplementation in the soil were subjected to herbivory by a specialist (Botyodes diniasalis) and a generalist (Spodoptera exigua), or to pathogen infection by a leaf pathogenic fungus (Pestalotiopsis microspora). Two additional tests with artificial media amended with a series of Cd concentrations were conducted for S. exigua and P. microspora to investigate the toxicity of Cd independently of other organic defenses present in P. yunnanensis leaves. The results showed that both herbivores strongly preferred control leaves over leaves containing high Cd. Feeding on leaves from Cd-treated plants significantly reduced the growth and survivals of both herbivores. Furthermore, plants grown on Cd-amended soil were more resistant to fungal infection. Growth of S. exigua and P. microspora on artificial media decreased with increasing Cd concentrations. In conclusion, we found that Cd accumulated in P. yunnanensis leaves could effectively reduce leaf herbivory and pathogen infection, which fully supported the Elemental defense hypothesis.

Biochar is increasingly deemed a potential sorbent for contaminants in soil and water remediation. We tested three biochars from different feedstocks (cattle manure, grain husk, and wood chips) produced at relatively low pyrolysis temperature (450 °C), for their sorption behavior towards trichloroethylene (TCE) and tetrachloroethylene (PCE) in single- and bi-solute systems. In single-solute experiments, all biochars show stronger sorption for TCE (about 50% based on solubility-normalized Freundlich coefficients). The lower sorption of PCE is attributed to steric effects, e.g. size exclusion in small micropores and specific interactions. Plant-derived, carbon-rich biochars with high specific surface area and microporosity predominantly sorb via pore-filling, as also observed in activated carbon. Biochar produced from manure, with higher ash content and polarity, and smaller total pore volume (PV tot ), shows significant contribution of partitioning. These findings also apply to bi-solute systems. TCE and PCE show different competition behavior depending on biochar properties. Plant-based biochars are pore-filling-dominated and show strong competition. However, competition behavior in microporous biochars depends on the concentration range. Manure biochar with high polarity and low PV tot shows significant partitioning and therefore less competition. Compared to the plant-based chars competition in manure biochar is not concentration-dependent. These results indicate that biochars with a large fraction of non-carbonized phase facilitate non-competitive sorption and might be a valuable sorbent in mixed contaminant systems.

Although several global/regional studies have detailed the high level of polycyclic aromatic hydrocarbons in urban areas worldwide, unfortunately, Nepal has never been part of any global/regional regular monitoring plan. Despite few sporadic studies exist, the systematic monitoring and integrated concentration of PAHs in urban region of Nepal are lacking. In this study, the concentrations, sources, and health risk assessment of 16 PAHs in air (n = 34) were investigated in suspected source areas/more densely populated regions of Nepal. Four potential source areas in Nepal were focused as it was conjectured that urban centers in plain areas (Birgunj and Biratnagar) would possibly be more influenced by PAHs as a result of intense biomass/crop residue burning than those in hilly areas (Kathmandu and Pokhara). The overall concentrations of ∑16PAHs ranged from 4.3 to 131 ng/m3 (median 33.3 ng/m3). ∑16PAH concentrations in plain areas were two folds higher than those in hilly areas. PHE was the most abundant followed by FLUA, PYR, and NAP, which accounted for 36%, 15%, 12%, and 9% of ∑16PAHs, respectively. Principal component analysis confirmed that PAHs in highly urbanized areas (Kathmandu and Pokhara) were related to diesel exhausts and coal combustion, while PAHs in less urbanized regions (Birgunj and Biratnagar) originated from biomass and domestic wood combustions. Furthermore, in the urban areas of Nepal, vehicular emission could also influence atmospheric PAHs. The lifetime cancer risk per million populations due to PAH exposures was estimated to be higher for plain areas than that for hilly areas, suggesting a relatively greater risk of cancer in people living in plain areas.

The aim of this study was to simulate a banned but widely spread practice of co-combustion of plastic with wood in a small residential boiler and to quantify its impact on emissions of gaseous pollutants, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and 1,3,5-triphenylbenzene (135TPB), a new tracer of polyethylene plastic combustion. Supermarket polyethylene shopping bags (PE) and polyethylene terephthalate bottles (PET) were burnt as supplementary fuels with beech logs (BL) in an old-type 20 kW over-fire boiler both at a nominal and reduced heat output. An impact of co-combustion was more pronounced at the nominal heat output: an increase in emissions of PM, total organic carbon (TOC), toxic equivalent (TEQ) of 7 carcinogenic PAHs (c-PAHs) and a higher ratio of c-PAHs TEQ in particulate phase was observed during co-combustion of both plastics. 135TPB was found in emissions from both plastics both at a nominal and reduced output. In contrast to findings reported in the literature, 135TPB was a dominant compound detected by mass spectrometry on m / z 306 exclusively in emissions from co-combustion of PE. Surprisingly, six other even more abundant compounds of unknown identity were found on this m / z in emissions from co-combustion of PET. One of these unknown compounds was identified as p-quaterphenyl (pQ). Principal component analysis revealed strong correlation among 135TPB, pQ and five unknown compounds. pQ seems to be suitable tracers of polyethylene terephthalate plastic co-combustion, while 135TPB proved its suitability to be an all-purpose tracer of polyethylene plastics combustion.

The aim of this study was to evaluate the efficiency of a large scale washing/wet sieving technique for a soil contaminated with wood impregnation chemicals by 1) defining the final distribution of trace elements (As, Cu, Cr, Zn) and polycyclic aromatic hydrocarbons (PAH) in separated soil particle size fractions; and 2) defining the leaching behavior of the contaminants in these soil fractions. A soil washing experiment was implemented at waste management facility in Sweden using a full scale soil sorting and washing equipment. Five tons of soil was loaded to the equipment and wet-sieved into the following fractions:16 mm, 8-16 mm, 2-8 mm, 0.2-2 mm,0.2 mm and a fraction that floated on top of the slurry before the final separation phase, composed of organic matter (OM). Analysis of total concentrations of contaminants in all soil fractions indicated that wet sieving/soil washing was not efficient to reduce the total volume of soil that needs further treatment. Even the coarsest soil fractions (8 mm) contained elevated concentrations of total As and PAH. Leaching of As from all washed soil fractions was so high, that none of the particle size fractions could be disposed of without additional treatment.

Determining the fate of preservatives in commercial wood products is essential to minimize their losses and improve protective impregnation techniques. The fate of triazole fungicides in ponderosa pine wood was investigated in both outdoor and controlled-environment experiments using a representative triazole, tebuconazole (TAZ), which was accompanied by propiconazole (PAZ) in selected experiments. The study was designed to mimic industrial settings used in window frame manufacturing. To investigate the TAZ fate in detail, loosely and strongly bound fractions were differentiated using a multi-step extraction. The loosely bound TAZ fraction extracted through two sonications accounted for 85± 5% of the total TAZ, while the strongly bound TAZ was extracted only with an exhaustive Soxhlet extraction and corresponded to the remaining 15± 5%. A significant fraction (∼80%) of the original TAZ remained in the wood despite a six-month exposure to harsh environmental conditions, maintaining wood preservation and assuring minimal environmental impact. Depletion of loosely bound TAZ was observed from cross-sectional surfaces when exposed to rain, high humidity and sunlight. Water leaching was deemed to be the major route leading to triazole losses from wood. Leaching rate was found to be slightly higher for TAZ than for PAZ. The contribution of bio-, photo- and thermal degradation of triazoles was negligible as both PAZ and TAZ sorbed in wood remained intact. Triazole evaporation was also found to be minor at the moderate temperature (20–25 °C) recorded throughout the outdoor study.

The main purpose of this work was to quantify and characterize chemically and morphologically the emission of soot particles from the open burning of several common solid waste including paperboard, wood, peel, chemical fiber, polyethylene (PE) and polyvinyl chloride (PVC). The experiment was conducted in a laboratory-scale open-burning combustor with a dilution sampling system to obtain soot particles. The thermogravimetric profiles (TGA) showed an increasing order of oxidation reactivity: PE > PVC > fiber > paper ≈ peel > wood. High resolution transmission electron microscopy (HRTEM) images revealed more detailed information about the morphology and the particle size of soot aggregates. Subsequent quantification of nanostructure by fringe analysis showed that plastics generated soot particles with the looser carbon layers with higher tortuosity compared to the three kind of biomass. Raman spectroscopy further confirms the observed differences. In addition, wood soot exhibited the highest content of C–OH group (17.5%) among the six samples (X-Ray photoelectron spectroscopy, XPS), whereas PE and PVC soot exhibited the highest absorption peaks of aliphatic C–H groups (Fourier transform infrared spectroscopy, FTIR). Comparative analysis revealed that the interlayer distance was more important on the evaluation of reactivity than soot morphologies. The present work concluded that the physiochemical characteristics of soot particles releasing during open burning are strongly depending on waste composition and provided new data for the understanding of soot emissions from open burning.

In this study, an acidic biochar and a neutral biochar were applied at 5 wt% into two soils for an 11-month incubation experiment. One Ferrosol soil (Ba) was slightly acidic with low organic matter and the other Dermosol soil (Mt) was slightly alkaline with high organic matter. The acidic (pH = 3.25) wood shaving (WS) biochar had no marked impact on nutrient levels, cation exchange capacity (CEC), pH and acid neutralization capacity (ANC) of either soil. By contrast, the neutral (pH = 7.00) chicken litter (CL) biochar significantly increased major soluble nutrients, pH, ANC of soil Ba. In terms of C storage, 87.9% and 69.5% WS biochar-C can be sequestrated as TOC by soil Ba and Mt, respectively, whereas only 24.0% of CL biochar-C stored in soil Ba and negligible amount in Mt as TOC. Biochars did not have significant effects on soil sorption capacity and sorption reversibility except that CL biochar increased sorption of soil Ba by around 25.4% and decreased desorption by around 50.0%. Overall, the studied acidic C rich WS biochar held little agricultural or remedial values but was favourable for C sequestration. The neutral mineral rich CL biochar may provide short-term agricultural benefit and certain sorption capacities of lower sorption capacity soils, but may be unlikely to result in heightened C sequestration in soils. This is the first study comprehensively examining functions of acidic and neutral biochars for their benefits as a soil amendment and suggests the importance of pre-testing biochars for target purposes prior to their large scale production. Refereed/Peer-reviewed

This study examined the impact of wood fuel consumption on health outcomes, specifically under-five and adult mortality in Sub-Saharan Africa, where wood usage for cooking and heating is on the increase. Generalized method of moment (GMM) estimators were used to estimate the impact of wood fuel consumption on under-five and adult mortality (and also male and female mortality) in the region. The findings revealed that wood fuel consumption had significant positive impact on under-five and adult mortality. It suggests that over the studied period, an increase in wood fuel consumption has increased the mortality of under-five and adult. Importantly, it indicated that the magnitude of the effect of wood fuel consumption was more on the under-five than the adults. Similarly, assessing the effect on a gender basis, it was revealed that the effect was more on female than male adults. This finding suggests that the resultant mortality from wood smoke related infections is more on under-five children than adults, and also are more on female adults than male adults. We, therefore, recommended that an alternative affordable, clean energy source for cooking and heating should be provided to reduce the wood fuel consumption.

Municipal waste is usually composted with an N-rich substrate, such as manure, to increase the N content of the product. This means that a significant amount of nitrogen can be lost during composting. The objectives of this study were (i) to investigate the effect of split addition of a nitrogen-rich substrate (poultry manure) on nitrogen losses and greenhouse gas emissions during composting and to link this effect to different bulking agents (coffee husks and sawdust), and (ii) to assess the effect of split addition of a nitrogen-rich substrate on compost stability and sanitisation. The results showed that split addition of the nitrogen-rich substrate reduced nitrogen losses by 9% when sawdust was used and 20% when coffee husks were used as the bulking agent. Depending on the bulking agent used, split addition increased cumulative N2O emissions by 400–600% compared to single addition. In contrast, single addition increased methane emissions by up to 50% compared to split addition of the substrate. Hence, the timing of the addition of the N-rich substrate had only a marginal effect on total non-CO2 greenhouse gas emissions. Split addition of the N-rich substrate resulted in compost that was just as stable and effective at completely eradicating weed seeds as single addition. These findings therefore show that split addition of a nitrogen-rich substrate could be an option for increasing the fertilising value of municipal waste compost without having a significant effect on total greenhouse gas emissions or compost stability.

Wood combustion has been shown to contribute significantly to emissions of polycyclic aromatic hydrocarbons and hydroxylated polycyclic aromatic hydrocarbons, compounds with toxic and carcinogenic properties. However, only a small number of hydroxylated polycyclic aromatic hydrocarbons have been determined in particles from wood combustion, usually compounds with available reference standards. In this present study, suspect and non-target screening strategies were applied to characterize the wood smoke particles from four different wood types and two combustion conditions with respect to hydroxylated polycyclic aromatic hydrocarbons and other organic compounds. In the suspect screening, 32 peaks corresponding to 12 monohydroxylated masses were tentatively identified by elemental composition assignments and matching of isotopic pattern and fragments. More than one structure was suggested for most of the measured masses. Statistical analysis was performed on the non-target screening data in order to single out significant peaks having intensities that depend on the wood type and/or combustion condition. Significant peaks were found in both negative and positive ionization modes, with unique peaks for each wood type and combustion condition, as well as a combination of both factors. Furthermore, structural elucidation of some peaks was done by comparing the spectra in the samples with spectra found in the spectral databases. Six compounds were tentatively identified in positive ionization mode, and 19 in negative ionization mode. The results in this present study demonstrate that there are significant overall differences in the chemistry of wood smoke particles that depends on both the wood type and the combustion condition used.

Electron storage capacity (ESC) is the capacity of a black carbon to store and reversibly donate and accept electrons in redox processes. Electrochemical and chemical analyses have shown the ESC of black carbon (e.g., plant-based biochars) was on the order of a few mmol/g. However, it remains unknown where ESC is located. The spatial distribution of ESC is important because it controls the bioaccessibility of ESC and the rates of biochar redox reactions. Here we used silver to tag the ESC of a wood-derived biochar. Ag+ was allowed to diffuse into the pores of reduced biochar at a constant pH. Up to 2.49 mmol Ag+/g biochar (corresponding to 62% of its ESC) was reduced to Ago nanoparticles (nAg), which served as an ESC marker and was visualized by electron microscopy. Abundant and dense nAg were observed on the biochar surface. In addition, microtomed samples showed ubiquitous and well-dispersed nAg in the interior of biochar, which explains pore diffusion-limited redox reactions and the partial bioaccessibility of its ESC. In addition to probing ESC distribution in black carbon, this method represents a new, ESC-based approach to incorporate large quantities of Ag and other redox-active elements into carbon media for potential environmental applications.

Antibiotics and heavy metals are frequently detected simultaneously in water environment. Effective elimination methods for antibiotics and heavy metals pollution should deserve our attention. This study investigates the adsorption performance of biochar modified with nano-hydroxyapatite (nHAP) on tylosin (TYL) and Cu from water simultaneously. Composite adsorbents of nHAP and biomass, derived from three waste residues, which were wood-processing residues (WR), wheat straw (WS) and Chinese medicine residues (CMR), were prepared. According to the results of orthogonal experiment, the degree of influence of the three factors on TYL and Cu were the pyrolysis temperature > the proportion of nHAP and biomass > the sources of biomass, and pyrolysis temperature> the sources of biomass> the proportion of nHAP and biomass, respectively. The optimum conditions for nHAP@biochar were screened. At pH 7.0, the adsorption quality of TYL changed slightly. At low pH, Cu and TYL could compete for the same adsorption sites on nHAP@biochars. The adsorption amount of TYL and Cu were both increased with increasing of the temperature. Compared with Langmuir model, Freundlich model could better fit the TYL adsorption on nHAP@biochars, with Kf values of TYL 62.35 (mmol/kg) (L/mmol)n (WR1) and 4.84 (mmol/kg) (L/mmol)n (CMR1), respectively.

In this study, cost-effective cellulosic biomass based activated wood charcoal was developed from Japanese Sugi tree (Cryptomeria japonica) by concentrated nitric acid modification for adsorption of Cs from contaminated water. The physicochemical properties of specimens were investigated using N2 adsorption-desorption isotherms (BET method), FESEM, FTIR, and XPS spectra analysis. The experimental results revealed that the surface area of the raw wood charcoal was significantly decreased after boiling nitric acid modification. However, several oxygen-containing acidic function groups (-COOH, –C O) were introduced on the surface. The adsorption study confirmed that the equilibrium contact time was 1 h, the optimum adsorption pH was neutral to alkaline and the suitable adsorbent dose was 1:100 (solid: liquid). The maximum Cs was removed when the concentration of Na and K were lower (5.0 mM) with Cs in solution. The Cs adsorption processes well approved by the Langmuir isotherm and pseudo-second-order kinetic models and the maximum adsorption capacity was 35.46 mgg−1. The Cs adsorption mechanism was clearly described and it was assumed that the adsorption was strongly followed by chemisorptions mechanism based on the adsorbent surface properties, kinetic model and Langmuir isotherm model. Most importantly, about 98% of volume reduction was obtained by burning (500 °C) the Cs adsorbed charcoal, which ensured safe storage and disposal of radioactive waste. Therefore, this study can offer a guideline to produce a functional adsorbent for effective Cs removal and safe radioactive waste disposal.

Owing to the seriousness of the ecological risk and human hazard of inorganic wood preservatives, their effective removal was gradually recognized. This paper details different types of wood preservatives, their perniciousness, and their potential removal alternatives, while the wood treatment process is briefly described. Among decontamination methods, microbial remediation is considered as an environmentally friendly approach with enormous potentialities over the conventional treatments. In the current review, the mechanism of bioremediation is summed up and recent advances, challenges, and future perspectives of microbial remediation are discussed. The removal of heavy metals from treated wood requires a combination of various technologies to obtain higher performance. Meanwhile, the decontaminated wood generated through bioremediation can be effectively reused.

Laboratory experiments suggest that polymeric Cr(III) could exist in aqueous solution for a relative long period of time. However, the occurrence of polymeric Cr(III) has not been reported in environmental media due partially to the lack of method for speciating polymeric Cr. We observed an unknown Cr species during the course of study on speciation of Cr in the leachates of chromated-copper-arsenate (CCA)-treated wood. Efforts were made to identify structure of the unknown Cr species. Considering the forms of Cr existed in the CCA-treated woods, we mainly focused our efforts to determine if the unknown species were polymeric Cr(III), complex of Cr/As or complex of Cr with dissolved organic matter (DOM). In order to evaluate whether polymeric Cr(III) largely exist in wood leachates, high performance liquid chromatography coupled with inductively coupled mass spectrometry (HPLC-ICPMS was used) for simultaneous speciation of monomeric Cr(III), polymeric Cr(III), and Cr(VI). In addition to wood leachates where polymeric Cr (III) ranged from 39.1 to 67.4 %, occurrence of the unknown Cr species in other environmental matrices, including surface waters, tap and waste waters, was also investigated. It was found that polymeric Cr(III) could exist in environmental samples containing μg/L level of Cr, at a level up to 60% of total Cr, suggesting that polymeric Cr(III) could significantly exist in natural environments. Failure in quantifying polymeric Cr(III) would lead to the underestimation of total Cr and bias in Cr speciation. The environmental implication of the presence of polymeric Cr(III) species in the environment deserves further study.

Isomer distribution patterns of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and naphthalenes (PCNs) were investigated in microwave-assisted pyrolysis (MAP) products of woody biomass. The feedstocks included bark and impregnated wood. The results indicated that isomer distributions in MAP are more selective compared to those reported from wood burning and waste incineration. Favored formation of 4-MoCDF and highly selective chlorine substitution at the 2,4-position observed during MAP suggested a preferred formation pathway of PCDFs involving (chloro)phenol precursors followed by subsequent chlorination. The PCDD distribution was dominated by isomers typically formed from chlorophenol condensation at relatively low temperature. The PCN isomer distributions showed a tendency for sequential chlorination from non-substituted naphthalene at successive positions. The presence of isomers such as 1-MoCDD, 4-MoCDF, 1,2,3-TriCN with low thermodynamic stability indicates that kinetic factors may be important in the MAP process. Bio4Energy

Sorption behavior of acetochlor (ACE), dibutyl phthalate (DBP), 17α-Ethynyl estradiol (EE2) and phenanthrene (PHE) with biochars produced from three feedstocks (maize straw (MABs), pine wood dust (WDBs) and swine manure (SWBs)) at seven heat treatment temperatures (HTTs) was evaluated. The bulk polarity of these biochars declined with increasing HTT while the aromaticity and CO2-surface area (CO2-SA) rose. The surface OC contents of biochars were generally higher than bulk OC contents. The organic carbon (OC)-normalized CO2-SA (CO2-SA/OC) of biochars significantly correlated with the sorption coefficients (n and logK(oc)), suggesting that pore filling could dominate the sorption of tested sorbates. SWBs had higher logK(oc) values compared to MABs and WDBs, due to their higher ash contents. Additionally, the logK(oc) values for MABs was relatively greater than that for WDBs at low HTTs (≤400 °C), probably resulting from the higher CO2-SA/OC, ash contents and aromaticity of MABs. Surface polarity and the aliphatic C may dominate the sorption of WDBs obtained at relatively low HTTs (≤400 °C), while aromatic C affects the sorption of biochars at high HTTs. Results of this work aid to deepen our understanding of the sorption mechanisms, which is pivotal to wise utilization of biochars as sorbents for hazardous organic compounds.

Highly porous activated carbons were resource-recovered from Leucaena leucocephala (Lam.) de Wit. wood through combined chemical and physical activation (i.e., KOH etching followed by CO2 activation). This invasive species, which has severely damaged the ecological economics of Taiwan, was used as the precursor for producing high-quality carbonaceous electrodes for capacitive deionization (CDI). Carbonization and activation conditions strongly influenced the structure of chars and activated carbons. The total surface area and pore volume of activated carbons increased with increasing KOH/char ratio and activation time. Overgasification induced a substantial amount of mesopores in the activated carbons. In addition, the electrochemical properties and CDI electrosorptive performance of the activated carbons were evaluated; cyclic voltammetry and galvanostatic charge/discharge measurements revealed a typical capacitive behavior and electrical double layer formation, confirming ion electrosorption in the porous structure. The activated-carbon electrode, which possessed high surface area and both mesopores and micropores, exhibited improved capacitor characteristics and high electrosorptive performance. Highly porous activated carbons derived from waste L. leucocephala were demonstrated to be suitable CDI electrode materials.

The objective of this work was to investigate the retention mechanisms of ammonium in aqueous solution by using progressively oxidized maple wood biochar at different pH values. Hydrogen peroxide was used to oxidize the biochar to pH values ranging from 8.1 to 3.7, with one set being adjusted to a pH of 7 afterwards. Oxidizing the biochars at their lowered pH did not increase their ability to adsorb ammonium. However, neutralizing the oxygen-containing surface functional groups on oxidized biochar to pH 7 increased ammonia adsorption two to three-fold for biochars originally at pH 3.7-6, but did not change adsorption of biochars oxidized to pH 7 and above. The adsorption characteristics of ammonium are well described by the Freundlich equation. Adsorption was not fully reversible in water, and less than 27% ammonium was desorbed in water in two consecutive steps than previously adsorbed, for biochars with a pH below 7, irrespective of oxidation. Recovery using an extraction with 2M KCl increased from 34% to 99% of ammonium undesorbed by both preceding water extractions with increasing oxidation, largely irrespective of pH adjustment. Unrecovered ammonium in all extractions and residual biochar was negligible at high oxidation, but increased to 39% of initially adsorbed amounts at high pH, likely due to low amounts adsorbed and possible ammonia volatilization losses.

Cellulose nanocrystals (CNC), also known as nanowhiskers, have recently gained much attention due to their biodegradable nature, advantageous chemical and mechanical properties, economic value and renewability thus making them attractive for a wide range of applications. However, before these materials can be considered for potential uses, investigation of their toxicity is prudent. Although CNC exposures are associated with pulmonary inflammation and damage as well as oxidative stress responses and genotoxicity in vivo, studies evaluating cell transformation or tumorigenic potential of CNC’s were not previously conducted. In this study, we aimed to assess the neoplastic-like transformation potential of two forms of CNC derived from wood (powder and gel) in human pulmonary epithelial cells (BEAS-2B) in comparison to fibrous tremolite (TF), known to induce lung cancer. Short-term exposure to CNC or TF induced intracellular ROS increase and DNA damage while long-term exposure resulted in neoplastic-like transformation demonstrated by increased cell proliferation, anchorage-independent growth, migration and invasion. The increased proliferative responses were also in-agreement with observed levels of pro-inflammatory cytokines. Based on the hierarchical clustering analysis (HCA) of the inflammatory cytokine responses, CNC powder was segregated from the control and CNC-gel samples. This suggests that CNC may have the ability to influence neoplastic-like transformation events in pulmonary epithelial cells and that such effects are dependent on the type/form of CNC. Further studies focusing on determining and understanding molecular mechanisms underlying potential CNC cell transformation events and their likelihood to induce tumorigenic effects in vivo are highly warranted.

A woody-biochar was added to waste biomass during a composting process. The resulting compost-char was amended to a metal contaminated soil and two plant species, L. perenne and E. sativa, were grown in a pot experiment to determine 1) plant survival and stress factors, 2) uptake of metals to plants and, 3) chemical characteristics of sampled soils and pore waters. Compost supplemented with biochar after the composting process were also tested, as well as a commercially available compost, for comparison. Co-composting with biochar hastened the composting process, resulting in a composite material of reduced odour, increased maturity, circum-neutral pH and increased moisture retention than compost (increase by 3% of easily removable water content). When amended to the soil, CaCl2 extractable and pore water metals s were reduced by all compost treatments with little influence of biochar addition at any tested dose. Plant growth success was promoted furthest by the addition of co-composted biochar to the test soil, especially in the case of E. sativa. For both tested plant species significant reductions in plant metal concentrations (e.g. 8-times for Zn) were achieved, against the control soil, by compost, regardless of biochar addition. The results of this study demonstrate that the addition of biochar into the composting process can hasten the stability of the resulting compost-char, with more favourable characteristics as a soil amendment/improver than compost alone. This appears achievable whilst also maintaining the provision of available nutrients to soils and the reduction of metal mobility, and improved conditions for plant establishment.

Characteristics of indoor volatile organic compounds (VOCs) and their health risks were investigated in kitchens and bedrooms during the heating season in rural Guanzhong Plain, China. Toxic-VOC concentrations in kitchens with traditional wood (299 ± 38.8 μg m−3) and liquefied petroleum gas (LPG) stoves (187 ± 54.6 μg m−3) were considerably higher than those in bedrooms. High levels of toxic VOCs in traditional kitchens were strongly correlated with wood combustion (R = 0.72). The coefficient of determination of VOC profiles between the kitchen and wood combustion was 0.27, indicating that VOCs in traditional kitchens are mainly derived from wood combustion. For women, who do most of the cooking, noncancer risk from exposure to toxic VOCs could reach 7600 and 2550 in traditional and LPG kitchens, respectively. Noncancer risks were much lower in bedrooms than in kitchens, but still two orders of magnitude higher than the United States Environmental Protection Agency (USEPA) threshold. Cancer risk from exposure to VOCs for women was 8.98 × 10−4 and 1.67 × 10−4 in both traditional and LPG kitchens, respectively, and ranged from 2.51 × 10−6 to 3.85 × 10−5 in bedrooms—all exceeding the USEPA threshold. Thus, during the heating season indicated that the rural Guanzhong residents were exposed to toxic VOCs from indoor heating and cooking at levels higher than the recommended safety levels. Moreover, traditional cooking and heating styles in rural Guanzhong need to be urgently updated to improve the indoor air quality for residents.

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in road and aerial dust to assess their concentration, composition profile, distribution, emission sources, and potential human health risks. Sixteen priority PAHs and Benzo [e]pyrene (BeP) were analyzed in 13 aerial dust samples from Jalalabad, and 78 road dust samples from Kabul and Jalalabad cities, Afghanistan. The mean concentration of ∑17PAHs in road dust from Kabul and Jalalabad were 427 μg kg−1 and 288 μg kg−1, respectively whereas ∑17PAHs in aerial dust from Jalalabad averaged 200 μg kg−1. Fluoranthene (Flu), Chrysene (Chr), Benzo [b]fluoranthene (BbF), Benzo [k]fluoranthene (BkF) and BeP were major individual PAH species. The composition patterns of the PAHs were dominated by 5-6-ring PAHs (51% in road dust from Kabul; 44% in road dust from Jalalabad; and 44% in aerial dust) followed by 4-ring and 2-3-ring PAHs. Source apportionment of the road dust PAHs by the molecular diagnostic ratios (MDR) and principal component analysis (PCA), indicated signatures of PAHs sources (including vehicular exhaust, coal/wood combustion and oil spill). The Benzo [a]pyrene (BaP) toxicity equivalent values (BaPeq17PAHs) for road dust were 75 μg kg−1 (Kabul) and 36 μg kg−1 (Jalalabad); and 35 μg kg−1 for aerial dust (Jalalabad). BaP and Dibenz [a,h]anthracene (DahA) together contributed > 50% of the BaPeq associated cancer risk. All incremental lifetime cancer risk (ILCR) due to human exposure to road and aerial dust PAHs were in the order of 10−7, which is one-fold lower than the threshold (10−6). The noncancerous risk (Hazard Index

There is increasing concern about the use of chromated copper arsenate (CCA) treated timber due to the possible leaching of toxic metals or metalloids. CCA-treated timber waste are currently stockpiled across Australia with limited information about their risks to the environment or human health. In this study, the treatment and utilisation of CCA-treated timber waste as garden mulch, garden retaining walls, and soil additive were investigated. Iron materials were used as immobilising agents. The bioavailability of Cr, Cu and As to Spinacia oleracea from CCA-treated timber, before and after treatment, was determined in the context of human health risk assessment. The results showed that the iron-based treatments resulted in significant decreases in the concentrations of Cu and As in spinach grown in CCA-treated timber in soil. Analyses of CCA derived Cu and As in spinach showed that they accumulated in the roots rather than in the leaves. The risks of toxicity to humans varied for different utilisation scenarios and the immobilisation amendments were shown to reduce carcinogenic and non-carcinogenic risks. The information obtained in this study can inform development of utilisation options for CCA-treated timber wastes.

Two common organic wastes from agriculture (rice straw) and forestry (sawdust) were applied to a petroleum-contaminated soil to estimate their effectiveness in the removal of total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs). Rice straw was the more effective amendment than the other treatments in reducing TPH contents and addition of sawdust resulted in a significant decrease in PAH removal, particularly high-molecular-weight (5-6 ring) PAHs. Principal coordinates analysis (PCoA) indicates that rice straw treatment separated only the bacterial community but sawdust greatly affected both the soil bacterial and fungal communities. Moreover, the abundance of some petroleum degraders such as the bacteria Sphingomonas, Idiomarina and Phenylobacterium and the fungi Humicola, Wallemia and Graphium was promoted by inputs of the two agricultural and forestry wastes. These results highlight the potential of waste applications in accelerating hydrocarbon biodegradation which may be attributed to the enrichment of keystone taxa that show strong positive associations with hydrocarbon degradation.

This work was aimed at studying particulate matter (PM) in the indoor atmosphere of two flats where airtight biomass systems were used for domestic heating. PM10 and PM2.5 samples were collected by means of nine parallel sampling units, located in the outdoor and indoor areas of each flat. The samples were analyzed for PM macro-components (organic carbon, elemental carbon, macro-elements and inorganic ions) and for the soluble and residual fractions of micro-elements; the influence of the main PM sources on the indoor air quality was evaluated. The results confirm that infiltration from outdoor represents the main source of fine particles, while dust re-suspension, enhanced by the movements of the inhabitants, is one of the most important sources of coarse particles. Biomass-fueled heating systems are a significant source of indoor pollution, mainly due to the cleaning operations required for the removal of residual ash, which release particles in both the fine and the coarse size range. The impact of these operations resulted in indoor to outdoor ratios higher than one for most of the considered PM components. Very high amounts of copper and manganese, elements likely involved in the generation of oxidative stress, were released into the environment during ash removal from the pellet stove. Although this operation was very limited in time (about 15 min), the average concentration of Cu and Mn in PM10 and PM2.5 during the study period (18 days) was more than six times (Cu) and about twice (Mn) the concentration values measured outdoors.

This study addresses human health concerns in the city of Temuco that are attributed to wood smoke and related pollutants associated with wood burning activities that are prevalent in Temuco. Polycyclic Aromatic Hydrocarbons (PAHs) were measured in air across urban and rural sites over three seasons in Temuco using polyurethane foam (PUF) disk passive air samplers (PUF-PAS). Concentrations of ΣPAHs (15 congeners) in air ranged from BDL to ∼70 ng m −3 and were highest during the winter season, which is attributed to emissions from residential heating by wood combustion. The results for all three seasons showed that the PAH plume was widespread across all sites including rural sites on the outskirts of Temuco. Some interesting variations were observed between seasons in the composition of PAHs, which were attributed to differences in seasonal point sources. A comparison of the PAH composition in the passive samples with active samples (gas + particle phase) from the same site revealed similar congener profiles. Overall, the study demonstrated that the PUF disk passive air sampler provides a simple approach for measuring PAHs in air and for tracking effectiveness of pollution control measures in urban areas in order to improve public health.

A series of biochars were prepared by pyrolyzing oak sawdust with/without LaCl3 involvement at temperature of 300-600 °C, and approximate and ultimate analyses were carried out to check their basic characteristics. Meanwhile, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars and the adsorption of NH4(+), NO3(-) and PO4(3-) by biochars were investigated. Results indicated that the involvement of LaCl3 in pyrolysis could advance the temperature of maximum mass loss by 10 °C compared with oak sawdust (CK), and potentially promoted biochar yield. Overall, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars were negatively related to pyrolysis temperature, and the releases were greatly weakened by La-biochars. Additionally, the adsorption to NH4(+) can be promoted by the biochars produced at low temperature. On the contrary, the NO3(-) adsorption can be improved by increasing pyrolysis temperature. The highest PO4(3-) adsorption was achieved by the biochars produced at 500 °C. According to the results of adsorption isotherms, the maximum adsorption capacity of NH4(+), NO3(-) and PO4(3-) can be significantly promoted by 1.9, 11.2, and 4.5 folds using La-biochars. Based on the observations of FT-IR, SEM-EDS, and surface functional groups, the improvement of NH4(+) adsorption was potentially associated with the existing acidic function groups (phenolic-OH and carboxyl C=O). The increased basic functional groups on La-biochars were beneficial to improve NO3(-) and PO4(3-) adsorption. Besides, PO4(3-) adsorption was also potentially related to the formed La2O3.