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A co-pyrolysis of woodchips and oil shale was conducted in a continuous reactor at 520 °C in a CO2 atmosphere. Experimental product yields were derived and an analysis of the liquid products was conducted, using gas chromatography, infrared spectroscopy, and physicochemical analysis. A maximum yield of liquids and gases was obtained as the share of biomass increased (43.9 and 35.1 wt%, respectively). Product characterization confirmed additive behavior in co-pyrolysis. The liquid products from co-pyrolysis blends exhibited fewer oxygenated compounds, derived from biomass, and fewer aromatic compounds, derived from oil shale. Co-pyrolysis liquids contained abundant aliphatic hydrocarbons (C6 to C11).

A co-pyrolysis of woodchips and oil shale was conducted in a continuous reactor at 520 °C in a CO2 atmosphere. Experimental product yields were derived and an analysis of the liquid products was conducted, using gas chromatography, infrared spectroscopy, and physicochemical analysis. A maximum yield of liquids and gases was obtained as the share of biomass increased (43.9 and 35.1 wt%, respectively). Product characterization confirmed additive behavior in co-pyrolysis. The liquid products from copyrolysis blends exhibited fewer oxygenated compounds, derived from biomass, and fewer aromatic compounds, derived from oil shale. Co-pyrolysis liquids contained abundant aliphatic hydrocarbons (C6 to C11). [ABSTRACT FROM AUTHOR]

The Energy Return On Investment (EROI) is a recognised indicator for assessing the relevance of an energy project in terms of net energy delivered to society. For woody biomass divergences remain on the right methodology to assess the EROI leading to large variations in the published estimates. This article presents an in‐depth discussion about the EROI of woody biomass in three different forms: woodchips, pellets and liquid fuels. The conceptualisation of EROI is further developed to reach a consistent definition for biomass post‐processed fuels. It considers, on top of the external energy investments, the grey energy associated with the energy used to enrich the fuel. With the proposed methodology, all woodchips have an EROI of the same order of magnitude, between 20 and 37, depending on forestry types, operations and machineries. For secondary residues, the first estimate is 170 if, as co‐products, no energy investment is allocated to the forestry operations and transport. On the basis of a mass allocation for forestry operations and transport, the EROI for secondary residues becomes of the same order of magnitude as that for wood chips. Woodchips can be further post‐processed into pellets or liquid fuels. Pellets have an EROI of 4–7 if the heat is externally supplied and 8–23 if internally supplied (self‐consumption of part of the raw material). Liquid fuels derived from primary wood and residues through gasification and Fischer‐Tropsch synthesis have an EROI between 4 and 16. Fuel enhancement with hydrogen (Power & Biomass to Liquids) impacts negatively the EROI due to the low EROI of hydrogen produced from renewable electricity. However, these fuels offer other advantages such as improved carbon efficiency. A correct estimate of EROI for forestry biomass, as proposed in this work, is a necessary dimension in assessing the suitability of a project. [ABSTRACT FROM AUTHOR]

In small populations and scattered communities, wastewater treatment through vegetation filters (VFs), a nature-based solution, has proved to be feasible, especially for nutrient and organic matter removal. However, the presence of pharmaceuticals in wastewater and their potential to infiltrate through the vadose zone and reach groundwater is a drawback in the evaluation of VF performances. Soil amended with readily labile carbon sources, such as woodchips, enhances microbial activity and sorption processes, which could improve pharmaceutical attenuation in VFs. The present study aims to assess if woodchip amendments to a VF's soil are able to abate concentrations of selected pharmaceuticals in the infiltrating water by quantitatively describing the occurring processes through reactive transport modelling. Thus, a column experiment using soil collected from an operating VF and poplar woodchips was conducted, alongside a column containing only soil used as reference. The pharmaceuticals acetaminophen, naproxen, atenolol, caffeine, carbamazepine, ketoprofen and sulfamethoxazole were applied daily to the column inlet, mimicking a real irrigation pattern and periodically measured in the effluent. Ketoprofen was the only injected pharmaceutical that reached the column outlet of both systems within the experimental timeframe. The absence of acetaminophen, atenolol, caffeine, carbamazepine, naproxen and sulfamethoxazole in both column outlets indicates that they were attenuated even without woodchips. However, the presence of 10,11-epoxy carbamazepine and atenolol acid as transformation products (TPs) suggests that incomplete degradation also occurs and that the effect of the amendment on the infiltration of TPs is compound-specific. Modelling allowed us to generate breakthrough curves of ketoprofen in both columns and to obtain transport parameters during infiltration. Woodchip-amended columns exhibited Kd and μw values from one to two orders of magnitude higher compared to soil column. This augmentation of sorption and biodegradation processes significantly enhanced the removal of ketoprofen to over 96%. [ABSTRACT FROM AUTHOR]

The performance of locally available agricultural carbon media (barley straw and hemp straw) was compared to woodchips for removing nitrate (NO3-N) and orthophosphate (PO4-P) in up-flow laboratory bioreactors. These media were tested in three replicates to quantify variability. The production of greenhouse gases nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) were quantified. Influent water with NO3-N and PO4-P flowed continuously through bioreactors at a 4-h hydraulic retention time at 20 °C for 16 weeks. Nitrate removal reached up to 37% across all carbon media after the fifth week, with a removal rate of 64 g N m−3 d−1. Nitrate removal was affected by the type of carbon media in the order of barley straw > hemp straw > woodchips (P < 0.05). Most of the PO4-P rates declined rapidly after the first week for all carbon media meaning none were superior. Greenhouse gas production was dominated by CO2 with less CH4 and N2O produced. Production of N2O relative to nitrate removal for the three media remained low at 0.16 to 0.75%. The findings suggest that agricultural residues could perform better than woodchips for NO3-N removal although there was slightly higher N2O and CO2 production for these residues than woodchips. HIGHLIGHTS Barley straw was more effective in reducing nitrate compared to hemp straw and woodchips.; PO4-P removal efficiencies and rates declined rapidly for the three carbon media.; Greenhouse gas production was dominated by CO2 with less CH4 and N2O produced.; Production of N2O relative to nitrate removal for the three media remained low.;

This paper presents methodologies and equipment for SI-traceable inline measurements of water content (a critical quality parameter) in solid biofuels. Inline measurement systems for water content are commonly used at CHP plants, providing continuous real-time data. However, the accuracy of these systems is in most cases unsatisfactory, mainly because the systems are not calibrated representatively for the relevant material, and until now, calibrations traceable to the SI system have not been available. To provide reliable and accurate inline water content data, new procedures and equipment for calibrating measurement systems were developed. Two reference methods for the determination of water content were developed; one measures the airflow and dewpoint of desorbed water in the air passing a test sample, while the other uses a P2O₅-sensor. Additionally, a transfer standard based on a cavity resonance sensor was developed for fast onsite calibration of the inline sensor at the power plant. This new instrument allows for quick and accurate measurements. The transfer standard is made metrologically traceable to the primary measurement standards. The entire system was demonstrated by calibrating an inline microwave-based (MW) sensor at the CHP plant of VERDO in Randers, Denmark. Thus, a complete metrological traceability chain was established from an industrial to a primary standard. [ABSTRACT FROM AUTHOR]

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Abstract The Energy Return On Investment (EROI) is a recognised indicator for assessing the relevance of an energy project in terms of net energy delivered to society. For woody biomass divergences remain on the right methodology to assess the EROI leading to large variations in the published estimates. This article presents an in‐depth discussion about the EROI of woody biomass in three different forms: woodchips, pellets and liquid fuels. The conceptualisation of EROI is further developed to reach a consistent definition for biomass post‐processed fuels. It considers, on top of the external energy investments, the grey energy associated with the energy used to enrich the fuel. With the proposed methodology, all woodchips have an EROI of the same order of magnitude, between 20 and 37, depending on forestry types, operations and machineries. For secondary residues, the first estimate is 170 if, as co‐products, no energy investment is allocated to the forestry operations and transport. On the basis of a mass allocation for forestry operations and transport, the EROI for secondary residues becomes of the same order of magnitude as that for wood chips. Woodchips can be further post‐processed into pellets or liquid fuels. Pellets have an EROI of 4–7 if the heat is externally supplied and 8–23 if internally supplied (self‐consumption of part of the raw material). Liquid fuels derived from primary wood and residues through gasification and Fischer‐Tropsch synthesis have an EROI between 4 and 16. Fuel enhancement with hydrogen (Power & Biomass to Liquids) impacts negatively the EROI due to the low EROI of hydrogen produced from renewable electricity. However, these fuels offer other advantages such as improved carbon efficiency. A correct estimate of EROI for forestry biomass, as proposed in this work, is a necessary dimension in assessing the suitability of a project.

Introduction: Compost heat recovery systems (CHRS) represent an emerging technology to recover residual woody biomass from agroforestry and forestry activities and use the heat that is naturally produced during aerobic biodegradation (composting). However, a low oxygen concentration in the gas phase and self-drying and compaction of the compost body often limit efficient oxidation by microbial communities. Woodchip-derived biochar has often been proposed as a bulking agent and improver of water retention and of oxygen accessibility in the composting process, but the literature reporting its effects in the CHRS is scarce. Methods: Here, biochar (average particle size of 10 mm) was added at 10% (on weight basis) to chipped pruning residues into two bench-scale-controlled reactors (0.2 m3), operated in parallel for 57 days. Results and Discussion: The addition of 10% (w/w) biochar to the composting body increased biodegradation yields by approximately 50% and improved oxidation rates over readily biodegradable organic fractions (addition of cheese whey). Temperatures were on average 1.34°C higher, and heat extraction flux was also improved in the presence of biochar (0.3kW/m3) versus in its absence (0.1 kW/m3). The organic matter mass balance resulted in approximately 50% higher biodegradation yield and improved oxidation rates over readily biodegradable organic fractions. Microbial analysis highlighted a higher concentration of thermophilic species and a lower concentration of well- known pathogenic and antibiotic-resistant genera in the presence of biochar. [ABSTRACT FROM AUTHOR]

Introduction: Compost heat recovery systems (CHRS) represent an emerging technology to recover residual woody biomass from agroforestry and forestry activities and use the heat that is naturally produced during aerobic biodegradation (composting). However, a low oxygen concentration in the gas phase and self-drying and compaction of the compost body often limit efficient oxidation by microbial communities. Woodchip-derived biochar has often been proposed as a bulking agent and improver of water retention and of oxygen accessibility in the composting process, but the literature reporting its effects in the CHRS is scarce.Methods: Here, biochar (average particle size of 10 mm) was added at 10% (on weight basis) to chipped pruning residues into two bench-scale-controlled reactors (0.2 m3), operated in parallel for 57 days.Results and Discussion: The addition of 10% (w/w) biochar to the composting body increased biodegradation yields by approximately 50% and improved oxidation rates over readily biodegradable organic fractions (addition of cheese whey). Temperatures were on average 1.34°C higher, and heat extraction flux was also improved in the presence of biochar (0.3 kW/m3) versus in its absence (0.1 kW/m3). The organic matter mass balance resulted in approximately 50% higher biodegradation yield and improved oxidation rates over readily biodegradable organic fractions. Microbial analysis highlighted a higher concentration of thermophilic species and a lower concentration of well-known pathogenic and antibiotic-resistant genera in the presence of biochar.

Population growth and the associated increase in the use of Onsite Wastewater Treatment Systems (OWTS) in the Black Hills have been a reason for interest in nitrate contamination within the public water supply over the past few years. The main concern for the Black Hills is the presence of karst formation that all OWTS for wastewater travel faster, limiting the natural attenuation of wastewater contaminants. The treatment performance of common soils in the Black Hills and wood-based media was evaluated using soil column experiments and a numerical model, HYDRUS 2D. Nitrate treatment performances were evaluated using alluvial and cedar soils collected from the Black Hills, sand, woodchips (loose and dense), and biochar. This research investigated hydraulic and reaction parameters through a combination of experimental and inverse modeling approaches. A good agreement was obtained between the measured and model-predicted soil moisture content, with R2 values ranging from 0.57 to 0.99. The model was calibrated using flow data and nitrate concentration data measured from leachate collected at the bottom of the experimental columns. Nitrate removal rates varied from 32.3% to 70%, with the highest removal rate in loose woodchips, followed by dense woodchip and biochar, and the lowest removal rate in alluvial materials. The biochar and loose woodchips removed an additional 20% compared to common soils, attributable to the enhanced denitrification rate due to higher water content and organic content. The use of woodchips and biochar should be implemented in OWTS, where there are known karst formations.

This paper presents the application of prediction in the analysis of market price volatility in Polish conditions of wood processing by-products in the form of biomass. The ARIMA model, which takes into account cyclical, seasonal, irregular fluctuations of historical data on the basis of which the forecast and long-term trends of selected wood products were made, was used in predicting prices. Comparisons were made between the ARIMA prediction method and the multiplicative Winters–Holt model. During the period studied (2017–2022), the changes in the market price of biomass were characterized by a wide spread of values. On average, the price of these products increased from 2017 to the end of 2022 by 125%. The price prediction analysis showed seasonal fluctuations in the case of wood chips. The uncertainty in price prediction is due to changes in supply resulting from the influence of global factors. The Diebold–Mariano test of matching accuracy confirms that the price prediction of the analyzed by-product sorts using the ARIMA and WH models is possible. The conclusion reached by comparing these two methods is that each can be used under certain market conditions of certain assortments. In the case of a stable wood product, the choice of the ARIMA model should be resolved, while in the case of price volatile products, WH will be a better choice. The difference between the predicted and actual price with ARIMA ranged from 2.4% to 11.6% and for WH from 3.7% to 29.8%. [ABSTRACT FROM AUTHOR]

In Asian countries, the primary palm oil producers, used cooking oil (UCO) is the primary feedstock for biodiesel production. It can be converted into an eco-fuel for application in heavy machinery and diesel engine vehicles due to its low carbon emissions and low global warming potential. However, the illegal dumping of UCO containing triglyceride into flowing water bodies (resulting in wastewater treatment and purification complications) has prompted the design of smart UCO collection systems. This study aims to investigate the heterogeneous catalytic performance of biochar as a support catalyst derived from woodchips calcined at 400 °C and 800 °C under nitrogen gas flow. The catalyst was synthesized through the wet impregnation method using two metal oxides (5 wt.%, nickel and molybdenum) via transesterification to enhance the biodiesel yield. High biodiesel yield was obtained through the controlled parameters: 65–95 °C temperature, 10:1 methanol to oil ratio, and 2 h reaction time. The synthesized catalyst was characterized through X-ray Diffraction (XRD) and Field Emission Scanning Electron (FESEM). The biodiesel production was confirmed by Fourier Transform Infra-Red (FTIR) Spectroscopy. The results showed that the highest biodiesel yield was produced by the catalyst calcined at 800 °C, which shows a consistent trend in the yields obtained at temperatures in the order 75–85–95–65 °C. In conclusion, calcination at 800 °C resulted in a higher yield (74.66%) and catalyst reusability (≥5 cycles). [ABSTRACT FROM AUTHOR]

The future of conventional fuels has limited sustainability and creates disquietude because of the ubiquitous energy crisis worldwide. The judicious use of biomass or wood-based fuels is inevitable. The quality of wood fuels depends on the moisture content, and subsequently, solar drying solutions can play a vital role in adequately storing and controlling moisture in the fuels. In the present study, a novel forced convection cabinet-type solar dryer was developed and investigated for its thermal performance. An artificial neural network (ANN model) was created to predict the final moisture content of the drying system. The drying behavior of three distinct wood fuels, i.e., woodchips, sawdust, and pellets, was kept under observation to plot the drying curve based on their calculated moisture ratio. The dryer reached a maximum temperature of 60 °C while maintaining a temperature gradient of 10–20 °C. The maximum thermal energy and exergy efficiency was recorded as 55% and 51.1%, respectively. The ANN-optimized model was found suitable with reasonable values of coefficient of correlation (R) for the model. [ABSTRACT FROM AUTHOR]

This paper presents methodologies and equipment for SI-traceable inline measurements of water content (a critical quality parameter) in solid biofuels. Inline measurement systems for water content are commonly used at CHP plants, providing continuous real-time data. However, the accuracy of these systems is in most cases unsatisfactory, mainly because the systems are not calibrated representatively for the relevant material, and until now, calibrations traceable to the SI system have not been available. To provide reliable and accurate inline water content data, new procedures and equipment for calibrating measurement systems were developed. Two reference methods for the determination of water content were developed; one measures the airflow and dewpoint of desorbed water in the air passing a test sample, while the other uses a P2O₅-sensor. Additionally, a transfer standard based on a cavity resonance sensor was developed for fast onsite calibration of the inline sensor at the power plant. This new instrument allows for quick and accurate measurements. The transfer standard is made metrologically traceable to the primary measurement standards. The entire system was demonstrated by calibrating an inline microwave-based (MW) sensor at the CHP plant of VERDO in Randers, Denmark. Thus, a complete metrological traceability chain was established from an industrial to a primary standard.

The simultaneous firing characteristics of woodchips and spent mushroom substrates (SMS) were studied in a stoker-type industrial boiler. The type of spent substrate intended for combustion consisted of oyster mushrooms. SMS from mushroom farms generally have a high water content. Dryers are therefore used for combustion. The moisture content of SMS was reduced to achieve low moisture to combust sufficiently at about 20%. First, the basic characteristics of the boiler were confirmed by conducting a woodchip combustion test under various operating loads of 30, 50, 70, and 100%. Thereafter, a simultaneous combustion test of woodchips and SMS was performed. During the experiment, exhaust gas concentrations in the boiler combustion chamber were measured, such as the temperature of oxygen (O2), carbon monoxide (CO), and nitrogen oxides (NOx). In addition, industrial and basic analyses were performed on woodchips and SMS. The main differences in the fuel analysis results between woodchips and SMS were ash, nitrogen, sulfur content and net calorific value. According to the analysis, the nitrogen content of SMS was 2.6%, which was 8.7 times higher than that of woodchips, and the ash content was also 14.8%, which was 18.5 times that of woodchips. As a result of the combustion experiment, the woodchip experiment revealed that the values of O2 and CO decreased and the combustion chamber temperature increased as the amount of fuel increased. Due to higher combustion temperature, thermal NOx also increased. When comparing this combustion test with the co-firing test, there was no significant difference in O2, CO, and combustion chamber temperature. However, with regard to the NOx value, the results showed a sharp increase from 64 ppm to 135 ppm. Although the NOx value increased, SMS had enough heat to be burned as fuel. Therefore, the utility of various agricultural byproducts as fuel has prospects for achieving an effective approach to energy cost reduction. [ABSTRACT FROM AUTHOR]

Currently, woodchips and logging residues form the greatest share of biomass fuels used to generate heat in combined heat and power plants. They are supplied from various regions of the EU. The calorific values of the wood species used as biomass may vary significantly depending on the moisture and composition of the fuel, harvest seasonality, location, and other factors. This article presents the main resources of forest biomass and its characteristic features, as well as the calorific value of woodchips depending on the moisture content. Our research is based on the source data of forest resources from the State Forests National Forest Holding (PGLLP) in Poland. The research conducted by the main forestry enterprise in Poland covered a period of four years. The data on the harvesting of woodchips and logging residues converted into the calorific values of biomass were based on our research and a review of reference publications. Standard methods were used in the research, which included an analysis of the species and assortment structure of the forest biomass of energetic significance that was available for use. The research showed that the moisture content of the woodchips and lump wood was about 30%. The average annual energy value of the wood in the total area of forest resources was 0.07 GJ/ha, whereas the highest value was 0.14 GJ/ha. Between 2018 and 2021, the average energy resources of forest biomass in Poland increased from 351.8 TJ to 498.4 TJ. [ABSTRACT FROM AUTHOR]

Population growth and the associated increase in the use of Onsite Wastewater Treatment Systems (OWTS) in the Black Hills have been a reason for interest in nitrate contamination within the public water supply over the past few years. The main concern for the Black Hills is the presence of karst formation that all OWTS for wastewater travel faster, limiting the natural attenuation of wastewater contaminants. The treatment performance of common soils in the Black Hills and wood-based media was evaluated using soil column experiments and a numerical model, HYDRUS 2D. Nitrate treatment performances were evaluated using alluvial and cedar soils collected from the Black Hills, sand, woodchips (loose and dense), and biochar. This research investigated hydraulic and reaction parameters through a combination of experimental and inverse modeling approaches. A good agreement was obtained between the measured and model-predicted soil moisture content, with R2 values ranging from 0.57 to 0.99. The model was calibrated using flow data and nitrate concentration data measured from leachate collected at the bottom of the experimental columns. Nitrate removal rates varied from 32.3% to 70%, with the highest removal rate in loose woodchips, followed by dense woodchip and biochar, and the lowest removal rate in alluvial materials. The biochar and loose woodchips removed an additional 20% compared to common soils, attributable to the enhanced denitrification rate due to higher water content and organic content. The use of woodchips and biochar should be implemented in OWTS, where there are known karst formations. [ABSTRACT FROM AUTHOR]

Due to a continuous abandonment of marginal agricultural land, Mediterranean pine forests are growing both in biomass stock and area but remain mainly unmanaged. Pinus halepensis is one of the main pioneer species with strong expansion throughout the Mediterranean basin. In mature forests and pole stands, selective thinnings aimed to eliminate dominated and dead trees are necessary to improve the resilience and persistence of these forest ecosystems. Bioenergy market provides an opportunity to mobilise this woody material, helping to prevent and reduce wildfires in a context of climate change and energy transition. Despite the existing expertise on wood harvesting, there is a lack of practical knowledge about cost-effective methods for bioenergy use of selective thinnings in such forests. The objective of this study was to compare thinning harvesting methods in representative 63-year-old Pinus halepensis afforestation in pole stage for bioenergy uses, following the silvicultural treatments defined in the Spanish forest management plan. Time studies were performed over six representative plots in Navalón (Spain). Treatments included three plots with the traditional stem wood method combined with the logging of forest residues (integrated system), and three plots with the whole tree chipping (whole tree system). Time, productivity and fuel consumption were recorded for both systems. A woodchip quality assessment of each assortment was performed in the laboratory according to European standards. The results obtained demonstrated that time consumption and productivity were similar between the integrated harvesting system and the whole tree system. Regarding the total energy balance, it should be noted that both systems produce woodchips that contain over ten times more energy than that required to mobilise and process the obtained biomass. Fuel consumption, costs and degree of damage were slightly higher in the whole tree system due to the more intensive forwarding operation. The two assortments of woodchips in the integrated system had a higher (chipped log material) and lower quality (chipped crown material) than whole tree woodchips. In conclusion, integrated harvesting is a better option to diminish fuel consumption, cost and environmental impact, and also to obtain better quality woodchips for the production of added value biofuels (pellets).

The radioactive cesium (radio-Cs) released following the Fukushima Daiichi Nuclear Power Plant accident was unevenly distributed in soil, sediment, and buildings. It is therefore crucial to evaluate the impact of radio-Cs and to prevent its spread throughout various environments. Herein, we investigated the Cs adsorption capacity of woodchip-mixing porous mortar (WPM) as an ecologically friendly adsorbent for treating radioactively-contaminated water or soil. When the WPM was dipped into a solution containing stable-Cs for one month, the Cs adsorption to WPM was three times that of porous mortar without woodchips (PM). The WPM's retention of Cs was assessed by examining the specimens after adsorbing Cs and regularly determining the Cs concentration leached by dipping the WPM samples in pure water or salt solution (1–100 mmol/L KCl) over one year. The amounts of Cs leached from the WPM were lower than those leached from PM or woodchips, and the quantities increased depending on the KCl concentration. The chemical forms of Cs retained in the WPM via a sequential extraction procedure mainly included the ion-exchange form and the silicate-bound form. Accordingly, the enhanced Cs adsorptivity of WPM arises because of the strong interactions between Cs ions and the woodchip and cement components. [ABSTRACT FROM AUTHOR]

During summer and winter months, pastures and outdoor pens represent the conventional means of providing exercise for dairy cows housed in tie-stall barns in the province of Québec, Canada. Unfortunately, outdoor pens require large spaces, and their leachates do not meet Québec's environmental regulations. Therefore, there is a need to develop alternative approaches for these so-called wintering pens. A sustainable year-long approach could be a stand-off pad consisting of a filtering media to manage adequately water exiting the pad. Different filtering materials can be used and mixed (gravel, woodchips, biochar, sphagnum peat moss, sand, etc.). To find the best material and/or mixes, a laboratory study was carried out using 15 PVC pipes (5 cm in diameter and 50 cm long) to test five different combinations of materials over a 3-week period. Different contaminant-removal efficiencies were achieved with the alternative materials, including for chemical oxygen demand (11–38%), phosphates (8–23%), suspended solids (33–57%), and turbidity (23–58%). Alternative treatments with sand, sphagnum peat moss, and biochar improved the filtration capacity when compared to the conventional material (woodchips). However, after three weeks of experimentation, the treatment efficiency of sand gradually decreased for pollutants such as suspended solids and phosphates. [ABSTRACT FROM AUTHOR]

Microorganisms play a vital role in the degradation of organic matters such as Sawdust and woodchips. In this study, the Serial dilution method and pour plate techniques were used according to microbiological standards. The media used were nutrient agar, sabouraud dextrose agar, and cellulolytic medium to identify microorganisms and inoculated them into the Sawdust and woodchips and kept for 30 days at 37 oC and 25 oC. The total viable bacterial count for Sawdust and woodchips ranged between 9.0×103 - 6.0×103and 1.96×103 - 1.48×103, respectively. A total of 12 organisms were identified according to the biochemical reactions, six bacteria, and six fungi. Bergy's manual of determinative bacteriology confirmed the organism as Escherichia coli, Pseudomonas aeruginosa, Klebsiella sp, Staphylococcus aureus, Bacillus cereus, and Cellulomona sp. The fungal species identified include Rhizopus sp, Mucor sp, Saccharomyces cerevisiae, Candida sp, Aspergillus niger, and Aspergillus flavus. The bacteria with the highest potential to degrade Sawdust and Woodchips are Cellulomonas sp. (20.9%), Klebsiella sp (17.8%), Escherichia coli (8.3%), Bacillus cereus (7.15%), and Staphylococcus sp (6.2%). Furthermore, the fungi capable of degrading the Sawdust and woodchips are Mucor sp (19.90%), Aspergillus flavus (17.8%), Aspergillus niger (17.3%), Rhizopus (16.9%), and Saccharomyces cerevisiae (15.55%). From these results, it can be concluded that some microorganisms could be used for the biodegradation of lignocellulose materials. [ABSTRACT FROM AUTHOR]

An ultra-wide band measurement method for determining the complex refractive index of large-volume objects is presented. The method is intended for industrial non-destructive testing. It uses a frequency-domain technique in which transmitted radio pulses are analyzed and the effects of near field and coupling on the determined refractive index are compensated. Measurements were performed in an industrial setup with electromagnetic sensors buried in the object. The results are presented for woodchips as an object. The refractive index was experimentally determined in the frequency range 0.5-3.0 GHz. Additionally, we designed and manufactured planar quasi-differential elliptical-antennas as electromagnetic sensors. The results from the industrial measurement setup were compared with the results of the laboratory setup, in which the sensors were placed outside the test box and near field and coupling effects could be neglected. The complex refractive index determined for the two setups was in good agreement, which corroborates the proposed method for compensating for coupling and near-field effects. The complex refractive index of woodchips changes with the moisture content. It is experimental verified using the industrial setup that the moisture content can be determined with a 2 percent error. [ABSTRACT FROM AUTHOR]

Irrigation consumes three quarters of global water withdrawals each year. Strategies are needed to reduce irrigation water use, including increasing the efficiency of transfer methods and field application. Comprehensive restoration of soil health, specifically through organic matter amendments, can substantially reduce irrigation demand and increase crop yield. A program to restore severely degraded and desertified soils by incorporating coarse woodchips into the soil successfully increased rainfall capture and elevated soil moisture for several weeks between rainfall events at both Ningxia, north-west China and North Dakota, USA. With addition of fertilizer, woodchip incorporation further increased growth of wheat and alfalfa. Comprehensive soil health assessment of remnant grasslands was used to develop target reference soil profiles by which to guide restoration efforts. Given that most agricultural soils are degraded to some degree, soil health restoration can provide a powerful strategy toward achieving global food and water security.

This paper presents the application of prediction in the analysis of market price volatility in Polish conditions of wood processing by-products in the form of biomass. The ARIMA model, which takes into account cyclical, seasonal, irregular fluctuations of historical data on the basis of which the forecast and long-term trends of selected wood products were made, was used in predicting prices. Comparisons were made between the ARIMA prediction method and the multiplicative Winters–Holt model. During the period studied (2017–2022), the changes in the market price of biomass were characterized by a wide spread of values. On average, the price of these products increased from 2017 to the end of 2022 by 125%. The price prediction analysis showed seasonal fluctuations in the case of wood chips. The uncertainty in price prediction is due to changes in supply resulting from the influence of global factors. The Diebold–Mariano test of matching accuracy confirms that the price prediction of the analyzed by-product sorts using the ARIMA and WH models is possible. The conclusion reached by comparing these two methods is that each can be used under certain market conditions of certain assortments. In the case of a stable wood product, the choice of the ARIMA model should be resolved, while in the case of price volatile products, WH will be a better choice. The difference between the predicted and actual price with ARIMA ranged from 2.4% to 11.6% and for WH from 3.7% to 29.8%.

Intensive pastoral farming has been linked to adverse environmental effects such as soil degradation and increased fluxes of nitrogen, phosphorus, sediments, and pathogens into waterways, resulting in their degradation. Stand-off pads are engineered structures covered with bedding materials, available for occupation by stock to minimise those adverse effects to soil and water bodies. Wood chips are ideal for bedding due to their low cost, high water holding capacity, and stock preference as resting areas. While they reduce the mobility of both nutrients and pathogens, their effectiveness depends on the type of wood, size of the chips, pH, pad design, and feeding management used. Dissolved organic carbon, present in wood residue, may slow nitrogen mineralisation thereby decreasing loss via leachate. This effect depends on plant tannins and nutrients already stored within the plant tissue. Poplar and willow have high concentrations of tannins in leaves and bark with potential nitrification-inhibiting properties. When grown on-farm, these deep-rooted trees also reduce nitrogen leaching and prevent soil erosion. This review addresses the use of temporary stand-off pads within poplar or willow silvopastoral systems. Harvested trees can provide suitable wood chips for constructing the stand-off pad, while the deep rooting systems of the trees will reduce the moisture content of the pad, preventing waterlogging. A key objective is to discuss the feasibility and establishment of multiple temporary stand-off pads that allow for stock rotation from pad to pad, and subsequent on-site composting of wood-wastes into fertiliser, reducing both nutrient inputs and losses in agricultural systems. The review highlights the potential suitability of poplar and willow tree species for such a system.

Denitrification bioreactors have been proved successful in removing nitrate loads from agricultural drainage water. One of the key factors affecting bioreactor performance is the organic carbon substrate used in the bioreactor. The quest to find an appropriate carbon substrate that not only enhance nitrate-nitrogen (NO3— N) reduction to gaseous nitrogen (N2), but also increase longevity of the denitrification bioreactor becomes an important issue. In this study, five denitrification bioreactors having different combinations of rice-husk and woodchips were assessed using low (1 mg/L), medium (5 mg/L), and high (15 mg/L) influent concentrations. The results showed that a combination of both C-substrate led to a quick start and high removal rate of nitrate nitrogen, at hydraulic retention time of 8k, the removal rate was 0.98 gm-3 day-1, 6.98 gm-3 day-1 and 13.98 gm-3 day-1 for influent concentration of 1,5 and 15 mg/L, respectively. Better performance of the bioreactors (91% removal efficiency) was observed at higher influent concentration, indicating that nitrogen removal with bioreactors was highly dependent on influent concentration. The experimental results showed that a mixture of the readily and slowly available carbon substrate can be effectively used to remove nitrate nitrogen from agricultural drainage water. [ABSTRACT FROM AUTHOR]

Horses in equestrian sports are commonly trained in arenas with prepared footing. Information on the number and variants of such arenas is generally unknown. This paper provides an overview of the primary construction types of riding surfaces in Sweden including details on composition, constructions principles, usage frequency, maintenance, and cost of operation as well as to investigate rider perception of the ideal arena properties using a large population of riders. Data on 656 equestrian surfaces in Sweden obtained up to 2014 are presented, of which 373 were outdoor and 283 were indoor arenas. Dressage and show-jumping were the main disciplines conducted in the arenas. Sand-mineral arenas were most common outdoors and sand-woodchips arenas most common indoors, followed by sand-fibre arenas and even fewer synthetic arenas. Comparing the three most common arena types, dragging was most often done on sand-woodchips and sand-fibre arenas. Harrowing was less often done on sand-mineral arenas compared to sand-woodchips and sand-fibre arenas. Combining dragging, harrowing, deep harrowing, and rolling, arenas with higher usage were maintained more frequently, compared to those used less frequently. It was commonly claimed that the top-layer needs renovation every other-4th year or every 5th to 10th year. Few respondents allocated more than 10,000 SEK in yearly maintenance costs, with the exception for sand-woodchips and sand-fibre arenas followed by synthetic arenas. The shortest duration perceived between required renovations was found for sand-woodchips top-layer arenas. Ideal surface properties were evaluated by 3,158 riders. Dressage and show-jumping riders differed somewhat regarding ideal spans of functional arena properties: for impact firmness, responsiveness, and grip. The current study likely included well-utilised arenas, compared to those less well-utilised. The resources necessary to keep an arena consistent over time seemed underestimated. Knowledge of maintenance and priorities for arenas are important to users and arenas managers, be they construction companies or arena managers in order to maximise the outcome of efforts for arena improvement and optimise locomotor health for horses that use them. Further, many arenas were new and research into organic arena management is important, especially if equestrians continue to build and renew arena surfaces.

The simultaneous firing characteristics of woodchips and spent mushroom substrates (SMS) were studied in a stoker-type industrial boiler. The type of spent substrate intended for combustion consisted of oyster mushrooms. SMS from mushroom farms generally have a high water content. Dryers are therefore used for combustion. The moisture content of SMS was reduced to achieve low moisture to combust sufficiently at about 20%. First, the basic characteristics of the boiler were confirmed by conducting a woodchip combustion test under various operating loads of 30, 50, 70, and 100%. Thereafter, a simultaneous combustion test of woodchips and SMS was performed. During the experiment, exhaust gas concentrations in the boiler combustion chamber were measured, such as the temperature of oxygen (O2), carbon monoxide (CO), and nitrogen oxides (NOx). In addition, industrial and basic analyses were performed on woodchips and SMS. The main differences in the fuel analysis results between woodchips and SMS were ash, nitrogen, sulfur content and net calorific value. According to the analysis, the nitrogen content of SMS was 2.6%, which was 8.7 times higher than that of woodchips, and the ash content was also 14.8%, which was 18.5 times that of woodchips. As a result of the combustion experiment, the woodchip experiment revealed that the values of O2 and CO decreased and the combustion chamber temperature increased as the amount of fuel increased. Due to higher combustion temperature, thermal NOx also increased. When comparing this combustion test with the co-firing test, there was no significant difference in O2, CO, and combustion chamber temperature. However, with regard to the NOx value, the results showed a sharp increase from 64 ppm to 135 ppm. Although the NOx value increased, SMS had enough heat to be burned as fuel. Therefore, the utility of various agricultural byproducts as fuel has prospects for achieving an effective approach to energy cost reduction.

Volatile nitrogen (N) loss from dairy barns is a concern. In compost-bedded pack barns, where the cattle rest on an organic pack, controlled thermophilic composting of that pack could promote microbial conversion of inorganic N (excreted by the cattle on the pack) into organic form, resulting in a reduction of pack inorganic N concentration and of volatile N loss from the barn. We tested this hypothesis during an 8-month period, including winter, on a commercial farm in the Netherlands where a specific composting method had been developed for a woodchip-bedded pack. A conversion of excreted inorganic N into organic form was assessed by repeated pack analysis; volatile N loss from the barn by calculation of its accumulating N mass balance. Our results show that volatile N loss from the barn was closely related to pack C:N ratio (P < 0.001; R2 adj. = 83 %) and was negative during the first two months of composting. The negative loss was likely the result of NH 3 -absorption and/or N 2 -fixation by microorganisms from ambient air, two phenomena reported in literature. The critical pack C:N ratio, at which volatile N loss from the barn was zero, was 35, in line with critical ratios found in other studies. We conclude that controlled thermophilic composting of a woodchip-bedded pack, at a relatively high C:N ratio, has potential to minimise volatile N loss from compost-bedded dairy barns. • Pack composting resulted in low volatile nitrogen loss from a dairy barn. • Level of nitrogen loss was closely related to pack C:N ratio. • The critical pack C:N ratio of 35 was in line with ratios found in other studies. • Above this critical ratio, nitrogen from ambient air was probably fixed into the pack. [ABSTRACT FROM AUTHOR]

Currently, woodchips and logging residues form the greatest share of biomass fuels used to generate heat in combined heat and power plants. They are supplied from various regions of the EU. The calorific values of the wood species used as biomass may vary significantly depending on the moisture and composition of the fuel, harvest seasonality, location, and other factors. This article presents the main resources of forest biomass and its characteristic features, as well as the calorific value of woodchips depending on the moisture content. Our research is based on the source data of forest resources from the State Forests National Forest Holding (PGLLP) in Poland. The research conducted by the main forestry enterprise in Poland covered a period of four years. The data on the harvesting of woodchips and logging residues converted into the calorific values of biomass were based on our research and a review of reference publications. Standard methods were used in the research, which included an analysis of the species and assortment structure of the forest biomass of energetic significance that was available for use. The research showed that the moisture content of the woodchips and lump wood was about 30%. The average annual energy value of the wood in the total area of forest resources was 0.07 GJ/ha, whereas the highest value was 0.14 GJ/ha. Between 2018 and 2021, the average energy resources of forest biomass in Poland increased from 351.8 TJ to 498.4 TJ.

• A biofilter packaged with perlite, ripe compost, and oak woodchips was used to remove furfural from polluted air. • Totally, the mean values of removal efficiency and elimination capacity of the biofilter were 72 ± 12 % and 2.1 ± 1.5 g m−3 h−1. • The removal efficiency values under neutral and acidic conditions were 80 and 65 %, respectively. Furfural is a toxic compound that is widely used in various industries. Prolonged inhalation exposure to this pollutant, especially at workplaces, can induce detrimental health effects. Therefore it is important to remove it from the environment. The present study aimed to investigate furfural removal from polluted air streams using a biofilter system. In this regard, a 4-section biofilter packed with perlite, ripe compost, and oak woodchips was operated for a 108 day-period under different operating conditions. The effects of pH (natural and acidic), inlet concentration (18.8–81.6 mg m−3), the height of biofilter layers (4 sections), and empty bed residence times (EBRTs) of 120, 70, and 30 s on removal efficiency (RE) of the biofilter were evaluated. All sampling and measurements were performed according to standard methods. The RE values under neutral and acidic conditions were 80 and 65 %, respectively. At furfural inlet concentrations in the ranges of 18.8–21.3, 35.25–42.7, and 78.4–81.6 mg m−3, the RE values were 81, 68, and 57 %, respectively. Also, the RE values at EBRTs of 120, 70, and 30 s were 83, 73, and 61 %, respectively. About half of the total RE was related to the first section of the biofilter, where the number of bacterial (6.2 log 10 CFU g-1) and fungal (5.8 log 10 CFU g-1) were higher than the other sections. Due to the high RE (72 %) and low pressure drop (below 43 Pa m-1) of the biofilter, it can be concluded that biofiltration is a suitable process to remove furfural from the air. [ABSTRACT FROM AUTHOR]

Diversifying the Brazilian energy matrix by using residual biomass from planted forests requires searching for harvest technologies with sustainable applications. The aim of this study was to access the productive assessment and energy balance of grinding forest residues from full tree pine harvesting using a horizontal grinder in Brazil. A time study and moisture measurement were carried out at 15-year-old Pinus taeda L. stands located in the Santa Catarina State to determine mechanical delay, utilization rate, productivity per productive machine hour and production of a horizontal grinder in which energy balance was also calculated. For these variables, non-parametric bootstrap was performed, resampling a thousand times with replacement and producing new random samples, to calculate bias and confidence intervals at a 95% probability level. Non-working time consumed most of the scheduled machine hours, with only 46% being considered as working time. This was caused by the horizontal grinder's travel time and time spent waiting for the transport vehicles. The horizontal grinder's average productivities were 59 Mg per productive machine hour and 219 Mg per shift, considering the low machine utilization. The energy contained in the woodchips is 126.6 times higher than the energy consumed by the grinder, but this calculation only considers the grinding phase and excludes transport to the mill as well as the previous steps of stacking at the side of the field. The sustainability of this production is confirmed as the amount of energy consumed represents a small part of the potential present in the recovered forest residues. [ABSTRACT FROM AUTHOR]

BackgroundThe development of affordable woody biomass feedstocks represents a significant opportunity in the development of cellulosic biofuels. Primary woodchips produced by forest mills are considered an ideal feedstock, but the prices they command on the market are currently too expensive for biorefineries. In comparison, forestry residues represent a potential low-cost input but are considered a more challenging feedstock for sugar production due to complexities in composition and potential contamination arising from soil that may be present. We compare the sugar yields, changes in composition in Douglas-fir woodchips and forestry residues after pretreatment using ionic liquids and enzymatic saccharification in order to determine if this approach can efficiently liberate fermentable sugars.ResultsThese samples were either mechanically milled through a 2 mm mesh or pretreated as received with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate [C2mim][OAc] at 120°C and 160°C. IL pretreatment of Douglas-fir woodchips and forestry residues resulted in approximately 71-92% glucose yields after enzymatic saccharification. X-ray diffraction (XRD) showed that the pretreated cellulose was less crystalline after IL pretreatment as compared to untreated control samples. Two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) revealed changes in lignin and hemicellulose structure and composition as a function of pretreatment. Mass balances of sugar and lignin streams for both the Douglas-fir woodchips and forestry residues throughout the pretreatment and enzymatic saccharification processes are presented.ConclusionsWhile the highest sugar yields were observed with the Douglas-fir woodchips, reasonably high sugar yields were obtained from forestry residues after ionic liquid pretreatment. Structural changes to lignin, cellulose and hemicellulose in the woodchips and forestry residues of Douglas-fir after [C2mim][OAc] pretreatment are analyzed by XRD and 2D-NMR, and indicate that significant changes occurred. Irrespective of the particle sizes used in this study, ionic liquid pretreatment successfully allowed high glucose yields after enzymatic saccharification. These results indicate that forestry residues may be a more viable feedstock than previously thought for the production of biofuels.

In Italy, black pine has been largely used in reforestation projects in the past. Most of these reforestations are characterized by a high instability, vulnerability, and a limited resistance to atmospheric agents. In this situation, it is crucial to define silvicultural interventions able to increase the ecological stability of black pine stands and at the same time to guarantee the economic sustainability of the wood products obtained. Thinning in black pine forests can provide wood material for energy use. The main aim of the present study was to investigate the economic sustainability of a local wood-energy supply chain applying three different forest management options. The case study was Monte Morello forest, a degraded black pine forest located in Central Italy. The results show that the long-term economic sustainability of the wood-energy supply chain is ensured only when the use of bio-fuel is characterized by high energy efficiency. In addition, the results show that public contributions are fundamental to ensure that silvicultural interventions are realized with a positive economic balance and that to surmount this situation many loggings companies are organizing. Finally, the results highlighted the importance of the quantities of thermal energy sold to ensure the economic and environmental efficiency of the wood-energy supply chain.

Nowadays, there is increasing demand for the use of renewable energy sources such as woodchips. One of the important qualitative parameters of woodchips is the size distribution. The aim of this article is to determine the effect of a woodchipper disc’s torsional vibration on the evenness of woodchip length, as well as propose a mathematical solution to this problem by assuming one harmonic component of disc speed and the uniform feed of chipped material. The presented mathematical solution can be used to determine the unevenness of woodchip length when the parameters of torsional vibration are known.

Mature landfill leachate (MLL) tend to be highly contaminated due to the presence of refractory contaminants such as humic–fulvic substances, xenobiotic compounds, and heavy metals. This study investigated the treatment efficiency of MLL by deploying Cladosporium sp., Trichoderma asperellum, and Tyromyces chioneus fungal strains. Chemical oxygen demand (COD) and soluble COD (sCOD) removal efficiencies were assessed along with the evaluation of lignocellulosic enzymatic activities of laccase (Lac), lignin-peroxidase (LiP), and manganese-peroxidase (MnP). Glucose, woodchips, and wheat straw were utilized as co-substrates. Higher percentage of COD and sCOD reduction efficiencies and lignocellulosic enzymatic activities were found for woodchips than glucose and wheat-straw. The highest sCOD removal rates were 44%, 38% and 59% by Cladosporium sp., T. asperellum, and T. chioneus, respectively. Overall, Lac activity was significantly higher than LiP and MnP activity for all three species. Tyromyces chioneus was the most effective strain among the three selected fungi in terms of COD and sCOD reduction efficiencies and high enzymatic activities of 165, 14 and 20 U/L were detected for Lac, LiP, and MnP, respectively. Tyromyces chioneus is a potentially effective fungal strain for the enhanced bioremediation of MLL and its further investigation is recommended to explore the removal of recalcitrant contaminants from problematic wastewater. [ABSTRACT FROM AUTHOR]

This article describes the experimental setup for estimating the moisture in wood pellets and wood chips by measuring the attenuation of the first longitudinal acoustic resonance mode that is excited in the cylindrical container. The resonance quality is related to losses of sound energy, which are brought about by several phenomena and moisture is one of them. The metrological traceability was carried out by the "loss on drying" method, supported by calibrated balance and a set of reference materials. Using the "loss on drying" method, the amount of moisture in wood pellets was measured in the ranges of 0 %mc to 10 %mc. For acoustic tests in the range of 0 % mc to 56 % mc, reference woodchip material was used. Experimental results show feasibility of concept of traceable acoustic moisture measurement based device. [ABSTRACT FROM AUTHOR]

Popillia japonica Newman (Japanese beetle) is an invasive, polyphagous pest in North America, as adults feed on plant foliage and larvae on roots. Management in crops relies on foliar and soil applications of insecticides, but entomopathogenic nematodes (EPN) are effective biocontrol agents. In highbush blueberry, mulches (composts, woodshavings, sawdust, bark) are used for weed control and fertility. Therefore, our objective was to determine the effects of Heterorhabditis bacteriophora and Steinernema scarabaei on third-instar P. japonica in substrates commonly used as mulches in blueberry. In containers in the laboratory, larval mortality was 90–100% with H. bacteriophora for all substrates, but rates with S. scarabaei were lower and variable among substrates. A mixture of municipal compost + woodchips/sawdust resulted in 60% larval mortality without adding EPN, but few nematodes were recovered, indicating other causes of death. In a field microplot experiment in October, larval mortality rates were 50% at most for all EPN and substrate type combinations, likely due to lower than optimal soil and substrate temperatures for EPN survival and infectivity. Overall, a compost and woodchip/sawdust mulch should help suppress P. japonica populations in blueberry, and applying H. bacteriophora when temperatures are optimal to mulches can provide excellent larval control.

Nitrogen losses from utilised agricultural areas are responsible for water quality degradation and eutrophication. Denitrifying bioreactors can be used to reduce high nitrate concentrations in agricultural runoff in situ. The main factors affecting their function are the bioreactor fill medium and process parameters such as hydraulic retention time, temperature and inlet concentration of nitrates. The paper presents the results of laboratory experiments achieved with bioreactors filled with eight different wood-based materials, namely mulch, a mixture of spruce and pine sawdust, a mixture of pine and larch bark, and chips made of oak, poplar, larch, beech, and spruce wood. A sustainability index was used to assess the impact of the bioreactor on the environment. The best results were shown by beech, mulch and poplar and were achieved with hydraulic retention times 1.6-0.7-2.2 days, respectively, and inlet NO3--N concentration of 43.1 mg/L.

Mining activities are increasingly recognized for contributing to nitrogen (N) pollution and possibly also to emissions of the greenhouse gas nitrous oxide (N 2 O) due to undetonated, N-based explosives. A woodchip denitrifying bioreactor, installed to treat nitrate-rich leachate from waste rock dumps in northern Sweden, was monitored for two years to determine the spatial and temporal distribution of microbial communities, including the genetic potential for different N transformation processes, in pore water and woodchips and how this related to reactor N removal capacity. About 80 and 65 % of the nitrate was removed during the first and second operational year, respectively. There was a succession in the microbial community over time and in space along the reactor length in both pore water and woodchips, which was reflected in reactor performance. Nitrate ammonification likely had minimal impact on N removal efficiency due to the low production of ammonium and low abundance of the key gene nrfA in ammonifiers. Nitrite and N 2 O were formed in the bioreactor and released in the effluent water, although direct N 2 O emissions from the surface was low. That these unwanted reactive N species were produced at different times and locations in the reactor indicate that the denitrification pathway was temporally as well as spatially separated along the reactor length. We conclude that the succession of microbial communities in woodchip denitrifying bioreactors treating mining water develops slowly at low temperature, which impacts reactor performance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Abstract Atrazine and nitrate NO 3 - N are two agricultural pollutants that occur widely in surface and groundwater. One of the pathways by which these pollutants reach surface water is through subsurface drainage tile lines. Edge-of-field anaerobic denitrifying bioreactors apply organic substrates such as woodchips to stimulate the removal of NO 3 - N from the subsurface tile waters through denitrification. Here we investigated the co-removal of NO 3 − N and atrazine by these bioreactors. Laboratory experiments were conducted using 12-L woodchips-containing flow-through bioreactors, with and without the addition of biochar, to treat two concentrations of atrazine (20 and 50 μg L−1) and NO 3 − N (1.5 and 11.5 mg L−1), operated at four hydraulic retention time, HRT, (4 h, 8 h, 24 h, 72 h). Additionally, we examined the effect of aerating the bioreactors on atrazine removal. Furthermore, we tested atrazine removal by a field woodchip denitrifying bioreactor. The removal of both NO 3 − N and atrazine increased with increasing HRT in the laboratory bioreactors. At 4 h, the woodchip bioreactors removed 65% of NO 3 − N and 25% of atrazine but, at 72 h, the bioreactors eliminated all the NO 3 − N and 53% of atrazine. Biochar-amended bioreactors removed up to 90% of atrazine at 72-h retention time. We concluded that atrazine removal was primarily via adsorption because neither aeration nor NO 3 − N levels had an effect. At 4-h retention time, the field bioreactors achieved 2.5 times greater atrazine removal than the laboratory bioreactors. Our findings thus highlighted hydraulic retention time and biochar amendments as two important factors that may control the efficiency of atrazine removal by denitrifying bioreactors. In sum, laboratory and field data demonstrated that denitrifying bioreactors have the potential to decrease pesticide transport from agricultural lands to surface waters. Graphical abstract Image 1 Highlights • Edge-of-field mitigation of atrazine and nitrate was investigated. • Woodchip bioreactors simultaneously removed nitrate and atrazine. • Biochar amendment increased atrazine removal. • Nitrate and atrazine removal by the bioreactors followed first-order kinetic rates. [ABSTRACT FROM AUTHOR]

The paper concerns the analysis of harmful emissions during the combustion process in households. The subject of the analysis is a low emission heating device with an output of 50 kW for burning biomass of forest origin (low-quality hardwoods or softwoods). The proposed boiler is automatically fed from the connected container by means of a screw conveyor. In this way, the optimum amount of fuel is supplied for maximum heat output (adjustment of the ratio of primary air to fuel). The proposed biomass heating system is equipped with a primary and secondary air supply system and exhaust gas sensors. This ensures optimal regulation of the air mixture and efficient and clean combustion. Proper control of the combustion process, control of the air supply by means of a lambda sensor and power control of the system ensure a low-emission combustion process. The system precisely adjusts to the heat demand. This results in highly efficient heating technology with low operating costs. In the presented work, the emission of exhaust gases from the proposed heating device during the combustion of woodchips and beech–oak pellets were measured. It is demonstrated that the proposed design of the boiler equipped with intelligent control significantly reduces emissions when the biomass solid fuels are used, e.g., CO emissions from beech and oak chips and pellets in the low-emission boiler—18 extract pipes shows the value