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This research aimed to demonstrate the thermal pathway (torrefaction technology) to convert organic waste to be biochar/biocoal. Organic waste (cabbage) from Nonthaburi fresh market, Thailand was used as raw material. Torrefaction technology was processed in horizontal cylindrical batch reactor with Nitrogen gas purging during doing experiment. Temperature profile was preliminary checked to find out lag time. Amount of loaded weight and particle size of material were preliminary tested. Experimental conditions such as time and temperature were tested at 30 and 60 minutes, and range temperature of 220 to 300°C. Important property of product; calorific value of product in form of high heating value (HHV) and mass yield percentage were measured. The optimal conditions were evaluated with two parameters; increase of HHV compared to reference condition and % mass yield. Increase temperature was significant effect to increase HHV value of biochar. The optimal time and temperature for getting the highest heating value were 60 minutes and 280°C. [ABSTRACT FROM AUTHOR]

The global demand for biochar in agricultural and carbon sequestration applications is increasing; nevertheless, biochar production using the 50-liter household biomass gasifier stove (50L-HBGS) in Thailand found major issues that need to be improved. The objective of this study was to study the effects of the airflow in the non-uniform combustion core shape (NCCS) on the biochar production characteristic of the 50L-HBGS. The new design of the NCCS was constructed and studied to replace the existing combustion core shape (ECCS) at Mahasarakham University. The height, air inlet, and air outlet diameters of the NCCS were designed at 45, 24, and 11.4 cm, respectively. The NCCS with 21 holes of the pyrolysis gas outlet, a diameter of 4 mm for each, was integrated into the 50L-HBGS and performed comparative tests to the ECCS using 9 kg of bamboo wood chunks in three consecutive experiments. The airflow and the combustion behavior were studied through the stove temperature profiles, which were recorded every 5 minutes using a digital data logger. The biochar products were studied using the scanning electron microscope (SEM) with the energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and the proximate analysis technique. The study indicated that the 50L-HBGS with the NCCS made significantly improved the airflow rates in the combustion core, resulting in better continuous burning during the ignition state than with the ECCS. Moreover, the pyrolysis temperatures were significantly improved, it was provided temperatures during the pyrolysis process reached higher than 500 °C, resulting in the liquid tar being removed and no unburned wood chunks remaining at the end. The characterization result demonstrated that the 50L-HBGS with the NCCS had created biochar within a range of micropore and macrospore sizes and high fixed carbon content, which could be advantageously used for different agricultural and carbon sequestration applications. [ABSTRACT FROM AUTHOR]

The highly acid sulfate Rangsit soil series of Rangsit, Pathum-Thani district, Thailand poses a major problem for agriculture in the area. Water hyacinth is a naturally occurring weed that can grow aggressively, causing eutrophication and leading to many severe environmental impacts. Here, through the pyrolysis process, we convert water hyacinth to biochar and use it for acid soil amendment. We found the ratio between biochar, soil, and sand suitable for the cultivation of water convolvulus to be 50 g of biochar, 400 g of soil, and 100 g of sand (1:8:2). This soil mixture improved the pH of the soil from 4.73 to 7.57. The plant height of the water convolvulus grown in the soil mixture was the greatest at 20.45 cm and the plant weight with and without roots was greatest at 2.23 g and 2.52 g, respectively. Moreover, we demonstrated the dominance and high abundance of Bacillus among the community in soil with biochar amendment. Here we provide the first assessment of the appropriate amount of water hyacinth-derived biochar for mitigation of soil acidity and promotion of optimal water convolvulus growth. Moreover, biochar can optimally modify soil bacterial communities that benefit plant development. [ABSTRACT FROM AUTHOR]

Agricultural waste is a major problem in Thailand. To eliminate waste and constrain global warming, waste should be renewed for other purposes by thermochemical processes. Pyrolysis is a process that produces biochar, which is useful for amending soil, improving soil fertility, and creating microorganism habitats. This research aimed to produce biochar from agricultural wastes for use as a mushroom substrate and to increase the nutrient consumption by the mushrooms. Sugarcane leaf biochar had the lowest C:N ratio and neutral pH, which are important factors for Pleurotus pulmonarius mycelium growth and the formation of fruiting bodies. Moreover, this biochar has micropores suitable for fungal growth. According to the nutrient measurements, the proximate analysis showed that 1% sugarcane leaf biochar produced a higher yield and protein content than the others, whereas the biochar reduced the fat content but increased the moisture in the fruiting body, including aeration increasing. Thus, 1% sugarcane leaf biochar was suitable as an extra substrate for growing grey oyster mushrooms. From the result of this research, biochar production is an excellent process to convert agricultural wastes to be a renewable resource for improving the efficiency of crop production. [ABSTRACT FROM AUTHOR]

Soil erosion due to land use change is a major concern in agricultural areas. There is an urgent need to develop appropriate agricultural practices that promote higher biodiversity and improve soil properties. Little is known about the processes of natural vegetation recovery after disturbance by human activities in tropical humid climates. This is particularly the case for dispersion by water (hydrochory) that affects seeds. The displacement of native plant seeds on the soil surface by runoff may be influenced by soil properties and by the use of biochar in agriculture. As these effects have not been documented in tropical agroecosystems and on steep slopes, we present here an in‐field experiment on a steeply sloping maize field affected by rainfall and tillage erosion in Northern Thailand. Our objectives were to test the effect of catena position and biochar use on seed displacement, soil loss and nutrient losses. We used 24 plots of 1 m2 located at four positions in the catena. Two treatments were tested: (1) conventional system with tillage and (2) biochar incorporated into the soil. We measured the displacement of plastic beads (to imitate round seeds), runoff volume, soil and nutrient losses and soil surface features during in‐situ rainfall simulations. After two simulated rainfall events and four natural rainfall events, total bead exportation was 7.2%. We found that catena position and biochar had an impact on runoff, soil and nutrient losses. In this study, previously incorporated biochar reappeared at the soil surface after 8 months under natural conditions and acted like a crust at the soil surface. This biochar crust increased runoff, increased potassium concentration and decreased phosphorus concentration in runoff, decreased bead displacement and had no effect on soil loss. This study, under tropical climate and steep slope conditions, highlights differences in soil surface features and runoff along the catena. We should consider catena position for improving soil management and using appropriate agroecological practices. Highlights: The effect of catena position and biochar use on seed displacement, soil loss and nutrient losses were tested.These effects have not been documented in tropical agroecosystems and steep slopes.Catena position and biochar use had an impact on runoff, soil and nutrient losses.Catena position for improving soil management and using agroecological practices should be considered. [ABSTRACT FROM AUTHOR]

Summary: An on-farm field experiment was conducted in northeastern Thailand to assess the effects of different eucalyptus biochar (BC) application rates, in combination with mineral fertilizers, on upland rice and a succeeding crop of sugarcane on sandy soil. Soil mineral N and greenhouse gas emissions were also evaluated. The field experiment consisted of three treatments: no biochar (BC0), 3.1 Mg ha−1 of biochar (BC1), and 6.2 Mg ha−1 of biochar (BC2). All treatments received the same recommended fertilizer rate. Soil mineral N, and emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored after BC application. The results revealed that the BC2 treatment caused lower soil mineral N content than that of the BC0 treatment during the upland rice period. During the sugarcane period, the BC2 treatment induced a greater soil mineral N content than the BC1 treatment but had no significant difference from the BC0 treatment. The BC2 treatment resulted in significantly lower cumulative CH4 and N2O emissions than the BC0 treatment during the upland rice period. In conclusion, we found that the BC2 treatment alleviated the global warming potential from CH4 and N2O emissions throughout the experiment, causing slight changes in soil N availability in the upland rice–sugarcane cropping system. [ABSTRACT FROM AUTHOR]

Biochar has been recommended as a soil amendment to improve soil fertility and mitigate methane (CH4) emissions from rice cultivation. Its effects, however, vary depending on soil type, biochar characteristics, and application rate. This study was aimed to evaluate the potential of mangrove biochar on CH4 mitigation, soil properties, and the productivity of rice cultivated in a clay loam soil in Thailand. Biochar was used at a rate equivalent to 10 t ha−1 season−1, both with (biochar + fertilizer: BF) and without (biochar alone: BI) fertilizer, for two cultivation seasons. BI reduced CH4 flux at most stages of rice growth. Relative to control soil (no biochar, no fertilizer: CT), BI significantly decreased cumulative CH4 emissions by 21.1% in the first season and 24.9% in the second season. CH4 emissions from BF soil were also less than those from the use of fertilizer alone (FE). Rice grain yield in BI was 7.85% and 14.4% greater than in CT, and in BF by 1.47% and 3.72% greater than FE, in the first and second seasons, respectively. The decrease in CH4 emissions and increase in rice grain yield decreased CH4 emission intensity under biochar treatments. Soil pH, organic carbon, cation exchange capacity, and available nutrients in the soil increased with biochar addition. The soil organic carbon stock was significantly increased by 32.6% in BI and 27.5% in BF after the first season, and by 43.5% in BI and 39.6% in BF after the second season. [ABSTRACT FROM AUTHOR]

• A paddy field in Thailand contaminated with Cd (41.02 mg kg−1) was restored. • BZVI decreased Cd accumulation in rice grains by 83 %. • BZVI as soil amendment enriched Fe and Zn accumulation in rice grains by 10 %. • ZVI corrosion enhanced by biochar is the key to BZVI success. • This technique is suitable for community-driven soil restoration. Consuming rice grown in contaminated soil that has an elevated level of cadmium (Cd) is a health risk. This study revealed that using a combination of biochar and zerovalent iron (BZVI) reduces the concentration of Cd and enhances that of the essential elements zinc (Zn) and iron (Fe) in rice. The Cd concentration in brown rice grain cultivated in an untreated paddy was 0.84 ± 0.20 mg kg−1, double the acceptable level (0.4 mg kg−1). Soil amendment with BZVI successfully decreased Cd in brown rice by 83 % compared to the untreated field presumably due to the Cd sorption on biochar (BC) and enhanced ZVI corrosion by-products while ZVI and BC alone achieved only 40 % and 74 % reduction, respectively. Moreover, while using ZVI or BC alone decreased Fe in rice grain by 8–14 %, BZVI enhanced the Fe concentrations in rice grain by 11 % because of Fe2+/Fe3+ release from BC-enhanced ZVI corrosion. Similarly, the presence of BC in BZVI enhanced Zn accumulation in rice grain by 8% due to competitive sorption of Cd2+ on BZVI, which may desorb Zn2+, promoting Zn translocation to rice. Using ZVI alone decreased Zn in rice by 19 %. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in an environment is a critical problem in Thailand that needs to be addressed urgently, particularly contaminated soil. This research aims to study the adsorption of cadmium ion by unmodified biochar and sodium dodecyl sulfate modified magnetic biochar (SDS-MB) derived from Eichhornia Crassipes. The adsorbent and soil characteristics were determined. Observed by scanning electron microscope (SEM), the surface of unmodified biochar (B) was smoother than SDS-MB. The X-ray diffractometer (XRD) pattern showed peaks for iron oxide. The values of point of zero charge (pHPZC) and acid neutralization capability (ANC) were 3 and 1000.3 meq/kg, respectively. The greatest adsorption of cadmium occurred when the pH of the wastewater was 8. The adsorption reached equilibrium within 1 h. It followed Freundlich, Temkin, and Dubinin-Radushkevich isotherm model and the pseudo-second-order kinetic. SDS-MB was mixed with sandy clay loam soil (pH 7.87) contaminated with cadmium 50 mg per kilogram soil at the ratio of 0-5%. The results from the extraction with ethylenediaminetetraacetic acid (EDTA), ammonium acetate, calcium chloride, diethylene triamine pentaacetic acid (DTPA), and sequential extraction method indicated that 5% mixing ratio showed the best ability to reduce cadmium movement in the soil. Cadmium in a form that bound to oxide and a form that bound to organic matter significantly increased. [ABSTRACT FROM AUTHOR]

Agricultural residues are one of the large untapped sources of bio-energy in Thailand, with over 30 million tons available per year. They may be utilized to generate renewable liquid and solid fuels. In this work, pyrolysis of lignocellulosic biomass residues (corncobs, coconut shells, and bamboo residue) was carried out in an ablative pyrolysis reactor with rotating blades. Influences of inert carrier gas flows (5–15 L/min) and rotating frequency (4–8 Hz) at a fixed hot plate temperature of 500 °C on generating bio-oil were investigated. Characterization of bio-oil as well as biochar products was performed. Maximum bio-oil yield was found to be about 50% w/w for coconut shell at 5 L/min of flowrate and 8 Hz of the rotating frequency, and 45% w/w for bamboo residues at the same condition. For corncob, the highest bio-oil yield was 72% w/w at 5 L/min of flowrate and 6 Hz of the rotating frequency. Solid char yields were around 23–28% w/w. The heating values of the liquid oil and solid char were about 20–25 and 23–30 MJ/kg, respectively. Rotating blade ablative reactor was able to generate high yields of bio-oil for agricultural residues. The main compounds of the bio-oil obtained were phenolics, including furfuran, organic acids, aldehydes, alcohols, ethers, and ketones. [ABSTRACT FROM AUTHOR]

Biochar application and alternate wetting and drying (AWD) are emerging as promising technologies recommended for reducing CH4 emissions and water consumption in rice cultivation. In this study, we hypothesized that both technologies could be practiced in combination and this could further reduce CH4 emissions and water consumption when compared to practicing alone. The effects of biochar application and its co-application with chemical fertilizer or compost under conventional or AWD water management on CH4 emissions, productivity of rice, water use, and SOC stock, as well as cost and income were investigated. The experiment was carried out in an irrigated paddy field in the central plain of Thailand during both in the wet and dry seasons. Relative to control (CT), biochar application (BI), its co-application with compost (BC) or chemical fertilizer (BF) reduced seasonal CH4 emissions by 40.6%, 29.5%, and 12.3%, respectively. BI and BC significantly (p < 0.05) reduced grain yield by 19.9% and 10.8%, respectively, while BF significantly increased grain yield by 3.70%. In addition, BI, BC, and BF significantly enhanced soil organic carbon (SOC) stock by 21.2%, 21.4%, and 18.3%, respectively. Compared to the CT, higher production costs were found in BC and BF, but the farmer's net incomes were also higher in BF because of its higher grain yield. On the other hand, water management in all amendment treatments under AWD was resulted in the reduction of CH4 emissions by the average of 18.8% as compared to the conventional system. AWD decreased rice yield by an average of 2.29%. It significantly reduced irrigation water use by an average of 11.9%, resulting in reducing production cost for water pumping. The results show that the practice that combined biochar application, AWD and chemical fertilizer are feasible for CH4 emission mitigation, SOC stock increase and irrigation water saving without significant effects on yield and farmer income. [ABSTRACT FROM AUTHOR]

For an agricultural country such as Thailand, converting agricultural waste into biochar offers a potential solution to manage massive quantities of crop residues following harvest. This research studied the structure and chemical composition of biochar obtained from cassava rhizomes, cassava stems and corncobs, produced using a patented locally-manufactured biochar kiln using low-cost appropriate technology designed to be fabricated locally by farmers. The research found that cassava stems yielded the highest number of Brunauer-Emmett-Teller (BET) surface area in the biochar product, while chemical analysis indicated that corncobs yielded the highest amount of C (81.35%). The amount of H in the corncob biochar was also the highest (2.42%). The study also showed biochar produced by slow pyrolysis was of a high quality, with stable C and low H/C ratio. Biochar's high BET surface area and total pore volume makes it suitable for soil amendment, contributing to reduced soil density, higher soil moisture and aeration and reduced leaching of plant nutrients from the rhizosphere. Biochar also provides a conducive habitat for beneficial soil microorganisms. The findings indicate that soil incorporation of biochar produced from agricultural crop residues can enhance food security and mitigate the contribution of the agricultural sector to climate change impacts. [ABSTRACT FROM AUTHOR]

The mitigation of greenhouse gas (GHG) emissions and water usage optimization in rice cultivation is challenging for many agricultural countries, including Thailand, who have set goals of reaching net zero emissions and coping with droughts caused by climate change. Alternate wetting and drying (AWD) and biochar application are possible practices for achieving cleaner rice production through reduction of GHG emissions and water consumption. However, these methods' potential varies by site, especially in areas with limited control of water levels. This study assessed the effects of AWD at different drying levels (10, 15, and 20 cm below the soil surface) and rice straw biochar on GHG emissions, yield production, water use, soil characteristics, and economic aspects. This study was conducted over two rice cultivation seasons: a major season in 2022 and a second season in 2023 at a field in Kalasin Province, northeastern Thailand. Using AWD and biochar reduced annual GHG emissions by 48.2% and 8.01%, respectively. Deeper drying levels of AWD showed greater mitigation potential than shallow levels. The combination of AWD and biochar had additional potential for GHG mitigation, however, this impact did not show statistical change as compared to their separate potentials. The adoption of AWD and biochar could also maintain the amount of rice yield compared to traditional practice. All levels of AWD saved irrigation water consumption by an average of 16.8% per season; the highest potential was observed in AWD at 10 cm below the soil surface. Biochar improved soil health after two seasons by enhancing soil pH and organic carbon sequestration. The combination of AWD and biochar did not additionally augment the capacity in water saving of AWD or soil improvement of biochar. The AWD water regime also did not increase net profits, while biochar decreased net profits due to the required investment in biochar production. Using AWD is a feasible way to mitigate GHG emissions and save water without affecting rice productivity and net profits in northeastern Thailand. [Display omitted] • Alternate wetting and drying (AWD) mitigated greenhouse gas emissions by 48.2%. • AWD reduced irrigation water use by an average of 16.8%. • AWD at 15 cm of drying level without biochar is suggested as a mitigation tool. • Rice straw biochar showed the significant impact on soil organic carbon stock. [ABSTRACT FROM AUTHOR]

This study examines the conversion of durian peel to biochar and pyrolysis liquid via slow pyrolysis. The central composite design was utilized to optimize the conditions of three independent variables, namely pyrolysis temperature, cooling temperature, and holding time. Analysis of variance revealed that only pyrolysis temperature had a significant effect on biochar and pyrolysis liquid yields. The biochar and pyrolysis liquid yields fit by a second-order polynomial model agreed well with experimental results. As the pyrolysis temperature increased, the solid product yield decreased, while the pyrolysis liquid yield increased. The highest biochar and pyrolysis liquid yields were 56.11% and 38.53% that derive at 300 and 600 °C of pyrolysis temperature, respectively. The validation of both prediction models showed over 96% agreement. Biochar of high heating value (26.55 MJ/kg) was obtained at 600 °C pyrolysis temperature and 30 min holding time. According to the Van Krevelen plot, the molar ratios of the H/C and O/C of the biochar obtained at 600 °C of pyrolysis temperatures were similar to coal material. The high-quality biochar was of carbon storage class 4 according to the IBI classification; and the characteristics of pyrolysis liquid met community product standards of Thailand. An economic analysis was performed to assess the feasibility of converting 60 tons/year of durian peel into biochar and pyrolysis liquid. An internal project rate of return (IRR) of 25.91% with a payback period of 1.58 years was estimated. The findings of this study indicate the economic viability of immediately deploying large-scale pyrolysis utilizing a waste stream from agriculture. [Display omitted] • Pyrolysis temperature mainly determined biochar and pyrolysis liquid yields. • Maximum biochar (56%) and pyrolysis liquid yields (38%) were determined. • The biochar is rated as a high-class 4 of carbon storage by the IBI. • The durian peel pyrolysis liquid met community product standards of Thailand. • In an economic study IRR is 25.91% with a payback period of 1.58 years. [ABSTRACT FROM AUTHOR]

A heavy metal contamination problem in Thailand is an important issue that needs to be addressed urgently, particularly contaminated in water. Heavy metal contamination in water can spread to other environments faster. This research aims to apply chitosan-magnetic biochar synthesized from water hyacinth in order to solve the problem of copper and nickel contaminated in water. Data from SEM indicated that chitosan-magnetic biochar had a smoother surface and had smaller holes than the magnetic biochar. When tested with Autosorb-1, results indicated that the adsorbent with chitosan had a slightly lower porosity compared to without chitosan. Data from FTIR found evidence of chitosan on the adsorbent. According to the XRD study, peaks of iron oxide presented. The point of zero charges (pHPZC) of chitosan-magnetic biochar was 7.03. The adsorption isotherms, kinetics, and thermodynamics were observed. The adsorption of both Cu and Ni followed Langmuir isotherm. The value of qmax for Cu was 38.4615 mg/g and for Ni was 0.4858 mg/g. The R² value of Dubinin-Radushkevich isotherm was also high. The E value of Cu and Ni was 0.316 kJ/mol and 1.8962 kJ/mol, respectively. The best-fitting kinetic model for Cu was the pseudo-second-order model and for Ni was the intra-particle diffusion. The adsorption was an endothermic process. The process was spontaneous at high temperatures and non-spontaneous at low temperatures. [ABSTRACT FROM AUTHOR]

The utilization of agricultural residues for biochar processing has recently attracted attention due to the potential in many applications. One of the most urgent options for biochar is as a support material used in the catalytic process. In this study, activated biochar which has a high surface area and is inexpensive was prepared from pineapple waste mostly available in the southern and eastern parts of Thailand. The raw pineapple waste was previously carbonized at the desired temperature (400 and 600°C) using different heating rates (7 and 20°Cmin-1) and steam was added immediately as an activator. The BET surface area was developed from 0. 95 to 228. 34 m2g-1 by increasing the carbonization temperature with steam activation. A higher carbon percentage was also represented in a high-temperature condition. From the observed results, this new finding hints that the produced activated biochar from pineapple waste showed a beneficial characteristic which is available for use as a metal catalyst support or other functional materials. [ABSTRACT FROM AUTHOR]

Durian peel is a type of biomass derived from agricultural residues, which are found in abundant in Thailand. This study aims to investigate the thermal and chemical properties of three indigenous durian peels, namely Monthong (MDP), Puangmanee (PDP), and Bacho (BDP), as well as the characteristics of biochar and pyrolysis liquid derived from slow pyrolysis of the durian peel. MDP had the greatest volatile matter and fixed carbon content, with 73.97 and 18.43 wt%, respectively. MDP was applied for further research in order to produce biochar and pyrolysis liquid at pyrolysis temperatures of 400 and 600 °C. The maximum biochar yield was 36.01% at 400 °C, while the maximum pyrolysis liquid yield was 37.25% at 600 °C. The largest high heating value of biochar (24.48 MJ kg−1) was obtained at 600 °C more than the high heating value of feedstock (14.32 MJ kg−1). Biochar obtained at 400 °C can be categorized as fertilizer class 4, while biochar obtained at 600 °C can be classified as carbon storage class 2 using the IBI biochar classification tool. The quality of the pyrolysis liquid was determined to be of 3.14 pH and 1.052 g mL−1 specific gravity at a pyrolysis temperature of 600 °C, which meets Thailand standards. As a result, both 400 °C and 600 °C pyrolysis liquids produced significant chemicals that are employed in a variety of industries. Consequently, this research is strongly recommended to be expanded to produce high-quality durian peel biochar and pyrolysis liquid. [Display omitted] • Comprehensive physical, chemical, thermal properties of durian peels were explored. • Durian peel biochar can be categorized by the IBI as carbon storage class 2. • The biochar can be classified by the IBI as a high fertilizer class 4. • Pyrolysis liquid derived from the durian peel meet Thailand standards. • 81 main compounds with essential chemicals were detected in the pyrolysis liquids. [ABSTRACT FROM AUTHOR]

In agricultural studies, estimating and testing differences between treatment regimes in a designed experiment usually determines the subsequent success or failure of inputs or management practices. Fine-scale soil variability of the experimental site can reduce statistical power and should be determined in order to optimize the experiment design. Although randomization is often performed, there is a probability that such randomization does not cover for fine scale soil variability. To determine the effect of this fine scale soil variability, a well characterized test system comprising of biochar's effects on soil microbial communities were studied, in conjunction with Electrical Resisitivity Tomography (ERT) to identify its role on biochar's differential interaction with soil microbial communities. Two main soil profiles were identified by the ERT survey and soil characteristics and soil microbial communities were differently affected by the biochar application with regards to soil profile. Fungal communities (mycorrhization intensity and fungal richness in particular) seemed to be more strongly affected than bacterial communities, however, these effects didn't show a similar trend in between the two studied soil profiles. Consequently, most of the effects of biochar application were masked by the soil variability of the experimental site when analysed in a nested design with randomization. Our results support the relevance of taking fine scale soil variability into account prior to the establishment of a field trial to optimize experimental design. [ABSTRACT FROM AUTHOR]

The in-field burning of sugarcane leaf residues presents a major environmental and health burden in Thailand. In this study, sugarcane leaves were converted into a biochar-based slow release phosphorus (P) fertilizer via pyrolysis at 600 °C, and the influence of pre- and post-pyrolysis treatment on the P loading and release was investigated. The sugarcane leaves were pre-treated with an alkaline (diammonium phosphate, DAP) or an acidic P source (phosphoric acid, PA), with or without addition of MgO. Additionally, the biochar was post-treated with DAP to increase the P loading. Extraction of P in DI water and 2% formic acid were used as indicators for potential slow release. The microporous biochars had a specific surface area of 69–333 m2 g−1 and pre-treatment resulted in a P content of 34–82 g kg−1. When MgO was included in the pre-treatment, XRD analysis confirmed formation of crystalline Mg 2 P 2 O 7 , irrespective of the P source. This Mg 2 P 2 O 7 was responsible for slow P release in DI water over 240 h via a dissolution-controlled process. Post-treatment with DAP increased the P loading to 156 g kg−1 in the form of water-soluble monoammonium phosphate (MAP), which did not contribute to slow release. The tunable P release via combinations of pre- and post-pyrolysis treatment makes these engineered biochars attractive as P sources for crops and presents an attractive solution to mitigate in-field sugarcane residue burning. [Display omitted] • P-loaded biochar was prepared by co-pyrolysis of sugarcane leaves with P + MgO. • Addition of MgO in pre-pyrolysis treatment results in slow release of P. • The slow P release is controlled by dissolution of Mg 2 P 2 O 7. • Post-treatment with DAP increases water-soluble P but not slow-release P. [ABSTRACT FROM AUTHOR]

Biochar is an alternative adsorbent, with similar characteristics to activated carbon, that can be applied to water treatment to remove dissolved organic matter (DOM) as disinfection by-product (DBP) precursors with comparable efficiency and better cost-effectiveness and sustainability relative to commercial alternatives. We applied non-targeted analysis with Orbitrap mass spectrometry to investigate changes in molecular DOM and DBP formation after treating DOM-containing water with biochar. Two surface water sources, Phong River (PR) in Khon Kaen, Thailand and Suwannee river (SR), USA, were tested using three types of eucalyptus-derived biochar (i.e., KOH-modified, calcined, and both) were selected as adsorbents and compared to commercial coconut-based activated carbon (ccAC). The results showed that calcination increased the surface area, pore volume, and functional groups of biochar responsible for adsorption. The calcined biochar achieved higher DOC removal efficiencies for both rivers than other adsorbents. PR contains more adsorbable DOM as over 800 molecules with carbon, hydrogen, and oxygen (CHO) features that were decreased or totally removed by all adsorbents. In contrast, for SR treatment, KOH-modified and calcined biochar was found to decrease over 800 CHO features, compared to around 500 and 400 CHO features for calcined biochar and ccAC, respectively. However, numerous background CHO features with reduced character (i.e., low degree of oxidation) were found after water treatment by calcined biochar, resulting in higher DBP formation after chlorination compared to the other adsorbents. The results of this study have important implications for future preparation of biochar for water treatment., 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 © 2022 Elsevier B.V. All rights reserved.)

Production of biofuels via biomass pyrolysis has received a strong emphasis since it may produce a wide variety of renewable fuels in liquid (bio-oil), solid (biochar), and gas (syngas) forms. Sugarcane bagasse, waste from the sugar-alcohol industry, is largely produced in Brazil, India, and Thailand and appears as a great biomass option for pyrolysis due to its properties, abundance, and current underutilization. However, sugarcane bagasse properties and pyrolysis operating conditions may directly affect the product properties, distribution, and further application as fuels and chemicals. Thus, it is necessary a thorough study of these subjects. This review brings an overview of biomass and pyrolysis concepts, as well as a collection of improvements in the production of products (bio-oil, biochar, and gas) via sugarcane bagasse pyrolysis. In addition, this review discusses the interaction between process operating conditions and this biomass type to address how the products' properties and yields are affected. • Fast Pyrolysis: an efficient thermochemical process for bio-oil, biochar, and gas production. • Fast Pyrolysis concepts, operational conditions, and reactor configurations were reviewed. • Bio-oil, biochar, and gas production as an alternative for renewable energy world matrix. • Focus on sugarcane bagasse as a raw material for bio-oil, biochar, and gas production. • Upgrading methods for bio-oil, challenges, and future works in the pyrolysis field. [ABSTRACT FROM AUTHOR]

Drinking water treatment residuals (DWTRs) generated during drinking water treatment have been proposed for use in lake restoration as a solid-phase sorbent to inactivate phosphorus (P) in lake sediment. However, treatments that minimize leaching of nitrogen (N) and optimize P sorption capacity may be necessary prior to use. This study assessed seven different treatment methods, including washing and heat treatments at different temperatures and with and without oxygen limitation, among two DWTRs from Thailand. Results showed that oxygen-limited heat treatment at 600 °C substantially reduced N leaching (<0.2 mg/kg TKN) while also improving P sorption capacity (increase of 18–32% compared to untreated DWTR) to a maximum of 45.7 mg P/kg. Washing with deionized water reduced N leaching if a sufficient volume was used but did not improve P sorption. Heating at 200 °C with or without the presence of oxygen did not improve N leaching or P sorption. Regression of P sorption parameters from a two-surface Langmuir isotherm against physio-chemical properties indicated that oxalate-extractable (i.e., amorphous) aluminum and iron were significantly associated with total P sorption capacity (R2 = 0.94), but micropores and oxalate-extractable P modulated the P sorption from high-affinity to low-affinity mechanisms. In conclusion, this study confirmed the importance of amorphous aluminum in DWTRs for inactivating P, and the results suggest that high-temperature treatment under oxygen-limited conditions may be the most reliable way to optimize DWTRs for environmental remediation applications. [ABSTRACT FROM AUTHOR]

Organic amendments may improve the quality of acidic tropical agricultural soils with low organic carbon contents under conventional management (mineral fertilization and irrigation) in Southeast Asia. We investigated the effect of biochar, compost and their combination on maize growth and yield, soil physical, biological and chemical properties at harvesting time at four sites in three countries: Thailand, Vietnam and Laos. Treatments consisted of 10 t·ha−1 cow manure compost and 7 t·ha−1 of Bamboo biochar and their combination. Maize biomass production and cop yields were recorded for two seasons. Elemental content, pH and nutrient availability of soils were analyzed after the first growing season. We also characterized macrofauna abundance and water infiltration. Few changes were noted for maize biomass production and maize cop yield. Soil chemical parameters showed contrasting, site-specific results. Compost and biochar amendments increased soil organic carbon, pH, total K and N, P and K availability especially for sandy soils in Thailand. The combination of both amendments could reduce nutrient availability as compared to compost only treatments. Physical and biological parameters showed no treatment response. We conclude that the addition of compost, biochar and their mixture to tropical soils have site-specific short-term effects on chemical soil parameters. Their short-term effect on plants is thus mainly related to nutrient input. The site-dependent results despite similar crops, fertilization and irrigation practices suggest that inherent soil parameters and optimization of organic amendment application to specific pedoclimatic conditions need future attention. [ABSTRACT FROM AUTHOR]

An improved understanding of the historical variation in the emissions and sources (biomass burning, BB vs. fossil fuel, FF combustion) of soot and char, the two components of black carbon (BC), and polycyclic aromatic compounds (PACs) may help in assessing the environmental effects of the Atmospheric Brown Cloud (ABC) in SE Asia. We therefore determined historical variations of the fluxes of soot, char, and PACs (24 polycyclic aromatic hydrocarbons (PAHs), 12 oxygenated PAHs (OPAHs), and 4 azaarenes) in a dated sediment core (covering the past ∼150 years) of Phayao Lake in Thailand. The soot fluxes have been increasing in recent times, but at a far lower rate than previously estimated based on BC emission inventories. This may be associated with a decreasing BB contribution as indicated by the decreasing char fluxes from old to young sediments. The fluxes of high- and low-molecular-weight (HMW and LMW) PAHs, OPAHs, and azaarenes all sharply increased after ∼1980, while the ΣLMW-/ΣHMW-PAHs ratios decreased, further supporting the reduction in BB contribution at the expense of increasing FF combustion emissions. We also suggest that the separate record of char and soot, which has up to now not been done in aerosol studies, is useful to assess the environmental effects of ABC because of the different light-absorbing properties of these two BC components. Our results suggest that besides the establishment of improved FF combustion technology, BB must be further reduced in the SE Asian region in order to weaken the ABC haze. Image 1 • Deposition of black carbon, soot and PACs to a Thai sediment core sharply increased since ∼1980. • Variations in char and soot deposition in Thailand over the past 150 years were decoupled. • Decreasing biomass burning offset the recent increase in other soot emissions to the atmosphere. [ABSTRACT FROM AUTHOR]

Biochar is a potential tool to mitigate climate change by enhancing C sequestration in soils, but its use as a soil amendment to improve soil fertility and crop yields is still a contentious subject. In North East (NE) Thailand, biochar has been promoted to restore soil fertility in rubber tree plantations. Despite this, there is scarce information on the impact of biochar application on the soil biota, particularly on microbial communities associated with rubber trees. The effects of increasing doses of biochar on microbial communities were investigated in a rubber tree plantation in NE Thailand, 28 months after application. Biochar application resulted in increases of soil pH and nutrient contents and also had an impact on both bacterial and fungal communities. Changes in microbial composition and structure were observed although fungal communities were more markedly affected than bacterial communities. The nature and magnitude of the observed changes were strongly related to soil properties (pH, soil moisture and P content), while biochar dose (5, 10 or 20 tons/ha) effect was not significant. Our results highlight the need for additional research for a better understanding of the impact of biochar application on soil microbial communities and further cascading effects on ecosystem functions., (Copyright © 2019 Elsevier B.V. All rights reserved.)