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Waste Disposal & Sustainable Energy
Number of Followers: 0  Hybrid journal (It can contain Open Access articles)ISSN (Print) 2524-7980 - ISSN (Online) 2524-7891 Published by Springer-Verlag  [2467 journals]
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- The Martin moving grate technology
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Abstract: The thermal treatment of waste using grate-based systems has gained global acceptance as the preferred method for sustainable management of residual waste. This is because the energy content of the waste is utilized and quality products and residues are produced. Modern Waste-to-Energy (WtE) plants are extremely complex. Sound knowledge of “fuel” waste and its effects on the design and operation of WtE plants is crucial for the successful planning and operation of these plants. To respond to new challenges and/or priorities, developing and implementing innovative technologies is necessary. With long-term global partnerships and innovative grate and combustion technologies, Martin guarantees that in future, residual waste will be treated following ecological and economic constraints and in compliance with international legal requirements.
PubDate: 2023-03-22
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- Base- or acid-assisted polystyrene plastic degradation in supercritical
CO2-
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Abstract: Plastic has caused serious "white pollution" to the environment, and the highly inert characteristics of plastic bring a major challenge for degradation. Supercritical fluids have unique physical properties and have been widely used in various fields. In this work, supercritical CO2 (Sc-CO2) with mild conditions was selected and assisted by NaOH/HCl solution to degrade polystyrene (PS) plastic, and the reaction model was designed using response surface methodology (RSM). It was found that, regardless of the types of assistance solutions, the factors affecting PS degradation efficiencies were reaction temperature, reaction time, and NaOH/HCl concentration. At the temperature of 400 °C, time of 120 min, and base/acid concentration of 5% (in weight), 0.15 g PS produced 126.88/116.99±5 mL of gases with 74.18/62.78±5 mL of H2, and consumed 81.2/71.5±5 mL of CO2. Sc-CO2 created a homogeneous environment, which made PS highly dispersed and uniformly heated, thus promoting the degradation of PS. Moreover, Sc-CO2 also reacted with the degradation products to produce new CO and more CH4 and C2Hx (x=4, 6). Adding NaOH/HCl solution not only improved the solubility of PS in Sc-CO2, but also provided a base/acid environment that reduced the activation energy of the reaction, and effectively improved the degradation efficiencies of PS. In short, degrading PS in Sc-CO2 is feasible, and better results are obtained with the assistance of base/acid solution, which can provide a reference for the disposal of waste plastics in the future.
PubDate: 2023-03-18
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- Study on textile waste generation in the undifferentiated municipal solid
waste stream in Guimarães, Portugal-
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Abstract: Guimarães is a middle sized city and municipality located in northern Portugal. The municipality has committed to reducing the annual amount of undifferentiated municipal solid waste (MSW) from 371 kg/capita in 2021 to 120 kg/capita by 2030 under the Zero Waste Cities Certification process. In the municipality of Guimarães, one of the constant fractions of MSW composition is textile waste (TW), which the revised EU Waste Framework Directive requires separate collection by 1 January 2025. Therefore, two indicators of TW generation were analysed to identify waste collection routes with a high level of textile waste generation for the priority implementation of separate collection: TW composition in the undifferentiated MSW stream and TW generation per capita. Basic statistical analysis methods were used to process the source data of TW composition in the undifferentiated MSW stream. Cluster analysis was applied to the data set on TW generation per capita, considering the area typology (urban, rural or mixed) of collection routes. It was considered that 39% of the industrial sector of Guimarães consists of textile and clothing production and represents small- and medium-sized enterprises, which can affect TW generation in the undifferentiated MSW stream. Causal-comparative research was used to define the correlation between TW generation per capita and the economic activity of the textile and clothing industry in the municipality. As a result, applying a multi-disciplinary approach, a project of the Textile Waste Generation Map was presented.
PubDate: 2023-03-13
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- Plastic waste management for sustainable environment: techniques and
approaches-
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Abstract: Excessive exploitation, negligence, non-degradable nature, and physical and chemical properties of plastic waste have resulted in a massive pollution load into the environment. Consequently, plastic entres the food chain and can cause serious health issues in aquatic animals and humans. The present review summarizes currently reported techniques and approaches for the removal of plastic waste. Many techniques, such as adsorption, coagulation, photocatalysis, and microbial degradation, and approaches like reduction, reuse and recycling are potentially in trend and differ from each other in their efficiency and interaction mechanism. Moreover, substantial advantages and challenges associated with these techniques and approaches are highlighted to develop an understanding of the selection of possible ways for a sustainable future. Nevertheless, in addition to the reduction of plastic waste from the ecosystem, many alternative opportunities have also been explored to cash plastic waste. These fields include the synthesis of adsorbents for the removal of pollutants from aqueous and gaseous stream, their utility in clothing, waste to energy and fuel and in construction (road making). Substantial evidence can be observed in the reduction of plastic pollution from various ecosystems. In addition, it is important to develop an understanding of factors that need to be emphasized while considering alternative approaches and opportunities to cash plastic waste (like adsorbent, clothing, waste to energy and fuel). The thrust of this review is to provide readers with a comprehensive overview of the development status of techniques and approaches to overcome the global issue of plastic pollution and the outlook on the exploitation of this waste as resources.
PubDate: 2023-03-06
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- Manufacturing of high-performance light-weight mortar through addition of
biochars of millet and maize-
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Abstract: Agricultural wastes are environmental hazards, as these wastes can catch fire, resulting in the loss of human and animal lives and properties. Alternatively, the wastes are dumped in large spaces, which are already limited. Cementitious composites are quasi-brittle and develop cracks at the micro and nano level, which affect their strength, durability, and esthetics. Transforming agricultural wastes to biochar and using it as fibers in cementitious materials for crack arresting and enhancing fracture toughness is an environment-friendly approach. In this research, nano to microscale carbonaceous inert fibers (biochar) of millet and maize were prepared through pyrolysis followed by ball milling. The X-ray spectroscopy (EDX) revealed that 82.08% and 86.89% of the carbon content was retained in millet and maize, respectively. The scanning electron microscope (SEM) confirmed the presence of angular, flaky, and needle-like particles in the carbonaceous inerts, which may enhance the strength and the fracture response of the cementitious materials. These inerts were added individually to mortar specimens at dosage levels of 0, 0.025%, 0.05%, 0.08%, 0.2% and 1% by mass of cement. The dispersion of the synthesized nano inerts was ensured by UV–VIS spectroscopy. The compressive strength, flexural strength, porosity, and fracture toughness of cement mortar were evaluated. The carbonized nano intrusions reduced the porosity and density of the mortar specimens. The minimum porosity was noted with 1% and 0.08% dosages of millet and maize, respectively, whereas the minimum density was observed at 1% dosage for both. An increase in compressive and flexural strengths was also noticed. The compressive strength increased by 32% and 28% with 0.2% and 0.5% millet and maize, respectively. An increase of 168% and 114% in fracture toughness was noticed at optimized dosages of 0.5% and 1% of maize and millet, respectively. It is concluded that the addition of carbonaceous inert fibers of millet and maize resulted in light-weight porous mortars with enhanced strength and fracture toughness. The fracture toughness increases with dosage as the nanoparticles enhance the tortuosity.
PubDate: 2023-02-28
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- Predicting effect factors of dual bag filter system for PCDD/Fs removal
from hazardous waste incineration flue gas-
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Abstract: The dual bag filter (DBF) system is a new polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) emission control technology that has more efficient (PCDD/Fs) removal performance, a higher activated carbon utilization rate and less activated carbon consumption compared with the traditional single bag filter system. Moreover, few studies have been relevant to the mechanism of the PCDD/Fs removal process in the DBF system, and the selection of operating conditions of the DBF system lacks an academic basis. This study established a PCDD/Fs removal efficiency model of activated carbon injection combined bag filter (ACI+DBF) system for hazardous waste incineration flue gas and predicted the crucial effect factors. New adsorption coefficients k1=532,145 Nm3/(mol s) and k2=45 Nm3/(mol s), and the relationship expression between the number of available adsorption positions of recycled AC (AAC′) and cycle times (n) are proposed in the model. The results verify that the model error was below 5%. In addition, the PCDD/Fs removal efficiency model predicts that in a certain range, the PCDD/Fs removal efficiency increases with increasing activated carbon injection concentration. The best cycle number of activated carbon was less than 3, and the ratio of circulating activated carbon to fresh activated carbon in second bag filter (SBF) should be controlled at 7–8.
PubDate: 2023-02-23
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- In-situ catalytic decomposition of emitted ammonia from municipal solid
waste gasification by Ni–M bimetallic catalysts supported on sewage
sludge-derived biochar-
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Abstract: Gasification technology can effectively realize energy recovery from municipal solid waste (MSW) to reduce its negative impact on the environment. However, ammonia, as a pollutant derived from MSW gasification, needs to be treated because its emission is considered harmful to mankind. This work aims to decompose the NH3 pollutant from MSW gasification by an in-situ catalytic method. The MSW sample is composed of rice, paper, polystyrene granules, rubber gloves, textile and wood chips. Ni–M (M=Co, Fe, Zn) bimetallic catalysts supported on sewage sludge-derived biochar (SSC) were prepared by co-impregnation method and further characterized by X-ray diffraction, N2 isothermal adsorption, scanning electron microscopy, transmission electron microscopy and NH3 temperature programmed desorption. Prior to the experiments, the catalysts were first homogeneously mixed with the MSW sample, and then in-situ catalytic tests were conducted in a horizontal fixed-bed reactor. The effect of the second metal (Co, Fe, Zn) on the catalytic performance was compared to screen the best Ni-M dual. It was found that the Ni–Co/SSC catalyst had the best activity toward NH3 decomposition, whose decomposition rate reached 40.21% at 650 °C. The best catalytic performance of Ni–Co/SSC can be explained by its smaller Ni particle size that facilitates the dispersion of active sites as well as the addition of Co reducing the energy barrier for the associative decomposition of NH species during the NH3 decomposition process. Besides, the activity of Ni–Co/SSC increased from 450 °C to 700 °C as the NH3 decomposition reaction was endothermic.
PubDate: 2023-02-17
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- Influencing factors and optimization on mechanical performance of solid
waste-derived rapid repair mortar-
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Abstract: There is a great demand for high performance rapid repair mortar (RRM) because of the wide use of cement concrete. Solid-waste-based sulfoaluminate cement (WSAC) is very suitable as a green cementitious material for repair materials because of its characteristics of high early-age strength and short setting time. However, the influence and optimization of various factors of WSAC-based RRM, such as water-to-RRM ratio, binder-to-sand ratio and additives, as well as the further solid waste replacement of aggregate, remain to be studied. This paper comprehensively studied the influence of the above factors on the performance of WSAC-based RRM and obtained a green high-performance RRM by optimizing these factors. The experimental results showed that the early and late strength of the obtained RRM is excellent, and the setting time and fluidity are appropriate, which reflected good mechanical properties and construction performance. Ordinary Portland cement (OPC) doping could not improve RRM strength. It was feasible to prepare RRM with gold tailing sand replacing part of the quartz sand. This paper provides data and a theoretical basis for the preparation of high-performance RRM based on solid waste, expanding the high value utilization of solid waste, which is conducive to the development of a low carbon society.
PubDate: 2023-02-15
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- Potential of organic waste to energy and bio-fertilizer production in
Sub-Saharan Africa: a review-
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Abstract: Many growing cities of Sub-Saharan Africa (SSA) are marred by the inefficient collection, management, disposal and reuse of organic waste. The purpose of this study was to review and compare the energy recovery potential as well as bio-fertilizer perspective, from the organic waste volumes generated in SSA countries. Based on computations made with a literature review, we find that the amount of organic wastes varies across countries translating to differences in the energy and bio-fertilizer production potentials across countries. Organic wastes generated in SSA can potentially generate about 133 million GWh of energy per year. The organic waste to bio-fertilizer production potentials range from 11.08 million tons to 306.26 million tons annually. Ghana has the highest energy and bio-fertilizer potential among the SSA countries with a total per capita of 630 MWh/year and 306.26 million tons, respectively. The challenges and technical considerations for energy and bio-fertilizer approaches in the management of organic waste in SSA have also been discussed. This study is of help to the readers and strategic decision makers in understanding the contribution of bioenergy and bio-fertilizer to achieving sustainable development goals, namely, 7 (Affordable and Clean Energy) and 13 (Climate Action) in SSA.
PubDate: 2023-02-15
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- Performance, combustion, and emission characteristics of on a diesel
engine fuelled with hydrogen compressed natural gas and Kusum seed
biodiesel-
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Abstract: Renewable fuels have many advantages over fossil fuels because they are biodegradable and sustainable, and help mitigate social and environmental problems. The objective of the present study is to evaluate the performance, combustion, and emission characteristics of a compression–ignition engine using hydrogen compressed natural gas (HCNG)-enriched Kusum seed biodiesel blend (KSOBD20). The flow rate of HCNG was set at 5 L/min, 10 L/min, and 15 L/min, and the injection pressure was varied in the range of 180 bar to 240 bar. Brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) were improved when HCNG was added to the KSOBD20. Combustion characteristics, namely, cylinder pressure (CP) and net heat release rate (NHRR), were also improved. Emissions of carbon monoxide (CO), hydrocarbons (HC), and smoke were also reduced, with the exception of nitrogen oxides (NOx). The higher injection pressure (240 bar) had a positive effect on the operating characteristics. At an injection pressure of 240 bar, for KSOB20 + 15 L/min HCNG, the highest BTE and the lowest BSFC were found to be 32.09% and 0.227 kg/kWh, respectively. Also, the CP and NHRR were 69.34 bar and 66.04 J/°. CO, HC, and smoke levels were finally reduced to 0.013%, 47 × 10−6 and 9%, respectively, with NOx levels at 1623 × 10−6. For optimum results in terms of engine characteristics, the fuel combination KSOBD20 + 15 L/min HCNG at FIP 240 bar is recommended.
PubDate: 2023-02-08
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- Energy recovery from solid wastes in China and a Green-BRI mechanism for
advancing sustainable waste management of the global South-
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Abstract: The only proven alternative for the recovery of value from materials that cannot be recycled is waste to energy (WTE). The first part of the paper provides evidence as to the advantages of WTE over landfilling and examines the role of WTE in the urban environment. The second part of the paper is a holistic analysis of the legislative instruments used in China, that have led to the construction of nearly 400 plants from 2005 to 2019. The Chinese government was instrumental in the development of Public and Private Partnerships (PPPs), in form of Build-Operate-Transfer (BOT), or Build-Own-Operate (BOO) models with a lifetime of 20 years to 30 years. The government accepts most of the investment risk by participating in the equity structure, providing strong tax and policy incentives, and becoming fully engaged in public education and acceptance of new WTE projects. The construction and operation of these plants by the private sector had to comply with the governmental performance standards in order to receive incentives, such as an appreciable credit over the price of electricity received by coal-fired plants. The last part of this paper examines how the elements of the Chinese renewable energy and waste management laws, may be transposed to federal and state legislation for potential application in countries of the Belt and Road Initiative (BRI) region.
PubDate: 2023-02-05
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- Crucial role of iron plaque on thallium uptake by rice plant
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Abstract: Iron plaque is a Fe-containing oxide film produced by the oxidation of Fe(II) in the rice root system under the combined action of oxygen infiltration and other microorganisms. Owing to its special surface structure and physio-chemical properties, the iron plaque has a strong absorption capacity for a variety of heavy metal ions. This study aimed to first investigate the effects of Fe species on the geochemical fractionation of Tl in typical paddy soil systems affected by industrial activities, followed by pot culture experiments to probe the effects of Fe species on the uptake and translocation of Tl in rice plants. The results of field work preliminarily showed that iron at different valences affected the conversion of the Tl geochemical fraction in the soil. Oxidizable Tl exerted significant positive correlation relationships with Fe2+ and negative correlation relationships with Fe3+, while reducible Tl only displayed a positive correlation with Fe3+. Further analysis by pot culture experiments revealed that the contents of Fe were significantly positively correlated with Tl contents in Fe plaque (R2 = 0.529). In contrast, the water-soluble Tl contents in the soil were significantly negatively correlated with the contents of Fe (R2 = – 0. 90, p < 0.05). It suggests that the iron plaque promoted the absorption and fixation of Tl on the root surface of rice plants, causing Tl to accumulate in the iron plaque. Besides, the Tl content in the Fe plaque on the root surface of rice plants was greater than that in the above-ground tissues, which indicates that most Fe plaque exerts a certain degree of inhibition on Tl migration into the above-ground tissues of rice plants. All these findings indicate that Fe film is also an important carrier of Tl transfer in the soil–rice plant system, which provides new scientific support for the remediation of typical Tl-contaminated rice fields.
PubDate: 2023-01-30
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- Optimization of adsorbent dose and contact time for the production of
jackfruit waste nutrient-enriched biochar-
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Abstract: Raw biochar can be enriched with nutrients from digestates through adsorption producing nutrient-enriched biochar. The nutrient-enriched biochar can be used as a soil amendment to support sustainable agriculture. This study assessed the effect of adsorbent dose and contact time on the jackfruit waste biochar adsorption of essential nutrients of nitrogen, phosphors and potassium from the digestate. Response surface methodology (RSM) using central composite design (CCD) was utilized to optimize the adsorbent dose and contact time during the adsorption process. An adsorbent dose of 20–70 mg/g and contact time range of 48–120 h were used in this study. The optimal adsorbent dose and contact time were found to be 20 mg/g and 114.6 h, respectively. The corresponding optimum nitrogen, phosphorus and potassium adsorbed were 17.44, 20.94, and 21.36 mg/g, respectively. Models for the prediction of these values for nitrogen, phosphorus and potassium had R2 values of 0.9801, 0.9804 and 0.9843, respectively, and non-significant lack of fit (p<0.05). This indicates the suitability of the models in predicting the adsorption conditions of adsorbent dose and contact time to produce high-quality nutrient-enriched biochar. Graphical abstract
PubDate: 2023-01-27
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- Nitrite sensor using activated biochar synthesised by microwave-assisted
pyrolysis-
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Abstract: Developing applications for the by-products obtained from waste processing is vital for resource recovery. The synthesis of ZnCl2-activated biochar with high electrocatalytic activity was carried out by the microwave-assisted pyrolysis of pineapple peel and subsequent chemical activation process. Activated biochar is employed in the electrochemical sensing of nitrite by drop casting in a glassy carbon electrode (GCE). The activated biochar exhibited a stacked carbon sheet, 254 m2 g−1 Brunauer, Emmett and Teller (BET) surface area, 0.076 cm3 g−1 pore volume, 189.53 m2 g−1 micropore area and oxygen-containing functional groups. The electrochemical impedance spectroscopy of the modified GCE showed a reduced charge transfer resistance of 61%. This is crucial to determine the electrochemical properties of biochar. The sensor showed a significant current response and an excellent limit of detection of 0.97 µmol L−1. The modified-activated biochar electrochemical sensor demonstrated high selectivity, reproducibility (RSD=2.4%), and stability (RSD=2.6%). Graphical abstract
PubDate: 2023-01-17
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- Development of waste-to-energy through integrated sustainable waste
management: the case of ABREN WtERT Brazil towards changing status quo in
Brazil-
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Abstract: In the context of circular economy, it is known that once waste is generated, it should be subject to proper treatment for recovering material or energy before being disposed. Many countries worldwide, especially developing countries such as Brazil, have been struggling to effectively apply sustainable waste management in municipalities and still rely on dumpsites and unsuitable landfills. Misinformation, a weak legal framework, lack of financial resources and poor infra-structure as well as pressure from organizations profiting from the expansion of landfills are some factors contributing to the preservation of the negative status quo: the “landfill culture”. Material recovery, i.e., recycling and composting, is applied to less than 5% of Brazilian municipal waste, while 95% is disposed of in landfills or dumpsites. In this context, ABREN WtERT (Waste-to-Energy Research and Technology Council) Brazil was created in 2019 as the first permanent organization formed to promote the development of energy and material recovery from waste focused on the waste-to-energy (WTE) market. In this paper, the strategy proposed and implemented by the organization towards changing the status quo in Brazil through an integrated sustainable waste management approach is described. The proposed strategy integrates the concepts of Sustainability and Circular Economy for minimizing landfill disposal (avoiding methane emissions) and maximizing material/energy recovery. Among others, the approach focuses on changing the public opinion regarding thermal treatment facilities, mainly incinerators, which has been wrongly linked to pollution, excessive public expenditures and considered a harm to the recycling industry. The activities performed by ABREN include engaging public and private institutions, enhancing education, leading the publication of research and business studies, gathering industry members and academy experts, as well as creating strategic alliances with players around the globe. As a result, within a few years, major outcomes were achieved in Brazil, such as: (i) changes in the legal framework, (ii) launching of a specific public auction category for sponsoring electricity production from WTE facilities, and (iii) establishment of official targets for municipalities to decrease landfill disposal and increase recycling/biological treatment and energy recovery from thermal treatment. Among the national goals, it should be highlighted the target regarding the increase from zero to 994 MW of electricity production from municipal solid waste, which will require building dozens of new WTE facilities. Global outcomes are expected as well since Brazil is the seventh largest country of the globe and the most influential in Latin America. International and national business deals should thrive due to the need of operational skills and technology imports, and the avoidance of carbon emissions will positively reflect the world climate. In parallel, there is also potential for the academy to benefit from research projects and investments if the WTE national industry is to be developed in the long term.
PubDate: 2023-01-09
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- Biochar influences the cane fields’ microbiota and the development of
pre-sprouted sugarcane seedlings-
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Abstract: This research investigates the soil conditioning effect of sugar cane fields with biochar produced from sugarcane bagasse. Its influence on the physicochemical and microbiological conditions of the soil and the agronomic performance of sugarcane seedlings was verified. To this end, the biochar from sugarcane bagasse was produced by pyrolysis in a double drum oven and mixed with soil at rates of 0, 1%, 3%, and 5% (in weight). The experiment was installed in a greenhouse with two evaluation periods (30 days and 60 days) and five replicates. Each pot received a pre-sprouted cane seedling, and the analysis of colony-forming units (bacteria and fungi), physicochemical characteristics of the soil, and growth and development of sugarcane were performed per pot. The biochar showed a high fixed carbon content (72%) and a specific surface area estimated by the adsorption of methylene blue of 50 m2 g−1. Furthermore, its structure is porous and contains important nutrients (e.g., CaO, K2O, and P2O5). In the periods evaluated, the applications of the 3% and 5% (in weight) rates of biochar reduced most of the soil fertility parameters. However, the chemical analyses indicated that the sugarcane field soil collected already possessed high fertility. The microbiota was influenced, but only the application of the 3% (in weight) rate at 60 days after planting showed a significant positive effect on the number of bacteria forming units, with an increase of approximately 385%. On the other hand, no significant positive effect on sugarcane development was found. Therefore, biochar application in high-fertility sugarcane plantation soil did not result in gains for sugarcane development in the periods evaluated.
PubDate: 2023-01-04
DOI: 10.1007/s42768-022-00129-9
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- Stability of potentially toxic elements in municipal sludge biochars
modified by MgCl2 and phosphate-
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Abstract: Municipal wastewater sludge can be pyrolyzed as biochars to better use nutrients and stabilize carbon compared with other typical technologies, such as landfill and incineration. However, sludge-derived biochars might contain large amounts of potentially toxic elements (PTEs), such as Zn, Cu, Cr, Ni, Pb, and As. The stability of PTEs in biochars might be improved by higher pyrolytic temperatures, which can be further improved by different modifications. Herein, PO4-modification at 300 °C and Cl-modification at 700 °C were carried out, respectively, to enhance the stability of PTEs. Various leaching tests have been performed to assess the stability of PTEs in biochars, including the synthetic precipitation leaching procedure (SPLP), toxicity characteristic leaching procedure (TCLP), diethylenetriamine pentaacetate (DTPA) extraction, and in vitro simple bioaccessibility extraction test (SBET). The morphological structure, elemental mapping, and mineral formation of the pristine and modified biochars were studied by scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM–EDS) and X-ray diffraction (XRD). Our results suggested that the leachability, mobility, plant-availability, and bioaccessibility of most PTEs were decreased by pyrolysis, yet the total contents of PTEs were elevated, especially at 700 °C. Generally, modification by phosphates and MgCl2 enhanced the stability of PTEs in biochars. Nevertheless, it should be noted that higher bioaccessibility of PTEs was observed in biochars of P-modification than Cl-modification, which is associated with the dissolution of phosphate precipitates under acidic conditions (pH<2). Additionally, Cl-modification leads to higher plant-available Zn and Cu and bioaccessible Zn compared with the unmodified biochar produced at 700 °C.
PubDate: 2022-12-26
DOI: 10.1007/s42768-022-00128-w
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- Density functional theory for selecting modifiers for enhanced adsorption
of tetracycline in water by biochar-
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Abstract: Antibiotics and their metabolic byproducts are found in wastewater and natural water as a result of increased consumption, posing a major threat to humans and other living organisms. One of the most promising methods for their removal is adsorption using biochar because it offers excellent adsorption potential and is both affordable and environmentally beneficial. However, raw biochar frequently has a low adsorption capacity due to its limited pore structure and unfavorable surface characteristics. Biochar surface modifications using modifiers such as H3PO4, KOH, and NaOH have improved the surface area and thereby the adsorption capacity. Experimental methods for assessing the effectiveness and adsorption mechanism of modified biochar are costly and time-consuming. Density functional theory (DFT) was used to investigate the interfacial interactions and adsorption mechanism of tetracycline (TC), a widely used antibiotic for personal care and veterinary medication, on unmodified and modified biochar. The DFT calculations showed that the adsorption energy of TC on unmodified and modified biochar is in the following order: KOH-modified biochar (− 2.38 eV)<NaOH-modified biochar (− 2.20 eV)<unmodified biochar (− 1.56 eV)<H3PO4-modified biochar (5.48 eV). The lower adsorption energy is associated with a stronger and more stable interaction between the adsorbent and the contaminant. This suggests that the adsorption of TC on KOH-modified biochar is more prolific and stable compared to the other biochar. This study provides an understanding of the mechanism underlying the adsorption of TC by modified biochar and can be used as a guide to screen for biochar with promising adsorption potential prior to experimental efforts. Graphical abstract
PubDate: 2022-12-22
DOI: 10.1007/s42768-022-00125-z
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- Biochar-mediated removal of pharmaceutical compounds from aqueous matrices
via adsorption-
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Abstract: Pharmaceutical is one of the noteworthy classes of emerging contaminants. These biologically active compounds pose a range of deleterious impacts on human health and the environment. This is attributed to their refractory behavior, poor biodegradability, and pseudopersistent nature. Their large-scale production by pharmaceutical industries and subsequent widespread utilization in hospitals, community health centers, and veterinary facilities, among others, have significantly increased the occurrence of pharmaceutical residues in various environmental compartments. Several technologies are currently being evaluated to eliminate pharmaceutical compounds (PCs) from aqueous environments. Among them, adsorption appears as the most viable treatment option because of its operational simplicity and low cost. Intensive research and development efforts are, therefore, currently underway to develop inexpensive adsorbents for the effective abatement of PCs. Although numerous adsorbents have been investigated for the removal of PCs in recent years, biochar-based adsorbents have garnered tremendous scientific attention to eliminate PCs from aqueous matrices because of their decent specific surface area, tunable surface chemistry, scalable production, and environmentally benign nature. This review, therefore, attempts to provide an overview of the latest progress in the application of biochar for the removal of PCs from wastewater. Additionally, the fundamental knowledge gaps in the domain knowledge are identified and novel strategic research guidelines are laid out to make further advances in this promising approach towards sustainable development.
PubDate: 2022-12-16
DOI: 10.1007/s42768-022-00118-y
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- A comprehensive review of the effects of biochar on soil physicochemical
properties and crop productivity-
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Abstract: Intensive land use has several detrimental effects on land function and imposes an undue burden on the environment. Continuous farming and pollution by heavy metals have negatively influenced many soils. Biochar is now gaining attention as a major research subject in the areas of agriculture, environment, and energy as an eco-friendly soil conditioner. The use of biochar for agricultural and environmental purposes has been widely studied and reviewed. Unfortunately, there are few reviews on biochar structures and other biochar uses. This review presents an overview of current developments in the effects of numerous biochar physicochemical properties and biochar uses, such as utilization as a soil microbial activity, contaminant adsorbent, ion exchange, soil amendment, gas storage and water retention. The physical, chemical and biological properties have been discussed following amendments to the soil and conditions of preparation. However, scientific observation and research are required to identify the negative effects of biochar in preparations and applications. It is envisaged that further in-depth studies of biochar amendment will lead to a deeper understanding of biochar's relationships with soils and that reviews of the negative impacts of biochar could reveal ways in which they might be mitigated.
PubDate: 2022-11-08
DOI: 10.1007/s42768-022-00114-2
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