Upcycling biomass waste into Fe single atom catalysts for pollutant control

Contaminants of heavy metals and antibiotics, which are frequently detected in water, soil and food chains with increasing prevalence in our current society, can cause potential harm to human health and disrupt human ecosystem irreversibly. Herein, we have successfully utilized biomass waste ferns contaminated by iron mines, to fabricate a first-of-its-kind high-performance class of Fe single-atom catalysts(FeSAC) by a facile pyrolysis. The optimal FeSAC-800 shows an excellent efficiency in the fastphotocatalytic degradation of six types of quinolone antibiotics(e.g., norfloxacin, levofloxacin, ciprofloxacin, enrofloxacin, lomefloxacin, flumequine) in 1 h under the simulated natural light irradiation. Based on advanced characterization, a well-defined structure of FeN_(4), confined in the porous carbon is elaborated for the FeSAC-800. Mechanism of the photodegradation is via a Fenton-like oxidation process whereas the reactive oxygen species play a key role. These findings open a new avenue for efficient, sustainable utilization of biomass waste in pollutant control.

Characterization of bio-coal briquettes blended from low quality coal and biomass waste treated by Garant■bio-activator and its application for fuel combustion

Experimental research was carried out on the manufacturing of bio-coal briquettes from a blend of two different types of low-quality coal and biomass waste in the absence of coal carbonization,where the third blend of the material was fermented by adding a bio-activator solution before pressurizing the components into briquettes.The coal samples from Caringin-Garut Regency(BB-Garut)had a low calorific value and a high sulfur content(6.57 wt%),whereas the coal samples from Bayah-Lebak Regency(BB-Bayah)had a higher calorific value and a lower sulfur content(0.51 wt%).The biomass added to the coal blend is in the form of fermented cow dung(Bio-Kohe),and it had a calorific value of 4192 kcal/kg and a total sulfur content of 1.56 wt%.The main objective of this study is to determine the total decrease in the sulfur content in a blend of coal and biomass in which a fennentation process was carried out using a bio-activator for 24 h.The used bio-activator was made from Garant■(1:40)+molasses 1 wt%/vol,and its used amount was 0.2 L/kg.Also,the total sulfur content in the blend was 1.00 wt%-1.14 wt%,which fulfills the necessary quality requirements for non-carbonized bio-coal briquettes.The pyritic and sulfate content in the raw coal was dominant,and the organic sulfur,when fermented with Garant■,was found to be less in the produced bio-coal briquettes by 38%-58%.

Green process of biomass waste derived fluorescent carbon quantum dots for biological imaging in vitro and in vivo

In the context of the circular economy,the huge amounts of biomass waste should be converted into value-added materials and energy to diminish pollution,atmospheric CO_(2)levels and costly waste disposal.Biological imaging usually uses expensive and toxic chemicals e.g.,organic dyes,semiconductor quantum dots,calling for safer,greener,cheaper fluorescent probes for biological imaging in vitro and in vivo.In these regards,carbon quantum dots(CQDs)-based fluorescent probes using biomass waste as a precursor may have much higher potential.Here we transformed the biomass waste of peach leaves into value-added fluorescent CQDs through a low-cost and green one-step hydrothermal process.The obtained CQDs show excitation-dependent photoluminescence properties with a fluorescence lifetime of 5.96 ns and a quantum yield of 7.71%without any passivation.In addition,the CQDs have a fine size of 1.9 nm with good hydrophilicity and high fluorescent stability over pH 4.0-11.0 range.Fluorescence imaging of in vitro cell cultures and in vivo with zebrafish show that CQDs possess ultra-low toxicity and remarkable performance for biological imaging.Even when CQDs present at a concentration as high as500μg/m L,the organism can still maintain more than 90%activity both in vitro and in vivo,and present bright fluorescence.The cheaper,greener,ultra-low toxicity CQDs developed in this work is a potential candidate for biological imaging in vitro and in vivo.

Synthesis and Application of Granular Activated Carbon from Biomass Waste Materials for Water Treatment:A Review

There is an increased global demand for activated carbon(AC)in application of water treatment and purification.Water pollutants that have exhibited a greater removal efficiency by AC included but not limited to heavy metals,pharmaceuticals,pesticides,natural organic matter,disinfection by-products,and microplastics.Granular activated carbon(GAC)is mostly used in aqueous so-lutions and adsorption columns for water treatment.Commercial AC is not only costly,but also obtained from non-renewable sources.This has prompted the search for alternative renewable materials for AC production.Biomass wastes present a great potential of such materials because of their availability and carbonaceous nature.This in turn can reduce on the adverse environmental effects caused by poor disposal of these wastes.The challenges associated with biomass waste based GAC are their low strength and attrition resistance which make them easily disintegrate under aqueous phase.This paper provides a comprehensive review on recent advances in production of biomass waste based GAC for water treatment and highlights future research directions.Production parameters such as granulation conditions,use of binders,carbonization,activation methods,and their effect on textural properties are discussed.Factors influencing the adsorption capacities of the derived GACs,adsorption models,adsorption mechanisms,and their regeneration potentials are reviewed.The literature reveals that biomass waste materials can produce GAC for use in water treatment with possibilities of being regenerated.Nonetheless,there is a need to explore 1)the effect of preparation pathways on the adsorptive properties of biomass derived GAC,2)sustainable production of biomass derived GAC based on life cycle assessment and techno-economic analysis,and 3)adsorption mechanisms of GAC for removal of contaminants of emerging concerns such as microplastics and unregulated disinfection by-products.

Nanocellulose from various biomass wastes:Its preparation and potential usages towards the high value-added products

Biomass waste comes from a wide range of sources,such as forest,agricultural,algae wastes,as well as other relevant industrial by-products.It is an important alternative energy source as well as a unique source for various bioproducts applied in many fields.For the past two decades,how to reuse,recycle and best recover various biomass wastes for high value-added bioproducts has received significant attention,which has not only come from various academia communities but also from many civil and medical industries.To summarize one of the cutting-edge technologies applied with nanocellulose biomaterials,this review focused on various preparation methods and strategies to make nanocellulose from diverse biomass wastes and their potential applications in biomedical areas and other promising new fields.

Techno-Economic Analysis of Power Production by Using Waste Biomass Gasification

Energy recovery from waste biomass can have significant impacts on the most pressing development challenges of rural poverty and environmental damages. In this paper, a techno-economic analysis is carried out for electricity generation by using timber and wood waste (T & WW) gasification in Iceland. Different expenses were considered, like capital, installation, engineering, operation and maintenance costs and the interest rate of the investment. Regarding to revenues, they come from of the electricity sale and the fee paid by the Icelandic municipalities for waste collection and disposal. The economic feasibility was conducted based on the economic indicators of net present value (NPV) and discounted payback period (DPP), bringing together three different subgroups based on gasifier capacities, subgroup a: 50 kW, subgroup b: 100 kW and subgroup c: 200 kW. The results show that total cost increases as the implemented power is increased. This indicator varies from 1228.6 k€ for subgroups a to 1334.7 k€ for subgroups b and 1479.5 k€ for subgroups c. It is worth mentioning that NPV is positive for three subgroups and it grows as gasifier scale is extended. NPV is about 122 k€ (111,020 $), 1824 k€ (1,659,840 $) and 4392 k€ (3,996,720 $) for subgroups a, b and c, respectively. Moreover, DPP has an inversely proportional to the installed capacity. It is around 5.5 years (subgroups a), 9.5 months (subgroups b) and 6 months (subgroups c). The obtained results confirm that using small scale waste biomass gasification integrated with power generation could be techno-economically feasible for remote area in Iceland.

Recovery of Biomass Incinerated as Struvite-K Precipitates Followed Aluminium Removal

Phosphorus (P) and potassium (K) are non-renewable materials and widely in many industries such as agricultural sectors. On the other hand, the demand of P and K as fertilizers increases which following global population. The nutrient source of P and K which get from biomass waste i.e. incinerated of activated sludge and coffee husk biochar, respectively. The present study was conducted recovery of P and K as struvite-K (KMgPO4·6H2O) precipitates. The results showed that aluminium was released simultaneously with P from incinerated activated sludge with precipitate of Al:P of 1:1, K:P of 0.5, and Mg:P of 3. However, aluminium was inhibited to form struvite-K. Then, we examined cation removal especially for removed Al by dissolved 0.5 M HNO3 and the solution was mixed with KH2PO4 and MgCl2·6H2O as source of K and Mg, respectively. The results showed aluminium (Al) was removed with precipitate K:P of 0.5, and Mg:P of 0.8. This study was confirmed that recovery of biomass incinerated was successful as struvite-K and can be used as fertilizers.

Synthesis of porous carbon from orange peel waste for effective volatile organic compounds adsorption: role of typical components

Volatile organic compounds have posed a serious threat to the environment and human health,which require urgent and effective removal.In recent years,the preparation of porous carbon from biomass waste for volatile organic compounds adsorption has attracted increasing attention as a very cost-effective and promising technology.In this study,porous carbon was synthesized from orange peel by urea-assisted hydrothermal carbonization and KOH activation.The role of typical components(cellulose,hemicellulose,and lignin)in pore development and volatile organic compounds adsorption was investigated.Among the three components,hemicellulose was the major contributor to high porosity and abundant micropores in porous carbon.Higher hemicellulose content led to more abundant–COOR,amine-N,and pyrrolic/pyridonic-N in the derived hydrochar,which were favorable for porosity formation during activation.In this case,the toluene adsorption capacity of the porous carbon improved from 382.8 to 485.3 mg·g^(–1).Unlike hemicellulose,cellulose reduced the>C=O,amine-N,and pyrrolic/pyridonic-N content of the hydrochar,which caused porosity deterioration and worse toluene adsorption performance.Lignin bestowed the hydrochar with slightly increased–COOR,pyrrolic/pyridonic-N,and graphitic-N,and reduced>C=O,resulting in comparatively poor porosity and more abundant micropores.In general,the obtained porous carbon possessed abundant micropores and high specific surface area,with the highest up to 2882 m^(2)·g^(–1).This study can provide guidance for selecting suitable biomass waste to synthesize porous carbon with better porosity for efficient volatile organic compounds adsorption.

Co-pyrolysis of waste biomass and waste plastics(polystyrene and waste nitrile gloves)into renewable fuel and value-added chemicals

The present study addresses the influence of blending of waste plastics(i.e.,polystyrene,PS and waste nitrile gloves,WNG)with mahua seeds(MH)for co-pyrolytic liquid yield and its fuel properties.Various blends of waste plastics were mixed with biomass(10,20 and 30 wt%)and pyrolyzed in a semi-batch reactor at an optimized environment(550℃ temperature,80℃ min^(-1) heating rate,and 100 mL min^(-1) N_(2) flow rate).Physicochemical results displayed its ability to yield renewable fuel and valuable chemicals.Co-pyrolysis outcomes showed that blending of waste plastics at 20 wt%,yielded maximum liquid(44.18±1.2 wt%and 45.89±1.4 wt%for MH+WNG and MH+PS respectively)which was higher than thermal pyrolysis of individual MH(39.26±1.2 wt%).Further,characterization results revealed a substantial reduction in viscosity,oxygen content,moisture,and a positive increment in gross heating value,carbon content and acidity.FTIR examination exposed the attendance of mainly aromatics,acids,phenols,water,esters and ethers.Further,NMR analysis of pyrolytic oil confirmed an increase in aromaticity by blending of waste plastics(20 wt%)while there was a reduction in paraffinic compounds.GC-MS investigation revealed substantial improvement in hydrocarbons and minimization in the oxygen-rich products by blending of waste plastics at 20 wt%.

Material flow analysis and global warming potential assessment of an industrial insect-based bioconversion plant using housefly larvae

The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food chain.However,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(LCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day.The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,respectively.The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more power.The main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).

Exploring on the optimal preparation conditions of activated carbon produced from solid waste produced from sugar industry and Chinese medicine factory

The waste biomass produced from sugar industry and Chinese medicine factory such as bagasse,reed root residue,pueraria residue and liquorice residue were selected as the raw material for the preparation of activated carbon with zinc chloride as activator.With the same activation time,the influence of temperature and impregnation ratio on the preparation of activated carbon was investigated and the reasonable preparation conditions of activated carbon were monitored and analyzed.The obtained activated carbon samples were characterized by scanning electron microscopy,Brunauer-Emmett-Teller,methylene blue adsorption,thermogravimetric analysis and nitrogen adsorption-desorption.Analysis from the experimental data,bagasse,reed root residue,pueraria residue are suitable for preparing activated carbon.For bagasse,the optimum preparation condition was 700℃ and the impregnation ratio was 1:1,the adsorption capacity of methylene blue reached 246.83 mg/g at the moment.For reed root residue,the optimum preparation condition was 600℃ and the impregnation ratio was 1:2,the adsorption capacity of methylene blue reached 268.07 mg/g at the moment.For Pueraria residue,the optimum preparation condition was 700℃ and the impregnation ratio was 1:2.The adsorption capacity of methylene blue reached 297.33 mg/g at the moment.

One-step preparation of a novel graphitic biochar/Cu^(0)/Fe_(3)O_(4) composite using CO_(2)-ambiance pyrolysis to activate peroxydisulfate for dye degradation

Herein,a one-step co-pyrolysis protocol was adopted for the first time to prepare a novel pyrogenic carbon-Cu^(0)/Fe_(3)O_(4)heteroatoms (FCBC) in CO_(2)ambiance to discern the roles of each component in PDS activation.During co-pyrolysis,CO_(2)catalyzed formation of reducing gases by biomass which facilitated reductive transformation of Fe^(3+)and Cu^(2+)to Cu^(0)and Fe_(3)O_(4),respectively.According to the analysis,the resulting metal (oxide) catalyzed graphitization of biocharand decomposition of volatile substances resulting in an unprecedented surface area (1240 m^(2)/g).The resulting FCBC showed greater structural defects and less electrical impedance.Batch experiments indicated that Rhodamine B (RhB) degradation by FCBC (100%) was superior to Fe_(3)O_(4)(50%) and Cu^(0)/Fe_(3)O_(4)(76.4%) in persulfate (PDS) system,which maintained reasonable efficiency (75.6%-63.6%) within three cycles.The reactive oxygen species (ROS) associated with RhB degradation was identified by an electron paramagnetic resonance and confirmed by scavenging experiments.RhB degradation invoked both(sulfate and dominantly hydroxyl) radical and non-radical (singlet oxygen,^(1)O_(2)) pathways.Regarding FCBC,Cu^(0)can continuously react with Fe^(3+)in Fe_(3)O_(4)to generate larger quantities of Fe^(2+),and both Cu^(0)and Fe^(2+)activated PDS to yield sulfate radicals which was quickly converted to hydroxyl radical.Besides,Cu^(0)/Cu^(2+)could complex with PDS to form a metastable complex,which particularly contributed to1O_(2)generation.These cascade reactions by FCBC were reinforced by carbonyl group of biochar and favorable electron transfer ability.This work highlighted a new approach to prepare a magnetic and environment-benign heterogonous catalyst to remove organic pollutants in water.

Development of the Self-doping Porous Carbon and Its Application in Supercapacitor Electrode

The massive discharge of biomass wastes not only causes waste of resources,but also pollutes the environment.Therefore,converting biomass wastes into carbon materials is an effective way to solve the above problems.Here,using biomass waste pig nails as raw materials and K_(2)CO_(3) as chemical activators,the N-doped porous carbon(KPNC)is prepared by direct pyrolysis.As an electrode for supercapacitors,the electrochemical tests of KPNCs showed that they exhibited good electrochemical performance and excellent cycling stability.When the current density is 0.2 A/g,the specific capacitance is up to 344.6 F/g.Moreover,it still maintains 97.6%initial capacitance retention after 2000 cycles at a high current density of 5 A/g.Above exceptional electrochemical performances may be ascribed to an appropriate porous structure(Smicro/Stotal=80.31%,Vmicro/Vtotal=76.19%),high nitrogen contents(4.44%,atomic fraction),oxygen contents(9.13%,atomic fraction)as well as small internal resistance.The above experimental results show that the conversion of pig nails to porous carbon can reduce the waste of resources and alleviate environmental pollution.

Biochar as construction materials for achieving carbon neutrality

Biochar is a waste-derived material that can sequester carbon at a large scale.The development of low-carbon and sustainable biochar-enhanced construction materials has attracted extensive interest.Biochar,having a porous nature and highly functionalised surface,can provide nucleation sites for chemical reactions and exhibit compatibility with cement,asphalt,and polymer materials.This study critically reviewed the state-of-the-art biochar-enhanced construction materials,including biochar-cement composites,biochar-asphalt composites,biochar-plastic composites,etc.The efficacies and mechanisms of biochar as construction materials were articulated to improve their functional properties.This critical review highlighted the roles of biochar in cement hydration,surface functional groups of engineered biochar for promoting chemical reactions,and value-added merits of biochar-enhanced construction materials(such as humidity regulation,thermal insulation,noise reduction,air/water purification,electromagnetic shielding,and self-sensing).The major properties of biochar are correlated to the features and functionalities of biochar-enhanced construction materials.Further advances in our understanding of biochar’s roles in various composites can foster the next-generation design of carbon-neutral construction materials.

Regulating closed pore structure enables significantly improved sodium storage for hard carbon pyrolyzing at relatively low temperature

The closed pore has been considered as the key structure for Na ion storage in hard carbon.However,the traditional view is that closed pores can only be formed by the curling of graphite-like crystallites in the case of high temperature carbonization.Ingenious designing of closed pore structures at lower temperature is still blank.Herein,for the first time,engineering the wall thickness and number of closed pores in waste rosewood-derived hard carbon was successfully achieved at a low temperature of 1100℃ by removing the lignin and hemicellulose components in wood precursor.When applied as an anode material,the optimum sample exhibits a high capacity of 326 mAh/g at 20 mA/g and a remarkable rate capability of 230mAh/g at 5000 mA/g,significantly higher than those of the untreated sample(only 33 mAh/g at 5000 mA/g).The significantly improved Na storage performance should be attributed to abundant closed pores that provide sufficient spaces forNa storage and thin porewall structure that is beneficial to the diffusion of Na^(+)in the bulk phase.This work provides a new idea for the future application of biomass-based hard carbon for advanced Na ion batteries.