Sustainable biochar as an electrocatalysts for the oxygen reduction reaction in microbial fuel cells

Microbial fuel cells(MFCs)have gained remarkable attention as a novel wastewater treatment that simultaneously generates electricity.The low activity of the oxygen reduction reaction(ORR)remains one of the most critical bottlenecks limiting the development of MFCs.To date,although research on biochar as an electrocatalyst in MFCs has made tremendous progress,further improvements are needed to make it economically practical.Recently,biochars have been considered to be ORR electrocatalysts with developmental potential.In this review,the ORR mechanism and the essential requirements of ORR catalysts in MFC applications are introduced.Moreover,the focus is to highlight the material selection,properties,and preparation of biochar electrocatalysts,as well as the evaluation and measurement of biochar electrodes.Additionally,in order to provide comprehensive information on the specific applications of biochars in the field of MFCs,their applications as electrocatalysts,are then discussed in detail,including the uses of nitrogen-doped biochar and other heteroatom-doped biochars as electrocatalysts,poisoning tests for biochar catalysts,and the cost estimation of biochar catalysts.Finally,profound insights into the current challenges and clear directions for future perspectives and research are concluded.

Facile designing a superhydrophobic anti-icing surface applied for reliable long-term deicing

While superhydrophobic coatings have shown promise as potential anti-icing coatings, the surface roughness of these coatings is prone to damage during repeated icing-deicing cycles. Herein, two kinds of superhydrophobic anti-icing coatings are prepared from organic resin and micro-nano particles using two strategies, and their excellent anti-icing properties are also investigated. However, superhydrophobic surface Ⅰ(SF1), prepared by first strategy, cannot be used for extended periods of time due to irreversible damage to the surface roughness during the icing–deicing process. Finite element simulations and experimental studies are preformed to investigate the fatal issue of such roughness damage. In contrast,the anti-icing properties of superhydrophobic surface Ⅱ(SF2), prepared by second strategy, can easily regain through a simple sandpaper abrasion treatment even the surface roughness was damaged during the icing–deicing process. These exploratory results and SF2 preparation strategy provide a facile design of anti-icing coating, and the derived restorable anti-icing coating is expected to be useful for a wide application.

Microalgae-based wastewater treatment:Mechanisms,challenges,recent advances,and future prospects

The rapid expansion of both the global economy and the human population has led to a shortage of water resources suitable for direct human consumption.As a result,water remediation will inexorably become the primary focus on a global scale.Microalgae can be grown in various types of wastewaters(WW).They have a high potential to remove contaminants from the effluents of industries and urban areas.This review focuses on recent advances on WW remediation through microalgae cultivation.Attention has already been paid to microalgae-based wastewater treatment(WWT)due to its low energy requirements,the strong ability of microalgae to thrive under diverse environmental conditions,and the potential to transform WW nutrients into high-value compounds.It turned out that microalgae-based WWT is an economical and sustainable solution.Moreover,different types of toxins are removed by microalgae through biosorption,bioaccumulation,and biodegradation processes.Examples are toxins from agricultural runoffs and textile and pharmaceutical industrial effluents.Microalgae have the potential to mitigate carbon dioxide and make use of the micronutrients that are present in the effluents.This review paper highlights the application of microalgae in WW remediation and the remediation of diverse types of pollutants commonly present in WW through different mechanisms,simultaneous resource recovery,and efficient microalgae-based co-culturing systems along with bottlenecks and prospects.

Multistage defense response of microalgae exposed to pharmaceuticals in wastewater

Recently, the use of microalgae for bioremediation of pharmaceuticals(Ph As) has attracted increasing interest. However, most studies focused more on microalgae removal performance, its defensive response to the Ph As during wastewater treatment remains unexplored. Herein, microalgal three defensive systems have been investigated in synthetic wastewater, with six Ph As as the typical drug. Results show that Ph As could bind to EPS, and this action in turn could help to alleviate the direct toxicity of Ph As to microalgae. Subsequently, the physiological analyses revealed the increase of superoxide dismutase(SOD), catalase(CAT), and peroxidase(POD) activities, potentially reducing the oxidative stress induced by Ph As. Furthermore, the enzyme activities of cytochrome P450(CYP450) and glutathione-S-transferase(GST) were significantly upregulated after exposure to SMX, CIP and BPA, followed by a significant decrease in biodegradation rates after the addition of CYP450 inhibitors, suggesting that the biotransformation and detoxification of Ph As occurred. Meanwhile, molecular docking further revealed that CYP450 could bind with Ph As via hydrogen bond and hydrophobic interaction, which proved their abilities to be metabolized and form transformation products in microalgae. These findings provide an advancing understanding of microalgae technologies to improve the treatment of wastewater contaminated with Ph As.

Recent advances in MXenes-based glucose biosensors

It is established that monitoring blood glucose on a daily basis is one of the most effective solutions to prevent and treat diabetes.Consequently,developing a glucose sensing platform with outstanding sensing performance occupies an indispensable position for the early diagnosis and risk assessment of diabetes.Recently,biosensor has been deemed as a promising apparatus to acquire the signals for glucose monitoring based on 2D materials.However,it is unsatisfied to deploy some materials widely as a result of some inherent defects.Carbon nanotubes have comparatively high toxicity.MoS_(2) with unfavourable biocompatibility are still arduously implemented on being functionalized.Fortunately,MXene,a brand-new and rapidly developing two-dimensional material,exhibits marvellous application potential in the domain of biosensing.Therefore,it has exerted tremendous attention from diverse scientific fields owning to its remarkable properties,such as excellent hydrophilicity,metal-like conductivity,abundant surface functional groups,unique layered structure,large specific surface area and remarkable biocompatibility.This review mainly focuses on the main synthetic route of MXenes,as well as the recent advancements of biosensors involving MXenes as an electrode modifier for glucose detection.In addition,the promising prospects and challenges of glucose sensing technology based on MXenes are also discussed.

Immobilized microalgal system:An achievable idea for upgrading current microalgal wastewater treatment

Efficient wastewater treatment accompanied by sustainable“nutrients/pollutants waste-wastewaterresources/energy nexus”management is acting as a prominent and urgent global issue since severe pollution has occurred increasingly.Diverting wastes from wastewater into the value-added microalgalbiomass stream is a promising goal using biological wastewater treatment technologies.This review proposed an idea of upgrading the current microalgal wastewater treatment by using immobilized microalgal system.Firstly,a systematic analysis of microalgal immobilization technology is displayed through an in-depth discussion on why using immobilized microalgae for wastewater treatment.Subsequently,the main technical approaches employed for microalgal immobilization and pollutant removal mechanisms by immobilized microalgae are summarized.Furthermore,from high-tech technologies to promote large-scale production and application potentials in diverse wastewater and bioreactors to downstream applications lead upgradation closer,the feasibility of upgrading existing microalgal wastewater treatment into immobilized microalgal systems is thoroughly discussed.Eventually,several research directions are proposed toward the future immobilized microalgal system for microalgal wastewater treatment upgrading.Together,it appears that using immobilization for further upgrading the microalgae-based wastewater treatment can be recognized as an achievable alternative to make microalgal wastewater treatment more realistic.The information and perspectives provided in this review also offer a feasible reference for upgrading conventional microalgae-based wastewater treatment.

Revealing the role of microalgae-bacteria niche for boosting wastewater treatment and energy reclamation in response to temperature

Conventional biological treatment usually cannot achieve the same high water quality as advanced treatment when conducted under varied temperatures.Here,satisfactory wastewater treatment efficiency was observed in a microalgae-bacteria consortia(MBC)over a wide temperature range because of the predominance of microalgae.Microalgae contributed more toward wastewater treatment at low temperature because of the unsatisfactory performance of the accompanying bacteria,which experienced cold stress(e.g.,bacterial abundance below 3000 sequences)and executed defensive strategies(e.g.,enrichment of cold-shock proteins).A low abundance of amoA-C and hao indicated that conventional nitrogen removal was replaced through the involvement of microalgae.Diverse heterotrophic bacteria for nitrogen removal were identified at medium and high temperatures,implying this microbial niche treatment contained diverse flexible consortia with temperature variation.Additionally,pathogenic bacteria were eliminated through microalgal photosynthesis.After fitting the neutral community model and calculating the ecological niche,microalgae achieved a maximum niche breadth of 5.21 and the lowest niche overlap of 0.38,while the accompanying bacterial community in the consortia were shaped through deterministic processes.Finally,the maximum energy yield of 87.4 kJ L^(-1)and lipid production of 1.9 g L^(-1)were achieved at medium temperature.Altogether,this study demonstrates that advanced treatment and energy reclamation can be achieved through microalgae-bacteria niche strategies.

Publishing a sound paper of environmental science and ecological technology:Some experiences and tips for young researchers

Two factors are of great significance for enhancing young researchers'international engagement:continuously improving their academic level and publishing advanced progress in scientific journals.The journals in the field of environmental science and ecological technology(ESET)are committed to improving research independency of young researchers,so as to promote excellent scientific research achievements.In this editorial,we integrate major challenges that young researchers must cope with in preparing their submissions.

Role of biochar surface characteristics in the adsorption of aromatic compounds:Pore structure and functional groups

Biochar(BC)are widely used as highly efficient adsorbents to alleviate aromatics-based contaminants due to their ease of preparation,wide availability,and high sustainability.The surface properties of BCs usually vary greatly due to their complex chemical constituents and different preparation processes and are reflected in the values of parameters such as the specific surface area(SSA),pore volume/size,and surface functional groups(SFGs).The effects of SSA and pore volume/size on the adsorption of aromatics have been widely reported.However,the corresponding mechanisms of BC SFGs towards aromatics adsorption remains unclear as the compositions of the SFGs are usually complex and hard to determine.To address in this gap in the literature,this review introduces a new perspective on the adsorption mechanisms of aromatics.Through collecting previously-reported results,the parameters log P(logarithm of the Kow),polar surface area,and the positive/negative charges were carefully calculated using Chem Draw3D,which allowed the hydrophobicity/hydrophilicity properties,electron donor-acceptor interactions,Hbonding,and electrostatic interactions between SFGs and aromatics-based contaminates to be inferred intuitively.These predictions were consistent with the reported results and showed that tailor-made BCs can be designed according to the molecular weights,chemical structures,and polarities of the target aromatics.Overall,this review provides new insight into predicting the physicochemical properties of BCs through revealing the relationship between SFGs and adsorbates,which may provide useful guidance for the preparing of highly-efficient,functional BCs for the adsorption of aromatics.

Revolutions in algal biochar for different applications:State-of-the-art techniques and future scenarios

Algae are potential feedstock for the production of bioenergy and valuable chemicals.After the extraction of specific value-added products,algal residues can be further conve rted into biogas,biofuel,and biochar through various thermochemical treatments such as conventional pyrolysis,microwave pyrolysis,hydrothermal conversion,and torrefaction.The compositions and physicochemical characteristics of algal biochar that dete rmine the subsequent applications are compre hensively discussed.Algal biochar carbonized at high-temperature showed remarkable performance for use as supercapacitors,CO_(2) adsorbents,and persulfate activation,due to its graphitic carbon structure,high electron transport,and specific surface area.The algal biochar produced by pyrolysis at mode rate-temperature exhibits high performance for adsorption of pollutants due to combination of miscellaneous functional groups and po rous structures,whereas coal fuel can be obtained fro m algae via torrefaction by pyrolysis at relatively low-tempe rature.The aim of this review is to study the production of algal biochar in a cost-effective and environmental-friendly method and to reduce the environmental pollution associated with bioenergy generation.achieving zero emission enerev production.

Biological remediation of acid mine drainage:Review of past trends and current outlook

Formation of acid mine drainage(AMD)is a widespread environmental issue that has not subsided throughout decades of continuing research.Highly acidic and highly concentrated metallic streams are characteristics of such streams.Humans,plants and surrounding ecosystems that are in proximity to AMD producing sites face immediate threats.Remediation options include active and passive biological treatments which are markedly different in many aspects.Sulfate reducing bacteria(SRB)remove sulfate and heavy metals to generate non-toxic streams.Passive systems are inexpensive to operate but entail fundamental drawbacks such as large land requirements and prolonged treatment period.Active bioreactors offer greater operational predictability and quicker treatment time but require higher investment costs and wide scale usage is limited by lack of expertise.Recent advancements include the use of renewable raw materials for AMD clean up purposes,which will likely achieve much greener mitigation solutions.

Algae-mediated antibiotic wastewater treatment:A critical review

The existence of continually increasing concentrations of antibiotics in the environment is a serious potential hazard due to their toxicity and persistence.Unfortunately,conventional treatment techniques,such as those utilized in wastewater treatment plants,are not efficient for the treatment of wastewater containing antibiotic.Recently,algae-based technologies have been found to be a sustainable and promising technique for antibiotic removal.Therefore,this review aims to provide a critical summary of algae-based technologies and their important role in antibiotic wastewater treatment.Algal removal mechanisms including bioadsorption,bioaccumulation,and biodegradation are discussed in detail,with using algae-bacteria consortia for antibiotic treatment,integration of algae with other microorganisms(fungi and multiple algal species),hybrid algae-based treatment and constructed wetlands,and the factors affecting algal antibiotic degradation comprehensively described and assessed.In addition,the use of algae as a precursor for the production of biochar is highlighted,along with the modification of biochar with other materials to improve its antibiotic removal capacity and hybrid algae-based treatment with advanced oxidation processes.Furthermore,recent novel approaches for enhancing antibiotic removal,such as the use of genetic engineering to enhance the antibiotic degradation capacity of algae and the integration of algal antibiotic removal with bioelectrochemical systems are discussed.Finally,some based on the critical review,key future research perspectives are proposed.Overall,this review systematically presents the current progress in algae-mediated antibiotic removal technologies,providing some novel insights for improved alleviation of antibiotic pollution in aquatic environments。

Tailoring a novel hierarchical cheese-like porous biochar from algae residue to boost sulfathiazole removal

Aquatic pollution caused by antibiotics poses a significant threat to human health and the ecosystem.Inspired from“Emmental Cheese”that owns lots of natural pores,we here fabricated a hierarchical cheese-like porous Spirulina residue biochar(KSBC)activated by KHCO_(3)for efficiently boosting the removal of sulfathiazole(STZ).Through learning form nature that the CO_(2)produced by bacteria can serve as the natural pore maker(like cheese-making),KHCO_(3)was thus selected as the gas generating agent in this study.The effect of adding KHCO_(3)on the surface properties of KSBC was comprehensively investigated.Benefiting from the activation,the KSBC with the mass ratio of 2:1(2K-SBC)possessed the largest specific surface areas(1100 m^(2)g^(-1)),which was approximately 81 times that of the original(not activated)Spirulina residue biochar(SBC)(13.56 m^(2)g
^(-1)).Moreover,2K-SBC exhibited the maximum adsorption capacity for STZ(218.4 mg g^(-1)),dramatically higher than the SBC(25.78 mg g^(-1)).The adsorption kinetics and adsorption isotherms exhibited that the adsorption behavior of 2K-SBC for STZ was consistent with the pseudo-second-order and Langmuir models.Additionally,the adsorption thermodynamics revealed that the adsorption of STZ on 2K-SBC was spontaneous and exothermic.The pore-filling and electrostatic interaction were considered the main mechanism for the adsorption of STZ on 2K-SBC,whereas the p-p electron donor-acceptor(EDA)interaction and hydrogen bond would also partially contribute to the adsorption process.

Effective purification of oily wastewater using lignocellulosic biomass:A review

Due to the frequent occurrence of oil spills and the large-scale production of oily wastewater, the treatment of oily sewage has become an important issue for sustainable development. Recently, materials prepared from lignocellulosic biomass(LCB) for oil-water separation have been found to be effective due to their high separation efficiency, good recyclability, and superior sustainability. However, few reviews have focused on the advantages and limitations of LCB for sewage treatment. This review summarizes the performance of modified LCB in oily wastewater treatment, in terms of the advanced modification methods applied and the structural dimensions of LCB materials according to the principle of superwetting oil-water separation. Research on the preparation technologies, separation mechanisms, and treatment efficiency of different LCB materials are briefly summarized, along with the characteristics of different LCB material types for oily wastewater treatment. Finally, the future prospects and challenges faced in the development of LCB materials are discussed.