Green Solution Research Articles

Tripolyphosphate-functionalized cellulose: A green solution for cadmium contamination

This study introduces a highly efficient tripolyphosphate -tethered cellulose sorbent for cadmium (Cd2⁺) removal from aqueous solutions. Characterization through FTIR and SEM revealed the material's structural properties. The sorbent achieved 99% Cd2⁺ removal even at a minimal dosage of 0.05 g. Optimal sorption occurred within the pH range of 4–6, influenced by the sorbent's weak acidic functional groups. Rapid kinetics, reaching equilibrium within a minute, and a high sorption capacity (up to 18.03 mg/g at 50 °C) were observed. Langmuir isotherm modeling confirmed monolayer sorption, and thermodynamic studies indicated a spontaneous, endothermic process with increased randomness at the solid-liquid interface. Selectivity studies demonstrated strong Cd2⁺ removal performance in the presence of competing ions, with minimal interference from monovalent ions but notable effects from divalent ions. The sorbent exhibited consistent reusability over multiple cycles. XPS analysis conclusively established an ion exchange mechanism between Cd2⁺ and negatively charged P3O105− groups as the primary removal pathway. This research highlights the potential of TPP-tethered cellulose as a promising sorbent for effective Cd2⁺ remediation.

OVERVIEW OF THE METHODS AND TOOLS FOR ENVIRONMENTAL COMPONENTS MONITORING

Monitoring of environmental components is an important process for determining the level of pollution and tracking changes in the environment, and plays a key role in ensuring the health and comfort of residents, as well as in preserving the environment. Continuous monitoring of environmental components is key to ensuring human health, protecting nature and reducing the negative impact on the climate and ecosystems, as well as achieving sustainable development. In order to combat environmental pollution, it is necessary to implement effective measures to limit emissions of harmful substances, use environmentally friendly technologies and green solutions in all sectors of the economy, and raise public awareness of the problem of environmental pollution. From the analysis of the sources reviewed, a pattern was identified that the information technologies mainly used to monitor environmental components are either Internet of Things (IoT) technologies using modern sensors and data transmission components or artificial intelligence technologies such as computer vision. Less commonly, the use of robots, UAVs, and digital twins is being traced. Based on a critical analysis of methods and tools for environmental components monitoring, there is a need to develop such methods and tools for environmental components monitoring that would: perform cheaper and more versatile environmental components monitoring than existing analogues, but at the same time have no less accuracy and speed; monitor the state of the environment; identify sources of environmental pollution; warn of environmental disasters; assess the state of natural resources; support environmental decision-making; collect and analyze various environmental indicators in real time; assessed the level of quality and safety of environmental components, which will allow immediate response to quality changes and promptly take the necessary measures, etc., which will be the focus of the authors' further efforts.

Advancements and challenges of fuel cell integration in electric vehicles: A comprehensive analysis

Fuel cell technology emerges as a promising green solution, offering mitigation to global warming, air pollution, and energy crises. This eco-friendly approach is witnessing a surge in adoption within the automotive sector, with fuel cell buses, cars, scooters, forklifts, and more, becoming increasingly prevalent. The automobile industry has been rapidly advancing fuel cell technology, inching closer to the commercialization of fuel cell vehicles. As various technical hurdles are surmounted and costs are reduced, fuel cell vehicles are poised to become a competitive force in the automobile market, presenting an excellent solution for environmental sustainability and energy efficiency. This review paper delves into the fundamentals of fuel cells, their characteristics, and their applications in the automotive realm, exploring their prospects in comparison to traditional technologies. Furthermore, it sheds light on the existing research and industrial developments in hydrogen and fuel cell technologies. Additionally, a comprehensive comparison is provided between various fuel cell cars that have already been commercialized, enabling readers to understand the current market landscape. The review also analyses the advantages and challenges associated with fuel cell technology, offering insights into its future development trajectory. Through this comprehensive exploration, readers can gain a deeper understanding of fuel cell technology and its potential in revolutionizing the automotive industry.

On the viscoelastic-electromagnetic-gravitational analogy

The analogy between electromagnetism and gravitation was achieved by linearizing the tensorial gravitational equations of general relativity and converting them into a vector form corresponding to Maxwell’s electromagnetic equations. On this basis, we use the equivalence with viscoelasticity and propose a theory of gravitational waves. We add a damping term to the differential equations, which is equivalent to Ohm’s law in electromagnetism and Maxwell’s viscosity in viscoelasticity, to describe the attenuation of the waves. The differential equations in viscoelasticity are those of cross-plane shear waves, commonly referred to as SH waves. A plane-wave analysis gives the phase velocity, the energy velocity, the quality factor and the attenuation factor of the field as well as the energy balance. To obtain these properties, we use the analogy with viscoelasticity; the properties of electromagnetic and gravitational waves are similar to those of shear waves. The presence of attenuation means that the transient field is generally a composition of inhomogeneous (non-uniform) plane waves, where the propagation and attenuation vectors do not point in the same direction and the phase velocity vector and the energy flux (energy velocity) are not collinear. The polarization of cross-plane field is linear and perpendicular to the propagation-attenuation plane, while the polarization of the field within the plane is elliptical. Transient wave fields in the space–time domain are analyzed with the Green function (in homogeneous media) and with a grid method (in heterogeneous media) based on the Fourier pseudospectral method for calculating the spatial derivatives and a Runge–Kutta scheme of order 4 for the time stepping. In the examples, wave propagation at the Sun–Earth and Earth–Moon distances using quadrupole sources is considered in comparison to viscoelastic waves. The Green and grid solutions are compared to test the latter algorithm. Finally, an example of propagation in heterogeneous media is presented.

Low field assisted electrocaloric effect and energy storage responses through optimization of morphotropic phase boundary by sintering temperature for lead-free Ba0.95Ca0.05Sn0.09Ti0.91O3 ceramics

The development of lead-free ferroelectric materials is highly desired for next-generation energy storage and superior electrocaloric effect (ECE) applications. However, one of the significant challenges in lead-free dielectric materials is to obtain enhanced ECE and energy storage density at lower applied electric fields, needed for realization of sustainable and efficient energy solutions. Herein, the sol-gel elaborated lead-free Ba0.95Ca0.05Sn0.09Ti0.91O3 ceramics have been synthesized and sintered at temperatures 1100 and 1200 ˚C. The sample sintered at 1200 ˚C exhibits low field assisted improved ∆T ∼ 0.42 K and ∆S ∼ 0.52 J/kg/K values and are closely associated with presence of MPB and relaxor characteristics. The enhanced recoverable energy density (Wrec) and total energy density (Wtot) are also obtained as 79 mJ/cm3 and 87 mJ/cm3 for the same sample sintered at 1200 ˚C with excellent conversion efficiency of 91 % under a very low applied electric field of 30 kV/cm. The results demonstrate that the optimization of sintering temperature significantly affects the MPB evolution, microstructure and emergence of relaxor characteristics owing to vibrant polar-nano regions that result in enhanced ECE and energy storage characteristics. The present work would be beneficial for advancement of lead-free ferroelectric materials as an efficient electrocaloric cooling and sustainable green energy solutions.

Gossypol derivate as a green anti-corrosion agent in the aqueous phase of crude oil.

Keeping recruitment of green and cost-effective solutions for environmental challenges in view, the current work was designed to solve the problems related to metal corrosion in the aqueous phases of crude oil in chemical industries. Green materials can play an important role in protecting metals from this corrosion. Hence, the green anti-corrosion material based upon gossypol derivate is suggested to solve the above problems. The electrochemical characteristics were appraised by cyclic voltammetry, electrochemical impedance spectroscopy, potentiodynamic polarization, and electrochemical noise methods. The thermodynamics were studied by gravimetric analyses. The surface morphology was scrutinized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. Density functional theory and molecular dynamic simulations were exploited in theoretical analyses. The gossypol derivate is green, non-toxic, more efficient, non-volatile, and chemically stable anti-corrosion material for gas and oil industries. Carbon steel corrosion simulated in aqueous phases of crude oil (NaCl solutions (1.0M) saturated with H2S and CO2) was maximally prohibited by forming a protective layer of binaphthalene. Its protection degree is 96.71% (at 100.0mg/L/0.107mM). The gossypol ring is a suitable core for preparing the next modification materials to protect against corrosion. The rigid adsorption progressed mainly via hydroxyl functional moieties. Compared to the inhibition behavior of the neutral form of gossypol, the optimized protonated form causes a greater inhibition.

Green and Reflux method synthesis of CeO2/rGO for their characterization and Photodegradation of dye

In this study, cerium oxide (CeO2) was synthesized using a green and eco-friendly solution combustion method with lemongrass as the fuel source. The synthesis process was simple and environmentally friendly, leveraging a straightforward reflux technique to prepare the CeO2/rGO composite. The resulting CeO2 and CeO2/rGO composite was characterized using various analytical techniques, including XRD, FE-SEM, FTIR, EDX, UV-Vis, XPS, and BET analysis. The photocatalytic performance of the CeO2/rGO composite was evaluated through the degradation of Methyl Violet (MV) dye, demonstrating a remarkable photocatalytic efficiency with approximately 99 % degradation following a first-order reaction kinetics. The half-life period (t₁/₂) of the degradation process was determined to be 19.01 minutes, and the rate constant (k) was calculated to be 0.03971 min⁻¹. The study also explored various factors affecting the photocatalytic activity, including pH levels, dye concentration, light source, and the amount of catalyst used. Additionally, scavenger studies were performed to identify the reactive species involved, and the total organic carbon (TOC) removal efficiency was evaluated. The reusability of the CeO2/rGO catalyst was also investigated, demonstrating its potential for sustainable and effective application in environmental remediation processes.

Advancements in IoT Routing and Energy Efficiency: A Comprehensive Review of Algorithms and Technologies

The rapid expansion of the Internet of Things (IoT) has led to a significant increase in connected devices, resulting in growing challenges related to efficient data transmission, energy consumption, and network scalability. Routing protocols and energy-efficient algorithms play a pivotal role in addressing these challenges, enabling IoT systems to optimize performance while minimizing power usage. This review provides a comprehensive analysis of recent advancements in IoT routing techniques and energy-efficient solutions, focusing on multi-objective optimization algorithms such as fractional gravitational search, grey wolf optimization, and hybrid salp swarm-differential evolution algorithms. Additionally, we explore context-aware routing, cluster-based methods, and the integration of machine learning to enhance decision-making in dynamic IoT environments. The review also highlights the critical role of energy-efficient routing in IoT applications, such as smart agriculture, healthcare, and smart cities, emphasizing its importance in prolonging network lifetime and reducing overall operational costs. The potential of blockchain technology and AI-driven algorithms to enhance security and energy efficiency in IoT networks is discussed, alongside future directions in green routing solutions. By addressing the complexities of IoT routing and energy management, this review aims to provide insights into the latest research trends and guide future innovations in IoT systems.

Harnessing waste glass as an expansive agent controller for enhanced Geopolymer performance in oil and gas wells

Geopolymers have gained traction as suitable alternate cementitious materials for oil and gas cementing operations. However, its bonding properties are limited because of shrinkage. Meanwhile, there is an enormous amount of waste glass in our immediate environment, an urgent concern for the environment and human health, which could be reutilized or recycled. This study investigates the potential use of waste glass as an expansive agent controller to improve the performance of the geopolymers. The waste glass was attached to the CaO to create a composite expansive agent to control the geopolymers' expansion rate. The synthesised agents were evaluated for their impact on linear expansion, compressive strength, shear bond strength, and hydraulic sealability. The synthesised agents were tested for their impact on linear expansion, compressive strength, shear bond strength, and hydraulic sealability. The results revealed that the incorporation of 30%–70% waste glass in the expansive formulation significantly enhances the linear expansion of geopolymers by 15%–20% while improving the compressive strength in the long term by 10%–15%. These improvements are crucial for maintaining geopolymers' mechanical integrity preventing issues related to uncontrolled expansion. This study confirms that the waste glass can effectively be valorised as an expansive agent controller, offering a green and cost-effective solution for enhancing well integrity and promoting the development of more environmentally sustainable practices in the oil and gas industry.

Green Solution Processing of Halide Perovskite Solar Cells: Status and Future Directions

Halide perovskite solar cells have achieved impressive efficiencies above 26%, making them a promising technology for the future of solar energy. However, the current fabrication methods rely on highly toxic solvents, which pose significant safety and environmental hazards. It is crucial to develop greener and safer alternatives to these solvents to facilitate the commercialization of perovskite solar cells. In this review, the safety and hazard evaluations of conventional toxic solvents and discuss the selection criteria for solvents that affect the morphology, nucleation, crystallization, and performance of perovskite solar cells. Furthermore, recent research into green solvent alternatives is evaluated and their properties are compared to those of commonly used solvents. In this review, fundamental insights are provided into the progress and challenges of green‐solution processing of perovskite solar cells, which will be essential for advancing this technology toward commercialization.

Realizing enhanced photoresponse for self-powered broadband photodetector with asymmetric contacts based MoTe2/WSe2 van der Waals heterostructure

Self-powered photodetectors constructed by two-dimensional (2D) materials are significant in advanced science and technology with the growing focus on green and energy-efficient solutions. The built-in electric field in photodetector drives efficient separation and transfer of photogenerated electron–hole pairs. However, traditional metal-2D material-metal structures have more interface defects and larger Schottky barrier to hinder carrier transport. In this work, an asymmetric electrode material structure is constructed by adding graphene to provide a more efficient transport channel for photogenerated carriers. Graphene electrodes can play a variety of roles in efficient separation and collection of photogenerated carriers, reducing the barrier and improving the contact quality. Compared with the device using symmetric gold electrodes, the device prepared with asymmetric contacts show optimized performance. The MoTe2/WSe2 heterostructure exhibits brilliant self-powered photoresponse (a responsivity of 268 mA/W and a detectivity of 7.48*1011 Jones). And the rise/decay times are up to 145μs/125μs. Additionally, the detector has a broadband detection capability from visible light to near-infrared. These results provide a promising and simple way to fabricate a MoTe2/WSe2 self-powered broadband photodetector with high performance

Effects of Protein on Green Tea Quality in a Milk-Tea Model during Heat Treatment: Antioxidant Activity, Foaming Properties, and Unbound Small-molecule Metabolome

Tea drinks/beverage has a long history and milk is often added to enhance its taste and nutritional value, whereas the interaction between the tea bioactive compounds with proteins has not been systematically investigated. In this study, a milk-tea model was prepared by mixing green tea solution with milk and then heated at 100°C for 15 min. The milk tea was then measured using biochemical assay, antioxidant detection kit, microscopy as well as HPLC-QTOF-MS/MS after ultrafiltration. The study found that as the concentration of milk protein increased in the milk-tea system, the total phenol-protein binding rate raised from 19.63% to 51.08%, which led to a decrease in free polyphenol content. This decrease of polyphenol was also revealed in the antioxidant capacity, including 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability and ferric ion reducing antioxidant power, in a dose-dependent manner. Untargeted metabolomics results revealed that the majority of small-molecule compounds/polyphenols in tea, such as epigallocatechin gallate, (-)-epicatechin gallate, and Catechin 5,7,-di-O-gallate, bound to milk proteins and were removed by ultrafiltration after addition of milk and heat treatment. The SDS-PAGE and Native-PAGE results further indicated that small molecule compounds in tea formed covalent and non-covalent complexes by binding to milk proteins. All above results partially explained that milk proteins form conjugates with tea small-molecule compounds. Consistently, the particle size of the tea-milk system increased as the tea concentration increased, but the polymer dispersity index decreased, indicating a more uniform molecular weight distribution of the particles in the system. Addition of milk protein enhanced foam ability in the milk-tea system but reduced foam stability. In summary, our findings suggest that the proportion of milk added to tea infusion needs to be considered to maintain the quality of milk-tea from multiple perspectives, including stability, nutritional quality and antioxidant activity.

Facile Biogenic synthesis of Europium doped lanthanum silicate nanoparticles as novel supercapacitor electrodes for efficient energy storage applications

In this work, we demonstrated for the first time, use of Europium doped lanthanum silicate nanoparticles (LS NPs) as electrodes for supercapacitor applications. Europium (Eu3+) doped (5 mol%) LS NPs were synthesized by green solution combustion method using Mexican mint leaf extracts. Various analytical techniques such as High-Resolution Transmission Electron Microscopy (HRTEM), Selected Area Diffraction (SAED), Powder X-ray Diffraction (PXRD), Fourier Transform Infra-Red Spectroscopy (FTIR) and Diffuse Reflectance Spectroscopy (DRS) techniques were used to confirm the morphological and structural characteristics of the synthesized nanoparticles. The HRTEM and SAED patterns confirms the formation of NPs having agglomerated structure with a particle size less than 50 nm. The PXRD patterns reveals crystalline cubic structure for the NPs. Further, the FT-IR spectra reveal the successful doping of Europium in Lanthanum Silicate NPs. The DRS (Diffuse Reflectance Spectroscopy) studies confirm the reduced band gap for Europium (Eu3+) doped (5 mol%) LS NPs. Cyclic voltametric and electrochemical impedance spectroscopy experiments were performed in an alkaline medium to compare the electrochemical activity of Eu3+ doped LS NPs with that of their undoped counterpart. The Eu3+ doped (5 %) LS NPs electrodes attained a specific capacitance of 373.3 Fg-1 at a current density of 0.5 Ag-1 in comparison to pure LS NPs which is about 267 Fg-1. The long-term stability of the Eu3+ doped (5 %) LS NPs electrodes show excellent stability up to 4000 cycles of operation in comparison pure LS NPs electrodes. Doping of Eu3+ had a favourable effect on the conductivity and electrochemical activity of LS NPs. Due to favourable green combustion synthesis, superior electrochemical performance, these Eu3+ doped LS NPs could be potential materials for new generation supercapacitors in energy storage applications.

Mechanistic insight into assimilation capture: Implication for high-efficiency nitrogen removal from mature landfill leachate

The AO (Anoxic/oxic) process for treating high-strength ammonia in landfill leachate requires external carbon source and alkalinity. Alternatively, the processes of partial nitrification-Anammox (PNA) and partial denitrification-Anammox (PDA) with less or no carbon source have been developed, but enabled modulation difficulty due to nitrogen valence transformation. Ammonia assimilation for nitrogen removal immobilize ammonia (NH4+-N) as organic nitrogen, without nitrogen valence conversion and reducing greenhouse gases emission. This study offers a novel approach for nitrogen removal from low chemical oxygen demand (COD) to nitrogen (C/N) ratio leachate. The nitrogen removal response of biomass to ammonia assimilation in landfill leachate was established. Results demonstrated that the nitrogen removal contribution of ammonia assimilation and organics utilization by microorganisms significantly increased with biomass. When the initial mixed liquor suspended solid (MLSS) was 11200 mg/L, the removal efficiency of total nitrogen (TN) and COD in the landfill leachate achieved 98.42 ± 0.12 % and 80.60 ± 0.35 % after 30 days of operation, respectively. The corresponding assimilation contributions for TN and COD removals were 82.00 ± 0.96 % and 52.24 ± 0.82 %, respectively. Cell protein analysis showed that higher biomass significantly increased the production of intracellular and extracellular proteins or amino acids. The enrichment of bacterial genera such as Defluviicoccus, Aequorivita, Truepera, and Proteiniphilum played a crucial role in organics removal and NH4+-N assimilation. Functional gene analysis further demonstrated that most NH4+-N and organics were removed through bacterial assimilation. This research offered a green, efficient, and economical solution for the treatment of low C/N ratio landfill leachate.

Bacillus Species’ Gaseous Metabolites Prolong the Shelf Life of Apples and Grapes

In view of the threat to the environment posed by the widely used plant and fruit preservation chemicals in current agricultural practices, and the indispensability of fruit and plant preservatives in ensuring the yield of agricultural products, it is urgent to explore environmentally friendly and efficient preservative alternatives. Against this backdrop, bacterial preservatives stand out as a potential green solution. In this study, 12 strains of Bacillus derived from different ecological niches were carefully screened to evaluate the inhibitory efficacy of their gaseous metabolites against Anthracnose colloidospora, a common fruit pathogen, by bisectional method. The results showed that the bacterial suspension of strain B4 was the most prominent in inhibiting the growth of Colloidosporum anthracnose, and it significantly narrowed the growth circle of pathogenic bacteria, so it was selected as the object for further optimization and application. Subsequently, we designed a practical application test for fruit preservation, in which the bacteria of strain B4 were directly placed in the same environment as the fruit to be preserved, and the observation was continued for five days. By comparing and analyzing the fruit state before and after treatment, we were pleased to find that strain B4 showed a positive effect on inhibiting fruit rot, indicating its great potential as a natural fruit preservative. This discovery not only provides a scientific basis for reducing the use of chemical preservatives, but also contributes to the sustainable development of agriculture and the protection of the ecological environment.

Advances in Intelligent Sports Based on Triboelectric Nanogenerators

In the realm of intelligent sports, the integration of triboelectric nanogenerators (TENGs) marks a transformative approach toward energy sustainability and more advanced athletic monitoring. By leveraging the principle of triboelectricity, TENGs ingeniously convert mechanical energy from athletes’ movements into electrical energy, which offers a green and efficient power solution for wearable technology. This paper presents an innovative study on the application of TENG technology in sports science, with the results illustrating the potential utility of TENGs in revolutionizing the way we monitor, analyze, and enhance athletic performance. Through the development of self-powered wearables and equipment, TENGs facilitate real-time data collection on physiological and biomechanical parameters, ultimately enabling personalized training adjustments and injury prevention strategies. Our findings underscore the dual benefit of TENGs in promoting environmental sustainability by reducing the overall reliance on traditional energy sources and growing the capabilities of intelligent sports systems. This research contributes to the burgeoning field of nano-energy sports applications while setting the stage for future explorations into the optimization of TENG integration in athletic performance enhancement. Finally, the paper concludes by discussing remaining challenges in this area and opportunities for further research.

A facile and versatile preparation method of sodium alginate-copper sulfide photothermal coating for efficient solar evaporation

Utilizing inexhaustible solar energy for water purification represents a green and sustainable solution to water scarcity. However, the developments of efficient, inexpensive, convenient and reliable photothermal materials remain a major challenge. Herein, a facile and versatile preparation strategy of sodium alginate (SA)-CuS composite coating with superior adhesion and stability has been proposed toward high-efficiency solar-driven interfacial evaporation. The fabrication process can be quickly completed in aqueous solution with cheap reagents. The SA-CuS coating can be firmly adhered on different substrates, which can withstand rinsing treatment, iterative freeze-thaw cycles as well as high and low pH environments. The SA-CuS coating can convert various substrates into photothermal materials with broad light absorption for desirable solar evaporation because of high CuS loading and rough surface. As a proof of concept, a wood evaporator covered with the SA-CuS coating can achieve a water evaporation rate of ∼2.2 kg m−2 h- 1 under one sun illumination, which is superior to most reported wood-based solar evaporators.

Remote Sensing Analysis of Smog-Inducing Aerosol Optical Depth: An Integrated Approach for Air Pollution Mitigation

Aerosol aggravation poses a significant challenge in the administrative Lahore Division of Punjab, Pakistan and contributes greatly to the persistent issue of smog. Since 2017, the division has experienced recurrent episodes of smog pollution, most notably in the months of October and November. In the present study, aerosol optical depth (AOD) has been analyzed alongside three metrological parameters: temperature, humidity and rainfall. These were tracked in October and November of 2018, 2020, and 2022 using remote sensing data and satellite imaging. Additionally, anthropogenic emissions data from automobile exhaust, industries and stubble burning were derived from secondary sources. Ultimately, the study helped piece together the complex environmental picture in Lahore Division in October and November. The results showed that AOD levels not only increased during this time, they were significantly influenced by a full range of metrological variables such as low temperature, high relative humidity, lack of rainfall and emissions from a variety of human activities. It was found that trucks, tractors and buses were among the worst contributors, alongside industry and stubble burning. Therefore, the present study suggests multi sectoral plans to mitigate aerosol levels and combat the smog menace, promoting environmental sustainability in the Lahore Division. A full set of recommendation is included, divided into three categories: industry, transport and agriculture. These are focused on technology, control systems, disposal, incentives, green solutions and more. At all levels, commitment, collaboration, and coordination are absolutely vital.

Green solutions for desalinated water drip irrigation systems: Organic acids outperform inorganic acids in fouling control

Desalinated saline water (DSW) has been widely applied in many fields due to global water scarcity. However, fouling formation in desalinated saline water distribution systems (DSWDS) raises serious technical concerns. The conventional approaches (e.g., inorganic acids) for DSWDS fouling control is not only ineffective sometimes but also lead to serious environmental and health risks. Accordingly, this study introduces a greener method utilizing organic acids for antifouling in DSWDS. The performances and influences of three types of inorganic acids (hydrochloric acid (HCl), phosphoric acid (H3PO4) and hydrofluoric acid (HF)) and three types of organic acids (citric acid (C6H8O7), formic acid (CH2O2) and oxalic acid (H2C2O4)) on DSWDS fouling control were investigated and compared. The obtained results indicated that in general, organic acids exhibited higher antifouling capacities than inorganic acids. Among the selected six acids, CH2O2 was the most effective, followed by H2C2O4, H3PO4, C6H8O7, HCl, and HF. In comparison with the most commonly used inorganic HCl, the fouling dry weights in the samples treated with C6H8O7, CH2O2, and H2C2O4 reduced by an average of 8.9 %, 45.3 %, and 33.2 %, respectively. Despite the higher acidity of inorganic acid solutions compared to organic acids, the latter exhibited a stronger chelating capacity for cations (e.g., Ca2+, Mg2+) in DSW, showing a lower tendency to form precipitation in their treated groups. Moreover, organic acids could increase the crystal cell volume and change the chemical bond length of chemical precipitation, resulting in lattice distortions. Furthermore, organic acids can slow down the flocculation and settling of suspended particulate matter, thereby alleviating the formation of particulate fouling. Overall, these findings suggest that the application of organic acids is a more effective and environmental-friendly approach for fouling control compared to inorganic acids, which provides qualitative and quantitative insights into developing greener antifouling protocol for DSW delivery in actual field practices.

A self-floating and windproof Janus biomass composite hydrogel with magnetic controllability and salt rejection for polluted seawater desalination

To alleviate the global freshwater crisis, a self-floating magnetic Janus biomass composite hydrogel has been fabricated through a rational asymmetric bilayer structure design, which exhibits many merits such as remarkable light-absorption, photothermal conversion, water-evaporation, salt rejection, wind-resistant, etc. Specifically, sodium alginate, cellulose nanofibrils (from corn straw), and acrylic acid were crosslinked by triple interpenetrating networks (chemical cross-linking, ionic cross-linking and hydrogen bonding). Janus hydrogel evaporator was constructed by incorporating the top layer containing light-absorbing core–shell magnetic nanoparticles (Fe3O4@PDA NPs), and the bottom layer composed of self-floating foam gel due to the addition of foaming agent. Under one solar irradiation, the average evaporation rate and photothermal conversion efficiency of Janus biomass composite hydrogel reached 2.89 ± 0.09 kg·m−2·h−1 and 95.66 ± 2.68 %, respectively. Its evaporation stability and salt tolerance capability have been demonstrated by extended period of simulated desalination. Furthermore, Janus biomass composite hydrogel also had excellent mechanical property (ultimate stress of 1.6 MPa) and magnetic performance, which can not only effectively resist the stress induced by wind and waves, but also enable the magnetic maneuvering and wind-resistance floating on the sea. When the input voltage of electromagnet was 24 V, the furtherest response displacement and maximum resisted wind speed were 9 cm and 7.2 m/s, respectively. Therefore, such magnetic self-floating Janus biomass composite hydrogel serving as interfacial solar-driven evaporator system offers a green, efficient and sustainable solution for clean freshwater production.