The research was driven by a persistent and growing global problem. Across much of the developing world, rapid population growth, urbanization, industrial expansion, and intensified agriculture have multiplied the discharge of untreated wastewater into rivers and streams. Suspended solids, organic matter, pathogenic microorganisms, and toxic metals accumulate in these waters, degrading ecosystems and raising the risk of waterborne disease. Conventional treatment plants rely heavily on chemical coagulants—typically aluminium and iron salts—which excel at clumping suspended particles together so they can settle out. But these chemicals carry well-documented downsides: they generate chemically complex sludge that does not biodegrade, they can disturb the delicate pH balance of treated water, they add cost, and they leave behind residual metal species that have been linked in some studies to neurological harm.

Scientists have long sought greener alternatives, and plant-derived coagulants have emerged as front-runners. Seed extracts of Moringa oleifera, for example, have achieved turbidity removal of 80 to 99 percent in prior research, while papaya seed extracts and watermelon seed preparations have delivered removal efficiencies of 70 to 90 percent for suspended solids. The active ingredients in these plants—proteins, polysaccharides, and polyphenols—work through charge neutralization, adsorption, and inter-particle bridging, destabilizing colloidal particles so that they aggregate into settleable flocs. What has been largely overlooked, however, are plant leaves, despite being chemically rich in tannins, flavonoids, alkaloids, and saponins, compounds known for their metal-chelating and adsorptive properties. Soursop and avocado leaves, both abundant and widely available across the tropics, seemed ideal but untested candidates.

To test that hypothesis, a team led by S. M. Ajiboye of Bamidele Olumilua University of Education, Science and Technology, in Ekiti State, Nigeria, collected fresh leaves from trees in Ado-Ekiti, washed them repeatedly in distilled water, sun-dried them for five to seven days until crisp, and ground them into a fine powder. The powder was sieved into precise fractions between 0.144 and 0.145 microns using a rotary sieve shaker and stored in airtight containers. The test water itself came from the Ureje River, a surface freshwater body that receives runoff from surrounding residential, commercial, and agricultural activities. Samples were collected during the rainy season, when surface runoff drives suspended particle levels and turbidity to their highest, providing a realistic and demanding medium for evaluating coagulation performance.

The experimental design was straightforward but rigorous. Dried leaf powders were applied to raw water samples at dosages ranging from 0.1 to 0.4 grams, after which the researchers measured a full panel of physicochemical parameters using standard analytical methods. Turbidity was quantified with a HACH 2100P nephelometer, pH with a calibrated digital meter, total hardness by EDTA titration with Eriochrome Black T indicator, total suspended solids by filtration and gravimetric drying, and electrical conductivity, salinity, temperature, and total dissolved solids with calibrated meters and probes. Heavy metals—chromium, copper, and iron—were digested in concentrated nitric acid and analyzed with a HACH DR 1900 spectrophotometer following APHA Method 3111 B. All results were reported as means with standard deviations, and differences among treatment groups were tested statistically using analysis of variance with Duncan’s multiple range post hoc test at the 0.05 significance level.

The results revealed a clear dose-dependent pattern with an important twist: less proved to be more. The best contaminant removal occurred at the lowest dosages of 0.1 to 0.2 grams, where charge neutralization and floc formation were most efficient. Turbidity fell by approximately 56 percent in soursop-treated water and 51 percent with avocado leaf powder, with values dropping from an initial range of 2.59 to 5.90 NTU. Color removal followed a similar trajectory, reaching about 56 percent for soursop and 47 percent for avocado, as humic substances and other chromophoric compounds adsorbed onto the surfaces of the bio-coagulant flocs. At higher dosages, however, performance degraded: turbidity and color crept back up, a phenomenon the researchers attribute to overdosing effects that restabilize colloids, and to the leaching of fine organic particles and natural pigments from the plant material itself—a cautionary signal that dosage optimization is essential to avoid secondary contamination.

Perhaps the most striking results involved heavy metals, where the leaf extracts outperformed expectations. Chromium concentrations dropped by up to 87.5 percent, copper by 97.6 percent, and iron was removed almost entirely—approaching 100 percent—under optimal conditions. The researchers attribute this exceptional metal capture to adsorption, complexation, and co-precipitation mechanisms, in which dissolved metal ions bind to functional groups such as hydroxyl, carboxyl, and phenolic moieties abundant in the leaves’ bioactive constituents. Notably, these removal efficiencies are comparable to those reported for Moringa oleifera, the most celebrated of plant-based coagulants, which achieves up to 90 percent removal for certain metals. The finding positions soursop and avocado leaves as serious contenders in the biocoagulant arena, particularly for treating metal-contaminated surface water in settings that cannot afford advanced treatment infrastructure.

Equally significant was what the natural coagulants did not do: they did not destabilize the water’s chemistry. Treated water maintained pH values between 6.5 and 8.5 throughout the experiments, squarely within the WHO’s recommended range. This contrasts sharply with conventional chemical coagulants, which often require pH adjustment before or after dosing and can leave treated water too acidic or too alkaline. The researchers suggest the pH stability stems from the buffering capacity of hydroxyl and carboxyl functional groups in the extracts. Meanwhile, total dissolved solids and electrical conductivity showed moderate reductions at optimal dosages, total hardness declined through partial removal of calcium and magnesium ions, and total suspended and total solids fell measurably, improving both water clarity and aesthetic quality. Slight increases in dissolved solids at high dosages likely reflect the dissolution of soluble organic compounds from the leaf powders themselves.

The broader implications are considerable. Both plant species grow abundantly across tropical regions, their leaves require only washing, sun-drying, and grinding to become active treatment agents, and the resulting coagulants are fully biodegradable and low in toxicity. For communities and small industries that depend on rivers degraded by urban runoff, agricultural activity, and wastewater discharge, the study points toward a treatment approach that is simultaneously cheap, sustainable, and locally sourced. The authors are careful to frame their work as a foundation rather than a finish line. They recommend further research into optimizing extraction methods, evaluating microbial removal efficiency, and assessing the long-term stability and scalability of the leaf coagulants in real-world treatment systems, along with direct comparative trials against conventional chemical coagulants. But the core message is clear: two trees that millions of people pass every day may hold an accessible, green answer to one of the world’s most pressing public health challenges, transforming fallen leaves into a first line of defense for cleaner water.

Beyond the headline removal efficiencies, the study offers practical lessons for how plant-based coagulants behave under real-world conditions. The observation that lower doses outperformed higher ones mirrors a well-known feature of coagulation chemistry: particle destabilization depends on achieving the right balance of surface charge, and excess coagulant can actually coat particles and restore their repulsive forces. For operators considering leaf-derived treatments, this suggests that small, carefully calibrated additions—not generous handfuls—are the key to both performance and avoiding the secondary contamination that can arise when organic material from the plant powder dissolves into the water.

The choice of test water also strengthens the findings. Because the Ureje River samples were collected during the rainy season, when runoff carries peak loads of suspended sediment, the coagulants were evaluated against genuinely challenging conditions rather than artificially prepared turbid water. This matters for communities in tropical regions, where seasonal rains routinely push surface water beyond the capacity of simple sedimentation or cloth filtration, and where a locally harvestable treatment aid could bridge the gap until conventional infrastructure arrives.

Another advantage worth emphasizing is the nature of the waste stream. Conventional alum and iron salt treatment produces sludge laden with hydroxide precipitates that resists degradation and complicates disposal. Flocs formed from leaf extracts, by contrast, are predominantly organic and should decompose far more readily, reducing the environmental burden of sludge handling—a significant ongoing cost for small treatment facilities.

The researchers also note that the leaves’ rich content of tannins, flavonoids, alkaloids, and saponins likely underpins both the coagulation and the metal-binding behavior, since these compound classes carry functional groups capable of chelating dissolved ions. Future work, the authors suggest, should isolate which biomolecules drive performance, verify microbial removal, and confirm that treated water is safe for long-term consumption—steps needed before leaf powders can move from promising laboratory results to routine household or industrial practice.

Subject of Research: Plant-based natural coagulants derived from soursop and avocado leaves for sustainable water treatment

Article Title: Performance of Annona muricata (Soursop) and Persea americana (Avocado pear) Leaves as Natural coagulants in water treatment

Article References: Ajiboye, S. M., Aduloju, M. O., & Pii, B. T. (2026). Performance of Annona muricata (Soursop) and Persea americana (Avocado pear) Leaves as Natural coagulants in water treatment. Discover Green Chemistry, 1(1), Article 24. https://doi.org/10.1007/s44509-026-00026-y

Image Credits: AI Generated

DOI: 10.1007/s44509-026-00026-y

Keywords: natural coagulants, water treatment, Annona muricata, Persea americana, turbidity removal, heavy metals, green chemistry, sustainable technology, surface water, biocoagulation, Performance, Annona

The study highlights an innovative approach to separating the critical nickel, cobalt, and manganese (NCM) materials utilized in the cathodes of lithium-ion batteries. These elements are essential for the production of high-performance batteries required for electric vehicles and renewable energy storage systems. As demand for such technologies surges, the importance of resource recovery becomes increasingly clear. This research aims not only to mitigate environmental risks associated with battery waste but also to alleviate the pressure on raw material supplies critical to battery production.

A core element of the study is the development of a novel separation process that employs advanced hydrometallurgical techniques. These methods capitalize on the unique chemical properties of NCM materials, allowing for their efficient extraction from the battery residues. The research team meticulously assessed various chemical agents and operational conditions to optimize the separation efficiency. Their findings suggest that the selected process can achieve high recovery rates of nickel, cobalt, and manganese, highlighting its potential effectiveness in commercial applications.

Moreover, this research underscores the challenges faced in the recycling industry regarding purity and recovery rates. Traditional methods often fall short, resulting in a significant loss of materials and creating economic disincentives for recycling efforts. By enhancing the separation process, Zheng and colleagues hope to pave the way for increased profitability in the recycling sector, incentivizing companies to invest in greener practices.

The escalating demand for electric vehicles and energy storage solutions underscores the necessity of establishing robust recycling protocols. With millions of lithium-ion batteries reaching their end of life each year, the environmental impact of improper disposal is profound. The researchers emphasize that developing efficient recovery methods for battery materials is paramount in reducing landfill waste and conserving natural resources, thus promoting environmental sustainability.

In addition, the study is positioned within the larger context of global initiatives aiming to reduce carbon emissions and promote the use of renewable energy. By recovering valuable materials from discarded batteries, the researchers are contributing to a more sustainable energy ecosystem. The transition to electric mobility and renewable energy storage solutions cannot be fulfilled without addressing the lifecycle of battery materials, making this research timely and relevant.

The implications of this research extend beyond environmental benefits; they also hold significant economic potential. The recovery of nickel, cobalt, and manganese from discarded batteries could lead to reduced dependency on imported raw materials, enhancing national energy security. Recycling operations could stimulate job creation in the green technology sector, further contributing to economic growth while addressing environmental concerns.

Importantly, this work lays the groundwork for future investigations into battery recycling methods, inspiring further academic exploration in the field. With ongoing advancements in material science and engineering, researchers are encouraged to seek innovative solutions to the challenges posed by battery waste. This study serves as a clarion call for collaboration across industries, urging stakeholders to engage in responsible resource management practices.

The publication of these findings is poised to generate interest within both academic circles and the wider community, particularly among policymakers and industry leaders. The compelling evidence supporting the economic and environmental benefits of efficient battery material recovery can serve as a catalyst for legislative action and investment in recycling infrastructure. As awareness of environmental issues rises, public pressure may further drive the adoption of sustainable practices across industries.

In conclusion, the research conducted by Zheng, Chen, Wang, and their team offers a promising glimpse into the future of battery recycling. Their innovative approach to separating valuable materials from discarded lithium-ion batteries not only contributes to environmental sustainability but also holds the potential for significant economic benefits. The importance of this work cannot be overstated as we navigate the challenges of a rapidly changing world where technological advancements must harmonize with ecological preservation. As further studies emerge in this domain, the journey towards a more sustainable and circular battery economy continues to evolve.

In summary, this research signifies a crucial step towards enhancing the efficiency of material recovery from lithium-ion batteries—a step that is not only essential for advancing sustainable technology but also for ensuring the longevity and viability of the electric vehicle and renewable energy sectors.

Subject of Research: Efficient separation of nickel cobalt manganese ternary cathode materials from discarded pouch lithium-ion batteries.

Article Title: Process study for the efficient separation of nickel cobalt manganese ternary cathode materials from discarded pouch lithium-ion batteries.

Article References:

Zheng, B., Chen, M., Wang, W. et al. Process study for the efficient separation of nickel cobalt manganese ternary cathode materials from discarded pouch lithium-ion batteries.
Ionics (2025). https://doi.org/10.1007/s11581-025-06801-4

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s11581-025-06801-4

Keywords: Lithium-ion batteries, recycling, nickel, cobalt, manganese, sustainable technology, materials recovery, circular economy.

The hydrothermal conversion process utilized by the researchers operates at a temperature of 230 °C, employing a water-based environment that negates the need for either extensive drying or the use of harsh chemicals. This efficiency underscores the potential for reusing materials that would otherwise be discarded. The end products of this conversion include biofuels, bio-adsorbents, fluorescent carbon nanodots, and nutrient-rich water, all of which have varieties of applications in energy production and environmental remediation.

At the heart of this study lies the impressive yield of carbon dots—tiny, fluorescent particles measuring between 1.5 to 26 nanometers. These carbon dots possess the remarkable ability to emit bright blue light and showcase photocatalytic properties, making them ideal candidates for environmental clean-up initiatives. Notably, the conversion process resulted in the degradation of over 42 percent of the dye methylene blue from wastewater, revealing a promising capability for efficient pollutant removal.

Furthermore, the hydrochar produced from the oilseed rape straw exhibited exceptional adsorption properties. It effectively removed nearly 69 percent of methylene blue, with an adsorption capacity reaching up to 275 milligrams per gram. This material not only serves as a bio-adsorbent but also contributes to the production of solid fuels, which demonstrated an impressive energy content of 27.8 megajoules per kilogram. Such energy outputs are comparable to conventional biofuels, positioning this method as a viable alternative in the endeavor to transition towards sustainable energy sources.

The integration of these two biomaterials—microalgae and agricultural residues—sets the stage for a multi-faceted approach to sustainable energy production. The aqueous byproduct resulting from the conversion of microalgae has been found to hold incredible potential as a nutrient source for cultivating new algal biomass. This innovation effectively closes the recycling loop, allowing for a continuous cycle of biomass re-utilization and nutrient replenishment within ecosystems.

Professor Ao Xia, the corresponding author of the study, emphasized the significance of their findings, stating, “Our approach makes full use of both microalgae and crop residues to produce clean energy and valuable materials simultaneously. It offers an integrated pathway for sustainable waste utilization and carbon recycling.” This philosophy of utilizing waste materials aligns seamlessly with the broader goals of increasing efficiency in resource use and minimizing environmental impacts.

The methods presented in this research provide a comprehensive blueprint for future studies aiming to produce biofuels, nanomaterials, and biological nutrients from renewable biomass. By focusing on common agricultural residues and microalgae, scientists can explore more extensive applications and improvements in efficiency, leading to further advancements in the field of sustainable energy technologies.

In the context of increasing global concerns regarding climate change and environmental degradation, the potential applications of these findings are manifold. The ability to create valuable materials from waste reduces the carbon footprint of energy production while simultaneously addressing the challenge of waste management. Furthermore, as the world transitions towards a circular economy, approaches like these pave the way for integrating waste into the fabric of renewable resource systems.

The exploration of carbon dots also opens a new frontier in materials science, with implications for various industries, including electronics, medicine, and environmental science. Their properties enable researchers to develop innovative solutions for pollution control, making them essential tools in the fight against environmental contaminants.

In conclusion, the breakthrough research from Chongqing University signifies a major step forward in the quest for sustainable practices within energy production. The co-conversion of microalgae and agricultural byproducts marks a notable advancement in ecological innovation, underscoring the importance of utilizing renewable resources to address contemporary environmental challenges. Future studies will undoubtedly build upon this foundation, exploring new methods and technologies to further harness the potential of biomass in promoting a greener and more sustainable world.

The research published in the academic journal, Biochar, is a testament to the critical role of interdisciplinary collaboration in addressing global challenges. This exploration not only sheds light on innovative technological applications but also emphasizes the pressing need for ongoing research in bioengineering and environmental science, focusing on sustainable solutions capable of supporting a healthier planet.

Subject of Research: Not applicable
Article Title: Production of carbon dots, biofuels, bio-adsorbents, and biological nutrients via hydrothermal conversion of Chlorella pyrenoidosa and oilseed rape straw
News Publication Date: 11-Sep-2025
Web References: Biochar Journal
References: Zhang, J., Zhang, B., Xia, A. et al. Production of carbon dots, biofuels, bio-adsorbents, and biological nutrients via hydrothermal conversion of Chlorella pyrenoidosa and oilseed rape straw. Biochar 7, 109 (2025).
Image Credits: Jingmiao Zhang, Bin Zhang, Ao Xia, Qingming Zhou, Xianqing Zhu, Yun Huang, Xun Zhu & Qiang Liao

Keywords

Bioeconomy, Carbon dots, Hydrothermal conversion, Renewable energy, Environmental remediation.

The emergence of smart sensor technology has fundamentally changed how agricultural producers monitor and control environmental variables critical for crop health, particularly temperature and humidity. In the face of unpredictable weather patterns and climate change, the urgency to innovate has never been greater. The introduction of paper-based temperature and humidity sensors, created through a technique called dry additive nanomanufacturing, underscores a remarkable fusion of technology with ecological responsibility.

Traditional sensors often rely on plastic-based materials, which contribute to the growing problem of electronic waste. Researchers have sought to find a sustainable alternative, one that can deliver high accuracy and functionality without compromising environmental integrity. Consequently, the exploration of cellulose fibers as a medium for sensor construction has surfaced as a promising solution, addressing waste and pollution issues while maintaining performance standards.

The process of dry additive nanomanufacturing allows for precise control over the production of these sensors. By employing this technique, researchers print silver lines onto various biodegradable paper substrates. This novel approach not only enhances flexibility in manufacturing but also ensures that the sensors retain their effectiveness in monitoring crucial parameters in agricultural environments.

As these sensors engage with moisture in the air, they exhibit changes in capacitance, which corresponds directly to shifts in humidity levels. This relationship is critical, as maintaining optimal humidity is essential for crop growth and post-harvest storage. The reliability of these printed sensors in detecting minute fluctuations in environmental conditions offers farmers an unprecedented level of insight and control over their cultivation practices.

Moreover, the temperature-sensing mechanism integrated into these sensors functions through alterations in resistance. The interplay between increasing temperature and its effects on resistivity allows for continuous monitoring, which is critical to preemptively address conditions that could adversely impact crop yields. This dual capability of the sensors ensures comprehensive environmental monitoring, empowering farmers with real-time data to make informed decisions.

The sensors developed by the research team have demonstrated impressive sensitivity across a range of humidity levels, accurately detecting changes from a relative humidity of 20% to 90%. Additionally, their temperature monitoring capability spans from 25°C to 50°C, rendering them suitable for a variety of agricultural climates. The tunability of these sensors means that they can adapt to different growing conditions and agricultural needs, further enhancing their utility.

One of the greatest advantages of these biodegradable sensors is not only their effectiveness but also their cost-efficiency. Traditional electronic sensors can carry hefty price tags, often making them less accessible for smaller farms or local producers. In contrast, the affordability of these paper-based sensors opens the door for broader adoption, thereby supporting sustainable practices across diverse agricultural settings.

Once their lifecycle is complete, these sensors offer a safe disposal solution as they are biodegradable. The ability to recycle agricultural technology aligned with environmental stewardship represents a significant advancement in sustainability within the agricultural sector. This innovation addresses not only the immediate needs of farmers but also the long-term ramifications of agricultural waste.

Mahjouri-Samani’s research marks a turning point in the application of smart technology for precision agriculture. By integrating advanced printing techniques with biodegradable materials, the research showcases a forward-thinking approach that acknowledges the urgent need for environmentally responsible agricultural technology. This synthesis of innovation and ecological mindfulness offers the potential to shape the future of food production, directly influencing practices in smart farming.

Furthermore, the research emphasizes a collective responsibility to advance agricultural technology that minimizes negative ecological footprints while maximizing productivity. As the agricultural sector faces unprecedented challenges due to climate change and market demands, it is innovations like these that will pave the path toward resilience and sustainability.

With the publication of the article titled "Laser-assisted dry printing eco-friendly paper-based humidity and temperature sensors" in the esteemed Journal of Laser Applications, the research team not only contributes to the scientific community but also inspires agricultural practitioners to rethink their technology choices. This pivotal advance harnesses the power of cutting-edge research aimed at intensifying agricultural efficiency while fostering an environment of sustainability.

As the need for innovative agricultural technologies grows, the integration of eco-friendly materials and advanced manufacturing processes will be critical in shaping future practices. The work being done at Auburn University exemplifies how the merger of science and industry can yield groundbreaking results that cater to the pressing demands of modern agriculture while upholding our commitment to the planet.

Subject of Research: Eco-friendly paper-based temperature and humidity sensors
Article Title: Laser-assisted dry printing eco-friendly paper-based humidity and temperature sensors
News Publication Date: 21-Jan-2025
Web References: DOI: 10.2351/7.0001652
References: Journal of Laser Applications
Image Credits: Masoud Mahjouri-Samani

Keywords: Sensors, Printing, Environmental Monitoring, Food Production