Illustration showing how the sponge nanocomposite material recovers phosphate and metals from water. (Image source: Kelly Matuszewski, Northwestern University)

Researchers have created a functional sponge that is capable of efficiently soaking up certain pollutants from water and then releasing them on demand

Industrial manufacturing and agriculture, in particular, experience mineral and fertiliser loss due to runoff, leaving valuable non-renewable resources as pollutants in bodies of water. Those resources include heavy metals like zinc and copper and also phosphate. 

The innovation presents a reusable and low-cost solution for cleaning storm runoff while simultaneously recovering valuable metals like zinc and copper, as well as phosphate. Using surface iron oxide nanoparticles specialised for capturing specific contaminants, the sponge collects the minerals and then discharges them only when triggered by changes in pH. These findings were achieved by researchers at Northwestern University and published in the American Chemical Society's journal Environmental Science and Technology Water.

Doctoral student and first author on the paper, Kelly Matuszewski believes it is important to understand the interaction between these minerals and utilise them, rather than finding ways to discard them. Through her research she discovered that lowering water pH flushed out the captured copper and zinc from the sponge, while raising water pH loosened the phosphates.

In an attempt to commercialise the sponge-based technology, Vinayak Dravid, co-author and Northwestern professor of materials science and engineering has co-founded a startup with additional NSF support through the Small Business Innovation Research programme, which will further develop the material for real-life scenarios.

"The technology can be used as a universal sorbent or 'catch-all,' or it can be tailored to certain groups of contaminants like metals, plastics or nutrients," said Dravid. In their future research, the team plans to account for biofilms, clogging or water flow dynamics on the sponge's performance, while also testing the maximum mineral levels the sponge can absorb.

PH-sensitive chromic COF-based sensor powders developed by SMART DiSTAP researchers that exhibit visual colour changes upon early detection of drought stress in plants. (Image source: SMART)

Researchers from the Singapore-MIT Alliance for Research and Technology (SMART) have pioneered the world’s first Covalent Organic Framework (COF) sensors that provide an early indication of drought stress in plants

These sensors are integrated within silk fibroin (SF) microneedles that are capable of detecting pH changes in plant xylem tissues. This advanced technology can detect a reduction in acidity in plant xylem tissues, providing early warning of drought stress in plants up to 48 hours before traditional methods.

A number of agricultural challenges – including those posed by climate change, rising costs and lack of land space – continue to escalate and adversely affect crop production and yield, due to which farmers are often unable to implement proactive measures or pre-symptomatic diagnosis for early and timely intervention. This underscores the need for improved sensor integration that can facilitate in-vivo assessments and timely interventions in agricultural practices.

SMART’s breakthrough addresses a long-standing challenge for COF-based sensors, which were - until now - unable to interact with biological tissues. COFs are networks of organic molecules or polymers - which contain carbon atoms bonded to elements like hydrogen, oxygen, or nitrogen - arranged into consistent, crystal-like structures, which change colour according to different pH levels.

This novel COF-based sensor allows early detection of drought stress in plants through real-time measuring of pH levels in plant xylem tissues, thereby helping farmers optimise crop production and yield amid evolving climate patterns and environmental conditions.

DiSTAP researchers designed and synthesised four COF compounds that showcase tunable acid chromism – colour changes associated with changing pH levels – with SF microneedles coated with a layer of COF film made of these compounds. In turn, the transparency of SF microneedles and COF film allows in-vivo observation and visualisation of pH spatial distributions through changes in the pH-sensitive colours.

In a paper titled, 'Chromatic Covalent Organic Frameworks Enabling In-Vivo Chemical Tomography' recently published in Nature Communications, DiSTAP researchers documented their groundbreaking work, which demonstrated the real-time detection of pH changes in plant tissues. Significantly, this method allows in-vivo 3D mapping of pH levels in plant tissues using only a smartphone camera, offering a minimally invasive approach to exploring previously inaccessible environments compared to slower and more destructive traditional optical methods. 

“SF microneedles are robust and can be designed to remain stable even when interfacing with biological tissues. They are also transparent, which allows multidimensional mapping in a minimally invasive manner," said senior postdoctoral associate at SMART DiSTAP and co-first author, Dr Yangyang Han. "Paired with the COF films, farmers now have a precision tool to monitor plant health in real time and better address challenges like drought and improve crop resilience.” 

Results show almonds treated with Acadian biostimulants with improved Stem Water Potential in both stressed and non-stressed situations. (Image source: Acadian Plant Health)

Acadian Plan Health through its multi-year California almond water study, today, released expanded results demonstrating how biostimulant technologies can help growers reduce water use while maintaining yield

As chronic water shortages loom over the world, water reduction programmes are working to lower the local almond industry's water use by 20% from 2020-2025. Starting in 2026, California is looking to significantly reduce its water use, thus making biostimulant technologies all the more relevant for almond growers.

Starting from 2021, chosen almond trees were subjected to Acadian Organic treatments, following which weekly assessments of midday stem water potential were performed. Results from these assessments showed a consistent improvement in stem water potential and kernal weight in regular and deficit irrigation situations. 

According to director of Research and Development at Acadian Plant Health, Holly Little, the results were found to be promising. She highlighted that besides lowering stem water potential, these biostimulants can also lower the frequency or volume of irrigation required for the growth of healthy almond trees, while at the same time protecting yields. 

"As environmental and regulatory water restrictions challenge global agriculture, adopting multidisciplinary and holistic water management will be key to sustaining future orchard systems," said UC Davis Cooperative Extension Orchard Systems specialist Dr Guilia Marino. "These preliminary results suggest Acadian Plant Health's biostimulant technology has a positive effect on almond tree water status under experimental conditions and may reduce tree stress. Additional research will help determine the product's impact on orchard productivity, as well as tree physiology and productivity."

The partnership was officially launched at a dialogue hosted by the SIF, the World Economic Forum and the Global Commission on the Economics of Water (GCEW). (Image source: SIF)

The Singapore International Foundation (SIF), in collaboration with the World Economic Forum on 21 June, launched the first ever multi-stakeholder platform to address the critical challenges of climate change

The Southeast Asia Partnership for Adaptation through Water (SEAPAW), which primarily focuses on strengthening water resilience as an approach to climate change adaptation, is the first such platform in the region. The partnership focuses on galvanising action among stakeholders in support of a shared vision, fostering cross-border projects, and accelerating adaptation financing through public-private-philanthropic models. 

Besides growing the community and identifying projects in key areas of interest, SEAPAW will also report on the region’s progress in water-related resilience goals and climate adaptation, which will help identify areas of need for further action.

The partnership was officially launched at a dialogue hosted by the SIF, the World Economic Forum and the Global Commission on the Economics of Water (GCEW) and was held alongside the Singapore Water Week 2024. The President of the Republic of Singapore, Tharman Shanmugaratnam, was the Guest of Honour at the event. He highlighted the region’s growing vulnerability to water scarcity and the impacts of climate change, while also emphasising on the need to manage demand for more efficient and sustainable water use in every sector in Southeast Asia. 

Moreover, professor Khoo Teng Chye, who is currently the director of NUS Cities and a practice professor with the College of Design and Engineering at the National University of Singapore was announced as the chairperson of SEAPAW during the launch. 

“The water crisis is deeply intertwined with climate change; and countries need to work together to resolve it. SEAPAW serves as a crucial foundation to mobilise stakeholders and leverage innovative policies to scale up water investments, access, resilience, and sustainability," Teng Chye said. "As Chairperson of this pioneer platform in the region, I am committed to steer the discourse, and foster collaborations for a fair, inclusive, and climate resilient future.”