Periodic Reporting for period 1 - GreenP (Greenly synthesized nanomaterials for phosphorus recovering and recycling in agricultural catchment)
Reporting period: 2023-01-01 to 2024-12-31
The excessive and conventional use of phosphorus (P) in modern agriculture is disrupting its natural cycle, moving P from mineral reserves to farms and subsequently into water bodies [1,2]. This unsustainable use not only risks depleting non-renewable reserves which are predicted to be exhausted in the near future, but also accelerates the eutrophication of aquatic ecosystems [3]. Annually, around 30% of the 21 million tons of phosphate rock mined globally end up in water systems due to human activities [4,5]. Furthermore, there are no viable alternatives to P, and the primary supply from phosphate rock is limited to a few countries, creating an uneven distribution that could jeopardize global food security and political stability. Consequently, recovering and recycling P has become a global imperative to minimize its environmental impact [6]. Within this framework, the recovery of P from agricultural drainage and its reuse as an effective fertilizer presents an attractive solution, as it could help mitigate P scarcity, reduce dependence on rock phosphate, and close its loop in agriculture. However, there is a significant gap in the availability of cost-effective and environmentally friendly technologies that do not impose excessive economic burdens on farmers or introduce external pollutants, thereby safeguarding soil health in agricultural lands. Green synthesis offers an opportunity for creating cost-effective and environmentally friendly nanoparticles that can rapidly and safely recover P from agricultural drainage. Therefore, the overall objective of GreenP was to determine whether green-synthesized nanoparticles can perform as well as or better than chemically produced nanoparticles in recovering low levels of P from agricultural drainage. Additionally, the project aimed to explore the potential of recycling these nanoparticles with adsorbed P as an innovative composite nanofertilizer, promoting sustainable phosphorus management and supporting a circular economy in agriculture.
References
[1] Ockenden et al. (2017). Nature Communications 8 (1), 161-172.
[2] Tonini et al. (2019). Nature Sustainability 2 (11), 1051-1061.
[3] Brownlie et al. (2022). UK Centre for Ecology & Hydrology, Edinburgh.
[4] Cordell and White, (2014). Global Environmental Change 24, 108-122.
[5] Yang et al. (2021). Science of the Total Environment 768, 145106.
[6] Cordell and Neset, (2014). Annual review of environment and resources 39 (1), 161-188
References
[1] Ockenden et al. (2017). Nature Communications 8 (1), 161-172.
[2] Tonini et al. (2019). Nature Sustainability 2 (11), 1051-1061.
[3] Brownlie et al. (2022). UK Centre for Ecology & Hydrology, Edinburgh.
[4] Cordell and White, (2014). Global Environmental Change 24, 108-122.
[5] Yang et al. (2021). Science of the Total Environment 768, 145106.
[6] Cordell and Neset, (2014). Annual review of environment and resources 39 (1), 161-188
The extracts from two types of grasses, Festuca and Festulolium, were utilized for the green synthesis of nanoparticles. The synthesized ZnO nanoparticles were characterized using techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). Batch studies were conducted to evaluate the phosphorus (P) adsorption potential of the greenly synthesized nanoparticles. The adsorption efficiency was tested under various conditions, including solution pH, contact time, initial P concentration, adsorbent dosage, and temperature. To understand the interactions between the adsorbate and the adsorbent, and to characterize the nature of these interactions, Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isothermal models were applied. Additionally, the rate-controlling mechanisms for adsorption onto the nanoparticles were assessed using pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion kinetic models. Thermodynamic modeling was likewise performed to evaluate the spontaneity and feasibility of the adsorption processes. Finally, the nutrient release potential of the nanoparticles and their interactions with the soil microbial community were examined.
The studies achieved the following outcomes; i) Greenly synthesized nanoparticles are well-suited for long-term phosphorus removal from agricultural drainage due to their high adsorption capacity, ii) The nanoparticles offered a cost-effective and sustainable solution for phosphorus management, with superior reusability potential compared to other materials, iii) The adsorption process is governed by a dual mechanism, with physisorption dominating the initial rapid phase and chemisorption taking over in later stages, iv) Nanoparticles with adsorbed phosphorus (P) can be recycled as fertilizers for crop production, offering a sustainable solution to close the P loop and promote agricultural sustainability.
The studies achieved the following outcomes; i) Greenly synthesized nanoparticles are well-suited for long-term phosphorus removal from agricultural drainage due to their high adsorption capacity, ii) The nanoparticles offered a cost-effective and sustainable solution for phosphorus management, with superior reusability potential compared to other materials, iii) The adsorption process is governed by a dual mechanism, with physisorption dominating the initial rapid phase and chemisorption taking over in later stages, iv) Nanoparticles with adsorbed phosphorus (P) can be recycled as fertilizers for crop production, offering a sustainable solution to close the P loop and promote agricultural sustainability.
The findings reveal that nanoparticles represent an innovative, cost-effective, and sustainable approach to addressing long-term phosphorus removal and management challenges in agricultural drainage systems. Beyond their primary function as adsorbents, these nanoparticles with adsorbed phosphorus, hold immense potential as nanofertilizers, capable of enhancing crop productivity. This dual functionality not only mitigates the environmental impact of phosphorus runoff/leaching but also promotes a circular economy by transforming waste into valuable agricultural inputs. By integrating advanced nanotechnology into nutrient recovery, this approach sets a new benchmark for agricultural sustainability, offering scalable solutions to global challenges in water quality management and food security. To further maximize their potential, some key steps are necessary: i) Future research should focus on utilizing advanced regeneration methods to enhance the reusability of green-synthesized nanoparticles, ii) Large-scale demonstration projects and developing modular configurations for unified integration of these nanoparticles into existing drainage systems are necessary to enhance their practical applicability, iii) Conducting detailed cost-benefit analyses and life cycle assessments can further facilitate collaborations with agricultural cooperatives, environmental agencies, and industry stakeholders to secure funding and drive widespread adoption, iv) Securing intellectual property rights (IPR) for both the synthesis methods and the application of the nanoparticles will pave the way for successful commercialization, v) Building international research and development partnerships will help drive the adoption of this technology in diverse agricultural systems, fostering global outreach and scalability, vi) Establishing uniform protocols for the synthesis, application, and monitoring of the nanoparticles will ensure regulatory compliance and enhance market acceptance.