Gerrard E J Poinern

Subcritical thermochemical conversion (STC) offers a sustainable approach for livestock manure valorization by transforming organic waste into subcritical fecal fertilizer (SFF). While aligning with circular economy and net zero goals, the effects of SFFs on soil gaseous reactive nitrogen (Nr) remain largely unexplored. Herein, pig manure (PM), cattle manure (CM), and their derived SFFs (PSF and CSF produced at 180 °C and 260 °C) were applied to rice paddies to assess impacts on Nr emissions. The results showed that SFFs exhibited enhanced stability, such as oxygen-containing functional groups, lower pH and higher C/N ratio. PSF and CSF application reduced cumulative NH3 volatilization by 45.2–48.6 % and 38.7–55.0 %, respectively, relative to the control. Moreover, PSF significantly decreased cumulative N2O emissions by 30.1–33.3 % compared to PM. Mechanistically, SFFs lowered floodwater pH and modulated inorganic N dynamics, suppressing drivers of NH3 and N2O production. STC preparation temperatures and manure source synergistically influenced emission patterns across crop growth stages. Critically, SFF application lowered environmental damage costs by 38.5–54.6 % while elevating net ecological benefits by 4.6–77.6 %. This study demonstrates that STC-mediated SFF enables dual mitigation of Nr emissions through soil-water biochemical regulation, providing a scalable strategy to enhance nutrient cycling and reduce pollution in livestock-intensive agriculture.

The losses of reactive gaseous nitrogen (N), including ammonia (NH3) and nitrous oxide (N2O), represent a pressing environmental issue during composting. However, the impact of hydrothermal carbonization aqueous phase (HAP) on compost gaseous N emissions and the underlying mechanisms remain largely unexplored. Herein, Quercus acutissima leaves-derived HAP and its modified HAP (MHAP) were added to the chicken manure compost at 5 % (w/w) and 10 % (w/w) applied rates to observe changes in NH3 and N2O fluxes, compost properties and bacterial communities. Results showed that high application of HAP significantly decreased compost cumulative NH3 volatilization by 23–26 % compared to the control and MHAP. Compost NH3 and N2O emissions were significantly influenced by compost temperature and inorganic N concentrations. Moreover, HAP and MHAP at high rates reduced the relative abundance of Bacteroidota (5–29 %) and Proteobacteria (11–35 %), compared to those at low rates. Compost environmental factors and bacterial diversity were identified as dominant factors affecting gaseous N emissions, with 54 % and 25 % explanatory rates, respectively. Furthermore, high application rates of HAP are expected to reduce annual NH3 emissions from poultry manure compost by 40000 t. These findings provide insights into rational resource utilization of HAP and gaseous N emission reduction from composting.
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Significant concentrations of toxic dyes present in textile manufacturing effluents are discharged into natural water bodies ( lake and rivers) every day and results in the pollution of aquatic ecosystems. New and cost-effective sustainable water treatment strategies are urgently needed to tackle this global issue. The present study investigates the feasibility of using activated carbon produced from macadamia nutshells, a major agricultural waste product, to remove a commercially available textile RIT navy blue dye from aqueous solutions. This activated carbon was synthesized using a low-temperature hydrothermal ( LTH ) method that used H2SO4 as the activating agent. The textural and chemical properties of the engineered activated carbon were investigated by nitrogen adsorption-desorption measurements, XRD, SEM, TGA, Raman, and FT-IR spectroscopy. The activated carbon ( MAC ) had a micro-porous structure with a BET surface area of 478 m(2) g(-1 )for the MAC 10 sample. The linear pseudo-first order model described the kinetics of the adsorption process. The Langmuir model was found to be the most proper model for describing the adsorption isotherm data and revealed the activated carbon absorbent had a theoretical adsorption capacity of 57.8 mg g(-1). The study found the activated carbon has the potential to remove toxic dyes from wastewater, reduce agricultural waste, and this addresses the Sustainable Development Goals of the United Nations.

Developing alternative green and sustainable technologies to prevent, reduce, and remove toxic dyes present in effluent generated by the textile industry is of global importance. In this study, magnetite ( Fe3O4 ) nanoparticles ( MNPs ) were successfully synthesized using a co-precipitation method that used Indigenous Banksia Ashbyi ( BA ) leaf extract in varying amounts ( BA-MNP 1 to BA-MNP 4), to modulate particle size and size distribution. The formation of the MNPs was confirmed by a range of characterization techniques that included UV-visible spectrophotometry, Fourier transform infrared ( FTIR ) spectroscopy, x-ray diffraction ( XRD ) spectroscopy, thermo-gravimetric analysis ( TGA ) and scanning ( FIBSEM ) and high-resolution transmission ( HRTEM ) electron microscopy. The presence of the Fe-O bond located at 551 cm(-1 )in the FTIR spectra and XRD analysis of the samples confirmed the formation of crystalline MNPs. FIBSEM and HRTEM images of the BA-MNP 4 sample confirmed the MNPs were spherical ( 18 +/- 5 nm) and tended to agglomerate. Moreover, UV-visible spectrophotometry revealed a board absorption band and an optical band-gap energy of 2.65 eV. The catalytic activity of BA-MNP 4 samples towards the degradation of a commercially available navy-blue RIT dye ( BRD ) were investigated under three operational senarios: 1) ultrasonic irradiation ( US ) + BRD; 2) BA-MNP 4+ BRD, and 3) US + BRD + BA-MNP 4. The investigation found there was an additive effect when US ( 80 W) was used in conjunction with BA-MNP 4 s during the dye degradation process. With no US, the BA-MNP 4 sample only achieved a dye degradation of 52% in 25 min. However, over the same period of time with US, the BA-MNP 4 sample achieved a dye degradation of 89.92%. In addition, kinetic modelling found the combined US and BA-MNP 4 process followed a pseudo-first- order kinetic model.

Magnetite nanoparticles (MNPs) were synthesized by a straightforward one-step biogenic process using a leaf extract taken from the Australian indigenous plant Banksia ashbyi (BA). Several advanced characterization techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), and Raman spectroscopy were used to investigate the physical and chemical properties of synthesized MNPs. In addition, the size and morphology of the synthesized particles were examined using both focused ion beam scanning electron microscopy (FIBSEM) and transmission electron microscopy (TEM) methods. FT-IR analysis revealed the presence of a Fe-O band located at 551 cm- 1 , which confirmed the formation of BA-MNPs. Both FIBSEM and TEM image analysis confirmed the nanoparticles were spherical in shape and had a mean diameter of 18 nm with a particle distribution that ranged between 13 and 23 nm. The strong iron (Fe) and oxygen (O) peaks seen in the EDS analysis also confirmed the formation of the MNPs. TGA analysis revealed the leaf extract not only acted as the reducing agent but also served as a capping agent. The XRD analysis revealed that the synthesized MNPs exhibited a high degree of crystallinity and did not contain any impurities. Furthermore, X-ray peak profile analysis using Williamson-Hall methods found the average crystallite size was 9.13 nm, with the crystal lattice experiencing a compressive stress of 546.5 MPa and an average micro-strain of 2.54 x 10-3. In addition, other material properties such as density (5.260 kg/m3), average Young's modulus of elasticity (217 GPa), modulus of rigidity (90 GPa), and Poisson's ratio (0.235) were also estimated from the XRD data.

Agroforestry, as a phytoremediation measure, shows great potential for mitigating land degradation by constructing multidimensional and efficient agroforestry composite systems through regulating the microenvironment of agroforestry sites and improving soil properties. However, the effects of different agroforestry composite management modes on saline soils and the interactions between soil–plant systems under salt stress conditions in coastal areas remain largely unexplored. In this study, two salt-tolerant tree species (Sapium sebiferum (Linn.) Roxb and Zelkova serrata (Thunb.) Makino) and four crop species (Medicago sativa, Sesbania cannabina, Sorghum bicolour, and Avena sativa) were selected for intercropping in eight composite patterns via field experiments, with dynamics of soil physicochemical properties and crop photosynthesis observed. The results showed that treatments intercropped with M. sativa had the highest soil bulk density range (1.41–1.48 g cm−3). The dynamics of topsoil (0–10 cm) chemical properties showed similar change patterns among treatments, whereas those of the 10–40 cm soil chemical properties (especially soil pH, soil organic matter [SOM], and total nitrogen [TN]) showed heterogeneity. Moreover, planting S. sebiferum (L.) Roxb under the same crop conditions increased tree height growth rate and survival rate by 75%–114% and 14%–33%, respectively, relative to planting Z. serrata (T.) Makino. Furthermore, a significant negative correlation was observed between soil moisture with crop intercellular CO2 concentration (λ = −0.77), while significant positive correlations were found between crop net photosynthetic rate (Pn) with soil TN (λ = 0.71), as well as SOM with atmospheric CO2 content (λ = 0.72). Structural equation modeling showed significant direct effects between tree height growth rate with soil TN and SOM. Soil moisture (λ = 0.47) and tree height growth rate (λ = 0.53) were dominant drivers of crop Pn. Our findings provide useful information for the prevention of coastal saline soil degradation and sustainable development of agroforestry.

Globally, the presence of microplastic materials in the environment is widespread, and their largest concentrations can be found in coastal ecosystems and within mid-ocean gyres. Since the inception of mass plastic product manufacturing in the middle of the twentieth century, these durable, lightweight, and inexpensive materials have been, and continue to be, extensively exploited by humans. However, the presence of large numbers of microplastics in marine ecosystems in recent years has become a serious environmental issue that has attracted widespread interest in both the scientific and the broader community at large. In particular, the ingestion and subsequent detrimental health effects on many marine species are the most noticeable and alarming impacts of microplastics. Furthermore, recent studies have also shown microplastics can accumulate, concentrate, and act as vectors for conveying toxic pollutants within the food chain. Another feature of microplastics is their ability to transport marine species from one ecosystem to another where they become threats to local indigenous marine species. Because of the serious nature of microplastic pollution, it is important to understand their impact on coastal ecosystems and ocean gyres. This chapter discusses four aspects of microplastic pollution: 1) sources of both primary and secondary microplastics; 2) their physical and chemical behavioral properties; 3) bioavailability and behavioral properties of microplastics and their interactions with marine organisms; and 4) future perspectives, which highlights key areas of research needed to elucidate the effects of microplastic pollution in the marine environment. Importantly, understanding these four aspects of microplastic pollution will assist in directing future marine pollution research and assist policymakers to develop appropriate management strategies.

Currently, the main drivers for developing Li‐ion batteries for efficient energy applications include energy density, cost, calendar life, and safety. The high energy/capacity anodes and cathodes needed for these applications are hindered by challenges like: (1) aging and degradation; (2) improved safety; (3) material costs, and (4) recyclability. The present review begins by summarising the progress made from early Li‐metal anode‐based batteries to current commercial Li‐ion batteries. Then discusses the recent progress made in studying and developing various types of novel materials for both anode and cathode electrodes, as well the various types of electrolytes and separator materials developed specifically for Li‐ion battery operation. Battery management, handling, and safety are also discussed at length. Also, as a consequence of the exponential growth in the production of Li‐ion batteries over the last 10 years, the review identifies the challenge of dealing with the ever‐increasing quantities of spent batteries. The review further identifies the economic value of metals like Co and Ni contained within the batteries and the extremely large numbers of batteries produced to date and the extremely large volumes that are expected to be manufactured in the next 10 years. Thus, highlighting the need to develop effective recycling strategies to reduce the levels of mining for raw materials and prevention of harmful products from entering the environment through landfill disposal.

Hexagonal boron nitride (h-BN) has been widely utilized in various strategic applications. Fine-tuning properties of BN towards the desired application often involves ad-atom adsorption of modifying its geometries through creating surface defects. This work utilizes accurate DFT computations to investigate adsorption of selected 1st and 2nd row elements (H, Li, C, O, Al, Si, P, S) of the periodic table on various structural geometries of BN. The underlying aim is to assess the change in key electronic properties upon the adsorption process. In addition to the pristine BN, B and N vacancies were comprehensively considered and a large array of properties (i.e., atomic charges, adsorption energies, density of states) were computed and contrasted among the eight elements. For instance, we found that the band gap to vary between 0.33 eV (in case of Li) and 4.14 eV (in case of P). Likewise, we have illustrated that magnetic contribution to differ substantially depending on the adatom adsorbents. Results from this work has also lays a theoretical foundation for the use of decorated and defected BN as a chemical sensor for CO gases.

Calcium carbonate (CaCO3) micro/nanoparticles have attracted considerable medical research interest in therapeutic applications such as controlled pharmaceuticals for cancer treatment, tumor imaging, and gene therapy. The advantages of using CaCO3 micro/nanoparticles in these applications arise from their properties. Some of these advantageous properties include pH sensitivity, biocompatibility, safety, and biodegradability. Crucially, CaCO3 micro/nanoparticles are stable at normal physiological pH (~ 7.3) in the blood circulation system, while in more acidic pH tumor environments, they readily decompose. Thus, the slow degradation of their porous core allows these particles to be employed as carriers for contrast agents used in biomedical imaging procedures or utilized as sustained-release carriers for the targeted delivery of anticancer drugs and gene therapies. The chapter provides an overview of recent research into developing delivery carriers based on CaCO3 micro/nanoparticles for the transport of pharmaceutical agents to tumors. The study discusses cancer, the advantages of using a nanomedicine approach for treating cancer, and various methods for producing CaCO3 micro/nanoparticles. This is followed by a summary of the current research into using CaCO3-based particles for biomedical imaging, targeted drug delivery, and gene therapy. Notably, the chapter highlights the potential use of CaCO3 micro/nanoparticles as a safe and efficient drug delivery platform for cancer treatment.