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We assessed the effect of redox conditions on the mobility of lead (Pb), copper (Cu), and iron (Fe) from sediments affected by acid mine drainage (AMD). This was accomplished by integrating laboratory microcosm experiments, aqueous chemistry, diffraction, and electron microscopy. Microcosm experiments underwent 3 consecutive 5 day redox phases: oxic-anoxicoxic. The sediments contained Fe (51,000 mg/kg), Pb (307 mg/kg), and Cu (30 mg/kg), and minerals such as Illite, albite, and goethite. Microscopy analyses revealed that Pb and Cu are associated with Al-silicates and jarosite. Iron release peaked under anoxic conditions (∼250 mg/L), then decreased in the second oxic phase (<70 mg/L). Extraction experiments confirmed that Pb and Cu are water-labile at pH 3.4 (Pb: 27 μg/L exceeding the United States Environmental Protection Agency drinking water action level of 15 μg/L, Cu: 75 μg/L), but less labile at pH 6.4 (Pb: 7 μg/L, Cu: 3 μg/L). DNA sequencing detected metal-tolerant fungal genera (Trichoderma, Fusarium, Penicillium, and Aspergillus) in the sediments. This study provides insights into the biogeochemical processes influencing the lability of metals in AMD-affected sites, which have relevant implications for risk assessment, remediation strategies, and recovery of critical minerals. 

This review illuminates established knowledge of root–arbuscular mycorrhizal fungi (AMF)–plant mutualism to study the uptake of phosphorus (P) as a critical element for plant nutrition. We focus on P cycling, underscoring the role of AMF in enhancing P acquisition and plant resilience in the rhizosphere. The role(s) of plant roots, root exudates, and biomolecules in relevant soil processes is emphasized in this manuscript. Enhancing P uptake efficiency through AMF interaction presents a promising avenue for sustainable agriculture, with future research opportunities focusing on understanding underlying mechanisms and developing innovative technologies as a need to transition from the use of AMF as a biofertilizer or as an inoculation alternative for seeds to being an inspiration for the development of technology adapted to different crops. This is important to promote responsible agricultural practices and improve crop yields. We provide definitions of key terms and concepts for one of the best-known natural sustainable phosphorus systems. This manuscript illuminates and aims to inspire technology development to overcome the challenge of plant nutrition under P scarcity conditions. 

Abstract Phosphorus (P) is an essential element for all life forms and a finite resource. P cycle plays a vital role in regulating primary productivity, making it a limiting nutrient for agricultural production and increasing the development of fertilizers through extractive mining. However, excessive P may cause detrimental environmental effects on aquatic and agricultural ecosystems. As a result, there is a pressing need for conservation and management of P loads through analytical techniques to measure P and precisely determine P speciation. Here, we explore a new 2D sorbent structure (GO-PDDA) for sensing orthophosphate in aqueous samples. The sorbent mimics a group of phosphate-binding proteins in nature and is expected to bind orthophosphate in solution. Laser-induced graphene (LIG) was coated with GO-PDDA using a drop-cast method. Electrochemical impedance spectroscopy was used as a transduction technique for electrochemical sensing of orthophosphate (HPO₄²⁻) and selectivity assay for chloride, sulfate and nitrate in buffer at pH 8. The analytical sensitivity was estimated to be 347 ± 90.2 Ω/ppm with a limit of detection of 0.32 ± 0.04 ppm. Selectivity assays demonstrate that LIG-GO-PDDA is 95% more selective for ortho-P over sulfate and 80% more selective over chloride and nitrate. The developed sensor can be reused after surface regeneration with an acidic buffer (pH 5), with slight changes in sensor performance. Our results show that the sorbent structure is a promising candidate for developing electrochemical sensors for environmental monitoring of orthophosphate and may provide reliable data to support sustainable P management. 

Abstract     Organophosphorus pesticides are widely used in industrial agriculture and have been associated with water pollution and negative impacts on local ecosystems and communities. There is a need for testing technologies to detect the presence of pesticide residues in water sources, especially in developing countries where access to standard laboratory methods is cost prohibitive. Herein, we outline the development of a facile electrochemical sensor for amperometric determination of organophosphorus pesticides in environmental water samples. A three-electrode system was fabricated via UV laser-inscribing on a polyimide film. The working electrode was functionalized with copper nanoparticles with affinity toward organophosphate compounds. The sensor showed a limit of detection (LOD) of 3.42 ± 1.69 µM for glyphosate, 7.28 ± 1.20 µM for glufosinate, and 17.78 ± 7.68 µM for aminomethylphosphonic acid (AMPA). Sensitivity was highest for glyphosate (145.52 ± 36.73 nA⋅µM −1 ⋅cm −2 ) followed by glufosinate (56.98 ± 10.87 nA⋅µM −1 ⋅cm −2 ), and AMPA (30.92 ± 8.51 nA⋅µM −1 ⋅cm −2 ). The response of the sensor is not significantly affected by the presence of several ions and organic molecules commonly present in natural water samples. The developed sensor shows promising potential for facilitating environmental monitoring of organophosphorus pesticide residues, which is a current need in several parts of the world. Graphical Abstract