Environmental Technology & Innovation最新文献

Microalgae can contribute to sustainable agriculture and wastewater treatment. This study investigated Tetradesmus obliquus, grown in piggery wastewater (To-PWW), as a biostimulant/biofertilizer compared to biomass grown in synthetic medium (To-B). Subcritical water extraction was tested for disruption/hydrolysis of wet biomass, at three temperatures (120, 170, and 220 °C) and two biomass loads (1:10 and 1:80 (g dry biomass/mL water)). Extracts were evaluated for germination, and root formation/expansion. Residues were quantified for nutrient composition to assess their biofertilizer potential and tested for their affinity to oil compounds for bioremediation. The best germination was achieved by To-B extracts at 170 °C (1:10: 148 % at 0.2 g/L, 1:80: 145 % at 0.5 g/L). Only To-PWW extracts at 0.2 g/L had a significant germination effect (120 °C: 120–123 % for both loads; 170 °C: 115 % for 1:80). To-PWW extract at 120 °C and 1:10 significantly affected cucumber and mung bean root formation (224 and 268 %, respectively). Most extracts significantly enhanced root expansion, with all To-B extracts at 1:10 showing the best results (139–181 %). The residues contained essential nutrients (NPK), indicating their biofertilizer potential, helping decrease synthetic fertilizers demands. To-B residues had high affinity to toluene and diesel but lower to used cooking and car oils. To-PWW showed very low affinity to all oil compounds. Finally, all residues were only able to form stable emulsions with the used car oil. This study fully exploits the use of microalgal biomass in sustainable agriculture, producing biostimulant extracts, and residues for biofertilizer and bioremediation, from a low-cost wastewater source.

In the context of climate change, biochar application is a promising approach to mitigate the adverse effects of climate change on agriculture. However, the selection of suitable biochar produced from food waste and optimization of loading rates to improve soil quality remains a significant challenge. This study explores the potential impact of biochar application using an integrated analytical hierarchy process (AHP) and geographical information system (GIS) approach. The study first aims to develop an AHP model to prioritize the appropriate biochar source and dosage for soil amendment. The different biochar sources considered are: peas pod shell, pistachio shell, and mixed vegetable waste. The AHP design evaluated the weight percentage of different types of biochar amendments ranging from 0 % to 8 % based on soil quality, nutrient analysis and water retention capacity. Furthermore, an integrated spatial analysis case study was conducted for fodder farms across Qatar using GIS mapping with seasonal variation to evaluate the impact of biochar on water management. According to the AHP decision making, 2 % mixed vegetable waste biochar achieved the goal with the highest priority score, with a value of 0.29, followed by 2 % pistachio shell biochar with a score of 0.22. This is attributed to the high water retention rate determined from the experimental study. The 2% biochar amendment retained 20 % more water compared to the 0 % biochar. Results from the GIS mapping identified priority areas for improving water retention and soil quality. The evapotranspiration maps for winter and summer generated using GIS provide valuable insights into the spatial disributio of biochar application across Qatar fodder farms. The outcomes may encourage policymakers and stakeholders to consider valorizing food waste into biochar.

Soil copper (Cu) contamination is a ubiquitous and prevalent environmental problem in many countries (such as developed Cu-related industrial areas), endangering food safety and human health. Emerging as a crucial instrument, stable Cu isotope analysis is employed to differentiate between natural and human-induced sources of Cu and to employed the fate of Cu on the soil systems. This study provides an overview of: (i) the analytical methods for stable Cu isotopes, (ii) the Cu isotope compositions of possible end-members of Earth’s surface systems, including particulate matter and, dry and wet deposition to the soil, and (iii) the fractionation mechanisms of Cu isotopes in different types of pollutants, as a tracer for the origin of Cu in soils. These Cu isotope signatures have significant implications for the assessment and remediation of soil Cu pollution scenarios. However, the utilization of Cu isotope signatures remains limited to tracing the source of Cu-contaminated soils through Cu isotope analysis. As a result, this study also presents a perspective on the application of Cu isotopes to trace Cu sources and their fate in the soil.

In this study, hydrometallurgical and electrochemical methods were combined to achieve an innovative strategy for the effective recovery of the finest silver metal from silicon solar waste. The waste was thoroughly characterized by X-Ray diffraction, Scanning Electron Microscopy, X-Ray Absorption Spectroscopy, and Inductively Coupled Plasma Optical Emission Spectroscopy. A chemometric approach based on experimental design was used to find the best conditions for the leaching process based on a combined base-activated persulfate and ammonia system while a novel method known as electrodeposition-redox replacement was used to recover it. A remarkable pure silver recovery of 98.7±1.4 % was achieved. Additionally, Scanning Electron Microscopy analysis confirmed the enrichment of Ag particles on the electrode. Overall, these promising results showed how flexible the electrodeposition-redox replacement approach is in producing a range of valuable functional materials from intricate hydrometallurgical solutions including multiple metal impurities.

Material shortages in composting may pose limits or logistical problems in certain regions, which can be addressed with inert and reusable wastes. Very little research has been conducted on the subject of using alternative synthetic wastes as structuring agents to improve composting process parameters. The present work aimed to evaluate the use of used tennis balls (TB) as an inert bulking agent. Composting was carried out in an industrial composting plant with a ternary mixture of olive mill waste, the solid fraction of dewatered pig slurry, urban pruning residues, with the addition of TB as a synthetic bulking agent. Composting process parameters, monitored throughout the composting cycle, showed that TB significantly affected the thermal composting process parameters, with increases in operating temperatures, exothermic index, and mineralization of organic matter. Also, compost properties were seen to be of equal or superior quality at the end of the composting with addition of TB. These are the first experimental results testing the effect of a spherical synthetic reutilized product such as TB on composting processes, which was additionally carried out at an industrial scale, showing that using discarded materials such as used tennis balls can improve the efficiency and economy of composting.

Trivalent chromium [Cr (III)] is a frequently detected environmental contaminant that negatively affects plant metabolism, growth, and yield. Plant secondary metabolites are non-nutrient compounds involved in diverse physiological functions in response to abiotic stresses. This study performed biochemical and transcriptomic analyses to clarify the protective role and mechanisms of secondary metabolites in rice seedlings under Cr(III) stress. The content of measured secondary metabolites i.e., total soluble phenolics, flavonoids, lignin, and anthocyanin in rice tissues was significantly enhanced under Cr(III) exposure. Additionally, the activities of several enzymes including chalcone synthase, phenylalanine ammonialyase, peroxidase, and anthocyanidin synthase, were positively activated. Transcriptomic analysis revealed a number of differentially expressed genes (DEGs) in Cr(III)-treated rice seedlings and their expression patterns are tissue-specific. Additionally, the DEGs involved in secondary metabolism pathways were evident after KEGG enrichment analysis. Cr(III) exposure resulted in distinct genetic regulation strategies in rice tissues, with different DEGs activating various sub-pathways in the secondary metabolism pathways to cope with Cr(III) stress. Furthermore, the integrated correlation analysis of the secondary metabolites and transcriptome data identified key genes involved in different steps of the sub-pathways of secondary metabolism pathway in rice plants under Cr(III) stress. This study indicates that the accumulation of secondary metabolites in rice plants is a survival and detoxification strategy to reduce the adverse effects of toxic compounds. Future research should explore how key genes in secondary metabolism pathways aid in Cr(III) detoxification and enhance crop stress tolerance.

Although the collection and recycling of used cooking oils have been well-established, tempura powder debris discarded from the frying process has received little attention. Here, in collaboration with a local company that collects used cooking oil, we estimated that approximately 881,000,000 kg of tempura powder debris is discarded annually in South Korea. The debris was found to contain approximately 60 % of oils that can be extracted through a squeezing process. The resulting cake was proven to be beneficial for the fabrication of 3-dimensional biocomposites with waste biomass powders (e.g., used cardboard and coffee powders and rice straw powder), wherein the polysaccharides from the debris likely serve as a binder. Various complex structures were readily fabricated using heat-drying (90 ℃ for 30 minutes and then at 120 ℃ for 30 minutes for a dish and 130 ℃ for 24 hours for other shapes) and exhibited a compressive strength of 2500 kPa and a thermal conductivity of 0.089 W/(m·K). The overall composite shape was maintained under water soaking, while the compressive strengths were reduced by 40 % under a high humidity. Furthermore, strong sorption for toxic compounds, excellent biodegradability, low cytotoxicity, good-odor emission, and enhanced maize germination rates with bed soils were displayed by using the composites. The performance and function comparisons with commercial expanded polystyrene suggest that using the composites could be multi-beneficial. In conclusion, tempura powder debris from the fried food sector could become a significant bulk waste source, supporting the development of circular economy such as a low-performance plastic alternative.

As a class of emerging contaminants in marine environments, organophosphate esters (OPEs) have attracted increasing attention of environmental scientists and policymakers due to their ubiquity and ecotoxicity. However, little is known about the environmental geochemical behaviors of OPEs in seawater of the South China Sea (SCS). In this study, the concentration, composition, pollution source, and ecological risk of twelve typical OPEs were analyzed in the surface seawater of the northern SCS between August and September 2021. The results showed that five out of twelve OPEs were detectable with the total concentration of five OPEs (Σ₅OPEs) ranging from 7.17 to 67.6 ng/L in seawater. Chlorinated OPEs (Cl-OPEs) were the predominant OPEs, with a mean concentration of 18.4 ng/L, accounting for more than 69.8 % of Σ₅OPEs. Among the detected congeners, tris(2-chloroethyl) phosphate (TCEP) was the most abundant OPE (mean: 14.8 ng/L, 56.2 %), followed by triethyl phosphate (TEP) (mean: 7.75 ng/L, 29.5 %) and tris(1-chloro-2-propyl) phosphate (TCIPP) (mean: 2.07 ng/L, 7.87 %). Principal component analysis and Spearman correlation analysis indicated that terrestrial inputs, atmospheric deposition, and shipping activities were the potential sources of OPEs in the northern SCS. The ecological risk assessment revealed that TCEP posed low threats to algae and low ecological risks were predominantly observed from the mixture of OPEs. This work provides a basis for further investigation into the environmental behavior, toxicity, and risk of OPEs in the SCS and facilitates a better implementation of effective management actions.

Benzene, a common volatile organic compound (VOC) detected in indoor environments, poses challenges for its removal because of its stable molecular structure and low-concentration. In this study, we successfully synthesized tin-doped titanium dioxide (Sn-TiO₂) using a simple hydrothermal method. Various characterization techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunner–Emmet–Teller (BET) and molecular probes were employed to analyze the phase composition, structure and morphology, as well as photocatalytic properties of TiO₂ and Sn-TiO₂. The characterization results showed that moderate addition of tin doping not only effectively enhanced the capture ability of benzene molecules but also promoted hydroxyl radicals (·OH) generation, which was further validated by in-situ diffuse reflectance infrared Fourier transform (DRIFT) spectra and density function theory (DFT) calculations. Degradation experiments on gaseous benzene revealed that under 15 W ultraviolet (UV) light irradiation in humid and closed conditions for 60 min, 1 % Sn-TiO₂ achieved a benzene degradation efficiency of 93.14 %, with almost complete mineralization. Furthermore, flow system experiments demonstrated efficient decomposition of trace amounts of benzene (∼10 mg/m³) in the air to satisfy emission standards when employing 1 % Sn-TiO₂ at a flow rate of 100 L/min.

Investigating the heavy metal content and migration behavior in the soil and plant system of Epimedium origin is crucial for ensuring the safety and sustainable development of this valuable medicinal plant. The concentration of heavy metals in the soil of Epimedium was found to be highest in the residuel form (RS) and lowest in the water-soluble form (WS). Among the different parts of the Epimedium plant, leaves showed the highest content of Cr, Ni, Cu, As, and Pb with average contents of 0.02 mg.kg⁻¹, 0.01 mg.kg⁻¹, 0.11 mg.kg⁻¹, 0.16 mg.kg⁻¹, and 0.01 mg.kg⁻¹, respectively, and roots showed the highest content of Zn with average contents of 0.30 mg.kg⁻¹. The results of correlation analysis and linear fitting showed significant correlation and better linear fitting results between different parts of Epimedium (roots, stems and leaves) and various forms of heavy metals in soil. Among them, Zn (ion-exchange form) and Zn (leaf) showed the best fit with R² reaching 0.74. Results from random forest modeling indicated that the forms of heavy metals in soil, such as bound form, ion exchange form, and strong organic bound form, significantly influenced the distribution of heavy metals in roots, stems, and leaves of Epimedium. Overall, besides the readily available heavy metals in soil, other forms of heavy metals also play a critical role in the soil-plant migration system.