Environmental pollution has posed a major threat to terrestrial, aquatic, and marine ecosystems, thereby affecting microflora and micro-fauna populations. This study assessed the growth attributes of maize plants on crude oil-polluted soils amended with agro-wastes. Six kilograms each of composite soil sample was weighed and transferred into one hundred and fifty labeled plastic buckets with drainage holes for soil aeration and spiked with 300mls each of crude oil, allowing for 14 days of soil acclimatization. Soil amendments such as groundnut husks, cassava peels, empty fruit bunch of oil palm, and maize cob powder were applied and allowed for 90 days. Maize seeds were sowed, while periodic data were collected and subjected to a three-way ANOVA. The result obtained revealed that maize seeds grown on agro-wastes treated and pristine control soils show early seed germination than the crude oil-polluted control soil. The plant height obtained for GnH14P + MaC14P at 10% was the highest with a mean (of 152.81cm2), and the leaf area of the maize from soil treated with GnH14P + EFBOP14P at 10% had the highest mean (756cm2), the leaf length of maize from soil treated with GnH14P + CasP14P at 3%, 6%, and 10% was the highest with mean ranging (54-97 cm2) with no significant difference in mean values obtained. The stem girth, number of leaves, and leaf width were generally improved in the bio-remediated soils. The result for the yield performance of maize shows that the days to flowering were shortened in the bio-remediated soil compared to the prolonged flowering days observed in the crude-oil polluted control. The number of seeds per cob was high in the bio-remediated soils while no seed was obtained in the crude-oil-polluted control soils. It can be concluded that the ameliorated treatment with the agro-wastes improves the performance of maize plants in crude oil-polluted soils.

This study investigated the potential impact of a fertilizer factory in Upper Egypt on the surrounding soil's radioactivity levels. Gamma-ray spectrometry was used to measure the concentrations of naturally occurring radionuclides (226Ra, 232Th, and 40K) in soil samples collected near the factory. Additionally, radon gas concentrations were measured, and various radiological hazard indices were calculated. Activity concentrations of 238U, 226Ra, 232Th, and 40K varied in the soil samples, ranging from 110.63 to 326.12 Bq/kg for 238U, 172.72 to 582.37 Bq/kg for 226Ra, 25.63 to 189.15 Bq/kg for 232Th, and 252.20 to 713.24 Bq/kg for 40K. Radium equivalent activity, absorbed gamma dose, and external and internal hazard indices exceeded permissible levels. Radon gas concentrations varied from 20.89 to 192.30 Bq/m3, with an average of 104.43 Bq/m3. The calculated effective dose from radon inhalation exceeded the recommended limit. The elevated levels of radioactivity in soil and the high radon gas concentrations suggest a potential health risk for farmers and residents near the fertilizer factory. Further investigations and mitigation strategies may be necessary to ensure the safety of the surrounding population.

International audience | The cocktail of pesticides sprayed to protect crops generates a miscellaneous and generalized contamination of water bodies. Sorption, especially on soils, regulates the spreading and persistence of these contaminants. Fine resolution sorption data and knowledge of its drivers are needed to manage this contamination. The aim of this study is to investigate the potential of Mid-Infrared spectroscopy (MIR) to predict and specify the adsorption and desorption of a diversity of pesticides. We constituted a set of 37 soils from French mainland and West Indies covering large ranges of texture, organic carbon, minerals and pH. We measured the adsorption and desorption coefficients of glyphosate, 2,4-dichlorophenoxyacetic acid (2,4-D) and difenoconazole and acquired MIR Lab spectra for these soils. We developed Partial Least Square Regression (PLSR) models for the prediction of the sorption coefficients from the MIR spectra. We further identified the most influencing spectral bands and related these to putative organic and mineral functional groups. The prediction performance of the PLSR models was generally high for the adsorption coefficients Kdads (0.4 < R 2 < 0.9 & RPIQ > 1.8). It was contrasted for the desorption coefficients and related to the magnitude of the desorption hysteresis. The most significant spectral bands in the PLSR differ according to the pesticides indicating contrasted interactions with mineral and organic functional groups. Glyphosate interacts primarily with polar mineral groups (OH) and difenoconazole with hydrophobic organic groups (CH2, C=C, COO-, CO , CO -C). 2,4-D has both positive and negative interactions with these groups. Finally, this work suggests that MIR combined with PLSR is a promising and cost-effective tool. It allows both the prediction of adsorption and desorption parameters and the specification of these mechanisms for a diversity of pesticides including polar active ingredients.

The widespread and extensive use of pesticides in European crop production to reduce losses from weeds, diseases, and insects may have serious consequences on the ecosystem and human health. This study aimed to identify 20 active substances of high health risk, based on their detection frequency within and across the environmental matrices (soil, crop, water, and sediment) and to identify their associated hazardous effects. A sampling campaign was conducted across 10 case study sites in Europe and 1 in Argentina and included conventional and organic farming systems. In 31% of cases, the detected substances were found at a higher concentration in the soil than in the corresponding crops, 93% of the compounds were fungicides, and the remainder were insecticides. 43% of the substances, 57% of which were insecticides, were detected only in soil. There was a clear relationship between soils and crops in terms of contamination, but not between water and sediment. Portuguese soil (wine grapes) had the highest number of substances (12) with average concentrations (AC) varying between 1 and 162 μg/kg, followed by French (11 substances in wine grapes) (1≤AC≤64 μg/kg) and Spanish soils (9 substances in vegetables) (3≤AC≤59 μg/kg). The crops corresponding to these soils contained a relatively high number of detected substances and several in high average concentrations (AC). The risk quotient was consistently higher for conventional farms than for organic farms. For the soils from conventional farms, 5 active substances (chlorpyrifos, glyphosate, boscalid, difenoconazole, lambda-cyhalothrin, and one metabolite: AMPA) were considered high risk. For water samples, 2 substances (dieldrin and terbuthylazine) found were high risk, and for sediment, there were 3 substances (metalaxyl-M, spiroxamine, and lambda-cyhalothrin). There were 6 substances detected in crops that are suspected to cause human health effects. Uncontaminated soil is a prerequisite for the adoption of sustainable alternatives to pesticides. Efforts are needed to elucidate the unknown effects of mixtures, including biocides and banned compounds in addition to the substances used in agriculture.

The system of fertilizing agricultural soils with sludge or compost from wastewater treatment processes, as one of the principles of the circular economy, can lead to microplastic (MP) contamination. The existing technical standards for fertilization are very recent and do not consider this problem, although there is scientific evidence of their existence. Therefore, this study, on the one hand, evaluates the presence of MPs in agricultural soils, previously treated with sludge or compost from wastewater treatment plants for fertilization, and on the second hand, it studies the effect of these MPs on earthworms in three different locations in the south of Spain. For the study, selected composts deriving from the different stages of the composting process and three fertilized soils with increasing MP doses were followed. Samples were taken from different sections in depth (0–5, 5–10, and 10–20 cm) to study the shape, size, type, and abundance of MPs using infrared spectroscopy (FTIR). The results showed that the most abundant shape was fiber, followed by fragment and finally bulk, for both composts and soils. Regarding size distribution, 100 μm was the predominant size in composts (64.3% ± 9.8), while in the case of soils, the predominant range was from 100 to 500 μm. The prevalent polymers in both, composts and soils, were PTFE, TPE, PP, and PET, with four times higher amounts in composts than in soils. Ingestion of common MPs were also verified in two earthworm species, which ingested concentrations higher than 2.1% w/w. PP was the most ingested MP and Eisenia fetida was more voracious compared with Lumbricus terrestris. Therefore, it can be considered a suitable bioindicator for monitoring microplastic contamination in agricultural soil.

The project aims to remove reactive blue dye from the effluent of textile industries by utilizing coal-associated soil as an adsorbent, as it possesses effective physical properties and distinguishing characteristics. In comparison to other separation techniques, the adsorption method is the most effective, cost-effective, and straightforward. A batch adsorption investigation was carried out to examine the various adsorption-influencing factors, including solution pH, adsorbent dosage, contact time, temperature, and dye concentration. Contact time of 30 min, an adsorbent dosage of 10g.100 mL-1, a solution pH of 7, a temperature of 30°C, and an initial dye concentration of 100 mg.L-1 were found to be optimal for dye adsorption. Using two distinct kinetic models, the evaluation of kinetic studies revealed that the pseudo-second-order provided the greatest fit, with a higher R2 value than the pseudo-first-order. The thermodynamic parameters Gibbs free energy (ΔG°), entropy (ΔS°), and enthalpy (ΔH°) indicated that the current adsorption system was exothermic and spontaneous. Further study of the adsorption isotherm revealed that the Langmuir isotherm model provided the best fit, with an R2 value of 0.977%.