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Toxic contamination of agricultural soils by trace metal(oid)s can pose detrimental effects on human health and agroecological systems. In this view, the current research explored total and available metal(oid)s in surface soils and assessed the associated hazards using pollution indices, PMF modeling, PCA, and Montecarlo probabilistic human risk assessment with 10,000 repetitions. The mean concentrations of Cd, Pb, As, Cr, Ni, Cu, Zn, and Fe were 0.89, 24.86, 1.81, 19.10, 25.44, 7.98, 49.12 and 6183.32 mg kg-1 dry weight, respectively. These findings highlighted that the concentration of pollutants exceeded the values measured in the geochemical background. Soil enrichment by heavy metal (oid)s was confirmed by analyzing available fractions using DTPA ,CaCl2 and enrichment factor (EF). Additionally, pollution indicators (Igeo, PLI, and PERI) displayed significant contamination levels, with a higher ecological risk. Matrix Factorization (PMF) receptor and multivariate statistical analysis reflected that anthropogenic activities, particularly landfilling and agricultural practices were the main causes of the contamination. Furthermore, probabilistic and deterministic human risk assessments showed that carcinogenic risks exceeded the threshold values (10-4) set by the USEPA. Consequently, it is crucial to implement continuous monitoring and supervision of landfill sites to prevent additional pollution. These measures should be integrated into the management plans for waste management.

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Cigarette butts generated are one of the major sources of total solid waste production and lead to environmental issues. This article has the objective of evaluating the effects of cellulose acetate microfibers (CAFs) sourced from discarded cigarette filters (CFs) as fiber reinforcement on the physico-mechanical properties and thermal conductivity of cementitious materials. To do so, mortar samples were prepared using different incorporated quantities of fibers (0.5, 1, 1.5, 2, 2.5, and 5% compared to the quantity of sand added to the mixture) and subjected to different tests to characterize the influence of CAFs on the microstructure of elaborated materials, considering the changes in workability time, compressive strength, flexural strength, density, water absorption, and microstructural analysis. Furthermore, the life cycle assessment (LCA) of mortar mixes in terms of CO2 emissions is made. The results revealed that the increasing percentages of CAFs reduced the dry density and compressive strength, by approximately 1.62-51% and 37-69.64%, respectively, and a notable enhancement of insulation characteristics by about 5-47.5% was achieved. Microstructure analysis confirmed the experimental investigation and revealed that adding more than 1% of fibers resulted in a significantly low unit weight with greater entrapped air content. The studies prove the possibility of recycling cigarette butts for insulating cementitious matrix. In addition, applying mortar containing acetate cellulose fibers is recognized as a more environmentally friendly mixture in terms of reducing CO2 emissions and could participate significantly in the achievement of SDGs.

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Microbial fuel cells (MFCs) provide new opportunities for the sustainable production of energy, converting organic matter into electricity through microorganisms. Moreover, MFCs play an important role in remediation of environmental pollutants from wastewater with power generation. This work focuses on the evaluation of ferroelectric perovskite materials as a new class of non-precious photocatalysts for MFC cathode construction. Nanoparticles of BaTiO3 (BT) were prepared and tested in a microbial fuel cell (MFC) as photocathode catalytic components. The catalyst phases were synthesized, identified and characterized by XRD, SEM, UV-Vis absorption spectroscopy, P-E hysteresis and dielectric measurements. The maximum absorption of BT nanoparticles was recorded at 285 nm and the energy gap (Eg) was estimated to be 3.77 eV. Photocatalytic performance of cathodes coated with BaTiO3 was measured in a dark environment and then in the presence of a UV-visible (UV-Vis) light source, using a mixture of dairy industry and domestic wastewater as a feedstock for the MFCs. The performance of the BT cathodic component is strongly dependent on the presence of UV-Vis irradiation. The BT-based cathode functioning under UV-visible light improves the maximum power densities and the open circuit voltage (OCV) of the MFC system. The values increased from 64 mW m-2 to 498 mW m-2 and from 280 mV to 387 mV, respectively, showing that the presence of light effectively improved the photocatalytic activity of this ceramic. Furthermore, the MFCs operating under optimal conditions were able to reduce the chemical oxygen demand load in wastewater by 90% (initial COD = 2500 mg L-1).

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The present work is the first investigation of the electrocatalytic performances of ZrP2O7 as a cathode in a single-chamber Microbial Fuel Cell (MFC) for the conversion of chemical energy from wastewater to bioelectricity. This catalyst was prepared by a coprecipitation method, then characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), ultraviolet-visible-near-infrared spectrophotometry (UV-Vis-NIR), and cyclic voltammetry analyses. The acid-basic characteristics of the surface were probed by using 2-butanol decomposition. The conversion of 2-butanol occurs essentially through the dehydrating reaction, indicating the predominantly acidic character of the solid. The electrochemical test shows that the studied cathode material is electroactive. In addition, the ZrP2O7 in the MFC configuration exhibited high performance in terms of bioelectricity generation, giving a maximum output power density of around 449 mW m-2; moreover, it was active for wastewater treatment, reducing the chemical oxygen demand (COD) charge to 50% after three days of reaction.

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In order to improve the removal rates of paracetamol and amoxicillin present in water, activated carbons prepared from argan waste were designed as a support for a biofilm-based on E. coli yielding microporous materials with high surface areas, in such a way that the biofilm support could be made homogeneously on the internal and external surface of the material. Adsorption studies without the presence of the biofilm showed rapid kinetics with adsorption constants kPCT = 0.06 and kAMX = 0.007 min-1. The adsorption isotherms could be described by the Langmuir isotherm model reaching a maximum adsorption capacity of qPCT = 502 and qAMX = 319 mg g-1. In contrast, the results obtained for the materials that support the biofilm showed slow kinetics (kPCT = 0.007 and kAMX = 0.003 min-1) and a remarkable change in the shape of the adsorption isotherms, since the experimental data are better represented by a combined Langmuir-Freundlich model, in which three important stages are observed: (i) In a first stage, adsorption is carried out in those spaces available after supporting the biofilm in the surface of the ACs. Once these spaces have been saturated, a second stage (ii) is present with an exponential behavior typical of the Freundlich isotherm, attributed to the adsorption of the pharmaceutical compounds in the biofilm, Finally a third stage is observed (iii) where the asymptotic behavior typical of the saturation of the adsorbent according to the Langmuir model is already appreciated (qPCT = 504 and qAMX = 465 mg g-1).

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