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The aim of this study is to assess the performance of an industrial effluent steel industrial wastewater (SIWW) highly loaded with ferric salts from Maghreb Steel Company as coagulant for stabilized landfill leachate treatment. Response surface methodology and central composite design were applied to optimize the coagulation-flocculation process and to model the relationships between independent variables (coagulant dose and effluent pH) and responses (chemical oxygen demand (COD) and turbidity removal, and sludge production). Quadratic polynomial models developed for these responses indicated that the optimum conditions were 8 mL/L of SIWW at pH 2.75. These results showed good agreement between experimental and model predictions. 55.43% and 87.55% of COD and turbidity removal, respectively and with 19 mL/L of sludge production from treatment of this leachate by coagulation-flocculation using a SIWW-based coagulant were demonstrated. Accordingly, it is concluded that SIWW can be used as an effective and alternative coagulant for the pre-treatment of stabilized landfill leachate by a coagulation-flocculation process. [ABSTRACT FROM AUTHOR]

Activated carbon from grape seed was prepared using the chemical activation method, which consisted of treatment by potassium hydroxide (KOH). Factors influencing the activated carbon preparation were particle size, impregnation ratio, final temperature, heating rate, and the activating agent concentration were studied by using a central composite design. The methodology chosen in this paper is based on the use of a polynomial model to express the responses, yield of activated carbon synthesized, and adsorbed amount of methylene blue as a function of the five influencing factors. The significance of the factors was studied by analysis of variance using the Fisher test, linear effects diagram, response surface curves, and iso-response curves. According to the Response Surface Methodology, optimal conditions for the preparation of activated carbon have been identified to be a particle size of 300 μm, an impregnation ratio of 0.15, a final temperature of 650°C, a heating rate of 10°C/min and an activating agent concentration of 35%. Under these conditions, the synthesis yield of AC and 40%, while the adsorption capacity of methylene blue was 492 mg/g. The characteristics of activated carbon obtained under these experimental conditions were by FTIR analysis indicate the presence of a variety of functional groups on the surface of activated carbon. These results demonstrated that the grape seeds are a suitable precursor for the production of activated carbon. [ABSTRACT FROM AUTHOR]

This work focuses on the multi-objective optimization of the electrocoagulation process. The goal is to decolorize synthetic Reactive Black 5 wastewater using a single-channel reactor operating in a closed-circuit. Response Surface Methodology (RSM) is employed for the optimization. The Central Composite Design (CCD) is used to study the empirical relationship between two responses (decolorization efficiency (η) and energy consumption (W C)) and four independent variables (recirculation flow rate (Q v), current intensity (I), electrolysis time (τ e) and active electrode area (S a)), while the desirability function (D) is applied to determine optimal conditions. In addition, a novel approach for the exploitation of the RSM model is developed to set correlations between the limit of η (η Lim) and corresponding independent variables' limit values (below of which η < η Lim). The developed correlations showed a good agreement between the graphical data and the estimated values (R2 > 0.99). The CCD model fits well the experimental data with a R2 of 0.94 and 0.95, for η and W C , respectively. The analysis of variance allowed to build quadratic models for both responses. For a maximal overall desirability D of 0.88, optimal conditions are Q v = 70 L h−1, I = 100 mA, τ e = 34.6 min and S a = 621 cm2. Under these conditions, η = 70.9% and W C = 4.6 Wh.m−3 were achieved. The sludge characterization using X-ray diffraction, Scanning Electron Microscopy, and Fourier Transform InfraRed reveals the formation of the amorphous Al(OH) 3 without other precipitated substances and authenticates the successful sorption of RB5 onto the Aluminum hydroxide flocs. [Display omitted] [ABSTRACT FROM AUTHOR]

Sulfonamides are among the widespread bacterial antibiotics. Despite this, their quick emergence constitutes a serious problem for ecosystems and human health. Therefore, there is an increased interest in developing relevant detection method for antibiotics in different matrices. In this work, a straightforward, green, and cost-effective protocol was proposed for the preparation of a selective molecularly imprinted membrane (MIM) of sulfamethoxazole (SMX), a commonly used antibiotic. Thus, cellulose acetate was used as the functional polymer, while polyethylene glycol served as a pore-former. The developed MIM was successfully characterized through scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The MIM was used as a sensing platform in conjunction with a smartphone for optical readout, enabling on-site, selective, and highly sensitive detection of SMX. In this way, a satisfactory imprinting factor of around 3.6 and a limit of detection of 2 ng mL−1 were reached after applying response surface methodologies, including Box-Behnken and central composite designs. Besides, MIM demonstrated its applicability for the accurate and selective detection of SMX in river waters, wastewater, and drugs. Additionally, the MIM was shown to be a valuable sorbent in a solid-phase extraction protocol, employing a spin column setup that offered rapid and reproducible results. Furthermore, the developed sensing platform exhibited notable regeneration properties over multiple cycles and long shelf-life in different storage conditions. The newly developed methodology is of crucial importance to overcome the limitations of classical imprinting polymers. Furthermore, the smartphone-based platform was used to surpass the typically expensive and complicated methods of detection. Graphical illustration of the preparation of a new molecularly imprinted membrane (MIM) and the smartphone-based MIM platform for the sensitive, selective, and on-site detection of sulfamethoxazole in water samples and drugs. [Display omitted] • Straightforward and green preparation of a novel molecularly imprinted membrane (MIM). • Application of MIM as a sorbent in SPE-spin column setup for pollutant removal. • Smartphone-based MIM platform for relevant detection of sulfamethoxazole (SMX). • Selective, sensitive, and rapid detection of SMX in river waters, wastewater, and drugs. • MIM demonstrated exceptional stability, reusability, and recoveries. [ABSTRACT FROM AUTHOR]