A new cloud point methodology was successfully used for the extraction of carcinogenic pesticides in milk samples as a prior step to their determination by spectrophotometry. In this work, non-ionic silicone surfactant, also known as 3-(3-hydroxypropyl-heptatrimethylxyloxane), was chosen as a green extraction solvent because of its structure and properties. The effect of different parameters, such as the type of surfactant, concentration and volume of surfactant, pH, salt, temperature, incubation time and water content on the cloud point extraction of carcinogenic pesticides such as atrazine and propazine, was studied in detail and a set of optimum conditions was established. A good correlation coefficient (R2) in the range of 0.991–0.997 for all calibration curves was obtained. The limit of detection was 1.06 µg l−1 (atrazine) and 1.22 µg l−1 (propazine), and the limit of quantitation was 3.54 µg l−1 (atrazine) and 4.07 µg l−1 (propazine). Satisfactory recoveries in the range of 81–108% were determined in milk samples at 5 and 1000 µg l−1, respectively, with low relative standard deviation, n = 3 of 0.301–7.45% in milk matrices. The proposed method is very convenient, rapid, cost-effective and environmentally friendly for food analysis.
In this study, activated carbon (AC) coated with a green silicone surfactant (SS) was further incorporated with magnetite particles (Fe3O4) to enhance the separation of the newly designed magnetic AC–SS (Fe3O4@AC–SS) in a magnetic field.
Hydrogen is considered as an environmental friendly energy carrier but its actual impact on the environment depends on the way it is produced. A strategy of plant-wide modelling and advanced process control with optimization is currently developed for the Hydrogen production via the Iodine-Sulphur thermochemical cycle process. The objectives of this paper are two-folds: (1) to optimize the trade-off between steady-state profitability and dynamic operability of the Bunsen section subject to multiple constraints, and (2) to design practical control strategy based on the multi-scale control concept. A multi-scale modelling for the Bunsen section in the Hydrogen production via the Iodine-Sulphur thermochemical cycle process is presented. Based on this multi-scale model, a practical control design is developed and applied to Bunsen section. The suitable sets of control variables and manipulated variables are chosen via a sensitivity study incorporating the multivariate Response Surface Analysis method. By dint of simulation study, it can be shown that the proposed control strategy is able to produce a good closed-loop performance where its robustness depends strongly on the selected schemes of Bunsen section. It is worth highlighting that, the proposed multi-scale control strategy demonstrates robust performance in the face of the worst case uncertainty scenario. Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.
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