A novel sinusoidal design for an electrocoagulation reactor followed by an electro-Fenton reaction and a porous ceramic filter for the treatment of polluted waters.

In this research work, a novel design of an electro-Fenton reactor for the treatment of polluted water was investigated. In addition to the reactor with iron electrodes, a ceramic filter was also used. An electrical circuit was designed to change the cathodes and anodes every 24 s via an electrical relay between the electrodes. The untreated water was sucked into the reactor with an air pump and entered the electrocoagulation chamber after filtration with a ceramic filter. Then, it flows to the polyethylene filter to separate the coagulated particles from the fresh water. To produce 12 L of clean water, the system consumed 100 W of energy. Analysis of a river sample showed a reduction in nephelometric turbidity units (NTUs), total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Turbidity reduction studies have shown that the system can improve water transparency by 95%, thereby improving water quality to acceptable levels. Further, this system reduced TSS by more than 86%. In addition, BOD was reduced by more than 84% and COD by more than 88%, as shown by the change in the ratio of BOD to COD from 0.44 to 0.625, indicating improved water quality. According to the results, the treatment system can clean polluted waters, particularly during floods and when industries discharge their effluents into rivers.

Nanoporous hydrogel absorbent based on salep: Swelling behavior and methyl orange adsorption capacity.

This study used the gas-blowing method to develop a nanoporous hydrogel using poly (3-sulfopropyl acrylate-co-acrylic acid-co-acrylamide) grafted onto salep. The synthesis of the nanoporous hydrogel was optimized by various parameters for maximum swelling capacity. The nanoporous hydrogel was characterized using FT-IR, TGA, XRD, TEM, and SEM analyses. Images from SEM showed numerous pores and channels in the hydrogel with an average size of about 80 nm, forming a honeycomb-like shape. The change in surface charge was investigated by zeta potential and revealed that the surface charge of the hydrogel ranged from 20 mV at acidic conditions to -25 mV at basic conditions. The swelling behavior of optimum superabsorbent hydrogel was determined under different environmental conditions, such as different pH values, ionic strengths of the environment, and solvents. In addition, the swelling kinetics and the absorbance under loading of the hydrogel sample in different environments were investigated. Moreover, Methyl Orange (MO) dye was removed from aqueous solutions using the nanoporous hydrogel as an adsorbent. The adsorption behavior of the hydrogel was examined under various conditions, and the adsorption capacity of the hydrogel was found tobe 400 mg g-1. The maximum water uptake was obtained under the following conditions: Salep weight = 0.01 g, AA = 60 µL, MBA = 300 µL, APS = 60 µL, TEMED = 90 µL, AAm = 600 µL, and SPAK = 90 µL. Lastly, the adsorption kinetics was studied by employing pseudo-first-order, pseudo-second-order, and intra-particle diffusion models.