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In this article, attapulgite (ATP) as a raw material, hexadecyltrimethylammonium bromide (CTAB) as a modifier, and chitosan (CTS) as a composite are used to prepare a natural mineral-based composite adsorbent CTAB-ATP/CTS for the adsorption of norfloxacin in water. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and specific surface area (BET) were used for characterization. When the initial pH is 7, the dosage of adsorbent is 3 g/L, and the initial concentration of norfloxacin is 50 mg/L, the reaction temperature is 25 °C, the shaking time is 4 h, and the maximum removal rate and adsorption capacity of CTAB-ATP/CTS for norfloxacin reached 94.62% and 23.66 mg/g, respectively. The adsorption of norfloxacin by CTAB-ATP/CTS is more consistent with the pseudo-second-order kinetic model (R2 = 0.9999, 0.9998, 0.9999 at initial concentrations of 25 mg/L, 50 mg/L, 75 mg/L), and the Langmuir isotherm adsorption model(R2 = 0.9903, 0.9935, 0.9933 at temperatures of 25 °C, 30 °C, 35 °C), indicating that the adsorption process of the composite material is controlled by chemical adsorption and its adsorption behavior is mainly single-layer adsorption. [ABSTRACT FROM AUTHOR]

As people's material quality of life continues to improve, water resources become subjected to varying degrees of contamination. As one of the most commonly utilised agents in water treatment, a flocculant exhibits a diverse range of forms and a vast scope of applications. However, the application of flocculants gives rise to a series of issues, including the use of large doses, the formation of sludge, the difficulty of recycling flocculants, and other concerns. The development of new flocculation technology has become a crucial step in enhancing the purification of wastewater and reducing environmental pollution. Magnetic flocculation can be classified into two main categories: magnetic seeds flocculation and magnetic flocculation. This paper presents an overview of the factors influencing magnetic flocculation, including the type of magnetic seeds, magnetic seeds particle size, and other pertinent considerations. Furthermore, the classification of magnetic flocculants in the process of magnetic flocculation is discussed. This includes the types of magnetic flocculant, namely, inorganic composite magnetic flocculants, organic composite magnetic flocculants, and biological composite magnetic flocculants. Inorganic composite magnetic flocculants are inexpensive and simple to produce; however, their dosage is considerable, and the resulting floc is not tightly formed, which impairs the efficacy of flocculation. The use of organic composite magnetic flocculants requires a smaller dosage and exhibits a strong flocculating ability; however, it may possess toxic properties and potentially cause harm to the water body. The biological composite magnetic flocculant exhibits high efficiency and no pollution, yet it is subject to stringent environmental conditions, displays poor stability, and is applicable to a relatively limited range of treatment scenarios. Furthermore, the integration of magnetic flocculation technology with other techniques is classified and summarised in diverse contexts, and the prospective research focus and direction of magnetic flocculants are proposed. [ABSTRACT FROM AUTHOR]

Red mud was modified by impregnation with Co element loading. The Co-RM catalyst was characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-ray fluorescence (XRF), and UV full-band scanning. The results showed that the modified Co-RM catalyst successfully loaded the Co element and formed an irregular pore structure on the surface, thereby increasing the number of active sites of the red mud catalyst and effectively improving the degradation efficiency of tetracycline. Under the optimal conditions of a catalyst dosage of 0.3 g/L, a persulfate dosage of 3 g/L, a reaction temperature of 50 °C, and a pH value of 7, a removal rate of 50 mg/L of tetracycline can be achieved: 89.5% after 90 min. The effects of common anions and humic acids in water, as well as radical quenchers (anhydrous ethanol and tert-butanol), on the degradation of tetracycline were investigated. The results showed that Cl−, CO32−, HCO3−, H2PO4−, NO32−, HPO42−, and humic acids showed inhibitory effects on the degradation of tetracycline, while SO42− showed a promoting effect on the degradation of tetracycline. The free radical quenching experiment showed that the most important free radicals that can degrade tetracycline in the system are sulfate radicals. [ABSTRACT FROM AUTHOR]