The degradation of recalcitrant organic pollutants by sulphate radical (SO₄^•-) represents one of the most recent developments in oxidation-based water treatment. In most cases, persulfate (PS) acts as a precursor of sulphate radicals. This study employed ultrasound-activated PS to generate reactive species, facilitating the degradation of bisphenol S (BPS), a well-known contaminant of emerging concern (CECs). An ultrasound with a frequency of 620 kHz and 80 W power was utilised for the degradation studies. The applied oxidation system successfully resulted in the complete degradation of BPS in both pure and real environmental water samples. Additionally, the Chemical oxygen demand (COD) was reduced to an acceptable limit in both matrices, with a reduction of 85 % in pure water and 73 % in river water. The degradation was monitored by varying chemical parameters such as pH, inorganic ions, and organics concentration. The results indicate that under specific pH conditions, the degradation efficiency followed the order of pH 3 > 4 > 7 > 11. The presence of coexisting matrices suppressed the efficiency by scavenging the reactive species. Utilizing high-resolution mass spectrometry (HRMS) analysis, this study identified seven intermediate products during identified during the degradation of BPS. Furthermore, a comprehensive mechanism has been deduced for the transformation and degradation process. All the results presented in this study underscore the applicability of the US/PS system in the removal of CECs.

The regulating of a structure and a pores volume of activated carbons by mechanical, chemical and thermal activations of agricultural wastes, such as apricot kernel shells were studied. The mechanical activation was provided in the grinding mill, in the aqueous medium. The chemical activation was implemented by treatment with sulfuric, hydrochloric, phosphoric acids at the concentrations of 5%–40% and by zinc chloride at the penetration coefficients of 0.1÷0.6. The thermal activation was effected in carbon dioxide atmosphere at the temperatures of 300÷100 ? ?. It was researched an influence of acid concentration, ZnCl 2 coefficient of impregnating, CO 2 temperature per volume of micro-, meso- and macropores. Activated carbons have arranged porous structures in the following line: processed by ZnCl 2 and CO 2 > processed by ZnCl 2 > processed by H 2 SO 4 > processed by H 3 PO 4 . For the samples are treated by ZnCl 2 and subsequent CO 2 , the activation optimal parameters are following: temperature of CO 2 =500 ? ?; the penetration coefficient = 0.4.

This study focused on monitoring phosphorus (P) concentrations in the water of the Ramsar site, Lake Vembanad, with a special focus on the mouths of the river bodies draining into the lake, a known hotspot for eutrophication. Four phosphorus fractions—total reactive phosphorus (TRP), total acid hydrolysable phosphorus (TAHP), total organic phosphorus (TOP), and total phosphorus (TP)—were monitored during the pre-monsoon and post-monsoon seasons. The results revealed high levels of all monitored phosphorus fractions, with an average concentration exceeding 300 ppb P across both seasons, indicating a highly eutrophic state. Notably, TRP, TOP, and TP showed high concentrations in both the pre-monsoon and post-monsoon periods. These data suggest significant phosphorus input into the lake’s surface water, potentially triggering excessive algal growth and threatening the biodiversity of this rich wetland ecosystem.

The aim of the research is the production of activated carbon from the plum pit shells in a drum-type steam-gas furnace. To study the production of activated carbon, methods were used based on the study of individual patterns, analysis of the specific surface, determination of the porous structure, analysis of the structural-sorption and physicochemical characteristics of the pit shell. The novelty is research on determining the characteristics of activated carbon and the effect of thermal activation temperature in a flow of CO2 and H2O in a mass ratio of 20:80 on the pore volume. During activation at a process temperature of 780 °C, the surface was destroyed by powerful thermal activation, and as a result, micropores of 8–10 μm formed and a cell configuration arose. The adsorption kinetics showed that the maximum efficiency is achieved at a duration of 0.5 h for chloroform-extracted and 2 h for hexane-extracted oil products, as well as an adsorbent dose of 4 kg/m3. The results obtained in the research of the process of oily wastewater treatment showed that the effect of treatment with the activated plum pit shells (95.5%) is greater than the effect of treatment with coagulants and clays (88.5–71)%.

The aim of this work is to develop an adsorber with a fixed bed of adsorbent and a mathematical model of the adsorption bed. On the basis of the theory of fractal clusters, an equation for calculating the layer porosity that takes into account the average cluster radius, the fractal dimension of the cluster structure and the anisotropy index of the adsorbent layer is proposed. The adsorption mechanism in the layer was established, and the proportionality coefficients were estimated based on the tetrahedral packing of grains in the layer. Based on the analysis of the movement of the carrier through the adsorption layer and its deformation, an equation that describes the change in the porosity of the granular layer when the water flow moves through it, depending on the proportionality coefficients, is proposed. An equation that made it possible to calculate the change in the porosity of the layer in comparison with the porosity of the stationary stacking was obtained. An effective design for the adsorber that made it possible to increase the efficiency of using the structure of porous adsorption layers was developed. Equations of the heat and mass transfer taking into account the granule shape coefficient, effective diffusion coefficient and mass transfer coefficient were derived. These equations establish the relationship between the average distance between active centers on the adsorption surface and the degree of filling of the adsorption surface with the adsorbed component.

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