A Review: Subcritical Water Extraction of Organic Pollutants from Environmental Matrices

Abstract

Most organic pollutants are serious environmental concerns globally due to their resistance to biological, chemical, and photolytic degradation. The vast array of uses of organic compounds in daily life causes a massive annual release of these substances into the air, water, and soil. Typical examples of these substances include pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Since they are persistent and hazardous in the environment, as well as bio-accumulative, sensitive and efficient extraction and detection techniques are required to estimate the level of pollution and assess the ecological consequences. A wide variety of extraction methods, including pressurized liquid extraction, microwave-assisted extraction, supercritical fluid extraction, and subcritical water extraction, have been recently used for the extraction of organic pollutants from the environment. However, subcritical water has proven to be the most effective approach for the extraction of a wide range of organic pollutants from the environment. In this review article, we provide a brief overview of the subcritical water extraction technique and its application to the extraction of PAHs, PCBs, pesticides, pharmaceuticals, and others form environmental matrices. Furthermore, we briefly discuss the influence of key extraction parameters, such as extraction time, pressure, and temperature, on extraction efficiency and recovery.

Investigating the possibility of using subcritical water for extracting polycyclic aromatic hydrocarbons from soils of the dry-steppe zone

“…The study tested different parameters of temperature (200°C, 250°C and 300°C) and extraction time (10, 20 and 30 minutes). The tested range of temperature and pressure is most commonly found as a recommendation for performing the extraction of organic compounds, including PAHs in subcritical water media (Sushkova et al, 2015(Sushkova et al, , 2016Taki et al, 2018;Yabalak et al, 2024;Zhu et al, 2024).…”

“…Subcritical aqueous method of processing chicken manure allowed to obtain a liquid extract containing organic acids, characterized by the presence of basic functional groups, high content of organic carbon and trace elements . Subcritical and supercritical states of water were used as extractants in the extraction of some individual PAH compounds (benz(a)pyrene, phenanthrene, fluoranthene, pyrene) from Calcic Chernozems, Andosols, sandy substrates and sewage sludge (Islam et al, 2013;Sushkova et al, 2013Sushkova et al, , 2014Sushkova et al, , 2015Yabalak et al, 2024). The development of pollutant extraction technology for qualitative assessment of ecosystem ecological state requires selecting conditions and testing the method of subcritical water extraction of the entire pool of priority PAHs for soils most vulnerable to pollution.…”

Preparation of CS-LS/AgNPs Composites and Photocatalytic Degradation of Dyes

“…Although there are many methods for treating dye wastewater, most of them are complex. Relatively, adsorption has been found to be a more effective method [ 7 , 8 , 9 ], and, as reported elsewhere, it has emerged as a promising and versatile technique for water purification.…”