STUDY OF THE PROCESS OF REMOVING PHENOL FROM WATER USING POLYSULFONE MEMBRANES

Ensuring environmental safety and preserving natural resources are the most important tasks of environmental engineering. The state of the environment directly depends on the level of development of technologies used to protect it.Often, modern enterprises of the petrochemical, chemical, and coking industries form wastewater containing various types of pollution that have a negative impact on the environment. The development and implementation of new, more efficient wastewater treatment methods and the possibility of their reuse are relevant in our time.Phenolic wastewater poses a great danger to the environment. Phenols enter the wastewater of coke, oil refining and petrochemical industries.One of the most promising methods for removing phenol from water, in small concentrations, are membrane methods. The authors studied the characteristics of domestic polysulfone membranes of the ORM31K and ORM32KM brands (Vladimir) in the purification of phenolic-containing waters, and the dependences of selectivity and permeability on operating pressure were constructed.As part of the study, it was found that the initial polysulfone membranes of the ORM31K and ORM32KM brands have low selectivity for phenol, while their permeability increases with increasing pressure. Modification of the membranes by applying chitosan and treatment with nitric oxide (IV) has significantly improved their performance. A chitosan layer up to 0.01 mm thick forms a diffusion barrier on the membrane surface, providing an increase in selectivity of up to 62 % for the ORM31K membrane and up to 67 % for the ORM32KM membrane. However, this modification reduces the permeability of this membrane by 2.8–5.2 times. Treatment with nitric oxide (IV) proved to be the most effective: a selectivity of 98 % was achieved at 6 atm for the ORM31K membrane, 77 % at 6 atm for the ORM32KM membrane. The permeability of the ORM32KM membrane also decreased by 6.3–11.3 times after chemical modification.Thus, both modification methods significantly increase the selectivity of the membranes while reducing permeability, and treatment with nitric oxide (IV) provides the best balance of characteristics. The most promising membrane for purifying phenolic waters is the ORM31K membrane modified with nitrogen (IV) oxide, which removes phenol with an efficiency of at least 97% in the pressure range from 6 to 13 atm.