Defluorization of water by a modified membranes from natural materials
Keywords:ceramic and lignocellulosic membranes, microfiltration, modification, dynamic membrane, defluorization of water
Conditions for modification of membranes from natural materials — ceramic from clay minerals and lignocellulosic (from wood) hydroxocompounds Al (III) in the form of dynamic membranes (DM) for water defluorization are established. It is shown that the normative values of MPC for F– in drinking water during defluorination of solutions with ceramic and lignocellulosic membranes were achieved at the initial concentration of F– up to 10 mg/dm3, pH 6.5—7.0, operating pressure 1.0 MPa, concentration Al(III) in the modifying solution, respectively, 33.4—65.0 and 42.2—65.6 mg/dm3 and membrane-supporting additive — 11 mg/dm3. Under these conditions, the concentration of Al(III) in the permeate was lower than its MPC in drinking water. As a result, an additional retention layer in the form of DM was formed on the surface of both membranes from Al(III) hydroxоcompounds, which reduced their specific productivity. The high efficiency of defluorization of solutions can be explained by the formation of stable alumina fluoride complexes between F– ions and positively charged Al(OH)3 particles at pH below the isoelectric point. The adsorption of unbound fluoride ions occurred on the surface of a DM formed of Al(OH)3. An important role in improving the efficiency of the water defluorization process was also played by an additional retention layer of Al(OH)3, which was formed on the surface of both membranes. This was due to the adsorption of F– aluminum hydroxide, which was supplied as a membrane-supporting additive. It is also proposed to use these membranes for the joint purification of water from Al(III) and F– ions at initial concentrations F– up to 10 mg/dm3 and Al(III) 30 mg/dm3, pH 6.5—7.0 and an operating pressure of 1.0 MPa. The effectiveness of defluoridation can be explained by the formation of stable alumina-fluoride complexes that are retained by membranes.
Mamchenko, A. V., Gerasimenko, N. G., Deshko, I. I. & Pakhar, T. A. (2008). Fluorine in drinking water and methods for its removal. Voda i vodoochysni tekhnolohii, No. 6, pp. 10-23 (in Russian).
Boyko, I. A. (2011). General characteristics and features of the conditions of groundwater formati on in the Poltava region as the main source of water supply. Visnyk Poltavskoi derzhavnoi ahrarnoi akademii, No. 2, pp. 169-173 (in Ukrainian).
Akhmedova, G. R., Nogaeva, K. A. & Nurkeev, S. S. (2012). Methods and technologies of water defluorination. Nauka i novie tekhnolohii, No. 2, pp. 110-113 (in Russian).
Amor, Z., Bariou, B., Mameri, N., Taky, M., Nicolas, S. & Elmidaouiet, A. (2001). Fluoride removal from brackish water by electrodialysis. Desalination, 133, No. 3, pp. 215-223. https://doi.org/10.1016/S0011-9164(01)00102-3
Goncharuk, V. V., Deremeshko, L. A., Balakina, M. N. & Kucheruk, D. D. (2013). Regularities of process water defluorination by reverse osmosis of low pressure. Khimia i tehnologia vody, 35, No. 3, pp. 221-228 (in Russian).
Pervov, A. G., Dudkin, E. V., Sidorenko, O. A., Antipov, V. V., Khakhanov, S. A. & Makarov, R. I. (2002). RO and NF membrane systems for drinking water production and their maintenance techniques. Desalination, 132, pp. 315-322. https://doi.org/10.1016/S0011-9164(00)00166-1
GOST 4386-89. Drinking water. Method for determining the mass concentration of fluorides. Moscow: Izdvo standartov, 2002 (in Russian).
Novikov, Yu. V., Lastochkina, K. O. & Boldina, Z. I. (1990). Methods for studying the quality of water in reservoirs. Moscow: Medytsyna (in Russian).
Zapolsky, A. K. (2010). Physical and chemical theory of coagulation water purification. Kyiv: NUPT (in Russian).
Kucheruk, D. D. (1991). Dynamic membranes from aluminuma hydroxopolymers. Khimia i tehnologia vody, 13, No. 7, pp. 664-669 (in Russian).
Pilipenko, A. T., Falendysh, N. F. & Parkhomenko, E. P. (1982). State of aluminum in aqueous solutions. Khimia i tehnologia vody, 4, No. 2, pp. 135-150 (in Russian).
Karelin, V. A. (2012). Water treatment. Physical and chemical bases of water treatment processes. Tomsk: Izd-vo Tomskogo politekhnicheskogo universiteta (in Russian).
Malafeeva, A. V. & Dokuchaeva, Yu. A. (2013). Fluorine compounds are surface water pollutants in the zone of influence of cryolite production. Izvestyia Orenburhskogo gosudarstvennogo agrarnogo universiteta, No. 4, pp. 209-211 (in Russian).
Shugalei, I. V., Garabadzhiu, A. V., Ilyushin, M. A. & Sudarikov, A. M. (2012). Some aspects of effect of aluminium and its compounds on living organisms. Ekologicheskaia khimia, 21, No. 3, pp. 172-186 (in Russian).
Didik, M. V., Kropacheva, T. N. & Ermakova, M. E. (2013). Adsorption of fluoride ions on aluminum oxide. Vestnik Udmurtskogo universiteta, Ser. 4. Fizika I khimia, No. 1. pp. 29-34 (in Russian).
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