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A method for processing of rice wastes (husk, straw) into activated carbon was proposed. The thermolysis of raw material and the activation of carbonizate were carried out at 500oС and 800oС temperatures respectively. The properties of obtained activated carbon are determined by standard methods. The porous structure of obtained carbon have been studied under scanned electronic microscope. According to the results of experimental studies, activated charcoal obtained from rice husks corresponds to the WAC brand, activated charcoal obtained from rice straw corresponds to BAU-A grade. The research will allow rational use of agricultural waste in order to obtain useful secondary adsorbent products intended for adsorption and liquid media. References [1] Biswas B., Singh R., Kumar J., Singh R., Gupta P., Krishna B.B., Bhaskar T. Pyrolysis behavior of rice straw under carbon dioxide for production of bio-oil // Renewable energy. 2018. Vol. 129. P. 686-694. [2] Wu J., Collins S.R.A., Elliston A., Wellner N., Dicks J., Roberts I.N., Waldron K.W. Release of cell wall phenolic esters during hydrothermal pretreatment of rice husk and rice straw // Biotechnology for biofuels. 2018. Vol. 11. DOI: 10.1186/s13068-018-1157-1. [3] GOST 6217. Ugol' aktivnyj drevesnyj droblenyj. Tehnicheskie uslovija. M.: IPK Izd-vo standartov, 2003. [4] GOST R 56357-2015. Ugol' aktivirovannyj AG-3. Tehnicheskie uslovija. M.: Standartinform. 2016. [5] Kinle H., Bader Je. Aktivnye ugli i ih promyshlennoe primenenie. L.: Himija, 1984. 216 p. [6] Himicheskij jenciklopedicheskij slovar'. M.: Sovetskaja jenciklopedija, 1983. 19 p. [7] Arezou Niksiar, Bahram Nasernejad. Activated carbon preparation from pistachio shell pyrolysis and gasification in a spouted bed reactor // Biomass and Bioenergy. 2017. Vol. 106. P. 43-50. [8] Yeru Liang, Chen Yang, Hanwu Dong, Wenqi Li, Hang Hu, Yong Xiao, Mingtao Zheng, Yingliang Liu. Facile Synthesis of Highly Porous Carbon from Rice Husk // ACS Sustainable Chem. Eng., Just Accepted Manuscript. DOI: 10.1021/acssuschemeng.7b01315. Publ. (Web): 24.06.2017. [9] Wenli Zhang, Nan Lin, Debo Liu, Jinhui Xu, Jinxin Sha, Jian Yin, Xiaobo Tan, Huiping Yang, Haiyan Lu, Haibo Lin. Direct carbonization of rice husk to prepare porous carbon for supercapacitor applications // Energy. 2017. Vol. 128. P. 618-625. [10] Pred.patent RK №15933. Sposob poluchenija karbonizirovannogo sorbenta dlja izvlechenija zolota iz rastvorov // Data opubl. 15.07.2005, bjul. №7. Mansurov Z.A., Mansurova R.M., Nikolaeva A.F., Vasil'ev D.G. [11] Hoang Kim Bong, Timofeev V.S., Tjomkin O.N., Gafarov I.G., Timoshenko A.V., Artamonova T.V., Gorbacheva O.V., Kol'vah I.P., Mishulin G.M., Shhepakin M.B., Kozhura E.A., Haziev R.M., Vatolin A.K. Sposob poluchenija aktivirovannogo uglja iz othodov sel'skogo hozjajstva // Patent RF №2315712. Data opubl. 27.01.2008. [12] Muhin V.M., Voropaeva N.L., Karpachev V.V., Harlamov S.A., Spiridonov Ju.Ja., Gur'janov V.V., Dmitrjakova E.E. Sposob poluchenija aktivnogo uglja iz rastitel'nyh othodov // Patent RF №2527221. Data opubl. 27.08.2014. [13] Hanum F., Bani O., Wirani L.I. Characterization of Activated Carbon from Rice Husk by HCl Activation and Its Application for Lead (Pb) Removal in Car Battery Wastewater // IOP Conf. Series: Materials Science and Engineering 180 (2017) 012151 doi:10.1088/1757899X/180/1/012151. [14] Hanum F., Bani O., Izdiharo A.M. Characterization of Sodium Carbonate (Na2CO3) Treated Rice Husk Activated Carbon and Adsorption of Lead from Car Battery Wastewater // IOP Conf. Series: Materials Science and Engineering 180 (2017) 012149 doi:10.1088/1757899X/180/1/012149. [15] Yeru Liang, Chen Yang, Hanwu Dong, Wenqi Li, Hang Hu, Yong Xiao, Mingtao Zheng, Yingliang Liu. Facile Synthesis of Highly Porous Carbon from Rice Husk // ACS Sustainable Chem. Eng., Just Accepted Manuscript. DOI: 10.1021/ acssuschemeng.7b01315. 262[16] GOST 17219. Ugli aktivnye. Metod opredelenija summarnogo obema por po vode. M.: Izdatel'stvo standartov, 1988. [17] GOST 12597. Sorbenty. Metod opredelenija massovoj doli vody v aktivnyh ugljah i katalizatorah na ih osnove. M.: Izdatel'stvo standartov, 1989. [18] GOST 16190. Sorbenty. Metod opredelenija nasypnoj plotnosti. M.: Izdatel'stvo standartov, 1970.

A strategy to create highly effective antimicrobial agents was proposed based on the conjugation of three functional components: a cationic quaternary ammonium salt (QAS) that exerts a membrane-disrupting effect and promotes selective accumulation on bacterial surfaces; a phosphonamidate linker for controlled activation; and a sterically hindered phenol (SHP) fragment as a potential redox component. This approach enabled the preparation of 40 target phosphonamidate–SHP/QAS hybrids in high yields (88–98%). Evaluation of their antimicrobial activity against major pathogens and methicillin-resistant Staphylococcus aureus (MRSA) revealed high potency against Gram-positive bacteria. The lead compounds achieved minimum inhibitory concentration (MIC) values of 0.7–2.8 μM, which is up to 10 times lower than that of the reference drug, norfloxacin. Mechanistic studies confirmed that these hybrids disrupt the bacterial membrane. In addition, an increase in intracellular ROS levels was observed for the most active compound. The SHP/QAS hybrids retained high activity against S. aureus ATCC 209P after 17 passages and showed low cytotoxicity (SI = 62–92) and negligible hemolysis. These properties indicate that this approach may offer a useful strategy for developing antibacterial agents with a potentially lower risk of inducing conventional resistance mechanisms.

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