Study on the effect of oxidation-ultrasound treatment on the electrochemical properties of activated carbon materials
Authors: Yafeng Fu
Jun Zhao
Zhiqin Zheng
Xindong Ding
Journal: Ultrasonics Sonochemistry (2020)
Discipline: CHEMISTRY
Keywords: Activated carbon; Microwave; Ultrasound.
Affiliations: College of Mining Engineering of TUT, Taiyuan University of Technology, Taiyuan 030024, China., College of Civil Engineering, Guizhou University, Guiyang 550025, China., Sichuan College of Architectural Technology, Deyang 618000, China; State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China., Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory, Southwest University of Science and Technology, Mianyang 621010, China; National Co-Innovation Center for Nuclear Waste Disposal and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010, China; School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 621010, China. Electronic address: .

Abstract:  Activated carbon (AC) has been widely used in water treatment because of its rich pore structure, large specific surface area, simple production process, low preparation cost and wide source of raw materials. In this paper, the regeneration efficiency of low-frequency ultrasonic pretreatment (40 kHz, 115Μw/cm3) on biological activated carbon (BAC) is investigated, and its principle is discussed. The results show that the micro-jet and micro-liquid flow with high temperature and pressure produced by micro-bubble rupture during ultrasonic cavitation play an important role in the regeneration of activated carbon. And optimum ultrasonic treatment time is determined (5 min). In addition, the preparation of cu-loaded activated carbon by ultrasound-microwave method is investigated to pretreat wastewater produced in paracetamol production. The results show that Cu and Cu oxides can be loaded on activated carbon surface by ultrasonic-microwave pretreatment. Finally, the pretreatments of activated carbon by physical, chemical and physical-chemical method are investigated. The effects of the above different pretreatment methods on the structure and adsorption properties of activated carbon are compared and evaluated. 

Retracted: No

PubPeer comments:
 Could the authors explain what is going on in the final sentence? Surely a string of references to random papers needs some kind of rationale, not just  these are also interesting problems .  This work can provide insights into other potential applications (e.g., photocatalytic [47], - [47] W. Chen, L. Chang, S.-B. Ren, Z.-C. He, G.-B. Huang, X.-H. Liu, Direct Z-scheme 1D 2D WO2.72 ZnIn2S4 hybrid photocatalysts with highly-efficient visible-lightdriven photodegradation towards tetracycline hydrochloride removal, J. Hazard. Mater. 384 (2020) 121308.  anaerobic fermentation [48,49,50]) - [48] J. Zhao, M. Xin, J. Zhang, Y. Sun, S. Luo, H. Wang, Y. Wang, X. Bi, Diclofenac inhibited the biological phosphorus removal: Performance and mechanism, Chemosphere 243 (2019) 125380. - [49] J. Zhao, Y. Jing, J. Zhang, Y. Sun, Y. Wang, H. Wang, X. Bi, Aged refuse enhances anaerobic fermentation of food waste to produce short-chain fatty acids, Bioresour. Technol. 289 (2019) 121547. - [50] F. Lan, X. Gong, H. Da, H. Wen, How do population inflow and social infrastructure affect urban vitality? Evidence from 35 large-and medium-sized cities in China, Cities 102454 (2019), https: doi.org 10.1016 j.cities.2019.102454. as well as algorithm fields [51,52] in the future. - [51] J. Su, Z. Sheng, A.X. Liu, Y.u. Han, Y. Chen, A group-based binary splitting algorithm for UHF RFID anti-collision systems, IEEE Trans. Commun. 68 (2) (2020) 998u20131012, https: doi.org 10.1109 TCOMM.2019.2952126. - [52] J. Su, Z. Sheng, V.C.M. Leung, Y. Chen, Energy efficient tag identification algorithms for RFID: survey, motivation and new design, IEEE Wireless Commun. 26 (3) (2019) 118u2013124. The concluding sentence and its cargo of citations seem to be a last-minute addition; they are not present in [a pre-proof version of the paper] . Very similar lists of random papers appear at the ends of [Zheng et al (2020)] , [Zheng et al (2019a)] , [Zheng et al (2019b)] , [Laio et al (2020)] . Are the authors under some kind of contractual obligation? --------------------- The other References generally relate to  the electrochemical properties of activated carbon materials , but they seem to be an unstructured grab-bag of papers, with no attempt to match them to the in-text citations. E.g.  Among them, the most studied pretreatment reagents are HCl, H2SO4, HNO3, HF, NaOH, H2O2, etc. [9u201311]. - [9] C. Long, X. Chen, L. Jiang, Porous layer-stacking carbon derived from in-built template in biomass for high volumetric performance supercapacitors, Nano Energy 12 (2015) 141u2013151. - [10] M. Mousavi-Kamazani, R. Rahmatolahzadeh, S. Amin Shobeiri, F. Beshkar, Sonochemical synthesis, formation mechanism, and solar cell application of tellurium nanoparticles, Ultrason. Sonochem. 39 (2017) 233u2013239. - [11] T.T. Nguyen, Y. Asakura, N. Okada, S. Koda, K. Yasuda, Effect of ultrasonic cavitation on measurement of sound pressure using hydrophone, Jpn. J. Appl. Phys. 56 (2017) 07JE06.  Because different adsorbents have different requirements for the performance of activated carbon adsorbents, in order to meet different needs, activated carbon is often treated to obtain the required surface structure and chemical properties [12u201314]. - [12] Z. Wang, C. Yin, State-of-the-art on ultrasonic oil production technique for EOR in China, Ultrason. Sonochem. 38 (2017) 553u2013559. - [13] J. Hou, C. Cao, X. Ma, From rice bran to high energy density supercapacitors: a new route to control porous structure of 3D carbon, Sci. Rep. 4 (2014) 7260. - [14] I. Tzanakis, G.S.B. Lebon, D.G. Eskin, K.A. Pericleous, Characterizing the cavitation development and acoustic spectrum in various liquids, Ultrason. Sonochem. 34 (2017) 651u2013662  Ozone biological activated carbon (O3 BAC) combined process has been widely used in recent years, while the treatment efficiency of biological activated carbon will decrease with the extension of use time, and replacement or regeneration is required at a certain time [15]. - [15] N.F. Tehrani, J.S. Aznar, Y. Kiros, Coffee extract residue for production of ethanol and activated carbons, J. Cleaner Prod. 91 (2015) 64u201370.  Although traditional heating regeneration can greatly restore the adsorptive properties of activated carbon, such as iodine value and methylene blue value, it will also cause a significant decrease in mechanical strength and a significant increase in loss (generally between 10% and 30%) [16]. - [16] A. Heidari, H. Younesi, A. Rashidi, A. Ghoreyshi, Adsorptive removal of CO2 on highly microporous activated carbons prepared from Eucalyptus camaldulensis wood: effect of chemical activation, J. Taiwan Inst. Chem. Eng. 45 (2014) 579u2013588  As a new method of activated carbon regeneration, ultrasonic has attracted people s attention. However, most of them focus on the regeneration of activated carbon for adsorption, and there is no clear conclusion on the regeneration efficiency of biological activated carbon [23]. - [23] L. Wang, J. Yu, X. Dong, Three-dimensional macroporous carbon Fe3O4-Doped porous carbon nanorods for high-performance supercapacitor, ACS Sustain, Chem. Eng. 4 (3) (2016). These are [all familiar references] . ,