Study on Photocatalytic Desulfurization and Denitrification Performance of Cu- and Cr-Modified MWCNT
Round 1
Reviewer 1 Report
Submitted manuscript titled: Study on Desulfurization and Denitrification Performance of MWCNTs Modified by Cu and Cr, by Yi Sun et. al., represents an interesting work. Generally, well done concerning both scientific point of view and the results presentation. Synthesis, characterization, adsorption properties and evaluation of the results, all done comprehensively and precisely.
English - there are many grammatical errors which should be corrected throughout the text:
– for example, some grammatical errors are highlighted (some corrected) in the Abstract and Introduction Sections (see attached pdf file of the manuscript).
XPS Figures: y-ax- it is not explained what C/S means (supposedly Counts per second). It might be better to put: Intensity (a.u.) or Intensity (cps).
Comments for author File: 
Comments.pdf
Author Response
请参阅附件。
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments concerning manuscript:
Study on Desulfurization and Denitrification Performance of 2 MWCNTs Modified by Cu and Cr
By Yi Sun, Weiwei Jian, Siqi Tong, Danzhu Ma, Bohan Zhuang* and Fnegrui Jia
The presented manuscript is long and counts 24 pages. It describes thoroughly by many techniques properties and structures of newly prepared sorbents with the composition of MWCNTs/TiO2 doped with Cu and Cr.
The aim of this work was to develop technologically important effective SO2 and NO adsorbent. Generally the target was achieved. There are few question that should be answered before the manuscript could be qualified for publication.
The comments / questions are as follows:
- Should the title not indicate that it is a photocatalytic process?
- The opening part of the manuscript is clearly poorly written in English; so many suggestions for corrections are listed below and highlighted in the original manuscript (attached). Much better English is in discussion.
- The preparation of the adsorbent using sol-gel technique is not exhausting
- The temperature of the adsorption processes is not given; so what happens to the sulfates formed from SO2 at this temperature?
- The lack of this work work is, for example, a mention of the energy level required to carry out the process
Line 8 Carbon nanotubes is one promising adsorbent - consider: Carbon nanotubes are one of promising adsorbents
13 the MOLAR??? ratio Cu to Cr is 3 displays
14 36.828 and 12.341 mg/g. Seems to me the values should be rounded.
15 m3 should be m3
16 and space velocity 1003 h-1 is it cubic meters per hour??? Replace space velocity by volumetric speed
16 were – suggested is or was?
28 application – applications?
30 Remove And
32 for -> of
34 it’s necessary to pay more attention to desulfurization and denitrification at the same time. Suggested: Therefore, more attention should be paid to the simultaneous desulphurization and denitrification.
36 Adsorption: suggested Adsorptive
49 place try to substitute by container
51-52 Moreover, carbon nanotubes reduce the agglomeration activity of TiO2 in the catalytic oxidation process and improve the catalytic oxidation performance consider: - carbon nanotubes reduce the agglomeration tendency of TiO2 what improves efficiency of catalytic oxidation.
53-54 On the basis of loading TiO2 on carbon nanotubes, doping with metal improves the adsorption property of the adsorbents – consider: carbon nanotubes loaded with TiO2 and doped with metal(s) improved the adsorption property of such materials.
54-55 Some researches were carried out for wastewater treatment consider: - Some studies were carried out for wastewater treatment.
55 Wang et al.[22] introduced metal Au on CNT-TiO2 showed higher activity…
56 remove the
58 under visible light consider – illuminated with visible light
58-59 Shaari et al.[24] synthesized Ce into CNT-TiO2 and eliminated 94% of phenol. Consider: Shaari et al.[24] eliminated 94% of phenol from water (???) using CNT-TiO2 doped with Ce.
59-63 Chen et al.[25] prepared CNT-TiO2 composite with Ni to photocatalytic degradation methylene blue, methylene orange, and rhodamine, with the … Consider: Chen et al.[25] prepared CNT-TiO2 composite with Ni for photocatalytic degradation of methylene blue, methyl orange, and rhodamine, with the degradation efficiency of 94%, 87.5%, and 87.5%, respectively.
53-61 the paragraph is not clear: whether the CNT-TiO2 system was doped with metal(s) or their derivatives, e.g. salts
62 In recent years, the doped metal of carbon nanotubes consider: In recent years, the metal doped carbon nanotubes
64 were replace by of
67 removal, put removal;
69 and 71 CNT-TiO2 consider CNT/TiO2
72 single metal-doped, none about bimetal-doped. -> single metal doped, and not about doped with two metals.
74 detected -> characterized
76 The influenceS of O2, H2O composition -> is only oxygen and water the components of the studied mixture? It is not clear. Replace space velocity by volumetric speed in all cases
82 of -> used in
91 It’s necessary to acidize the raw MWCNTs before synthesize -> It was necessary to acidify the raw MWCNTs before synthesis
91-96 Consider changes of the part by: Firstly, the raw MWCNTs was immersed in a mixture of H2SO4 and HNO3 is 3:1(v/v)[29] and then sonicated well for 30 min. After that, the acid treated MWCNTs were rinsed with distilled water until the pH of the filtrate was 6-7. Finally, the products were dried at 80°C in a drying oven, and then placed in a desiccator for next study or use.
97 remove stated
98 acid treated -> of acid treated
101 dripping -> adding
101-102 Followed, leave the gel obtained for 2 h, and then dried for 24 h at 80 °C. -> Following/next, the gel obtained was left for 2 h, and dried for 24 h at 80°C.
106 detected by different equipment. Transmission -> were characterized by transmission …
109 characterized -> characterize
97-104 Question: At chich stage and how the MWCNTs are combined with gels of Cu or Cr salts? It is not described
127 diameter, -> and
130 to -> below???
136 arranged -> distributed???
139-140 Waiting for the concentration of simulated flue gas displayed stability in the flue gas analyzer -> after the composition of flue gas showed by gas analyzer were stabilized …
149 space velocity -> volumetric speed/velocity Correct this in all cases. Space velocity may mean cosmic velocity.
162 are100, 20, and 20 nm -> it is not clear!!!
164 was -> were
164 unacidified -> in fact the applied procedure is connected with oxidation. Hence carbonyl and carboxyl groups are formed on MWCNTs surface and cutting proceeds
185 was participate -> participate
296 Cuo -> CuO????
308 into -> onto
309 (0.077nm) and Cu2+ (0.075nm)….. (0.074nm) -> (0.077 nm) and Cu2+ (0.075 nm)…… (0.074 nm)
The same holds to line 312 and 313
333 235 min put space
472 hydrolyzes --> converts???
503 duo to generale --> due to generation of
Figure No 13 is probably damaged (black rectangle at the bottom)
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
This version is much improved. There are only few mistakes that are highlighted (almost black) in the body text. The corrected version with some remarks is attached.
I recommend this version to be published in PROCESSES.
Regards
Jan Biernat
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
