Evaluation and Simulation of the Adsorption Capacity of Octocrylene Sunscreen on Commercial Carbon and Biochar from Spent Coffee Beans

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Comments to author

            Rocha et al investigated the “Use of commercial carbon and biochar from spent coffee grounds in the adsorption of the octocrylene sunscreen”. The author wrote the manuscript in a well-manner. Though, the manuscript requires minor revision before publication. The comments to the authors are given below.

1.      The title is very general. I suggest the author to modify the title efficiently.

2.      What is the novelty of the work?

3.      What is the source of commercial carbon?  

4.      In line no 96, why do you increase the temperature?

5.      What is the λmax value of octocrylene?

Author Response

Response to the Reviewer Comments:

REFEREE 1 - in yellow on the Revised Manuscript

Authors: We are grateful for the comments and questions from reviewer 1.

 

COMMENTS FOR AUTHORS PROCESSES 3047376

General Comments: Rocha et al investigated the “Use of commercial carbon and biochar from spent coffee grounds in the adsorption of the octocrylene sunscreen”. The author wrote the manuscript in a well-manner. Though, the manuscript requires minor revision before publication. The comments to the authors are given below.

Specific comments:

Issue 1) The title is very general. I suggest the author to modify the title efficiently.

authors' response: We agree. We modified the title.

Modified title: Evaluation and Simulation of the adsorption capacity octocrylene sunscreen on commercial carbon and biochar from spent coffee beans

 

Issue 2) What is the novelty of the work?

authors' response: We emphasize the novelty brought by the manuscript at the end of the introduction, as follows:

Line 113-117: This manuscript brings important results due to: evaluate, for the first time, adsorption techniques using charcoal (commercial and biochar) to remove octacrylene solar filter from the aqueous medium and use, for the first time, biochar from used coffee grounds (a recalcitrant residue in soil and water, produced on a large scale around the world) to remove octacrylene from the aqueous medium.

 

Issue 3) What is the source of commercial carbon?

authors' response: Commercially available activated carbon can be generated from natural materials such as biomass, lignite, or coal. One of the characteristics of activated carbon is its low cost, so companies make activated carbon commercially available based on coal because it has lower operating costs [1].

1. Rafatullah, M.; Sulaiman, O.; Hashim, R.; Ahmad, A. Adsorption of Methylene Blue on Low-Cost Adsorbents: A Review. J. Hazard. Mater. 2010, 177, 70–80, doi:10.1016/j.jhazmat.2009.12.047.

 

Issue 4) In line no 96, why do you increase the temperature?

authors' response: The temperature increase to 110°C is to remove all relative humidity from the functional material obtained, so that the material does not funnel or aggregate.

 

Issue 5) What is the λmax value of octocrylene?

authors' response:  We input the wavelength of octacrylene, please look at Line 164-166.

Line 164-166: After shaking, the samples were filtered and measured at a wavelength of 305 nm for octocrylene, according to Santo et al. [4].

 

4. Santo, D.E.; Dusman, E.; da Silva Gonzalez, R.; Romero, A.L.; dos Santos Gonçalves do Nascimento, G.C.; de Souza Moura, M.A.; Bressiani, P.A.; Filipi, Á.C.K.; Gomes, E.M.V.; Pokrywiecki, J.C.; et al. Prospecting Toxicity of Octocrylene in Allium Cepa L. and Eisenia Fetida Sav. Environ. Sci. Pollut. Res. 2023, 30, 8257–8268, doi:10.1007/s11356-022-22795-2.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript compares the adsorption of Octocrylene on zinc chloride-modified coffee biochar and commercial carbon. The authors performed novel work, which is of great interest to biochar-related research. Therefore, the manuscript is worthy of publication in the Journal of Processes. To further clarify the paper, the authors are encouraged to address the following points:

1. The Langmuir capacity numbers mentioned in the abstract do not match the numbers obtained from Langmuir fit. 

2. Mention the purity of Octocrylene under section 2.1

3. Mention the particle sizes of commercial carbon and charcoal under section 2.2

4. Correct the chemical formulas in lines  273 and 311.

5. Explain the chemical interactions between Octocrylene and adsorbent during the adsorption

6. Explain the use of zinc chloride modification for the adsorption of Octocrylene

7. The chemical or physical characteristics of adsorbent materials are not mentioned. 

8. Include a graphical abstract to improve the interest of the readers.

Author Response

Response to the Reviewer Comments:

REFEREE 2 - in green on the Revised Manuscript

Authors: We are grateful for the comments and questions from reviewer 2.

 

COMMENTS FOR AUTHORS PROCESSES 3047376

General Comments: This manuscript compares the adsorption of Octocrylene on zinc chloride-modified coffee biochar and commercial carbon. The authors performed novel work, which is of great interest to biochar-related research. Therefore, the manuscript is worthy of publication in the Journal of Processes. To further clarify the paper, the authors are encouraged to address the following points:

Specific comments:

Issue 1) The Langmuir capacity numbers mentioned in the abstract do not match the numbers obtained from Langmuir fit.

authors' response: We agree. We change the score as in Figure 3.

Line 26: …with a capacity of 37.822 ± 0.005 µg∙mg^-1 compared to 33.602 ± 0.202 µg∙mg^-1 for commercial…

 

Issue 2) Mention the purity of Octocrylene under section 2.1

authors' response: Agreeing with the comment by the reviewer. We cite in the manuscript the purity of octacrylene.

Line 122: …analytical grade, i.e.100% purity, as were…

 

Issue 3) Mention the particle sizes of commercial carbon and charcoal under section 2.2

authors' response: We agree. We insert it in Line 127-132.

Line 127-132: Commercial coal has only carbon and hydrogen as its structure, has a BET surface area of 543.4 m²∙g^-1, pore volume of 0.28 cm³∙g^-1 and micropore volume of 0.20 cm³∙g^-1 [28]. Biochar was produced from coffee grounds, predominating carbon and lignocellulosic material. Rocha study [15], the surface area was 564.4 m²∙g^-1, pore volume was 0.32 cm³∙g^-1, and micropore volume was 0.25 cm³∙g^-1.

15. Rocha, B.C. da S.; Moraes, L.E.Z. de; Santo, D.E.; Peron, A.P.; Souza, D.C. de; Bona, E.; Valarini, O. Removal of Bentazone Using Activated Carbon from Spent Coffee Grounds. J. Chem. Technol. Biotechnol. 2024, 99, 1342–1355, doi:10.1002/jctb.7630.
16. Fletcher, A.; Somorin, T.; Aladeokin, O. Production of High Surface Area Activated Carbon from Peanut Shell by Chemical Activation with Zinc Chloride: Optimisation and Characterization. Bioenergy Res. 2024, 17, 467–478, doi:10.1007/s12155-023-10683-7.

 

Issue 4) Correct the chemical formulas in lines 273 and 311.

authors' response: We corrected the superscripts.

Line 347-348: …octacrylene 600 µg.L^-1 with (a) Commercial Carbon, (b) Biochar ZnCl₂.

Line 385-386: …with C₀ ranging from 600 µg.L^-1: (a) Commercial Carbon, (b) Biochar ZnCl₂.

 

Issue 5) Explain the chemical interactions between Octocrylene and adsorbent during the adsorption

authors' response: We agree. Based on our normative articles, we inserted a paragraph about the possible mechanism.

Line 324-338: The mechanism of interaction between octocrylene and the adsorbents Biochar and commercial charcoal remains unclear. Grilla [45], Rocha [15], Mrozik [46], and Giannakopoulos [47] proposed an adsorption mechanism between the pollutant and the adsorbent that considered that the reactions occurred between radicals and non-radicals. Thus, based on assumptions, in aqueous solutions, Biochar has a radical (Cl^-) and commercial charcoal only (OH^-), as it does not present any chemical agent on its surface. Next, intermediate products related to oxygen groups are generated on the surfaces of the adsorbents. The octocrylene adsorption process initially occurs on the surface of biochar and commercial charcoal due to interactions between the octocrylene aromatic ring and the functional material. [47]. This occurs due to the OH- group on the surface of the adsorbent due to the charge generated from the octocrylene with the functional material. Biochar anions can also be adsorbed on sites that contain oxygen. The OH^- groups on the surface of functional materials can participate in oxidation-reduction reactions, mainly in transferring π electrons from the adsorbed octocrylene molecule, as the aromatic phase can increase the transfer capacity of electrons displaced in the adsorption process. [45].

 

15. Rocha, B.C. da S.; Moraes, L.E.Z. de; Santo, D.E.; Peron, A.P.; Souza, D.C. de; Bona, E.; Valarini, O. Removal of Bentazone Using Activated Carbon from Spent Coffee Grounds. J. Chem. Technol. Biotechnol. 2024, 99, 1342–1355, doi:10.1002/jctb.7630.
16. Grilla, E.; Vakros, J.; Konstantinou, I.; Manariotis, I.D.; Mantzavinos, D. Activation of Persulfate by Biochar from Spent Malt Rootlets for the Degradation of Trimethoprim in the Presence of Inorganic Ions. J. Chem. Technol. Biotechnol. 2020, 95, 2348–2358, doi:10.1002/jctb.6513.
17. Mrozik, W.; Minofar, B.; Thongsamer, T.; Wiriyaphong, N.; Khawkomol, S.; Plaimart, J.; Vakros, J.; Karapanagioti, H.; Vinitnantharat, S.; Werner, D. Valorisation of Agricultural Waste Derived Biochars in Aquaculture to Remove Organic Micropollutants from Water – Experimental Study and Molecular Dynamics Simulations. J. Environ. Manage. 2021, 300, doi:10.1016/j.jenvman.2021.113717.
18. Giannakopoulos, S.; Frontistis, Z.; Vakros, J.; Poulopoulos, S.G.; Manariotis, I.D.; Mantzavinos, D. Combined Activation of Persulfate by Biochars and Artificial Light for the Degradation of Sulfamethoxazole in Aqueous Matrices. J. Taiwan Inst. Chem. Eng. 2022, 136, doi:10.1016/j.jtice.2022.104440.
19. Heo, J.; Yoon, Y.; Lee, G.; Kim, Y.; Han, J.; Park, C.M. Enhanced Adsorption of Bisphenol A and Sulfamethoxazole by a Novel Magnetic CuZnFe₂O₄–Biochar Composite. Bioresour. Technol. 2019, 281, 179–187, doi:10.1016/j.biortech.2019.02.091.

 

Issue 6) Explain the use of zinc chloride modification for the adsorption of Octocrylene

authors' response: We agree. Based on our normative articles, we inserted a discuss about zinc chloride modification.

Line 308-323: The surface of activated carbon without a chemical activator can accommodate elements such as oxygen, hydrogen and nitrogen in the form of functional groups, arising from the activation process. For the most part, the solid interface is predominantly composed of oxygenated functional groups, such as: carboxylic acids; hydroxyl groups (when associated with aromatic chains they confer a phenolic character); carbonyls; lactones; quinones [41,42].

The use of chemical activators contributes to the formation of pores and an increase in channel functional groups in the activated carbon matrix [28]. The use of precursor and volatile materials, such as ZnCl₂, are used as a dehydrating effect on lignocellulosic materials, such as spent coffee grounds in natura, previously carbonized, ZnCl₂ increases the mass proportion and causes the easier release of volatile substances, so that the absorption of nitrogen increases in the Biochar, which consequently increases its surface area [43]. The use of ZnCl₂ breaks down the cellulose molecules and leads to an increase in different cavities, which causes a greater surface area on the activated carbon. Upon activation with ZnCl₂, the yield of activated carbon increases due to polymerization by creating some aromatic compounds with large rings, facilitating the adsorption of contaminants [44].

28. Fletcher, A.; Somorin, T.; Aladeokin, O. Production of High Surface Area Activated Carbon from Peanut Shell by Chemical Activation with Zinc Chloride: Optimisation and Characterization. Bioenergy Res. 2024, 17, 467–478, doi:10.1007/s12155-023-10683-7.
29. Boehm H P Surface Oxides on Carbon and Their Analysis: A Critical Assessment. Carbon N. Y. 2002, 40, 145–149.
30. Boehm, H.P. Some Aspects of the Surface Chemistry of Carbon Blacks and Other Carbons. Carbon N. Y. 1994, 32, 759–769, doi:10.1016/0008-6223(94)90031-0.
31. Heidarinejad, Z.; Dehghani, M.H.; Heidari, M.; Javedan, G.; Ali, I.; Sillanpää, M. Methods for Preparation and Activation of Activated Carbon: A Review. Environ. Chem. Lett. 2020, 18, 393–415, doi:10.1007/s10311-019-00955-0.
32. Anisuzzaman, S.M.; Joseph, C.G.; Krishnaiah, D.; Bono, A.; Suali, E.; Abang, S.; Fai, L.M. Removal of Chlorinated Phenol from Aqueous Media by Guava Seed (Psidium Guajava) Tailored Activated Carbon. Water Resour. Ind. 2016, 16, 29–36, doi:10.1016/j.wri.2016.10.001.

 

Issue 7) The chemical or physical characteristics of adsorbent materials are not mentioned.

authors' response: We inserted the chemical modification part in question 6. The physicochemical characteristics of the adsorbents were not mentioned in this article, because these characterizations have already been published by the group in the article Rocha et al. 2024. Reference no. 15 in this manuscript. Therefore, in order to ensure conflicts of interest, and not to republish data that have already been published using another emerging pollutant, we did not insert the data already published in this scientific research.

15. Rocha, B.C. da S.; Moraes, L.E.Z. de; Santo, D.E.; Peron, A.P.; Souza, D.C. de; Bona, E.; Valarini, O. Removal of Bentazone Using Activated Carbon from Spent Coffee Grounds. J. Chem. Technol. Biotechnol. 2024, 99, 1342–1355, doi:10.1002/jctb.7630.

 

Issue 8) Include a graphical abstract to improve the interest of the readers.

Response 8) We agree. We send the graphic abstract by email to Processes.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript (processes-3047376) concerns research on the adsorption of octocrylene from aqueous solutions with the use of commercial activated carbon and biochar from spent coffee grounds activated with ZnCl₂. Although this paper discusses an important topic, which is the use of low-cost adsorbent to remove octocrylene, there are serious challenges regarding the correctness of the experiment and quality of the manuscript.

In my opinion, the manuscript is not a solid work. It seems to have been prepared hastily and is missing a lot of information. My comments and suggestions are listed below.

1. The Introduction section is described too briefly and should be supplemented with information on e.g., wastewater containing octocrylene and biochar from spent coffee grounds (methods of preparation, application).
2. The article does not include the characteristics of the adsorbents used (commercial activated carbon and biochar from spent coffee grounds).
3. How many times runs described in Table 1 (R1-R10) were repeated? Please notice that there are many factors affecting the repeatability of adsorption experiments:

·       prepared adsorbent may be heterogenous material,

·       octocrylene is rather low soluble in aqueous solution and may be adsorbed on the walls of the used glassware especially at low concentrations.

It is recommended to add information about uncertainties for individual runs. Did the authors perform blank runs (without the addition of adsorbent)? At such a low concentration of octocrylene, it is possible that most of the octocrylene will be removed from the sample by contact with glassware and during the typical experimental procedure.

Adding detailed information on repeatability is crucial to evaluate the proposed model. Please note that the model developed by the authors (Table 2, equations 7 and 8) has 6 coefficients fitted only on the basis of 10 experimental points. In my opinion, such a model may be overfitted and is probably not well justified statistically. It is recommended to add at least 5 another runs. Please note that the range of ER results is very narrow (90.2-98.5 for commercial carbon; 91.0-99.1 for biochar) – perhaps in any other case such high efficiencies will be measured regardless of the adopted values ​​x1 and x2. Please add a negative example to Table 1, for example values of x1 and x2 at which the ER will drop to at least 50%.

4. Table 4 is not included in the manuscript. Table 3 is included twice in the text of the manuscript.
5. References do not appear in the text of the manuscript in the correct order.
6. Reference 14 in References section is written incorrectly.
7. The manuscript contains typographical errors.

·       Line 47: A period is missing at the end of the sentence.

·       Line 51: A different style of citing references was used (“(Stien et al. 2018)”).

·       Lines 273 and 311: Tere is no subscript in the ZnCl₂ formula.

·       Lines 272 and 311: “-1” in “L-1” should be written in superscript.

·       Line 478: Tere is no subscript in the MnO₂ formula.

·       Line 484: Tere is no subscript in the ZnCl₂ and H₃PO₄ formula.

·       The dot between units should be corrected throughout the manuscript, it should be middle dot instead of point.

In conclusion, the manuscript needs to be revised before it can be published.

Author Response

Response to the Reviewer Comments:

REFEREE 3 - in blue on the Revised Manuscript

Authors: We are grateful for the comments and questions from reviewer 3.

 

COMMENTS FOR AUTHORS PROCESSES 3047376

General Comments: The manuscript (processes-3047376) concerns research on the adsorption of octocrylene from aqueous solutions with the use of commercial activated carbon and biochar from spent coffee grounds activated with ZnCl₂. Although this paper discusses an important topic, which is the use of low-cost adsorbent to remove octocrylene, there are serious challenges regarding the correctness of the experiment and quality of the manuscript. In my opinion, the manuscript is not a solid work. It seems to have been prepared hastily and is missing a lot of information. My comments and suggestions are listed below. In conclusion, the manuscript needs to be revised before it can be published.

 

Specific comments:

Issue 1) The Introduction section is described too briefly and should be supplemented with information on e.g., wastewater containing octocrylene and biochar from spent coffee grounds (methods of preparation, application).

authors' response: We have enriched the Introduction about wastewater containing octocrylene and biochar from spent coffee grounds.

Line 47-48: In sewage treatment plants in different countries, raw and treated effluents presented octocrylene in concentrations ranging from micrograms to nanograms [4,5].

Line 75-83: Activated carbons are used to treat industrial waste and water supply. Their application occurs due to their high capacity to interact with organic pollutants in aqueous and gaseous media. Activated carbons are classified as granules, powder, and pellets according to their size and defined according to their nomenclature, micro, meso, and macropores, correlated to their physical form of activation, chemical, and biological [16]. Activated carbons are formed based on the chemical compound carbon. Physical, chemical, and biological activations, especially chemistry, stand out for modifying the surfaces of activated carbons in such a way as to improve the selectivity of functional groups, such as carboxyl, carbonyl, phenols, quinones, and lactones [17].

Line 90-107: Biochar is a functional material developed from natural or industrial by-products, such as sludge and forestry waste, its applicability focuses on removing aquatic pollutants [21]. Its production process is similar to charcoal activated. However, Biochar needs to change its physical properties so that its adsorption capacity is similar to or greater than activated carbon [22]. The advantage of using Biochar is that using by-products can make a viable economy, reduce the greenhouse effect and global warming, and increase harvest yield and productivity [22].

The biochar from spent coffee grounds is of great interest because (Coffea arabica) is the second most traded product in the world, and Brazil is the largest producer of this food [23]. The residue produces around 2.1 billion per harvest of Coffea arabica [15]. This material's chemical composition is fifty percent carbon on its surface; in the pyrolysis processes, more volatile compounds such as oxygen and hydrogen break their bonds with the carbonic mass, detaching from the molecular structure. [24,25]. This calcination process forms a porous structure of the biochar, and its adsorption capacity will depend on the physical-chemical properties of the material obtained and can be enhanced by the type of activation, chemical, physical or biological, pyrolysis time, and temperature. [24,25]. Coffee grounds found in water resources can be toxic to aquatic animals due to the high concentration of caffeine [26,27].

 

4. Santo, D.E.; Dusman, E.; da Silva Gonzalez, R.; Romero, A.L.; dos Santos Gonçalves do Nascimento, G.C.; de Souza Moura, M.A.; Bressiani, P.A.; Filipi, Á.C.K.; Gomes, E.M.V.; Pokrywiecki, J.C.; et al. Prospecting Toxicity of Octocrylene in Allium Cepa L. and Eisenia Fetida Sav. Environ. Sci. Pollut. Res. 2023, 30, 8257–8268, doi:10.1007/s11356-022-22795-2.
5. dos Santos Gonçalves Nascimento, G.C.; da Cunha Barros, D.G.; Ratuchinski, L.S.; Okon, C.; Bressiani, P.A.; Santo, D.E.; Duarte, C.C.S.; Ferreira, P.M.P.; Junior, O.V.; Pokrywiecki, J.C.; et al. Adverse Effects of Octocrylene on Cultivated and Spontaneous Plants and in Soil Animal. Water. Air. Soil Pollut. 2023, 234, doi:10.1007/s11270-023-06774-y.
6. Rocha, B.C. da S.; Moraes, L.E.Z. de; Santo, D.E.; Peron, A.P.; Souza, D.C. de; Bona, E.; Valarini, O. Removal of Bentazone Using Activated Carbon from Spent Coffee Grounds. J. Chem. Technol. Biotechnol. 2024, 99, 1342–1355, doi:10.1002/jctb.7630.
7. Sultana, M.; Rownok, M.H.; Sabrin, M.; Rahaman, M.H.; Alam, S.M.N. A Review on Experimental Chemically Modified Activated Carbon to Enhance Dye and Heavy Metals Adsorption. Clean. Eng. Technol. 2022, 6, doi:10.1016/j.clet.2021.100382.
8. Wang, H.; Zhang, Z.; Sun, R.; Lin, H.; Gong, L.; Fang, M.; Hu, W.H. HPV Infection and Anemia Status Stratify the Survival of Early T2 Laryngeal Squamous Cell Carcinoma. J. Voice 2015, 29, 356–362, doi:10.1016/j.jvoice.2014.08.016.
9. Jagadeesh, N.; Sundaram, B. Adsorption of Pollutants from Wastewater by Biochar: A Review. J. Hazard. Mater. Adv. 2023, 9, doi:10.1016/j.hazadv.2022.100226.
10. Cheng, N.; Wang, B.; Wu, P.; Lee, X.; Xing, Y.; Chen, M.; Gao, B. Adsorption of Emerging Contaminants from Water and Wastewater by Modified Biochar: A Review. Environ. Pollut. 2021, 273, doi:10.1016/j.envpol.2021.116448.
11. Siregar, C.A.; Siregar, A.M.; ... Rancang Bangun Mesin Giling Kopi Untuk Menunjang Dan Membuka Unit Usaha Baru Mitra Deli Coffe. ABDI SABHA (Jurnal Pengabdi. Kpd. Masyarakat) 2022, 174–180.
12. Javier Sánchez, A. Characterization of Activated Carbon Produced from Coffee Residues by Chemical and Physical Activation. KTH Chem. Sci. Eng. 2011, 66.
13. Jagdale, P.; Ziegler, D.; Rovere, M.; Tulliani, J.M.; Tagliaferro, A. Waste Coffee Ground Biochar: A Material for Humidity Sensors. Sensors (Switzerland) 2019, 19, doi:10.3390/s19040801.
14. Fernandes, A.S.; Mello, F.V.C.; Thode Filho, S.; Carpes, R.M.; Honório, J.G.; Marques, M.R.C.; Felzenszwalb, I.; Ferraz, E.R.A. Impacts of Discarded Coffee Waste on Human and Environmental Health. Ecotoxicol. Environ. Saf. 2017, 141, 30–36, doi:10.1016/j.ecoenv.2017.03.011.
15. Ferraz, F.M.; Yuan, Q. Organic Matter Removal from Landfill Leachate by Adsorption Using Spent Coffee Grounds Activated Carbon. Sustain. Mater. Technol. 2020, 23, doi:10.1016/j.susmat.2019.e00141.

 

Issue 2) The article does not include the characteristics of the adsorbents used (commercial activated carbon and biochar from spent coffee grounds).

authors' response: We agree. We insert it in Line 127-132 .

Line 127-132: Commercial coal has only carbon and hydrogen as its structure, has a BET surface area of 543.4 m²∙g^-1, pore volume of 0.28 cm³∙g^-1 and micropore volume of 0.20 cm³∙g^-1 [28]. Biochar was produced from coffee grounds, predominating carbon and lignocellulosic material. Rocha study [15], the surface area was 564.4 m²∙g^-1, pore volume was 0.32 cm³∙g^-1, and micropore volume was 0.25 cm³∙g^-1.

15. Rocha, B.C. da S.; Moraes, L.E.Z. de; Santo, D.E.; Peron, A.P.; Souza, D.C. de; Bona, E.; Valarini, O. Removal of Bentazone Using Activated Carbon from Spent Coffee Grounds. J. Chem. Technol. Biotechnol. 2024, 99, 1342–1355, doi:10.1002/jctb.7630.
16. Fletcher, A.; Somorin, T.; Aladeokin, O. Production of High Surface Area Activated Carbon from Peanut Shell by Chemical Activation with Zinc Chloride: Optimisation and Characterization. Bioenergy Res. 2024, 17, 467–478, doi:10.1007/s12155-023-10683-7.

 

Issue 3) How many times runs described in Table 1 (R1-R10) were repeated? Please notice that there are many factors affecting the repeatability of adsorption experiments:---- prepared adsorbent may be heterogenous material, It is recommended to add information about uncertainties for individual runs. Did the authors perform blank runs (without the addition of adsorbent)?

authors' response: Agreeing with the comment by the reviewer we insert some sentences for better comprehension.

Line 141-146: For all runs (Table 1), after the adsorbent material produced was standardized on a 10 mesh sieve, physical variables were controlled, such as controlled temperature and agitation speed, equipment was calibrated without octocrylene, and such procedures were carried out so as not to affect the parameters of the adsorption process [29,30]. The pollutant removal efficiency tests were carried out in triplicate in order to minimize all random errors involved in the experiment.

 

Regarding octacrylene, being adsorbed on the walls of glassware, as we used the same glassware to carry out the entire process of this study, the toxicity test would indicate the lack of toxicity before the adsorption process, concluding that octacrylene was not in the medium. Another factor is that with the surfactant Tween 80, we solubilize the pollutant in water, so as not to affect the spectrophotometric measurements of octacrylene .

 

28. Fletcher, A.; Somorin, T.; Aladeokin, O. Production of High Surface Area Activated Carbon from Peanut Shell by Chemical Activation with Zinc Chloride: Optimisation and Characterization. Bioenergy Res. 2024, 17, 467–478, doi:10.1007/s12155-023-10683-7.
29. Debien, I.C.N.; Vardanega, R.; Santos, D.T.; Meireles, M.A.A. Pressurized Liquid Extraction as a Promising and Economically Feasible Technique for Obtaining Beta-Ecdysone-Rich Extracts from Brazilian Ginseng (Pfaffia Glomerata) Roots. Sep. Sci. Technol. 2015, 50, 1647–1657, doi:10.1080/01496395.2014.975361.

 

Issue 4) At such a low concentration of octocrylene, it is possible that most of the octocrylene will be removed from the sample by contact with glassware and during the typical experimental procedure.

authors' response: This was answered in the previous question.

 

Issue 5) Adding detailed information on repeatability is crucial to evaluate the proposed model. Please note that the model developed by the authors (Table 2, equations 7 and 8) has 6 coefficients fitted only on the basis of 10 experimental points. In my opinion, such a model may be overfitted and is probably not well justified statistically. It is recommended to add at least 5 another runs. Please note that the range of ER results is very narrow (90.2-98.5 for commercial carbon; 91.0-99.1 for biochar) – perhaps in any other case such high efficiencies will be measured regardless of the adopted values x₁ and x₂. Please add a negative example to Table 1, for example values of x₁ and x₂ at which the ER will drop to at least 50%.

authors' response: We partially agree, the repeatabilities were added to the manuscript. However, regarding the statistical part, the simplest projects to reduce experiments were carried out for industrial applications and processes for treating emerging pollutants. These projects can represent the same response as complex projects, with planning with low experimental error, such as Box-Behnken, which uses three factors and has 15 experiments. In this condition, only the central point is usually repeated, it is generally applied in 2k experiments or fraction experiments. It consists of reaching the region that contains the optimal point and then comparing the part of the design, which is made up of the axial points, with the aim of evaluating the curvilinear part there, to arrive at the optimal solution, which maximizes the results. of the system [1,2].

 

1. Mateus, N.B.; Barbin, D.; Conagin, A. Viabilidade de Uso Do Delineamento Composto Central. Acta Sci. Technol. 2001, 23, 1537–1546.
2. Ferreira, S.L.C.; Bruns, R.E.; Ferreira, H.S.; Matos, G.D.; David, J.M.; Brandão, G.C.; da Silva, E.G.P.; Portugal, L.A.; dos Reis, P.S.; Souza, A.S.; et al. Box-Behnken Design: An Alternative for the Optimization of Analytical Methods. Anal. Chim. Acta 2007, 597, 179–186, doi:10.1016/j.aca.2007.07.011.

 

Issue 6) - Table 4 is not included in the manuscript. Table 3 is included twice in the text of the manuscript.

- References do not appear in the text of the manuscript in the correct order.

- Reference 14 in References section is written incorrectly.

- The manuscript contains typographical errors.

- Line 47: A period is missing at the end of the sentence.

- Line 51: A different style of citing references was used (“(Stien et al. 2018)”).

- Lines 273 and 311: Tere is no subscript in the ZnCl₂ formula.

- Lines 272 and 311: “-1” in “L-1” should be written in superscript.

- Line 478: Tere is no subscript in the MnO₂ formula.

- Line 484: Tere is no subscript in the ZnCl₂ and H₃PO₄ formula.

- The dot between units should be corrected throughout the manuscript, it should be middle dot instead of point.

authors' response: Agreeing with the comments by the reviewer we introduced the other changes as suggested.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have made some corrections. However, I still have several remarks.

1. Lines 92 and 94: It should be “biochar” instead of “Biochar”.
2. Please check the cited references carefully. In my opinion, reference 17 does not discuss the topic related to the research presented by the authors. Are the authors sure that reference 17 is properly cited? Are the authors confident that reference 28 should be cited in line 129?
3. Table 3 and 4 are the same, they contain the same data. Please include the correct tables.
4. Line 460: It should be “Tables 3 and 4” instead of “Tables 3 e 4”.

Author Response

Response to the Reviewer Comments:

REFEREE 3 - in blue on the Revised Manuscript

Authors: We are grateful for the comments and questions from reviewer 3.

 COMMENTS FOR AUTHORS PROCESSES 3047376

Comments and Suggestions for Authors

The authors have made some corrections. However, I still have several remarks.

1. Lines 92 and 94: It should be “biochar” instead of “Biochar”.

Authors' response: We changed the term Biochar to biochar.

2. Please check the cited references carefully. In my opinion, reference 17 does not discuss the topic related to the research presented by the authors. Are the authors sure that reference 17 is properly cited?

Authors' response: We agree, we modify the sentence: Line 80-85: The activated carbon surface can accommodate elements such as oxygen, hydrogen and nitrogen in the form of functional groups, arising from the physical, chemical or biological activation process. For the most part, the solid interface is predominantly composed of oxygenated functional groups, such as carboxylic acids, hydroxyl groups (when associated with aromatic chains they confer a phenolic character), carbonyls, lactones and quinones [18,19].

3. Are the authors confident that reference 28 should be cited in line 129?

Authors' response: We agree, we modify the sentence: Line 130-131: … and particle size between 1.4 to 2 mm [30].

4. Table 3 and 4 are the same, they contain the same data. Please include the correct tables.

Authors' responses: we have inserted the correct Table 4 into the manuscript.

5. Line 460: It should be “Tables 3 and 4” instead of “Tables 3 e 4”.

Authors' Responses: We removed "Table 3 and Table 4" and inserted “Tables 3 and 4”.

Author Response File: Author Response.pdf