Polymeric Biomass Derived Adsorbents for Co(II) Remediation, Recycling and Analysis

Round 1

Reviewer 1 Report

TITLE: Polymeric Biomass Derived Adsorbents for Co(II) Remediation,  Recycling and Analysis

Comments:

With regard to introduction there is a correct definition regarding cobalt with respect to its uses and properties highlighting the key role of an efficient separation/pre-concentration method capable of meeting the requirements imposed for complete removal, quantitative recovery and analysis. of Co from different effluents and sources, where the background of the study is correctly mentioned, identifying the problem, distinguishing the discussion on the biosorption characteristics of polymer biomass as potential biosorbents and practical biosorbents for the efficient separation/preconcentration of Co(II) being of economic and analytical relevance.

Based on the biosorbents recommended as promising candidates for the separation of Co(II) from synthetic solutions, the biosorption capacities of polymeric biomass are efficiently discussed, where the first two categories of biosorbents have been more intensively investigated from the perspective of their integration in bioseparation strategies of heavy metals from real samples where it is shown that a favorable solution to this problem is the application of an immobilization, modification or immobilization/modification method on the improvement of the characteristics and/or functionalities of the biosorbent surface.

The bibliographic citations regarding the discussion on the basis of multivariate statistical analyses, where it has been assumed that the biosorbents with the highest amounts of -OH of alcohols and CH, C - O - C, C - N and P - O polysaccharides show a propensity to absorb Co(II) more than other biomaterials.

An interesting analysis was carried out on future research perspectives, focusing on the following topics: Expansion of the range of biosorbents to test the removal of Co(II) from aqueous solutions at concentrations that reflect industrial reality; Research on increasingly cleaner methods of modifying biosorbents; Fixed bed column Co(II) biosorption and the increasing number of desorption studies, highlighting the real applicability of Co(II) biosorption separation, especially in deep understanding of the interactions and dependencies of multicomponent systems of biosorption.

Regarding the Biosorbents integrated in practical approaches for the removal/recovery and determination of Co(II) from real samples, it is important to highlight the efficiency of the biosorption process for the removal of Co(II) from real effluents, where hardly The recyclability of biosorbents in real industrial conditions has been studied in comparison with other analytical methodologies such as the biosorption of Co(II) from large volumes of real matrices, correlated with its desorption and determination in small volumes of concentrated desorption solution using a adequate method of instrumental analysis.

With respect to the real applications of biosorbents for the elimination/recovery of Co(II), the importance of the works on the elimination and recovery by bioabsorption of Co(II) from real matrices is highlighted, where the expected advances towards practical applications large-scale pilot studies are required.

Regarding the analytical procedures based on biosorbents for the determination of traces of Co(II) from real samples, a good correlation was shown between the concentrations found for Co(II) and the certified values.

Therefore, in the conclusion, a correct assessment and discussion was made on the development of different ecological methodologies for the determination of Co(II) from a wide range of real samples.

Author Response

Thank you very much for your positive comments and very favorable appreciation on my work. The English has been revised by a native English-speaking colleague. The changes made have been  marked up using the “Track Changes” function

Reviewer 2 Report

I enjoyed reading this review of polymeric biomass derived absorbents for Co remediation. The review is appropriately focused on the materials issues for these materials and Co remediation. I appreciated the author's highlighting of the issues and thoughts on needed research directions for the different sections, though I felt at times the author could have been more specific. For example, on the top of page 9 the author notes "removal from aqueous solutions of concentrations that reflect industrial reality". From a reader's perspective an apt question is "such as what?". Some followup on this point that provides some context for what the industrial reality is would be a powerful addition to this review and its addition should be seriously considered by the author. Otherwise, the manuscript is well written and worthy of publication (with some minor English editing throughout). 

Author Response

Thank you very much for your favorable appreciation on my work.  The responses to your  comments are, as following:

• I appreciated the author's highlighting of the issues and thoughts on needed research directions for the different sections, though I felt at times the author could have been more specific. For example, on the top of page 9 the author notes "removal from aqueous solutions of concentrations that reflect industrial reality". From a reader's perspective an apt question is "such as what?". Some followup on this point that provides some context for what the industrial reality is would be a powerful addition to this review and its addition should be seriously considered by the author.

The concentrations that reflect industrial reality have been shown in the section 3.1 devoted to the real applications of biosorbents to Co(II) removal/recovery, being specified in Table 6 that summarizes the  reports  on  the  treatment of real wastewaters containing Co(II) by using biosorbents. Unfortunately, studies on this topic are still very few.Other data are unavailable, probably due to their confidentiality covered by industrial patents

• Otherwise, the manuscript is well written and worthy of publication (with some minor English editing throughout)

The English has been revised by a native English-speaking colleague. The changes made have been  marked up using the “Track Changes” function.