Brilliant Red HE-3B Dye Biosorption by Immobilized Residual Consortium Bacillus sp. Biomass: Fixed-Bed Column Studies

Round 1

Reviewer 1 Report

In the submitted manuscript a biosorption process of Brilliant Red HE-3B anionic dye on Bacillus sp. residual biomass deposited in sodium alginate was studied. The adsorption measurements were performed under very limited range of conditions and this is the largest drawback of this work. The manuscript would be much more interesting if it explained:

- what is the sensitivity of the biomaterial to pH, temperature and solution concentration?

- is it selective for selected types of pollutants?

- what is the proposed mechanism of the biosorption process?

- does the dye degrade during the process, which would release a more toxic product?

After completing the work with the above elements, I believe that it can be accepted for publication in Applied Sciences.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

COMMENTS TO AUTHORS:

I have reviewed the manuscript entitled " Brilliant Red HE-3B dye biosorption by immobilized Bacillus sp. residual biomass: Fixed–Bed-Column Studies" by Luiza Ioana Horciu et al.

This paper analyzes the ability of Bacillus sp. residual biomass (resulting from a process of removing fatty acids from industrial wastewater) immobilized in alginate in dye biosorption processes.

There are several important points to improve before it can be considered for publication.

I would like to suggest MAJOR REVISION needed for this manuscript.

Major comments:

Tittle. From my point of view the employed residual biomass is a consortium of Bacillus, (Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis and Bacillus orto-liquefaciens) but this information is unclear in the present form of tittle. I recommend rewrite this part.

Introduction.

- The authors non-exposed the objectives of the research, and this part is completely lacking. From my point of view, the objectives of the research must be clearly incorporated in the revision version of the manuscript at the end of introduction section.

- I recommend transferring “The obtained results reconfirmed that the studied residual biomass immobilized in alginate can be considered as a good aspirant of biosorbent in an open tank/reactor with agitation by aeration (air bubbling or dissolved air dispersion) applied in the treatment of different effluents containing organic dyes.” of this part of introduction to the conclusions section.

Material and methods.

-Figure 1. I doubt the copyright of two or three images, from my point of view the authors must use material from their property.

-One of the major concerns I observed, is on the experimental design. In my opinion, a growth curve of Bacillus sp. could have been a great assay rather than just an endpoint to see where the shift in cell damage occurs due to the toxic effect of Brilliant Red HE-3B on bacterial growth. This viability information about Bacillus sp. could explain better the biosorption process.

Results and discussion.

- I've would have liked more discussion regarding the role of Bacillus in biosorption process and compared to other microorganisms.

Conclusion. The authors should add the significance of this study and propose appropriate research prospects. This part is too short.

Minor comments:

-Throughout the manuscript substitute "micro-organisms" for "microorganisms"

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have revised their manuscript accordingly.

Reviewer 2 Report

In general, the authors have addressed all the comments and concerns, in most of them, very nice responses. Thank you very much for your thorough explanations.

I recommend acceptance in the present form of research paper.