Investigating chlorite dismutase biocatalyst reuse using columns

Kamalanathan, Indran

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https://hdl.handle.net/2142/106430 Copy

Description

Title

Investigating chlorite dismutase biocatalyst reuse using columns

Author(s)

Kamalanathan, Indran

Issue Date

2019-10-09

Director of Research (if dissertation) or Advisor (if thesis)

• Zilles, Julie L
• Guest, Jeremy S

Department of Study

Civil & Environmental Eng

Discipline

Environ Engr in Civil Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Biocatalysis
• Microcontaminants
• Chlorite
• Perchlorate
• Reuse

Abstract

Microcontaminants are compounds in water present below 1 ppm which have major long-term health impacts. Traditional treatment processes are not designed to treat these chemicals and existing treatment methods come with downsides including higher chemical input, higher energy input, production of a waste stream, use of high cost media, and/or production of toxic byproducts. Biocatalysis, using enzymes to degrade contaminants, has been proposed as a treatment method. This process would require reuse of the biocatalysts to reduce costs for continuously operated water treatment systems. To study the potential for biocatalyst reuse, experiments were conducted on a chlorite dismutase biocatalyst modified with a strep tag; this reuse system allows the biocatalyst to bind to coated resin beads that can be reused in a column system. Chlorite dismutase treats chlorite to chloride and oxygen. Activity tests were conducted in batch for the purified and attached biocatalysts and in column to determine impact of attachment on the biocatalyst’s activity and inactivation. Activity results showed no impact of tag addition, with a tagged biocatalyst Vmax of 34,600 ± 2,900 μmol chlorite min-1 μmol heme-1 and a Km of 106.6 ± 70.6 μM. The attached biocatalyst was able to reach the same maximal activity as the free biocatalyst with the introduction of a mass transfer limited region, which can be described with a kl of 0.1415 cm min-1. Column activity was difficult to measure but was similar to the attached batch result in four successful experiments. Finally, the maximum theoretical turnover number in the column system was 152,800 ± 11,800 μmol chlorite μmol heme-1. While more understanding of the inactivation kinetics is needed to enable a detailed comparison, based on the maximum theoretical turnover number, a fully loaded column is projected to be able to treat 86,000 bed volumes (equivalent to 59.7 days at design flowrate and concentration) before being fully inactivated.

Graduation Semester

2019-12

Type of Resource

text

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http://hdl.handle.net/2142/106430

Copyright and License Information

Copyright 2019 Indran Kamalanathan

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