Potential of carbonic anhydrase and urease bacteria for sequestration of CO2 into aerated concrete

A Faisal Alshalif,Ibrahim M Nasser,Algaifi Hassan,Jm Irwan,N Othman,Adel Al-Gheethi,Yaacob Haryati,Mohd Yunus Nor Zurairahetty,Ibrahim Izni Syahrizal

doi:10.1051/matecconf/201825003004

A Faisal Alshalif, Ibrahim M Nasser + Show 7 more

Open Access

https://doi.org/10.1051/matecconf/201825003004

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Abstract

The present study aimed to investigate the potential of bacterial strains from cement kiln dust (CKD) to sequestrate atmospheric CO2 into aerated concrete as a functional for carbonic anhydrase (CA) and urease enzymes. Five samples of CKD was collected from Cement Industries of Malaysia Berhad (CIMA). The most potent bacterial isolates were selected and adapted to grow in 5% of CO2 and in bio-aerated concrete medium. CA enzyme was detected by using a solution of 1.8 g of p-NPA (p-nitrophenyl acetate) and 25 mg of ampicillin at 7-pH. The results of thioglycolate broth medium assay indicated that the bacterial isolates were facultative anaerobic. Furthermore, the results of candle jar test reflected that the bacterial isolates have the ability to survive with 5% of CO2 concentrations. Two bacterial isolates distinctly grow in bio-aerated concrete simulation medium, while only one bacterial isolate was the most potent and has produced in a powder form using freeze dryer to be ready to apply in bio-aerated concrete.

Highlights

The concentration of CO2 rapidly increased worldwide especially in last five decades
The alkalinities of the collected sample cement kiln dust (CKD) were measured before isolation of bacteria, which in role gives prediction of the isolated bacteria, whether it have the capability to tolerate the extreme pH or not when they apply into aerated concrete
The drop of pH of the sample that collected from area 5 may due to the weathering conditions at that area, whereas, the this area was directly exposed to the rain, which may cause regression in the pH value compared to other samples

Summary

Introduction

The concentration of CO2 rapidly increased worldwide especially in last five decades. The emission of CO2 has increased from 300 ppm on 1950s to 400 ppm on 2010 as a result of anthropogenic activities [1,2,3]. Biological sequestration taking place via algae, which help on conversion of CO2 to calcite in the form of calcium carbonate (CaCO3) or magnesium carbonate (MgCO3)[8]. Different studies shifted to use bacterial cells, which have the ability to produce carbonic anhydrase (CA) enzyme as alternative technique to sequestrate CO2 [9,10]

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