Bacillus subtilis-based colorimetric bioassay for acute biotoxicity assessment of heavy metal ions

RSC Advances ◽  
2015 ◽  
Vol 5 (73) ◽  
pp. 59472-59479 ◽  
Author(s):  
Deyu Fang ◽  
Yuan Yu ◽  
Liangzhuan Wu ◽  
Yu Wang ◽  
Jinghua Zhang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Bacillus Subtilis ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Hydrolysis Of

β-Galactosidase generated byBacillus subtiliscatalyzes the hydrolysis of ONPG to produce ONP, which can be detected at 420 nm and used to evaluate acute biotoxicity of heavy metal ions that inhibit the activity of the enzyme.

scholarly journals Banana Rachis CNC/Clay Composite Filter for Dye and Heavy Metals Adsorption from Industrial Wastewater

2021 ◽  
pp. 44-56
Author(s):  
Md. Monjurul Islam ◽  
Md. Shafiqul Islam ◽  
Mohd. Maniruzzaman ◽  
Md. Minhaz-Ul Haque ◽  
Anika Amir Mohana
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Cellulose Nanocrystals ◽  
Industrial Wastewater ◽  
Heavy Metal Ions ◽  
Dye Adsorption ◽  
Before And After ◽  
Composite Filter ◽  
Hydrolysis Of ◽  
Adsorption Capability

This study demonstrates a successful processing and utilization of banana rachis cellulose nanocrystals (CNCs) dispersed clay composite filter which is capable of adsorbing dye and heavy metal ions namely Pb(II) and Cr(III) from industrial wastewater. The composite of different compositions was prepared by dispersing the cellulose nanocrystals, obtained by acid hydrolysis of banana rachis fibres, within the tri-ethyl amine treated clay. The CNC and treated clay were characterized by Fourier transform infrared (FTIR), X-ray diffractometry (XRD), and scanning electron microscopy (SEM) analyses. Industrial wastewater containing a basic yellow2 dye and two heavy metal ions, Pb(II) and Cr(III), was passed through the prepared filters set in a column. The dye and metal ions adsorption capability of the filters were analyzed by determining the dye and metal ions concentration into the water before and after passing through the composite filter. The concentration of dye and metal ions in water was determined by a UV-visible spectrophotometer and an atomic absorption spectrophotometer, respectively. It was found that the dye adsorption capacity of the composite filters was about 50 mg per gram of composite as well as Pb(II) and Cr(III) ions adsorption capacities of the composite filters were ˃10.0 mg and ˃12.4 mg respectively per gram of the composite when CNC content in the composite was ˃30 wt.%. It was also found that the metal ions adsorption capability of the composite filter was improved with increasing CNC content in the composites.

scholarly journals STUDY OF THE EFFICIENCY OF WATER PURIFICATION FROM HEAVY METAL IONS WITH MAGNETITE SORBENTS

2020 ◽  
pp. 46-51
Author(s):  
I.M. Trus ◽  
M.D. Gomelia ◽  
T.V. Krysenko ◽  
Ye.S. Bulhakov
Keyword(s):  
Heavy Metal ◽  
Water Treatment ◽  
Metal Ions ◽  
Sorption Capacity ◽  
Water Purification ◽  
Heavy Metal Ions ◽  
Sodium Sulfide ◽  
Partial Hydrolysis ◽  
High Degree ◽  
Hydrolysis Of

The process of water treatment from heavy metal ions on sorbents with magnetic properties was investigated. Samples of magnetite obtained at a ratio of the concentrations of iron (II) ions and iron (III) 1 : 2; 1 : 1 and 2 : 1, and samples modified with sodium sulfide were used. The effect of pH on the sorption efficiency of heavy metal ions on magnetite was studied. It was shown that the sorption capacity of magnetite towards heavy metal ions, as well as the efficiency of water treatment from these compounds, increases with an increase of the [Fe2+]/[Fe3+] ratio from 1 : 2 to 2 : 1. Sorption capacity of magnetite increases with increasing pH due to partial hydrolysis of heavy metal ions. Also sorption capacity of magnetite increases significantly if modified it with guanidine, thiosemicarbazide, and sodium sulfide. At the same time, the sorbent provides a high degree of water purification from heavy metal ions while reducing the metal concentrations to several µg/dm3. Ref. 12, Fig. 5, Tab. 1.

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