Original Article:
Removal of dye from polluted water using novel nano manganese oxide-based materials
Md. Aminul Islam, et al.
Journal of Water Process Engineering 32 (2019): 100911.
10.1016/j.jwpe.2019.100911
The presence of dyes in wastewater can cause serious problems for aquatic organisms and humans. So far, there have been many works reported on the use of nano-manganese oxide as a dye adsorbent. They are promising adsorbents for commercial use due to their amorphous nature, high specific surface area (SSA), mesoporous structure, and low to moderate point of zero charge (pHPZC). In this work, the authors summarize the research progress on the use of nano-manganese oxide adsorbents for the removal of dyes from wastewater.
Common Dyes in Wastewater
Generally, dyes are divided into cationic dyes, anionic dyes and nonionic dyes, common dye examples include:
- Cationic Dyes: methylene blue (MB), crystal violet (CV), brilliant green (BG) and malachite green (MG).
- Anionic Dyes: methyl orange (MO), Congo Red (CR), acid red-b (ARB), Rhodamine-B (RhB), orange green (OG), Prussian red (PR), alizarin red, rose Bengal, basic yellow 28 and pinacyanol chloride.
It has been reported that MnOs has been used as adsorbents to remove MB, MO, RhB, CV, and CR dye molecules in solution.
Dyes Removable by Manganese Oxide
Commonly used manganese adsorbents include hydrated manganese dioxide or birnessite (δ- MnO2), pyrolusite (β- MnO2), hausmannite (Mn3O4), manganite (MnOOH), cryptomelane (α-MnO2), Mn2O3 and their various composite materials or coatings. Here are just a few examples:
- Methylene blue (MB): There are studies using MnO, bixbyite (α-Mn2O3), hausmannite (Mn3O4), and birnessite (δ-MnO2) to treat MB polluted water. The results showed that hausmannite was the most effective MB adsorbent. In the presence of H2O2 at 80 °C, an initial MB concentration of 100 mg/L MB can be degraded by hausmannite by 99.3%.
- Malachite green (MG): Porous manganese oxide octahedral molecular sieve (OMS-2) (cryptophyllite phase) nanorods were prepared for the catalytic degradation (5 mg/L) of MG. The results showed that OMS-2 could degrade 99% of the dyes by pseudo-first-order kinetics within 1 h at room temperature.
- Methyl orange (MO): Zhang et al. prepared two composites, such as MnO2-M and MnO2/ Mn3O4-M, using birnessite (δ- MnO2), hausmannite (Mn3O4) and magnesium (M) wire. They successfully used these composites as oxidants or catalysts to treat MO from wastewater in presence hydrogen peroxide.
- Rhodamine B (RhB): Three different manganese oxides, cryptomelane (α-MnO2), pyrolusite (β-MnO2) and birnessite (δ-MnO2), were used to decolorize RhB solutions. Under the same conditions, different minerals had different decolorization rates, indicating that the decolorization effect of minerals on RhB depended on pHPZC, crystal type, and solution pH. Cryptomelane exhibited the greatest decolorization ability in the pH range of 2.0-6.0.
Chemicals Related in the Paper:
Catalog Number | Product Name | Structure | CAS Number | Price |
---|---|---|---|---|
ACM11129605 | Manganese oxide | 11129-60-5 | Price | |
ACM12244325 | Birnessite(Na4(Mn14O27).9H2O) | 12244-32-5 | Price | |
ACM1309553 | MANGANESE OXIDE | 1309-55-3 | Price | |
ACM1317346-1 | Manganese Oxide Nanoparticles / Nanopowder | 1317-34-6 | Price |