New Alumina Adsorbent to Remove Formaldehyde from Water

Iranian researchers succeeded in the production of a new type of nano-adsorbent which is capable of removing formaldehyde from water resources.

Taking into account the need for the production of materials able to eliminate formaldehyde, researchers studied the effective parameters on the reactivity of alumina nanoparticles. They carried out the project successfully by grafting 2,4-dinitrophenylhydrazine on alumina nanoparticles. They placed the synthesized sample and the alumina sample without grafting at a polluted environment with determined concentrations of formaldehyde, and they compared the amount of formaldehyde adsorption by the samples.

Observations showed that the presence of alumina nanoparticles in the polluted environment did not change the concentration of formaldehyde. In order to improve the reactivity of alumina nanoparticles, the researchers grafted 2,4-dinitrophenylhydrazine reactant to alumina nanoparticles, and they reported their observations. Results showed that the grafting process resulted in the adsorption of formaldehyde from the polluted environment up to 99%.

In addition, the effect of various parameters such as pH and the contact time between the polluted environment and the grafted alumina nanoparticles were also studied in this research. Results showed that high values of pH helped the decomposition of formaldehyde, which resulted in a decrease in the concentration of formaldehyde. However, this fact reduced the adsorption efficiency, and it caused interference in the adsorption process. They reported that a pH value of 7 was the most optimum pH value in order to obtain high efficiency.

Another result obtained from the research was that the presence of high concentrations of various ions, including calcium and sodium, did not significantly affect the adsorption capacity of the grafted alumina nanoparticles.