Lecturer (On Study Leave)

MALIHA CHOWDHURY   

Lecturer 

Educational Qualifications:

Publications: 

1. Biobased amphoteric aerogel derived from amine-modified clay-enriched chitosan/alginate for adsorption of organic dyes and chromium (VI) ions from aqueous solution
   Abstract:
   Naturally abundant and renewable macromolecular polysaccharides are now considered green and sustainable adsorbent material for toxic effluent treatment. However, to deal with complex wastewater, the need for an efficient amphoteric adsorbent is still a challenge. Herein a three-dimensional (3D) composite aerogel is prepared from dodecyl amine-modified clay (kaolinite) enriched chitosan/alginate via the freeze-drying method and a post-ionic crosslinking. The aerogel was characterized by Fourier transform infrared spectroscopy (FT-IRS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), solubility test and adsorption studies. The thermal stability of aerogel was significantly higher than that of chitosan/alginate polymer matrix and substantially increased upon the gradual addition of modified clay. The aerogel has ordered fishing net-like microstructure, and interconnected pores for dyes and metal ions adsorption. The adsorption capacities of composite aerogel on methylene blue, acid black, and hexavalent chromium [Cr (VI)] ions reached around 73.1, 71.5, and 62.4 mg/g respectively. The adsorption mechanism was electrostatic interaction and the mass ratio of chitosan and modified clay to alginate regulates the adsorption capacities for the anionic and cationic dyes. As a novel amphoteric adsorbent, the chitosan/alginate/modified clay composite aerogel showed the potential to remove both cationic, anionic dyes, and metal ions from wastewater. Moreover, the prepared biobased aerogel showed high adsorption efficiency in both acidic and basic media even after four cycles. The study demonstrated high performance, and low cost, with materials locally available, recyclable, and promising candidates for industrial wastewater treatment. ?
   Details - (link) 

2. IMPACT-FREE TANNING PROCESS: ECOLOGICAL LEATHER
   Abstract:
   The term “ecological” leather meant “toxicity-free” leather. Around 80% of leather is tanned using chromium. The chromium used in the tannery may be in the form of chromium (III), and (IV). But after the tanning process, for excessive pH and other reactions, it becomes Chrome (VI), which is very much toxic and carcinogenic. Most of the traditional tanning processes involve the use of heavy metals in different steps. Again, there are other chemicals like acids, and dyes that spread carcinoma. After a very long time, finally, a new process is introduced, which shows a way to transform raw hides and skins into finished leather without causing any harm to the environment or the user of this product. This new product is named “Ecological Leather”. Ecological leather is a product that is made without any kind of harmful chemicals and spreads no toxicity afterward. Mainly Synthetic tanning materials are involved in the production of this product, thus how this product is friendly for nature and the user. This new product is a bit expensive but very much useful and totally harmless. Sometimes Eco Leather performs even better than leathers made from traditional processes. It’s very essential and preferred for the use of children and patients.
   Details - (link) 

Training: 

1. Training on Anwar Tannery, Savar, Dhaka as an intern for 6 months in 2018.  

Extracurricular Activities: 

1. Served as former president for SED, DU.
2. Served as a vice president for Prothom AloBondhusova.
3. Arranged a large event with speakers from abroad for the Dhaka University health club.
4. Responsible for all activities for new students and a joint secretary of Youth Against Hunger, DU.