RESEARCH REVEALS THAT TARAP (ARTOCARPUS ODORATISSIMUS) SKIN & CORE CAN BE SUCCESSFULLY USED AS BIOSORBENTS FOR THE REMOVAL OF TOXIC DYES & HEAVY METALS

Artocarpus odoratissimus is a seasonal fruit commonly grown and consumed in South-East Asia and its maximum diversity occurs in Brunei Darussalam. Locally known as “Tarap” and “Marang” in English and like other highly liked sweet fruits such as the jackfruit, Tarap falls in a common family of fruits scientifically known as Artocarpus. Descriptively as can be seen below, Tarap’s skin and core (inedible part) are found to comprise more than 60% of its total mass.

This inedible part is usually thrown away without being put to further usage and thus significantly contributes to the waste disposal burden in places where it is commonly consumed.

In a collaborative research, Chieng Hei Ing a PhD student in the Department of Chemistry under the supervision of Associate Professor Dr. Linda B.L. Lim of Universiti Brunei Darussalam investigated a possibility of using Tarap skin/core as potential low-cost biosorbents for the removal of toxic dyes (e.g. methylene blue and methyl violet 2B) and heavy metals (e.g. Cu(II), Cd(II) etc).

Associate Professor Dr. Linda who is a specialist in Organic and Natural products chemistry has supervised several research studies aimed at investigating potential use of Natural Biomass as Biosorbents for removal of pollutants. This particular study was triggered by the ever growing alarm of the fact that, increasingly as a result of various human activities; pollutants are being released into the environment which mostly continues to affect the water resources. This in turn results into increased expenditure on efforts to remove toxic dyes and heavy metals from aqueous solutions. Asked as to why Tarap skin was chosen for the study, Chieng Hei Ing revealed that no studies had been reported on this specific fruit at the time of the commencement of this research and yet like other Artocarpus fruits, it’s commonly consumed in South-East Asia and particularly in Brunei Darussalam.

This investigative study of Tarap Skin involved the use of UV–Vis spectrophotometer (Shimadzu/Model UV-1601PC) for measurement of absorbance of dye solutions and Atomic Absorption spectrophotometer for analyses of heavy metals while FTIR spectrophotometer (Shimadzu Model IRPrestige-21) was used for measurements of solids. The contents present in Tarap skin were determined in the Elemental Analysis Laboratory at the National University of Singapore while Tescan Vega XMU scanning electron microscope (SEM) was used to investigate the morphological characteristics of the adsorbent surface and the coating of the biosorbent was done using SPI-MODULETM Sputter Coater.  

After a successful study and characterization of Tarap wastes, in order to understand the interaction with pollutants (with and without pretreatment), adsorption studies were carried out and results indicatethat Tarap skin and core can be successfully used as low-cost biosorbents for the removal of cationic dyes and heavy metals.

This work was featured and published by Taylor and Francis Online on the 24^th October 2013 and also in Environmental Science and Pollution Research in 2012. Chieng Hei Ing revealed that this research has been extended to other Artocarpus species (e.g. kemangsi, sukun, nanchem, etc) as well as other biomasses such as peat and vegetable wastes for the removal of heavy metals and dyes from aqueous solutions. To date, a total of 16 publications have resulted from this work and more results will be submitted for publication in future .

This research is in collaboration with Professor Namal Priyantha from the Department of Chemistry of the University of Peradeniya, Peradeniya, Sri Lanka.  Other contributors include Muhammad Khairud Dahri, Tasneem Zehra, Muhammad Raziq Rahimi Kooh and Nur Hakimah bte Mohd Mansor of the Faculty of Science, Universiti Brunei Darussalam.

This research was financed by the Government of Brunei Darussalam and Universiti Brunei Darussalam