Removal performance of elemental mercury by low-cost adsorbents prepared through facile methods of carbonisation and activation of coconut husk

Abstract

The preparation of chars and activated carbon as low-cost elemental mercury adsorbents was carried out through the carbonisation of coconut husk (pith and fibre) and the activation of chars with potassium hydroxide (KOH), respectively. The synthesised adsorbents were characterised by using scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption/desorption analysis. The elemental mercury removal performance was measured using a conventional flow type packed-bed adsorber. The physical and chemical properties of the adsorbents changed as a result of the carbonisation and activation process, hence affecting on the extent of elemental mercury adsorption. The highest elemental mercury (Hg°) adsorption capacity was obtained for the CP-CHAR (3142.57 µg g(-1)), which significantly outperformed the pristine and activated carbon adsorbents, as well as higher than some adsorbents reported in the literature.

Biosorption of toxic heavy metals from aqueous solution by Ulva lactuca activated carbon

“…However, materials used for preparation of higher quality activated carbon cost greater [12]. Searching for low cost activated carbon resources is of great importance in the removal of heavy metals from wastewater [13][14][15].…”

Sustainable Conversion of Coconut Wastes into Useful Adsorbents

“…Subsequently, Johari et al conducted a column study of elemental mercury removal using coconut fiber and its activated char variants [105]. In the study, the coconut fiber adsorbent was first carbonized at 700 C as to convert the fibers into char materials.…”

“…Table 3 shows that Johari et al and Saman et al have conducted comprehensive studies on determining the adsorptive capabilities of the coconut pith in removing mercury ions, methylmercury, and elemental mercury. Johari et al conducted a column elemental mercury removal using coconut pith as adsorbent source for activated char adsorbent [105]. In the study, the coconut pith was carbonized and subsequently was treated and activated with KOH solution.…”

Trapping Ionic Mercury Using Different Adsorbents

“…The thermodynamic studies also indicated that the process was spontaneous, feasible, and endothermic. Several other recent and relevant studies reported on mercury adsorption using different adsorbents are discussed …”