Page 196 - AJWEP-22-4

Shrestha

is not only resistant to biodegradation but also exhibits agents influence the structure, surface chemistry, and
carcinogenic and mutagenic properties, posing major RhB dye adsorption efficiency of carbons derived from
environmental and public health risks. Consequently, the same biomass.
3
it is frequently employed as a model pollutant in In addition, the study integrates thermogravimetric
adsorption studies for evaluating the efficiency of analysis (TGA)/differential scanning calorimetry
novel adsorbent materials in treating dye-contaminated (DSC)-based thermal optimization and demonstrates
industrial effluents. Adsorption is widely regarded as one ultrafast RhB removal with high efficiency,
of the most effective, economical, and environmentally outperforming commercial AC. A carbonization
friendly techniques for dye removal. Activated carbon temperature of 400°C was selected based on
(AC) remains the benchmark adsorbent due to its large TGA/DSC analysis, which indicated significant
surface area, well-developed porosity, and abundance thermal decomposition and stabilization of the
of surface functionalities. However, the commercial- biomass structure around this temperature. This
4
scale use of AC is often constrained by high production activation strategy represents a key innovation of the
costs and dependence on non-renewable precursors – study, enabling a direct comparison of acid-, base-, and
limitations that are particularly challenging in resource- salt-mediated activation routes on the same biomass
limited settings such as Nepal. – an approach rarely reported in the literature. These
8
In Nepal, approximately 70% of industrial effluents findings provide both mechanistic insight and practical
– including those from textile and dyeing operations value for developing cost-effective, sustainable
– are discharged untreated into rivers and streams, adsorbents for wastewater remediation, particularly in
contributing to elevated concentrations of synthetic dyes resource-limited settings like Nepal.
in surface water bodies. This growing dye pollution The resulting ACs – H PO -activated carbon (Bc-H),
5
is further exacerbated by rapid industrialization, poor KOH-activated carbon (Bc-K), and Na CO -activated
4
3
regulatory enforcement, and the lack of centralized carbon (Bc-Na) – were comprehensively characterized
3
2
wastewater treatment infrastructure. As a result, surface using X-ray diffraction (XRD), Raman spectroscopy,
water quality continues to deteriorate, threatening Fourier-transform infrared spectroscopy (FTIR),
aquatic ecosystems and public health. These challenges
highlight the urgent need for low-cost, effective, and scanning electron microscopy (SEM), and Brunauer–
scalable dye remediation strategies, such as those Emmett–Teller (BET) surface area analysis to evaluate
explored in the present study. their structural, morphological, and surface chemical
To address these challenges, growing attention has properties. Their RhB adsorption performance was
been directed toward biomass-derived ACs, which offer subsequently assessed under varying operational
a low-cost alternative while simultaneously valorizing parameters, including dye concentration, solution pH,
9
agro-industrial and forestry residues. In this context, adsorbent dosage, and contact time. Among these, Bc-H
Bombax ceiba – commonly known as the silk cotton exhibited the highest performance, achieving a surface
tree – has emerged as a promising lignocellulosic area of 1,451.2 m²/g and a maximum RhB removal
feedstock. It is wood dust, a byproduct of the furniture efficiency of 99.9% under optimized conditions. This
6
and carpentry industries, widely available across superior behavior is attributed to its extensive surface
Nepal, yet remains underutilized or discarded. Despite area, highly developed pore structure, and the abundance
its abundance, only a few studies have explored the of oxygenated surface groups.
potential of B. ceiba wood dust for AC production, and Overall, this study presents a waste-to-resource
none have systematically investigated the influence of approach strategy for B. ceiba wood dust and offers
different chemical activating agents on its dye adsorption a comparative framework for optimizing chemical
performance. This gap forms the basis and core novelty activation routes. The resulting material served as
7
of the present work. The novelty of this study lies in a cost-effective and efficient adsorbent for RhB
its first-ever systematic comparison of acid (phosphoric removal, with particular relevance to the textile
10
acid [H PO4]), base (potassium hydroxide [KOH]), and and dyeing sectors. The findings contribute to the
3
salt (sodium carbonate [Na CO3]) activation routes development of sustainable and scalable wastewater
2
applied to B. ceiba wood dust for the development of treatment technologies, offering practical solutions for
high-performance AC adsorbents. This approach is regions seeking affordable, environmentally friendly
unique in evaluating how different chemical activating alternatives aligned with global sustainability goals.

Volume 22 Issue 4 (2025) 188 doi: 10.36922/AJWEP025240191