Abstract:
Plastic waste constitutes a major
environmental concern within municipal solid
waste management systems. Its progressive
degradation and weathering facilitate the leaching
of hazardous additives, notably bisphenol A (BPA),
a well-documented endocrine-disrupting compound
with significant toxicological effects for aquatic
ecosystems and human health. The aim of this study
was to use municipal solid waste (MSW) compost
residue biomass, including coconut shell, coconut
husk, and wood fractions, to prepare nitrogen-
doped biochar (N-MSW-BC) for persulfate (PS)-
mediated catalytic degradation of BPA. The
biomass was pyrolyzed in the presence of urea and
sodium bicarbonate. The physicochemical
properties of N-MSW-BC were assessed using
proximate analysis, point of zero charge (pHpzc),
and Fourier transform infrared (FTIR)
spectroscopy. The potential of BPA degradation by
N-MSW-BC was evaluated through adsorption
experiments, pre-adsorption kinetics, and
synchronous degradation studies. FTIR verified the
integration of nitrogen-containing heterocycles into
the carbon matrix, which showed distinctive bands
near 3660–3280 cm−1 (O-H/N-H stretching) and at
1594 cm−1, attributed to overlapping aromatic C=C
and C=N stretching and N-H bending vibrations. A
stable carbon content of 41.83% was determined by
proximate analysis, suggesting a graphitic-rich
carbon matrix ideal for PS activation. BPA removal
remained consistently high (~99.7%) across a pH
range of 2-9 in a pH-edge experiment with the N-
MSW-BC persulfate (10 mM) system. At 180 min,
pre-adsorption followed by PS activation achieved
99.5% BPA elimination; whereas, the synchronous
system only achieved 90.5% within the same
exposure period. The electrostatic forces with BPA
and biochar were influenced by their pHpzc (~ 8.2).
These findings suggest an interfacial, adsorption-
mediated catalytic process, establishing N-MSW-
BC generated from compost residues as a
sustainable material for BPA remediation by
persulfate activation.
