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Charcoal-adsorption of antibiotic fermentation broth

highly porous structure. Its non-polar nature under the oxygen demand associated with organic matter
varied pH conditions also confers a unique affinity for decomposition. 18
organic acids such as lactic, acetic, and butyric acids. 7,10 In our previous study, the antibiotic pristinamycin was
Pradhan et al. conducted an experimental study synthesized by cultivating Streptomyces pristinaespiralis
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on the separation of lactic acid (<10 g/L) from a with date syrup as a glucose substitute. In this study,
model fermentation solution using granular AC. the effluent from this process was continuously treated
Thermodynamic analysis demonstrated that optimal with different charcoal concentrations at various
lactic acid adsorption occurs at a pH below the pKa temperatures to reduce its BOD and COD.
of lactic acid (3.86) through a physical adsorption The present study aims to remove organic materials
mechanism. The optimal conditions for using AC to from the antibiotic fermentation effluent using powdered
remove amoxicillin and tetracycline (TC) have also AC at varying concentrations (10, 20, and 30 mg/L) and
been examined. 12,13 Umrantezcanun et al. reported a temperatures (25, 50, and 75°C), and to determine the
12
maximum COD removal of 91.2% at 20°C and pH 5, optimal concentration and temperature for effective
using 0.15 g of AC and an initial TC concentration of removal.
100 mg/L after a 24-h adsorption period. Ranaweera
et al. applied AC adsorption with 200 mL of TC 2. Materials and methods
8
solution and 200 mg of AC, achieving a high TC
removal efficiency (>95%) from synthetic wastewater. 2.1. Samples
Spit et al. investigated the effects of coagulation, The antibiotic fermentation broth was collected from the
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ozonation, and granular AC filtration on the removal of fermentative bioreactors as described in our previous
19
small organic pollutants from treated wastewater, with study. Samples were obtained from three different
particular focus on pharmaceutical residues. Abbas and batches, with three replicates per batch for further
Trari identified the optimal conditions for amoxicillin analysis.
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removal as a dose of 0.124 g, a temperature of 45°C, 2.2. Determination of physicochemical properties
and pH 5.03, using the desirability function. The pH of the sample was measured directly using a
Mullai and Rajesh examined the post-treatment of pH meter (MP512-03, Hangzhou Tuqi Instrument
15
antibiotic wastewater using AC as the adsorbent. The Co., Ltd, China). Color of the sample was analyzed
findings indicated that the color removal efficiency using a colorimetric equipment (CR-400 Konica
of the wastewater increased over time, reaching Minolta, Japan), and total solids were determined
equilibrium after 120 min with 100 mg of AC under using a gravimetric approach, which involved drying
shaking conditions. The maximum COD removal and measuring the residue after a specified volume of
efficiency achieved was 43.3% with 100 mg of AC material had been evaporated. Sugar content, expressed
after 120 min. Zhanga et al. employed an integrated as glucose, was determined using high-performance
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approach combining powdered AC with ultrafiltration liquid chromatography (Agilent 1260, infinity,
and reverse osmosis to treat waste liquor generated Germany) based on the method established by Aleid,
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from TC production. The study demonstrated that the where different concentrations of glucose were prepared
performance of ultrafiltration–reverse osmosis was to plot a calibration curve for quantification. Elemental
enhanced by incorporating AC into the waste liquor, composition was determined using atomic absorption
with an optimal concentration of 8.0 mg/L. spectroscopy (NOVA 300, USA).
BOD represents the total dissolved oxygen (DO)
required by microorganisms to decompose organic 2.3. Treatment of antibiotic fermentation effluents
material in a water sample. Elevated BOD levels After fermentation, the antibiotic fermentation broth
indicate reduced oxygen availability in the analyzed was treated with three doses of AC (Sigma-Aldrich,
water body. DO in water samples contributes to the United States [USA]) at 10, 20, and 30 mg/L, under
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degradation of both organic and nitrogenous matter. three temperatures (25, 50, and 75°C). Nine treatments
The BOD curve comprises two distinct components: were analyzed, as presented in Table 1.
Carbonaceous BOD and nitrogenous BOD. The initial
5 days’ demand primarily reflects carbonaceous BOD, 2.4. Adsorption treatment
which constitutes approximately 70% of the total BOD. After 144 h of fermentation in a 100-L fermentor,
The 5-day BOD (BOD ) value generally indicates 200 mL of pristinamycin fermentation broth was
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Volume 22 Issue 6 (2025) 135 doi: 10.36922/AJWEP025240198