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Aleid, et al.

concentration, and agitation duration on TC removal. The most significant decrease in BOD occurred
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TC removal efficiency was temperature-dependent; when the broth was treated with 30 mg/L of AC at 25°C,
however, it improved with increasing adsorbent dose, where the BOD reduction was significantly higher
pH, initial antibiotic concentration, and agitation (p<0.05) at 30 mg/L than at 10 mg/L. The treatment
duration. At 20°C, pH 5, with 0.15 g AC and an initial reduced the BOD from 536 mg/L in the untreated
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TC concentration of 100 mg/L, the COD concentration sample to 487 mg/L in the treated sample (Figure 2).
decreased from 1,000 mg/L to 88 mg/L after 24 h, Unlike COD, BOD reduction was temperature-
indicating a removal efficiency of 91.2%. Based on dependent, as the introduction of charcoal at 50°C or
these findings, AC adsorption of TC from wastewater 75°C did not significantly decrease (p˃0.05) the BOD
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appears to be a viable treatment option. of the fermentation broth. This may be attributed to
25°C being a biologically optimal temperature for BOD
3.2.2. Effects of AC dose and temperature on BOD testing, reflecting the natural decomposition of organic
BOD quantifies the oxygen consumed by bacteria and waste in aquatic ecosystems. Elevated temperatures
other microorganisms during the aerobic decomposition (e.g., 75°C) facilitate procedures such as thermal
of organic matter at a designated temperature. hydrolysis or COD testing but compromise BOD
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During the 5-day incubation period, the DO in the analysis by killing the microorganisms essential to the
antibiotic fermentation broth is primarily utilized for test.
the decomposition of organic matter. BOD represents Elevated BOD values indicate increased oxygen
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the amount of DO consumed by microorganisms while depletion in the analyzed pristinamycin fermentation
converting organic matter into carbon dioxide and broth. The BOD results indicate the oxygen demand
water. To reduce the BOD of the fermentation broth, associated with pristinamycin organic waste discharge,
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samples were treated with AC at concentrations of supporting the assessment of its impact on the oxygen
10, 20, and 30 mg/L, under temperature conditions of levels of the receiving water body. Data from BOD tests
25°C, 50°C, and 75°C for each treatment. The BOD may be used to establish treatment criteria for the design
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was subsequently measured for each treatment group of pristinamycin wastewater treatment facilities. 22
and untreated samples. The results are illustrated in Antibiotic fermentation broths produce effluents
Figure 2. containing residual antibiotics, organic byproducts,
and nutrients, which pose environmental risks by
potentially promoting antimicrobial resistance and
disrupting aquatic ecosystems. Pristinamycin, a
streptogramin antibiotic derived from the fermentation
of S. pristinaespiralis, results in effluents that contain
residual antibiotics, organic acids, and macromolecular
byproducts such as proteins and sugars. Effluents
containing pristinamycin pose environmental risks
due to their persistence and potential to disseminate
antimicrobial resistance genes. Adsorption using an
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adsorbent material provides an effective treatment
method by utilizing its extensive surface area and
chemical affinity to capture pristinamycin and related
organic compounds. The processes involved in binding
antibiotics onto AC include hydrophobic interactions,
hydrogen bonding, and π–π interactions. The most
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effective adsorption was observed at a pH range of
Figure 2. Effect of activated carbon dosage and 6–7, which closely aligns with the isoelectric point
temperature on BOD reduction in the pristinamycin of pristinamycin, thereby reducing electrostatic
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fermentation broth. Dosages of 10, 20, and 30 mg/L repulsion. In this study, treatment with 30 mg/L of AC
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were evaluated, with the control receiving no at 25°C resulted in a 52% reduction in COD in antibiotic
activated carbon treatment. fermentation effluent. Although lower than the findings
Abbreviation: BOD : Biochemical oxygen demand reported by Umrantezcanun et al., this likely reflects
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over 5 days. our ultra-low adsorbent dosage (30 mg/L) compared

Volume 22 Issue 6 (2025) 138 doi: 10.36922/AJWEP025240198