The findings from Pareto charts, main effect plots, and interaction plots demonstrate the importance of polymer concentration. Increasing concentration improves the inhibition percentage and decreases the MIC₅₀. However, the primary factor that influences these changes is chitosan (CS). Additionally, the interaction between CS and PVP, along with other polymers, plays a crucial role in achieving better antimicrobial effects. These results enhance our understanding of the antimicrobial properties of the studied polymers and offer valuable insights for developing effective antimicrobial formulations. The MIC₅₀ value of M1–M16 was at a polymer percentage of 12.5%. At 12.5% polymer percentage, with the limits of [PVA], [PEG], and [PVP] being 0.002–0.004 g/mL and [CS] being 0.001–0.002 g/mL, using the 2-level full factorial method, the inhibition percentage is equal to 174.1 − 27,812 PVA − 18,561 PVP − 25,960 PEG − 38,752 CS + 9,263,047 PVA*PVP + 10,430,763 PVA*PEG + 15,397,157 PVA*CS + 7,088,313 PVP*PEG + 7,841,221 PVP*CS + 14,228,046 PEG*CS − 3,367,292,860 PVA*PVP*PEG − 5,671,998,721 PVA*PVP*CS − 6,619,041,275 PVA*PEG*CS − 3,917,095,529 PVP*PEG*CS + 2,273,661,969,470 PVA*PVP*PEG*CS. Theoretically, the most economical concentrations of PVA, PVP, PEG, and CS are 0.002, 0.002, 0.002, and 0.001 mg/mL at a concentration of 12.5% to reach an inhibition percentage of 99.162%, which coincides with the MBC value.

In medicine, the occurrence of antibiotic resistance was becoming a critical concern. At the same time, traditional synthesis methods of antibacterial agents often lead to environmental pollution due to the use of toxic chemicals. To address these problems, this study applies the green synthesis method to create a novel composite using a polymer blend (M8) consisting of chitosan (CS), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and silver nanoparticles. The results show that the highest ratio of AgNO₃:M8 was 0.15 g/60 mL, which resulted in a 100% conversion of Ag⁺ to Ag⁰ after 10 h of reaction at 80 °C. Hence, using M8, Ag nanoparticles (AgNPs) were synthesized at the average size of 42.48 ± 10.77 nm. The AgNPs’ composite (M8Ag) was used to inhibit the growth of Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Salmonella enterica (SAL). At 6.25% dilution of M8Ag, the growth of these mentioned bacteria was inhibited. At the same dilution percentage of M8Ag, PA was killed.

Due to the negative impacts the dye may have on aquatic habitats and human health, it is often found in industrial effluent and poses a threat to public health. Hence, to solve this problem, this study developed magnetic adsorbents that can remove synthetic dyes like methylene blue. The adsorbent, in the form of beads, consists of a polymer blend of chitosan, polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, and superparamagnetic iron oxide nanoparticles (average size of 19.03 ± 4.25 nm). The adsorption and desorption of MB from beads were carried out at pH values of 7 and 3.85, respectively. At a concentration of 9 mg/L, the loading capacity and the loading amount of MB after 5 days peaked at 29.75 ± 1.53% and 297.48 ± 15.34 mg/g, respectively. Meanwhile, the entrapment efficiency of MB reached 29.42 ± 2.19% at a concentration of 8 mg/L. The cumulative desorption capacity of the adsorbent after 13 days was at its maximum at 7.72 ± 0.5%. The adsorption and desorption kinetics were evaluated.

To investigate the effect of nanoparticle reinforcement, polymer blends (M8) comprising polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, and chitosan were modified using zinc oxide particles (M8/ZnO). This study introduces an M8-modified ZnO composite that offers a non-antibiotic approach relevant to antimicrobial resistance. The average particle size of the ZnO particles was determined to be 181.8 nm using scanning electron microscope (SEM) analysis. Based on the inhibition percentage, M8 has a minimum inhibition concentration (MIC) to have at least a 50% inhibition, or MIC50 value, against Pseudomonas aeruginosa (PA) and Salmonella enterica (SE) at 12.5 and 25% of M8, respectively. The MIC with at least a 90% inhibition percentage, or MIC90, of M8 against SE and PA is 25% of M8. On the other hand, the MIC50 of M8/ZnO against SE, Staphylococcus aureus (SA), and PA is 25, 12.5, and 50% of M8/ZnO, respectively. The MIC90 of M8/ZnO against SE and SA is 50% and 25% of M8/ZnO, respectively. However, M8/ZnO does not inhibit a minimum of 90% of the PA bacteria. Hence, the ratio optimization between M8 and ZnO or the usage of other particles should be considered as a topic for future study.

This study applied ferrate in aquaculture wastewater treatment as a multi-purpose agent for pollutants’ oxidation, coagulation, and disinfection. Pangasius catfish aquaculture wastewater samples were collected from three sources and their characteristics were analyzed. Face Centered Composite Central (FCCC) design was utilized for designing the experiments with two independent factors (i.e., pH and ferrate dose) and 6 responses (i.e., effluent concentrations of COD, turbidity, PO43-, TKN, NH4+, and log reduction of coliform). The effects of the two factors on the responses were evaluated and the optimum conditions for each response and also for all responses were discussed. The results showed that the wastewater with low frequencies of water renewing required treatment before discharging or recirculating. pH, ferrate dose, and their interaction affected differently on the responses. The treatment was preferred at the acidic conditions for COD, turbidity, and TKN removals, but the basic environments for coliform, NH4+, and phosphate removals. However, the effect of pH on the treatment depended on the ferrate dose. The optimum working condition for all responses was suggested at pH 3 and 20 mg/L of ferrate dose by which the treatment efficiencies reached 99.985 % (log reduction of 3.826), 96.8 %, 93.0 %, 85.7 %, 61.7 %, and 50.0 %, for coliform, PO43-, turbidity, COD, NH4+, and TKN, respectively. These pollutants’ effluent concentrations met well the allowable values for discharging while the pH value required adjustment post - treatment. A further study focusing on pH and NH4+ treatment is suggested for the recirculation purpose of the treated water.