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Equilibrium and kinetic investigation of solophenyl dye removal from aqueous solution using cellulose adsorbents
Hanieh Mirbolooki, Shahriar Mahdavi, Eisa Solgi, Babak Razdar, Mahboubeh Zarabi, Davoud Akhzari,
Volume 17, Issue 4 (3-2025)
Abstract
Background and Objective: Dyes are among the most widespread pollutants found in industrial wastewater. The aim of this study is to investigate the potential of vineyard wood waste as a green adsorbent for the removal of polyazo solophenyl dye from aquatic environments.
Materials and Methods: In this laboratory research, two forms of adsorbents modified with H₂SO₄ and NaOH were used. Data obtained from dye adsorption in synthetic solutions were fitted to isotherm, kinetic, and thermodynamic models, with all calculations performed using Excel software. Zeta potential analysis, along with FTIR, BET, and FESEM-EDS instrumental analyses, was conducted to determine the properties of the adsorbent. Additionally, the desorption rates of the adsorbents were analyzed.
Results: The results showed that the highest color removal efficiency for the adsorbent modified with H2SO4 was achieved at a contact time of 180 minutes and a reaction temperature of 50 °C, while for the adsorbent modified with NaOH, the highest efficiency was observed at a contact time of 105 minutes and a reaction temperature of 25 °C. For both adsorbents, the optimal pH was 4, and the optimal adsorbent dosage was 1 g. The adsorption data for both modified adsorbents followed the pseudo-second-order kinetic model, while the equilibrium data aligned with the Freundlich and Temkin isotherm models. The adsorption capacities were found to be 22.27 mg/g and 9.87 mg/g for the adsorbents modified with acid and base, respectively, under optimal conditions.
Conclusion: This study introduces a novel, low-cost adsorbent derived from natural waste for water pollution removal, transforming the current approach into a cost-effective and eco-friendly solution.
 

The treatment of papermaking effluent with the hybrid process of coagulation-ozonation-membrane filtration in order to recycle and reuse
Mahdi Elyasi Kojabad, Ali Aghdami,
Volume 18, Issue 2 (9-2025)
Abstract
Background and Objective: The paper industry is one of the most water-intensive sectors, generating a large volume of wastewater. Proper management of this waste—including its treatment, recycling, and reuse—can help prevent environmental pollution and conserve the country's water resources. In this study, a three-step process consisting of coagulation, ozonation, and membrane filtration was employed to treat papermaking wastewater.
Materials and Methods: A three-step process involving coagulation, ozonation, and membrane filtration was employed to treat the wastewater. In the first stage, polyaluminum chloride (PAC) was used to remove larger particles. This was followed by ozonation to degrade complex organic compounds. The final stage involved membrane filtration to further purify the water. At each stage, the chemical oxygen demand (COD) of the wastewater was measured and analyzed for comparative evaluation.
Results: Each stage played a critical role in the treatment process. Coagulation effectively removed a substantial amount of suspended particles, while ozonation addressed issues related to color and the breakdown of complex compounds. The final stage, membrane filtration, was instrumental in eliminating extremely fine suspended particles. Despite these efforts, the treated effluent exhibited a higher COD than the initial sample, possibly due to the release of intermediate compounds during treatment. However, the process successfully reduced the concentration of crude oil by 66%.
Conclusion: The membrane flux analysis revealed that at pH levels of 11 and 14, the effluent’s membrane flux closely approached that of pure water. This finding highlights the potential effectiveness of the proposed purification method for the treatment and recycling of papermaking wastewater.
 

Evaluating the efficacy of ozonation and membrane filtration as alternatives to chlorination for disinfecting drinking water from the Behbahan Maroon river source
Mohammad Jandkaripour, Mahdi Elyasi Kojabad, Raheleh Haghighi,
Volume 19, Issue 1 (6-2026)
Abstract
Background and Objective: Growing concerns over disinfection by-products (DBPs) resulting from conventional chlorination necessitate the exploration of alternative approaches in water treatment. This study investigates the efficiency of a combined system comprising ozonation and ceramic membrane filtration for drinking water treatment.
Materials and Methods: A ceramic membrane was fabricated using the slip-casting method, characterized, and evaluated for performance. Ozonation efficiency was assessed by injecting 1 g of ozone into a 2.5 L sample (concentration of 0.02 g/L) for 3 minutes. Water quality was monitored by measuring turbidity, total dissolved solids (TDS), major anions and cations, as well as microbiological indicators, including coliform bacteria and Escherichia coli.
Results: Morphological examination confirmed the porous structure of the membrane. The flux test results showed that the membrane flux decreased from 475 Lmh to 313 Lmh, with 96% recovery through backwashing. The membrane reduced turbidity from 1.72 NTU to 0.5 NTU, representing a 71% removal efficiency compared to the pre-filtration sample. Ozonation had no effect on water turbidity but achieved complete removal of coliform bacteria and Escherichia coli. In contrast, membrane filtration achieved 66% removal of these bacteria.
Conclusion: Membrane filtration removes the majority of contaminants when employed as a complementary method to either ozonation or chlorination, allowing for the subsequent use of a mild disinfectant to eliminate remaining trace microbial content. The combined application of low-concentration ozonation and chlorination prevents the formation of DBPs, representing a step toward providing safer and healthier drinking water.
 

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