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Showing 2 results for Hasani
Bioremediation of selected polycyclic aromatic hydrocarbons by Chlamydomonas reinhardtii algae in synthetic crude oil wastewater
Navid Ahmadi, Mozhgan Ahmadi Nodushan, Mohammad Hadi Abolhasani, Seyed Abbas Hosseini,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: The presence of PAHs in the environment can cause a problem as their presence has a deleterious effect on humans and animals. They also have the ability to cause tumors in humans and animals. Generally, to remove crude oil pollutants from seawater, various physicochemical and biological treatment methods have been applied worldwide. A biological treatment method using bacteria, fungi, and algae has recently gained a lot of attention due to its efficiency and lower cost. Chlamydomonas reinhardtii, microalgae have features such as a high proliferation rate, and cultivability in various water ecosystems.
Materials and Methods: In the present study, a total of 12 samples of synthetic oil wastewater were prepared at 2.5 g/L, 7.5 g/L, and 12.5 g/L that were called C1, C2 and C3.The gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, water samples were further analyzed for the amounts of biological oxygen demand (BOD), Chemical oxygen demand (COD), and total organic carbon (TOC). Chlorophyll A, biomass, amounts of nitrate, and nitrite ​​were also measured. Statistical analysis was performed using SAS 9/8 software.
Results: Results indicated that the removal rates from crude oil by C.reinhardtii microalgae were 100% on the 14th day for the three compounds of phenanthrene, fluorine, and anthracene at all concentrations, and 97.8%, 93%, and 92.7% for naphthalene compound at concentrations of 2.5 g in 1L, 7.5 g in 1L, and 12.5 g in 1 L, respectively (p<0.05). In terms of nutrients (NO-2 and NO-3), the highest amount of nitrate removal was observed at a concentration of 2.5 g/L from crude oil (C1) (p<0.05). The highest biomass was observed in the C3 treatment (p<0.05). Moreover, the greatest decline in BOD was observed in treatment C3 at 47.4%, while the greatest COD and TOC decline were observed in C1 treatment with the value of 84% and 94%, respectively (p<0.01).
Conclusion: The results showed that the cultivation of C.reinhardtii in crude oil in terms of nutrient removal potential, hydrocarbon composition, improving water quality and production of suitable biomass can be an acceptable option for exploitation in the biological treatment process.
 

Optimization of catalytic sono-praxone hybrid process in the presence of iron oxide-zinc oxide catalyst for the treatment of petroleum wastewater by central composite design
Mehrab Aghazadeh, Amirhesam Hasani, Mehdi Borghei,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: Based on its unique characteristics, oil industry wastewater must be treated before discharging into the environment. The study aimed to optimize the catalytic sonopraxone process in the treatment of petroleum wastewater using a statistical method.
Materials and Methods: The synthesis of Iron Oxide-Zinc Oxide was carried out by air oxidation and layer-by-layer self-assembly method. XRD, SEM, EDAX, FT-IR, BET, DRS, VSM and TGA techniques were used to investigate the structure. In this study, applied CCD method optimization of pH parameters, reaction time, ozone gas concentration, hydrogen peroxide concentration and catalyst amount in the process. In optimal conditions, BOD5 and TPH removal values, reaction kinetics and synergistic effect of mechanisms were studied. COD, TPH and BOD5 were measured by spectrophotometer (DR6000), GC-FID and incubator, respectively.
Results: The results indicated that the Fe3O4@ZnO structure is well formed. A quadratic model was proposed to model the process based on the correlation coefficient. Based on ANOVA analysis and p and f indices, the proposed model was reported to be significant. Optimum conditions include pH 6.4, ozone concentration 1.3 mg/L.min, hydrogen peroxide concentration 2.5 mL/L, reaction time 51 min and catalyst amount equal to 0.64 g/L. In these conditions, the amount of COD reduction was 82.3 and 70% theoretically and experimentally, respectively. Also, in optimal conditions, BOD5 and TPH removal rates were 90.5% and 85.8%, respectively. The kinetics of the process follows the kinetics of the first order (R2=0.98) and the presence of different mechanisms together causes a synergistic effect and increases the efficiency of the process.
Conclusion: This process can improve the quality of oil effluent based on COD, BOD5, and TPH removal.
 

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