The Efficiency of Electrocoagulation Process Using Iron Electrode in Removal of Humic Acid from Water in the Presence of Chitosan as a Coagulant Aid

Background: Natural organic substances in water cause problems during water treatment processes. The potential of these compounds as precursor of trihalomethanes formation has increased the necessity of removing these compounds from water more than ever. In the current study, the effect of chitosan, as a cheap and efficient coagulant, in the electrocoagulation process with iron electrode for removal of humic acid from aqueous solutions was evaluated. Methods: In this study, a batch reactor equipped with 4 iron electrodes in dimensions of 2*20*200 mm, with a volume of 1 L and connected to an electrical source was used. The effects of current density, initial humic acid concentration, chitosan concentration and pH in the electrocoagulation process were investigated. Excel software was used to analyze the obtained results. Results: The results indicated pH = 6, current density=40 V, and chitosan concentration= 2 mg/L as the optimal conditions for the process. Also, in the presence of chitosan as a coagulant aid in the electrocoagulation process, after 60 min, the process efficiency reached 68%. Conclusion: Based on the current findings, electrocoagulation process is a suitable process in removal of humic acid. Also, chitosan is an efficient coagulant aid in the electrocoagulation process with iron electrode and increases the process efficiency. Keywords: Electrocoagulation, Humic acid, Coagulant aid, Chitosa

Investigation on effect of chitosan aid in removal of humic acid from aqueous solutions by electrocoagulation process using aluminum electrode

زمینه و هدف: وجود اسید هیومیک در آب آشامیدنی می تواند به عنوان یک ترکیب پیش ساز سبب تولید ترکیبات جانبی گندزدایی گردد. این مطالعه با هدف ارزیابی تأثیر کیتوزان به عنوان کمک منعقد کننده کم هزینه و موثر در فرآیند انعقاد الکتریکی به همراه الکترود آلومینیم، برای حذف ماده آلی اسید هیومیک از محیط های آبی انجام شده است. روش بررسی: در این مطالعه تجربی، آزمایشات انعقاد الکتریکی با الکترود آلومینیوم در pH های 10-2 با و بدون حضور کیتوزان مورد مطالعه قرار گرفت. اثرات مقادیر متغیر پارامتر های دانسیته جریان، غلظت اولیه اسید هیومیک وغلظت کیتوزان به عنوان کمک منعقد کننده در فرآیند انعقاد الکتریکی در یک راکتور پایلوت از جنس پلکسی گلاس با جریان ناپیوسته مورد بررسی قرار گرفت. در مراحل مختلف مطالعه، غلظت اسید هیومیک با استفاده از دستگاه اسپکتروفتومتر اندازه گیری شد. یافته ها: دانسیته جریان برابر با 20 میلی آمپر بر سانتی متر مربع و pH معادل 6 به عنوان شرایط بهینه برای حذف اسید هیومیک از محیط آبی بدون کیتوزان حاصل شد. همچنین حضور کیتوزان در غلظت mg/l 5/2 به عنوان کمک منعقد کننده در فرآیند انعقاد الکتریکی باعث حذف حداکثری میزان اسید هیومیک (90 درصد) گردید. نتیجه گیری: ماده کیتوزان به عنوان یک کمک منعقد کننده مناسب و موثر در فرآیند انعقاد الکتریکی در حضور الکترود آلومینیم عمل می کند و می تواند سبب افزایش کارایی فرایند های انعقادی در حدف ماده آلی اسید هیومیک گردد

CuCoFe2O4@AC magnetic nanocomposite as a novel heterogeneous Fenton-like nanocatalyst for Ciprofloxacin degradation from aqueous solutions

Abstract CuCoFe2O4@Activated Carbon (AC) was synthesized by a fast, simple, and green microwave-assisted coprecipitation method, and then used as a new heterogeneous magnetic nanocatalyst in Fenton-like reaction for ciprofloxacin (CIP) degradation from aqueous media. CuCoFe2O4@AC was characterized by Field emission scanning electron microscopy (FE-SEM), Energy-Dispersive Spectroscopy (EDS), Mapping, Line scan, Fourier-transform infrared spectroscopy (FT-IR), Thermal gravimetric analysis (TGA), X-Ray diffraction analysis (XRD), vibrating-sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) techniques. The characterization results showed that the CuCoFe2O4@AC nanocomposite was in the ferrite phase with a mesoporous, uniform, quasi-spherical surface and a particle size of about 25 nm. The total volume of single-point adsorption pores was equal to 0.22 cm3 g−1 and the specific surface area was determined to be 199.54 m2 g−1. This nanocomposite had good thermal stability with high magnetic strength. In the presence of H2O2, the synthesized nanocomposite provided a Fenton-like reaction for CIP removal from aqueous solutions. The investigation of this process showed that neutral pH, 1 g L−1 of the nanocomposite, and 73.5 mM of H2O2 were the optimal conditions for CIP removal with an initial CIP concentration of 20 mg L−1. The maximum removal efficiency of 95.77% was attained after 120 min of contact time under the optimum conditions. The CIP degradation during this Fenton-like process followed a pseudo-first-order kinetic model with rate constants (K app) of 0.01 min−1. Finally, the CIP removal efficiency after 5 cycles of recovery and regeneration of CuFe2O4@AC was 87.65%. The excellent performance and high catalytic activity of CuCoFe2O4@AC in Fenton-like reaction for CIP removal make it have potential application foreground in the treatment of pharmaceutical wastewater

Comparing the performance of granular coral limestone and Leca in adsorbing Acid Cyanine 5R from aqueous solution

The effect of granular coral limestone and Leca as adsorbents for removing Acid Cyanine 5R (AC5R) from aqueous solution was studied. The optimum pH and adsorbent particles size in both adsorbents were determined to be 3 and 297 μm, respectively. The optimum dosages of coral limestone and granular Leca were 0.150 and 0.145 g/mg of dye, respectively. Also, results have shown that the adsorption efficiency by both coral limestone and Leca increased with the decreasing adsorbent particles size. Moreover, under similar conditions, the maximum removal efficiency by granular coral limestone and Leca was 94% and 88%, respectively. The results revealed that the performance of granular coral limestone was better in AC5R removal than that of Leca granulated under such condition. In total, granular coral limestone and Leca act as suitable adsorbents for removing dye pollutants from an aqueous solution