Najafpoor Ali Asghar, Davoudi Mojtaba, Rahmanpour Salmani Elham
Health Sciences Research Center, Department of Environmental Health Engineering, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran.
Department of Environmental Health Engineering, School of Health, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran.
J Environ Health Sci Eng. 2017 May 25;15:11. doi: 10.1186/s40201-017-0273-3. eCollection 2017.
Annually, large quantities of dyes are produced and consumed in different industries. The discharge of highly colored textile effluents to the aquatic environments causes serious health problems in living organisms. This paper investigates the performance of each of the electro-oxidation and electro-reduction pathways in the removal of reactive red 120 (RR120) from synthetic textile effluents using a novel electrochemical reactor.
In the current study, a two-compartment reactor divided by cellulosic separator was applied in batch mode using graphite anodes and stainless steel cathodes. Central Composite Design was used to design the experiments and find the optimal conditions. The operational parameters were initial dye concentration (100-500 mg L), sodium chloride concentration (2500-12,500 mg L), electrolysis time (7.5-37.5 min), and current intensity (0.06-0.3 A).
The results showed that electro-oxidation was much more efficient than electro-reduction in the removal of RR120. According to the developed models, current intensity was the most effective factor on the electro-oxidation of RR120 as well as in power consumption (Coefficients of 12.06 and 0.73, respectively). With regard to the dye removal through electro-reduction, electrolysis time (coefficient of 8.05) was the most influential factor. Under optimal conditions (RR120 = 200 mg.L, NaCl = 7914.29 mg.L, current intensity = 0.12 A, and reaction time = 30 min), the dye was removed as 99.44 and 32.38% via electro-oxidation and electro-reduction mechanisms, respectively, with consuming only 1.21 kwhm of electrical energy.
According to the results, electro-oxidation using graphite anodes in a cell divided by cellulosic separator is very efficient, compared to electro-reduction, in the removal of RR120 from aqueous solutions.
不同行业每年都会生产和消耗大量染料。高色度纺织废水排放到水生环境中会给生物带来严重的健康问题。本文使用新型电化学反应器研究了电氧化和电还原途径在去除合成纺织废水中活性红120（RR120）方面的性能。
在本研究中，使用纤维素分离器隔开的两室反应器以间歇模式运行，采用石墨阳极和不锈钢阴极。采用中心复合设计来设计实验并找到最佳条件。操作参数包括初始染料浓度（100 - 500 mg/L）、氯化钠浓度（2500 - 12500 mg/L）、电解时间（7.5 - 37.5分钟）和电流强度（0.06 - 0.3 A）。
结果表明，在去除RR120方面，电氧化比电还原效率高得多。根据所建立的模型，电流强度对RR120的电氧化以及功耗的影响最大（系数分别为12.06和0.73）。关于通过电还原去除染料，电解时间（系数为8.05）是最有影响的因素。在最佳条件下（RR120 = 200 mg/L，NaCl = 7914.29 mg/L，电流强度 = 0.12 A，反应时间 = 30分钟），通过电氧化和电还原机制分别去除了99.44%和32.38%的染料，仅消耗1.21 kwh/m³的电能。
根据结果，与电还原相比，在纤维素分离器隔开的电解槽中使用石墨阳极进行电氧化在从水溶液中去除RR120方面非常有效。
