Efficient azo dye decolorization in a continuous stirred tank reactor (CSTR) with built-in bioelectrochemical system

Abstract

h i g h l i g h t sA newly designed CSTR-BES was developed for efficient azo dye removal. BES module took an important role for increasing decolorization rate. The effects of anaerobic sludge and acetate concentration were investigated. a r t i c l e i n f o t r a c tA continuous stirred tank reactor with built-in bioelectrochemical system (CSTR-BES) was developed for azo dye Alizarin Yellow R (AYR) containing wastewater treatment. The decolorization efficiency (DE) of the CSTR-BES was 97.04 ± 0.06% for 7 h with sludge concentration of 3000 mg/L and initial AYR concentration of 100 mg/L, which was superior to that of the sole CSTR mode (open circuit: 54.87 ± 4.34%) and the sole BES mode (without sludge addition: 91.37 ± 0.44%). The effects of sludge concentration and sodium acetate (NaAc) concentration on azo dye decolorization were investigated. The highest DE of CSTR-BES for 4 h was 87.66 ± 2.93% with sludge concentration of 12,000 mg/L, NaAc concentration of 2000 mg/L and initial AYR concentration of 100 mg/L. The results in this study indicated that CSTR-BES could be a practical strategy for upgrading conventional anaerobic facilities against refractory wastewater treatment.

Determination of Kinetic Parameters of the Crystal Violet Reaction With Sodium Hydroxide Applying Absorbance Technique and the Laws of Lambeert-Beer and Arrhenius

“…A very common reactor in industrial processes is the CSTR (Continuous Stirred Tank Reactor) is a very common reactor in industrial processes. This reactor is used for liquid reagents, promoting the perfect mixing between them so that the reaction takes place in a more efficient way (CUI et al, 2016).…”

Azo dye decolorization in an up-flow bioelectrochemical reactor with domestic wastewater as a cost-effective yet highly efficient electron donor source

“…Bioelectrochemical systems (BESs) have been suggested to be a promising technology in reductive degradation or transformation of diverse contaminants, including nitroaromatics (Mu et al, 2009b;Wang et al, 2011), azo dyes (Cui et al, 2016a(Cui et al, , 2016c, halogenated compound (Kong et al, 2015;Liang et al, 2013), heavy metals (Huang et al, 2014;Luo et al, 2014), nitrate (Pous et al, 2014), etc. Although superior performance of BES compared to the traditional biological processes were extensively reported in these contaminants, this technology is still far away from the practice as most of the existed studies were performed at lab scale and under ideal conditions, such as strong buffered system, sufficient electron donors and excellent conductivity.…”

Analysis of electrode microbial communities in an up-flow bioelectrochemical system treating azo dye wastewater

“…The BES operated in batch mode and the medium composition used in this stage was glucose (2000 mg/L), phosphate buffer solution (PBS, 50 mM, pH $ 7.2), KCl (130 mg/L), NH 4 Cl (310 mg/L), trace element solution (10 mL/L) and vitamin solution (10 mL/L) [25]. In the first two cycles, 50 mL anaerobic activated sludge (obtained from Taiping Municipal Wastewater Treatment Plant, Harbin, China; SS of 31 g/L and VSS of 15 g/L) was added into the reactor as seed sludge.…”

“…By now, biological treatment is still the most widely applied wastewater remediation method. But the pure biological facilities can no longer satisfy the increasing wastewater amount and the stricter wastewater discharging standard [3][4][5]. It is urgent to explore a feasible, sustainable and economical strategy to deal with the wastewater issue.…”

“…With a small voltage supplied, BESs are capable of azo bond cleavage [6], nitro reduction [7], heavy metal recovery [8], sulfur transformation [9] and dehalogenation [10]. In some cases, BESs are used for recovering energy resources from waste(water)s in the form of H 2 [11], CH 4 [12] and electricity [13,14]. BES has been proved the superiority such as excellent performance and time-saving comparing to conventional anaerobic processes [15], and more cost-efficient and environment-friendly versus electric or electrochemical methods due to lower energy supplied and less by-products [7,16].…”