Integrated Biological and Electrochemical Oxidation Treatment for High Toxicity Pesticide Pollutant

Abstract

A novel integrated biological and electrochemical oxidation (BEO) process was proposed for the treatment of biorefractory pesticide wastewater with high toxicity. An acetamiprid solution of 1000 mg L -1 was used as the target pollutant. Its biodegradability in terms of biochemical oxygen demand in a 5-d test period (BOD 5 )/ total organic carbon (TOC) was only 0.0057, presenting its high biorefractory property. In the BEO system with boron-doped diamond electrode (BDD), the value of BOD 5 /TOC was improved to 1.17 and the toxicity was reduced by 40% in 3 h, maintaining the activity of microorganisms on a biofilter at an appropriate level. The intermediates (mainly small molecule carboxylic acids) produced in the electrochemical process served as nutrients for the microorganisms and then were biodegraded, while the biodegradation of these intermediates further enhanced the electrochemical oxidation of the original pollutant. The synergy of electrochemical and biological processes improved the removal of acetamiprid and TOC with higher efficiency and lower energy consumption. For the same TOC removal, the mineralization current efficiency (MCE) in the BEO was at least 40% higher than that in a single electrochemical oxidation (EO), and the energy consumption was only 53.3 (kW h)/m 3 in the BEO in 5 h, which was 44.5% lower than that in the EO. The BEO technique is an efficient method for the treatment of highly concentrated and biorefractory wastewater.

Electrocatalytic reduction of metronidazole using titanocene/Nafion®-modified graphite felt electrode

“…In recent years, the combined processes, in particular physicochemical and biological combined treatments, have received a growing attention for their efficiency to achieve complete mineralization of biorecalcitrant compounds with the objective to reduce operating costs [1][2][3][4][5][6][7][8][9][10][11][12]. In such systems, a physicochemical pretreatment such as an advanced oxidation process (AOP) or an electrochemical method is used to change the structure of pollutants.…”

Nicotine degradation by two novel bacterial isolates of Acinetobacter sp. TW and Sphingomonas sp. TY and their responses in the presence of neonicotinoid insecticides

“…It suggested that these two newly isolated bacteria may resist the toxicity of some neonicotinoid insecticides during the nicotinedegrading process, which would have practical implications for tobacco waste bio-treatment. Neonicotinoids are not readily degraded and are considered as biorefractory pesticide pollutants (Tomizawa and Casida 2005;Liu et al 2010), and only limited microbial species have been reported to transform neonicotinoid insecticides (Dai et al 2010a, b). However, maybe because neonicotinoids have a structural similarity to nicotine (Tomizawa and Casida 2005), nicotine-degrading bacteria TW and TY showed ability to degrade the tested neonicotinoids.…”

Electrochemical degradation of 2-diethylamino-6-methyl-4-hydroxypyrimidine using three-dimensional electrodes reactor with ceramic particle electrodes

“…Upon now, three-dimensional electrode technology has been http://dx.doi.org/10.1016/j.seppur.2015. 10.053 1383-5866/Ó 2015 Elsevier B.V. All rights reserved. successfully used to remove metal ions [21], cyanide [22], and dyes [23] from wastewater.…”

“…2-Diethylamino-6-methyl-4-hydroxy pyrimidine (DTMHP) is a typical pesticide intermediate widely used in agricultural, i.e., it is the main raw material for the synthesis of diazinon [3] and pirimiphos methyl [4], which are biorefractory and microtoxic. Recently, many methods have been used to treat this kind of wastewater, such as Fenton's reagent [5,6], photocatalysis [7][8][9], biological techniques [10,11] and electrochemical degradation [12,13]. However, Fenton's reagent will produce a large number of chemical sludge.…”