Degradation of herbicide diuron in water employing the Fe0/H2O2 system

Abstract

O sistema de degradação utilizando ferro metálico e peróxido de hidrogênio (reação de Fenton) foi empregado para a degradação do herbicida diurom. Visando obter as melhores condições de degradação, foram otimizados parâmetros que influenciam no processo, como pH, concentração de peróxido de hidrogênio (H 2 O 2 ) e quantidade de ferro. A degradação do herbicida foi acompanhada por cromatografia líquida com detecção por arranjo de diodos (CLAE-DAD) e cromatografia líquida com detecção por espectrometria de massas sequencial (LC-ESI-MS/MS), além da determinação de carbono orgânico total (COT). Nas melhores condições de degradação, pH = 2,5; 2 g de ferro e 2 mmol L -1 de H 2 O 2 , uma solução aquosa de diurom comercial (10 mg L -1), alcançou valores não detectáveis ao tempo de 10 min, para diurom e para o metabólito monitorado, 3,4-DCA. Ainda os valores de COT foram reduzidos, chegando a valores menores que 5 mg L -1 , mostrando a eficiência e rapidez do sistema.A degradation system using metallic iron and hydrogen peroxide (Fenton reaction) was employed for the degradation of the diuron herbicide. In order to obtain the maximum degradation the main conditions such as pH, hydrogen peroxide concentration and iron amount, were optimized. Herbicide degradation was evaluated by liquid chromatography with diode array detection (HPLC-DAD) and liquid chromatography tandem mass spectrometric detection (LC-ESI-MS/MS) and total organic carbon analysis (TOC). In the best degradation condition, pH = 2.5, 2 g of iron and 2 mmol L -1 of hydrogen peroxide, after 10 min a commercial diuron solution (10 mg L -1 ) had no detection values for diuron and its metabolic, 3,4-dichloroaniline (3,4-DCA). The TOC was reduced to values lower than 5 mg L -1 showing the efficiency of the system.

An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials

“…The pH and H 2 O 2 concentration were varied from 2.5 to 8.5 and from 2 to 4 M, respectively; Fe amount was evaluated from 1 to 3 g in the best pH and H 2 O 2 concentration. In the best condition (pH 2.5, 2 g of iron, and 2 mM of H 2 O 2 ), diuron (10 mg L −1 ) was completely removed from the solution in 10 min of reaction [94]. The process also resulted in an excellent degree of effluent mineralization, with ca.…”

State of the art of the environmental behaviour and removal techniques of the endocrine disruptor 3,4-dichloroaniline

“…At pH 2.5 more than 99.9% of the pesticide was removed after ten minutes, with only µg L -1 of 3,4-DCA found remaining in the effluent. [121] Electrochemical and electrohydraulic methods…”

Photocatalytic Degradation for Treating Multipesticide Residues Using [Ru(bipy)3] Cl2-Doped TiO2/SiO2Based on Surface Response Methodology

“…In this context, pesticides, pharmaceuticals, personal care products (PPCPs), polycyclic aromatic hydrocarbons (PAHs), textile dyes, and other substances can threaten the quality of water resources, because they are generally toxic and non-biodegradable. [4][5][6] Recent studies have reported the risk of water contamination by pesticides in Southern Brazil and detected pesticides in ground, surface and drinking waters. [7][8][9] In this context, finding a method to reduce the impact of these pollutants is of great relevance.…”