Degradation of tricyclazole by colloidal manganese dioxide in the absence and presence of surfactants
Introduction
Among the cereal grains, rice is an important staple food for the major part of the world. During recent years rice consumption has been increased tremendously in many countries. In order to fulfill the increasing demand of rice the use of pesticides, though harmful in many aspects, cannot be avoided. 5-Methyl-1,2,4-triazolo (3,4-b) benzothiazole (tricyclazole) is a very popular and one of the most common pesticides employed for its fungicidal activity in the plantation of paddy rice. It is used to control rice blast disease, caused by the fungus pyricularia oryzae, in both transplanted and direct seeded paddy rice [1], [2], [3]. Tricyclazole is advantageous over other rice blast fungicides because it provides long term protection during the entire growth period as it has long effectiveness which ruled out the requirement of multiple applications [1]. It is readily absorbed by plant roots and translocated to leaves, where it provides residual disease control. It inhibits the synthesis of 1,8-dihydroxy naphthalene (DNH) melanin, which is responsible for the rice blast disease. Among the commercially used melanin inhibitors, tricyclazole has been observed to be one of the most effective fungicides [4], [5], [6]. In spite of advantageous and unavoidable uses fungicides often contaminate the environment and cause public health problem due to their high toxicity and long persistence [7], [8], [9], [10]. The tricyclazole residue in paddy rice and environments has been monitored and analyzed by a number of investigators [10], [11], [12], [13], [14], [15], [16], [17]. It has been observed that this fungicide is quite persistent in the soil-water system with half life from 4 to 17 months in laboratory and about 6 months in the field [17]. Padovani et al. [17] have also reported that tricyclazole is not easily hydrolyzed in the environment and is stable up to 51 °C without volatilization. Therefore application of tricyclazole in agricultural field is associated with significant risk to aquatic system and water resources. Thus the treatment of tricyclazole, which can be executed by degradation of its molecules, is essential to eliminate or minimize its negative effect. In fact fate of a pesticide in soil is governed by its transformation process associated with the decomposition of molecules by chemical reaction. It is well known that humic and organic substances including pesticides have been known to undergo degradation in presence of manganese compounds and especially its dioxide (MnO2). In fact manganese is 12th most abundant element in earth's crust and available from 7 to 9000 ppm depending upon region with an average value of 440 ppm [18]. The MnO2 particles present in earth's crust and natural water are susceptible for reduction by humic and organic substances and pesticides as well. In fact oxidizing power of MnO2 is limited due to its insolubility under ordinary conditions. However, in recent years perfectly transparent colloidal solution of MnO2 has been prepared by the reduction of neutral or slightly acidic potassium permanganate solution by sodium thiosulfate. The water soluble colloidal MnO2 has successfully been used for the oxidative degradation of a number of substances such as aspartic acid [19], oxalic acid [20], [21], d-fructose [22], glycyl-glycine [23], formic acid [24], [25], glycolic acid [26], mandelic acid [27], l-methionine [28], dl-malic acid [29], glycyl-leucine [30], ascorbic acid [31], metribuzin [32], methomyl [33] etc. by different research groups. Literature survey reveals that the degradation studies on the oxidative degradation of tricyclazole are very limited and scarce. Recently, Phong et al. [34] have monitored the fate and transport of tricyclazole in paddy field after nursery-box-application and reported the mean half life value to be 11.8 and 305 days in paddy water and surface soil, respectively. They also pointed out that even less than 0.9% of tricyclazole were lost through run off during the monitoring period under 6.3 cm of rain fall. The interaction between degradation of phenonthrene and tricyclzole in soil and soil–mushroom compost has been studied by Liu et al. [35]. In the present investigation studies on the degradation kinetics of tricyclazole by water soluble colloidal MnO2 have been conducted.
Surfactants are used to lower the surface tension and can act as wetting, foaming, emulsifying and dispersion agents. A surfactant molecule contains at least one polar hydrophilic part and at least one nonpolar hydrophobic part. The coexistence of two opposite types of units inside the same molecule is the origin of local constraints which lead to spontaneous aggregation into microscopic labile structures [36]. These surface active agents in aqueous medium thus self aggregate at the concentration above critical micelle concentration (cmc) to form association colloids known as micelles. Surfactant micelles offer a relatively large microscopic nonpolar environment for solute partition (solubilization) resulting increase in solubility of solute (apparent water solubility) in micellar media in comparision with water solution [37]. Surfactants are therefore very commonly used in pesticide formulation to increase the solubility of pesticides and also to enhance their effectiveness by fine spray. In fact surfactants essentially consist of nonpolar hydrophobic (tail) and polar hydrophilic group (head) groups. According to the nature of latter group the surfactants may be classified as cationic, anionic, nonionic and zwitterionic. In the present investigation, effect of three common surfactants such as cetyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and Triton X-100 (TX-100) on the degradation kinetics of tricyclazole by colloidal MnO2 in presence of HClO4 has been studied. Selection of these surface active agents is based on the criteria of picking one member from each category of cationic, anionic and nonionic compounds as chosen in respective order. In order to generate various activation parameters the study has also been extended at different temperatures. The kinetic data have been analyzed in the light of Arrhenius and Eyring theories and also discussed in terms of different various activation parameters as generated.
Section snippets
Materials
Commercial grade tricyclazole (GSP Crop Science, India), scintillation grade TX-100 (CDH, India) and analytical reagent grade each perchloric acid (Merck, Germany), CTAB (CDH, India), SDS (SRL, India) potassium permanganate and sodium thiosulfate (Qualigens, India) were used in the present investigation. Following analytical reagent grade electrolytic salts: LiCl, NaCl, KCl, NH4Cl, MgCl2, CaCl2 and BaCl2 (each obtained from SRL, India) and SrCl2 (CDH, India) were used for the characterization
General consideration
All the measurements were formulated under the pseudo-first-order reaction conditions in which concentrations of tricyclazole and surfactants were taken in large excess over MnO2. The pseudo-first-order rate constants were calculated from the slope of log (absorbance) versus time plot. The plot of log (absorbance) versus time at a typical fixed concentrations of tricyclazole (6.0 × 10−3 mol dm−3), MnO2 (6.0 × 10−5 mol dm−3) and HClO4 (6.0 × 10−4 mol dm−3) at 30 °C shown in Fig. 2 is represented by straight
Conclusions
The kinetic studies for the oxidative degradation of tricyclazole by colloidal MnO2 in acidic medium have successfully been performed in the absence and presence of surfactants. The rate constants have been determined as function of the concentrations of tricyclazole, MnO2 and HClO4 under the pseudo-first-order reaction conditions. The order of the reaction has been observed to be first order in MnO2 and fractional order in both tricyclazole and HClO4. On the basis of variation of the rate
Acknowledgements
The authors are grateful to the Chairman, Department of Applied Chemistry, Faculty of Engineering and Technology, Aligarh Muslim University for providing necessary laboratory facilities. One of the authors (Qamruzzaman) is also thankful to the University Grants Commission, New Delhi for the award of Maulana Azad National Fellowship.
References (44)
- et al.
Pesticide Biochemistry and Physiology
(1978) - et al.
Biological Control
(2005) - et al.
Chemosphere
(2009) - et al.
Crop Protection
(2003) - et al.
Analytica Chimica Acta
(2010) - et al.
Journal of Chromatography A
(2011) - et al.
Journal of Chromatography A
(1995) - et al.
Comparative Biochemistry and Physiology Part C
(2009) - et al.
Chemosphere
(2006) - et al.
Colloids and Surfaces A
(2004)
Journal of Colloid and Interface Science
Colloids and Surfaces A
Colloids and Surfaces B
Colloids and Surfaces A
Journal of Saudi Chemical Society
Journal of Colloid and Interface Science
Journal of Hazardous Materials
Phytopathology
Phytopathology
Applied and Environmental Microbiology
Experimental Mycology
Food Microbiology
Cited by (30)
Potential application of Micellar nanoreactor for electron transfer reactions mediated by a variety of oxidants: A review
2020, Advances in Colloid and Interface ScienceCitation Excerpt :In order to further explain the role of TX-100 micelle, an equation was suggested by Tuncay et al. as follows:Unlabelled Image This mathematical model was used successfully to explain the catalytic role of TX-100 in the oxidative degradation of a number of compounds by colloidal MnO2 [85–87]. In most of the oxidative degradation of amino acids by colloidal MnO2, nonionic TX-100 was found to exhibit some catalytic rate enhancement [88,89] while anionic SDS had no considerable effect on the oxidation processes [90].
Development, characterization, and utilization of magnetized orange peel waste as a novel adsorbent for the confiscation of crystal violet dye from aqueous solution
2020, Groundwater for Sustainable DevelopmentCitation Excerpt :The quality of water has rigorously worsened globally from the last few decades, chiefly due to manifold increase in the human population, uncontrolled usage of freshwater, fast-growing industrialization, and unplanned urbanization (Schwarzenbach et al., 2010). The foremost source of water pollution includes the release of untreated industrial and agricultural runoff which comprises of various toxic and noxious pollutants such as heavy metals, dyes, pesticides, organic and inorganic pollutants (Fu and Wang, 2011; Nasar and Mashkoor, 2019; Qamruzzaman and Nasar, 2014a, 2014b; Tanweer et al., 2011). The presence of these pollutants in natural water bodies above the permissible limit creates a damaging effect on the environment, living organisms, and especially on human health.
Polyaniline/Tectona grandis sawdust: A novel composite for efficient decontamination of synthetically polluted water containing crystal violet dye
2019, Groundwater for Sustainable DevelopmentCitation Excerpt :Therefore, in order to maintain the quality of groundwater near to industrial regions, the treatment of dye-loaded wastewater is essential. Various methods, namely, electrodialysis (Korngold et al., 1977), photocatalysis (Bahnemann, 2004; Chong et al., 2010), electrofloatation (Chen et al., 2002), electrokinetics (Wang et al., 2004), coagulation and flocculation (Amuda and Amoo, 2007; Butani and Mane, 2017; Wang et al., 2007), nanofilteration (Chakraborty et al., 2003; Ivnitsky et al., 2007), reverse osmosis (Greenlee et al., 2009), chemical method (Andreozzi, 1999; Chamarro, 2001), ozonation (Andreozzi, 1999; Lin and Lin, 1993), chemical precipitation (Slokar and Majcen Le Marechal, 1998), electrochemical (Panizza, 2000), manganese dioxide oxidation (Qamruzzaman and Nasar, 2017, 2014a, 2014b, 2014c), biological method (Chan et al., 2009), adsorption (Anastopoulos et al., 2017; Bhatnagar et al., 2015; Bhatnagar and Sillanpää, 2017, 2010; Zhao et al., 2015b) are available to remove different pollutants such as dyes, heavy metals, pesticides and other organic matters from water and wastewater. However, most of these methods are conventional and not efficiently successful due to several restrictions.
Preparation, characterization and adsorption studies of the chemically modified Luffa aegyptica peel as a potential adsorbent for the removal of malachite green from aqueous solution
2019, Journal of Molecular LiquidsCitation Excerpt :Hence the removal of dyes before the discharge of effluent into the environment poses serious challenges to the researchers. Techniques such as electrodialysis [13], photocatalysis [14], electrofloatation [15], electrokinetics [16], coagulation and flocculation [17], nanofilteration [18], reverse osmosis [19], adsorption [20,21], chemical method [22], ozonation [23], chemical precipitation [24], electrochemical [25], biological method [26] and manganese dioxide oxidation [27–29] are used to remove different contaminants such as dyes, pesticides, heavy metals and other organic matters from water and wastewater. Among the various techniques, adsorption is generally preferred because it is one of the most effective, technically-simple, sustainable, insensitive to noxious pollutant, easy to operate and cost-effective wastewater treatment technique.
Bioaugmentation potential of a newly isolated strain Sphingomonas sp. NJUST37 for the treatment of wastewater containing highly toxic and recalcitrant tricyclazole
2018, Bioresource TechnologyCitation Excerpt :As a consequence, it is urgent to develop high-efficient and environmental-friendly approaches to solve the potential threat of tricyclazole contamination. Recently, several physico-chemical methods, such as chemical oxidation by colloidal manganese dioxide (Qamruzzaman and Nasar, 2014), electrochemical oxidation (Zhong et al., 2013), electro-Fenton oxidation (Xu et al., 2016) and photo-degradation (Gosetti et al., 2015), have been investigated for tricyclazole removal from contaminated water. Because of high cost, secondary pollution and by-products with higher toxicity, application of these physico-chemical methods is often limited (Qamruzzaman and Nasar, 2014; Zhong et al., 2013).