The Effect of Titanium Dioxide Nanoparticles on the Reduction of Arsenic Effect on Respiration and Soil Ecophysiological Indices in a Soil with Different Levels of Arsenic

Due to the increasing development of nanotechnology, its use has increased in all fields, especially in the field of environmental pollution as an absorbent. For this purpose, a factorial experiment was conducted in a completely randomized design with two factors; arsenic factor at four levels (0, 25, 50 and, 100 mg/kg) and TiO2 factor at three levels (0, 0.25 and, 0.5% by weight) and three replications in the laboratory and in a dark room at 25˚C for 8 months using the 1.3 L respiratory jars. Cumulative respiration percentile results showed that the highest respiration control treatment matched with 50 mg/kg arsenic plus 0.5% TiO2 (w/w). The highest and the lowest respiration rates were obtained in the first and eighth months of incubation, respectively, with control and 25 mg/kg arsenic with a difference of 33.78%. As the nanoparticle levels increased, the respiration rate increased, so that the highest respiration rate was obtained in the first month of 0.5% TiO2 treatment. The highest and the lowest MBC, as well as qmic, was obtained in 100 mg/kg arsenic treatments plus 0.25% TiO2 (w/w) and 50 mg/kg arsenic plus 0.5% TiO2 (w/w), respectively. Conversely, the highest and the lowest qCO2 were obtained from 50 mg/kg arsenic plus 0.5% TiO2 (w/w) and 100 mg/kg arsenic with 0.5% TiO2 (w/w), respectively. Cluster analysis of the variables showed that the MBC and qmic variables were the first cluster and the second, third, and fourth clusters were the BR, qCO2, and cumulative respiration, respectively. According to the results of this study, the application of 0.5% TiO2 (w/w) can reduce the toxic effects of arsenic and improved BR, cumulative respiration rate, and monthly respiration.