دانلود رایگان مقاله انگلیسی اثر آنتی بیوتیک ها بر پایداری علف کش ها در خاک تحت آلودگی ترکیبی - الزویر 2018

1. Introduction

 Antibiotics are widely used in public health and animal husbandry in the treatment and prevention of bacterial infections. The US Food and Drug Administration (FDA) reported that 14.6 million kilograms of annual domestic sales of antimicrobial drugs were used in food-producing animal husbandry in 2014 (FDA. 2014). Particularly, tetracyclines accounted for 71% of these sales. In many countries, the use of antibiotics both for animal disease treatment and growth promotion is unsupervised, which often leads to abuse of antibiotics. Most of veterinary antibiotics were poorly absorbed within the gastrointestinal tract of livestock, causing the presence of biologically active antibiotics in animal waste. It was not unusual to detect high concentrations 19 of antibiotic residues in animal manures (Qiao et al., 2012; Pan et al., 2011;Nordenholt et al., 2016). In an agricultural field at Hannover, the tetracycline (TTC) level in the dried manure from the soil surface was 4 mg/kg (Gerd Hamscher, 2002). Similarly, Martinez analyzed pig manure and turkey dung samples from livestock farms in Austria, Vienna.

4. Conclusion

 The impacts of OTC on the dissipation of triazine and chloroacetanilide herbicides under combined pollution were investigated. High concentrations of OTC inhibited the dissipation rate of the herbicides significantly, increasing the persistence in soil, and the inhibition effects still existed after 30 days in the OTC pretreated soil. OTC affected the activity of soil urease, catalase, and dehydrogenase especially at high concentration. In terms of soil microorganism, bacteria and fungi were also influenced by OTC, and fungi were more sensitive. When biodegradation was the predominant contributors to dissipation of pesticide, OTC influenced their dissipation and the impacts increased with OTC concentration level. For those the dissipation included the other processes like chemical dissipation or photodegradation, and did not mainly depend on microbial dissipation process, the effects of antibiotics on the dissipation were less affected. OTC might decrease the dissipation rate of herbicide through inhibiting soil enzyme and reducing microbial abundance, leading to high terminal residues of herbicides. These results indicate that for herbicides degraded by soil microorganisms, the presence of antibiotics may increase their.