RESUMEN
Thamirabarani river acquires large untreated sewage effluents from the Tirunelveli and Thoothukudi districts of South Tamil Nadu. This study examined the concentration of trace elements in water, sediment, and phytoaccumulation potential of aquatic weeds viz., A. cristata, E. crassipes, S. natans, and P. stratiotes, growing along Srivaikundam dam of Thamirabarani river. The Pb, As, Hg, Cd, and Ni concentrations in water were slightly higher than the US Food and Drug Administration (USFDA) drinking water guidelines; however, their accumulation in sediment was below WHO's sediment quality guideline. This study concludes that the phytoaccumulation factor (PAF) and translocation factor (TF) was >1 in E. crassipes and A. cristata, representing them as hyperaccumulators, suitable for phytoremediation in polluted localities. E. crassipes, A. cristata, and S. natans accumulated (100-500 fold) higher trace elements concentrations than that present in the water. Also, the concentrations of trace elements found in the aquatic weeds were below the recommended levels for the critical plant range (CRP). These selected aquatic weeds are more suitable for plant hybridization to be modified as superbug plants.
Asunto(s)
Metales Pesados , Oligoelementos , Contaminantes Químicos del Agua , Biodegradación Ambiental , Monitoreo del Ambiente , Sedimentos Geológicos , India , Metales Pesados/análisis , Ríos , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidadRESUMEN
Formalin has been used as the preservative of fishes in the concentration range of 15-25 mgL-1. However, there have been a high frequency of violations in the optimum use of formalin levels. The consumption of fishes treated with excessive formalin levels leads to nasopharynx, leukaemia and sinonasal cancer and there is a huge demand for the development of formalin sensor. Conventional formalin sensors such as chromogenic and mass balance sensors fall short in real-time analysis due to the lack of specificity and sensitivity in the interference medium. In this context, it has been emphasized to develop a non-enzymatic electrochemical biosensor with microwave synthesized CdS nanoparticles as a nanointerface owing to its surface limited kinetics. NaCl of 1 mM was considered as an electrolyte solution in the present study. Dynamic sensing characteristics with varying formalin levels of 5-50 mgL-1 was studied in three different concentration ranges as 5-15 mgL-1 (concentration of formalin < NaCl; conversion of formalin to formic acid), 20-30 mgL-1 (concentration of formalin â¼ NaCl; equilibrium between the oxidative and reductive product), 35-50 mgL-1 (concentration of formalin > NaCl; complete oxidation of formic acid to CO2). Hence, with the exhibition of such a dynamic sensitivity based on electrolyte, the developed biosensor acts as an electrochemical comparator showcasing a switch-like behaviour in detecting formalin levels. The threshold concentration of formalin required for the comparator effect was found to be 14.845 mgL-1. The developed biosensor, most essentially, exhibited a versatility in quantifying formalin levels in real-time fish samples.