Sediment characterisation and spatial distribution of heavy metals in the sediment of a tropical freshwater wetland of Indo-Burmese province. (July 2019)

• Record Type: Journal Article
• Authors: Kalita, Suravi; Sarma, Hari Prasad; Devi, Arundhuti
• Is Part Of: Environmental pollution. Volume 250(2019)
• Page Start: 969
• Page End: 980
• Publication Date: 2019-07
• Subjects: Knowledge gap -- Deepor beel -- Sediment parameter -- Pollution status -- Human input; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.04.112
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The sediment characterisation of wetlands belonging to the Northeastern Region of India particularly regarding the assessment of sediment carbon stock is very scanty. The presently available literature on the wetlands cannot be employed as a common model for managing the wetlands of the Northeastern Region of India as wetlands are a sensitive ecosystem with a different origin or endogenous interventions. Thereby, this research was conducted on Deepor Beel for investigating the spatial and seasonal variation of sediment parameters, the relationship between the parameters and pollution status of the wetland. Results revealed that the study area is of an acidic nature with a sandy clay loam type texture. Organic carbon, total nitrogen and available nitrogen were higher in sediments in the monsoon period. The mean stock of the sediment carbon pool of Deepor Beel is estimated to be 2.5 ± 0.7 kg m −2 . The average non-residual fraction percentage (63.2%) of Pb was higher than the residual fraction. Zn content ∼490 mg kg −1 exceeding its effect range medium (ERM) was determined to suggest frequent biological adverse effects. Highest metal enrichment factor (EF) values were shown by Zn and Pb, which ranged between 78 and 255. Risk assessment code (RAC) values of Pb between 21 and 29% indicated its high bio-accessibility risk. Pearson's coefficient matrix revealed a low degree of positive correlation between organic carbon content and metal concentration. Principal component analysis revealed that the first component comprising of EC, basic cations and metals accounted for 62.3% of variance while the second component (OM, OC, TN, AN, AP) and the third component (pH) accounted for 21.8% and 7.0% of the variance, respectively. The present study revealed the adverse impact of human inputs on the Deepor Beel quality status. Graphical abstract: Image 1 Highlights: First carbon stock report for freshwater wetland from northeastern region of India. Carbon stock of Deepor Beel sediment was estimated to be 2.5 ± 0.7 kg m −2 A significant percentage of Pb present in bioavailable exchangeable fraction. Zinc was determined with the potential to cause an adverse biological effect. Abstract : This study suggests a deteriorating sediment quality status of Deepor Beel wetland due to the effect of unchecked regional anthropogenic activities in and around the wetland.