Reconciliation of Spatiotemporal Influences on Two-Dimensional Distribution and Fate of Emerging Contaminants in a Subtropical River

Abstract

This study involves elucidation of spatial and temporal influences on horizontal and vertical distribution and fate of contaminants of emerging concerns (CECs) in riverain systems. In total, 23 CECs encompassing antibiotics, nonantibiotic drugs, and bisphenol analogues were detected. The antibiotic concentrations were relatively higher in deep water than in surface water. Spatial connectivity and spatial autocorrelation suggested the occurrence and concentration of the majority of the CECs devoid of neighboring site influences, owing to shorter correlation lengths than the average distances between the sampling sites, hence indicating the localized distribution of CECs in surface water. The PCA biplot indicated that bisphenol A and methyl paraben were mainly responsible for the seasonal variations. Both negative and positive correlations existed between CECs and the environmental parameters to cause temporal variations in CEC contaminants. Spatial structure analysis by singular vector decomposition (SVD) analysis was used to measure the sitewise contribution of CECs. The results indicated relatively higher CEC contaminants and deteriorated water quality in the downstream sites rather than in the upstream sites. This study effectively demonstrated the use of different chemometric techniques for in-depth understanding of various spatial and temporal influences on the fate and horizontal and depth distribution of CECs in riverain systems.

Occurrence, persistence, and ecological risk of bisphenol A in surface water receiving raw leachate from a municipal solid waste open dump in Kerawalapitiya, Sri Lanka

“…Similarly, Rashid et al. (2021) reported a negative correlation of BPA with electrical conductivity.…”

“…Gong et al (2019) have observed a negative correlation between the salinity of the water and BPA. Similarly, Rashid et al (2021) reported a negative correlation of BPA with electrical conductivity.…”

Hydrological dynamics drive the transition of antibiotic resistance genes between particle-attached and free-living lifestyles in a deep freshwater reservoir

“…Based on decreasing pattern of dissolved oxygen (DO) during stratified seasons, water columns were split into two zones: the shallow zone (0-10 m) with the average DOs higher than 3 mg/L, and the deep zone (20-53 m) with the average DOs lower than 3 mg/L. A total of 16 physico-chemical parameters and 22 micropollutant compounds were measured previously 24 , from which the most frequently detected micropollutants (> 30%; 17 micropollutants) were included in further analysis ( Table S1 ). Water samples (500 – 1,000 mL) were filtered through 3 μm filters and 0.22 μm filters to get size-fractionated sub-samples for DNA extraction.…”

An advection-reaction model of emerging contaminants in ground and surface waterbodies with known topology: a data-based approach

“…This is specifically done through the use of the Laplacian matrix, which captures the network topology and the interaction between adjacent sites through the advection process. The use of spatial (topological) relationships is not new, notably, the well-known Moran [4] and Geary [5] spatial correlation coefficients, as well as, their recent updated developments [ 6 , 7 ] have been widely used in many domains, including the aquatic environment [8] , [9] , [10] , [11] , [12] , [13] , [14] . Our approach allows obtaining relevant quantitative information relative to the dynamics of the measured contaminants such as the relative importance of the two main processes involved, i.e., the conservative transport across the aquifer vs. the local depletion, which gives a glimpse into their persistence.…”