An approach to models for transport and transformation of organochlorine pesticides in rivers

Abstract

This paper constitutes a novel proposal for predicting the accumulation–utilization rate for transport of the organochlorine pesticides (OCPs) as well as the kinetic coefficients of biodegradation of OCPs dissolved in water and sorbed on sediments in tropical rivers. Eight OCPs were determined in waters and sediments in the dry and rainy seasons from 2013 to 2016. The biochemical transport and transformation model was proposed in two directions, along the river false(∂COCP/∂xfalse)$({\partial {C_{{\rm{OCP}}}}/\partial x} )$, and across the river (direction z$z$), false(∂COCP/∂zfalse)$({\partial {C_{{\rm{OCP}}}}/\partial z} )$, providing kinetic parameters linked to Monod's equation under a steady‐state condition for particulate and soluble OCPs, being useful for designing bioremediation techniques to restore water bodies.

An approach to remediation of a tropical aquifer contaminated with hydrocarbons

“…These values for $${r_{m,S}}$$ indicate that the COD biodegradation for UAF‐2SS and UAF‐3SS was more effective when comparing to SBR for oxic phase in T1 and T2 in an order varying between 1.5 times. Due to natural attenuation in rivers, the kinetic parameters across the Tucutunemo River resulted in mean values of $${r_{m,S}}$$ ranged for degradation (−8.07 and −18.38 μg/L/m) and for accumulation (3.62 and 4.73 μg/L/m) (Cárdenas et al., 2021a). In addition, Cárdenas et al.…”

“…Air sparging implied to design an air injection system for bioremediation of hydrocarbons dissolved in water within the saturated zone, whose presence could be justified by a vertical transport from unsaturated zone and sorption–desorption process from the water–soil interface (Cárdenas et al., 2021a, 2021b), where the theoretical need for oxygen was obtained from the Biochemical Oxygen Demand (BOD) of the hydrocarbons and the amount of indigenous organisms produced daily within the in situ treatment system (Metcalf & Eddy, Inc. (1991)). From the point of view of the biological transformation of hydrocarbons by microorganisms, for example, the conversion of benzene is carried out according to the stoichiometry of Equations (6) and (7) (Chiang et al., 1989).…”

Calibration of diffusion‐advection process models for organochlorine pesticides in a tropical river

“…From the confirmative findings given in Cárdenas et al (2021aCárdenas et al ( , 2021b due to the high correlation between utilization-accumulation rate and the effluent remaining substrate demonstrated based on the modified…”

“…To overcome the lack of models that explain the microbial kinetics for the biodegradation of organic compounds in rivers until the first two decades of the 21st century, Cárdenas et al. (2021b) proposed biochemical transport and transformation models in two directions, along the river (x direction), and across the river (z direction), providing kinetic parameters linked to Monod's equation under a steady‐state condition for particulate and soluble OCPs, being useful for designing bioremediation techniques to restore water bodies. From the confirmative findings given in Cárdenas et al.…”

“…In a tropical river within an agricultural basin, Cárdenas et al (2018Cárdenas et al ( , 2019Cárdenas et al ( , 2021aCárdenas et al ( ,2021b characterized OCPs consisting of DDT and its isomers and DRINs dissolved in water and sorbed on sediments during the dry and rainy seasons in three monitoring stations distributed in (1966); Albertson and Davies (1984). (1966); Albertson and Davies (1984).…”