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Transient Movement and Transformation of Carbon Species in Soil During Wastewater Application
Author(s) -
Angelakis A. N.,
Rolston D. E.
Publication year - 1985
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr021i008p01141
Subject(s) - effluent , topsoil , adsorption , wastewater , mineralization (soil science) , diffusion , chemistry , soil science , soil water , environmental science , thermodynamics , environmental engineering , physics , organic chemistry
The transport and transformation of three C species (insoluble, soluble, and gaseous) in soil were mathematically described as functions of depth and time, subject to intervals of 0 < t ≤ t 1 and t 1 < t ≤ t max , where t 1 refers to time of application of insoluble and/or soluble C. Convective and convective‐dispersive transport for the first and second C species, respectively, gas diffusion for the third species, and first‐order kinetics as a tranformational mechanism were assumed. Linear adsorption isotherms for the first two species and a constant gas solubility were also assumed. Combined analytical and numerical solutions of three coupled partial differential equations were developed. The numerical model was used to study the microbial mineralization of organic C transformed under a biophasic scheme by applying a primary wastewater effluent to topsoil columns. Distribution of insoluble C concentrations were accurately predicted, particularly at large times. On the other hand, soluble C profiles were more accurately predicted at early times and shallow depths than for t > t 1 and large depths. Fitted gaseous diffusion coefficients were required to describe the measured CO 2 profiles instead of those measured in the top of the soil columns. Gaseous C profiles were accurately predicted, especially at early times and shallow depths.