Premium
Chemical Characterization of the Gaseous and Liquid Environments of Subsurface Drain Systems
Author(s) -
Meek Burl D.,
Grass Luther B.,
MacKenzie Arnold J.
Publication year - 1978
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1978.03615995004200050006x
Subject(s) - soil water , precipitation , subsurface flow , chemical composition , trench , hydraulic conductivity , effluent , geology , mineralogy , environmental chemistry , environmental science , chemistry , soil science , groundwater , environmental engineering , geotechnical engineering , physics , organic chemistry , layer (electronics) , meteorology
Chemical composition of subsurface drain effluents was determined in the field as a function of location (various depths and soil textures), entry point of the solution into the drainpipe, and distance from outlet (with or without a water trap). Liquid samples were analyzed for Fe, Mn, NO 3 ‐N, HCO 3 , organic carbon, electrical conductivity, pH, and dissolved oxygen, and gas samples were analyzed for O 2 and CO 2 . Manganese ranged from < 0.1 to 6.1 ppm and Fe ranged from < 0.1 to 14.2 ppm which illustrated the wide range of oxidation‐reduction conditions present in the soils drained by subsurface drain lines. Chemical composition changed little during the season. Water entering the upper portion of the drain lines was lower in Mn, which was the result of short flow paths through soil zones with higher O 2 levels, than the water moving through longer flowlines which entered the bottom of the drains. The solutions in the drain lines were undersaturated with respect to the drain line atmosphere, which indicated that O 2 flows downward through the drain trench backfill. This is an important factor in the oxidation of Fe and Mn in subsurface drain lines. However, longitudinal movement of O 2 into drain lines, via the outlets, is a minor factor contributing to the precipitation of Fe and Mn and does not account for the extensive amount of precipitation of Fe or Mn within the drain system.