Premium
Computer Modeling of Scale Formation During Treatment of Ground Water in Air Strippers
Author(s) -
Matisoff Gerald,
Narquis Clifford
Publication year - 1991
Publication title -
groundwater monitoring and remediation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 47
eISSN - 1745-6592
pISSN - 1069-3629
DOI - 10.1111/j.1745-6592.1991.tb00375.x
Subject(s) - precipitation , groundwater , chemistry , carbonate , fouling , outflow , inflow , tower , calcium carbonate , environmental science , aqueous solution , environmental engineering , meteorology , geology , biochemistry , physics , geotechnical engineering , organic chemistry , membrane , engineering , civil engineering
During treatment to remove volatile organic compounds from contaminated ground water, inorganic scale sometimes precipitates in an air stripper tower. This leads to increased costs and down‐time associated with tower media replacement. In order to determine the kind, quantity, and rate of scale formation, the ground water from five locations in Florida was simulated using an aqueous equilibrium chemistry and flow process model. In all cases the pH of the outflow water is higher than that of the inflow water because of degassing of CO 2 . This often results in the precipitation of calcium carbonate. The addition of air to reduced ground water results in the oxidation of iron and the precipitation of ferric hydroxides. Model estimates of scale formation are about a factor of two to five too high. This indicates that the precipitation reactions do not reach equilibrium within the air stripper. Future work will require the inclusion of biological fouling and a kinetic expression to account for the observed non‐equilibrium.