A thesis submitted in partial fulfillment of requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1985

An attempt was made to study the physical and biologicals clogging during artificial recharge with an experimental model which simulates artificial recharging practice by taking into consideration practical recharging practice by taking into consideration practical factors like effective infiltration rate of the media, size, porosity and media depth. Recharging was investigated experimentally in terms of suspended solids removal, BOD3 removal, TOC removal and COD removal at different sand sizes and infiltration rates. To understand the physical phenomena involved, the effect of suspended solids concentrations, infiltration rate and media size on headless, suspended solids removal efficiency and specific deposits was studied and verified with the use of simple mathematical models. Three stages of biological clogging were observed. It is possible to predict the cumulative discharge during artificial recharge with the knowledge of the initial infiltration rate and application time. This was compared with the experimental results. The use of the physical constants involved, which is a function of the infiltration rate and sand size, needs to be investigated further in order to understand its variation with sand size. Factors affecting BOD3 removal were investigated. At the steady-state condition, the effect of infiltration rate, sand size and suspended solids concertation on the reaction rate constant was also studied.