PHOSPHORUS TRANSPORT IN SATURATED SLAG COLUMNS - EXPERIMENTS AND MATHEMATICAL-MODELS

Excessive phosphorus (P as orthophosphate) is one of the major polluta nts in natural water that are responsible for algal blooms and eutroph ication. P removal by slag is an attractive solution if the P sorption capacity of slag is significant. To design an efficient land treatmen t facility, basic information on the behaviour of P in the media-water environment is required. In this study, detailed column experiments w ere conducted to study the P transport under dynamic condition, and ma thematical models were developed to describe this process, The column experiments conducted with dust and cake waste products (slag) from a steel industry as adsorbing media indicated that they had higher sorpt ion capacity of P than that of a sandy loam soil from North Sydney, Au stralia, P transport in the dust and cake columns exhibited characteri stic S-shaped or curvilinear breakthrough curves. The simulated result s from a dynamic physical non-equilibrium sorption model (DPNSM) and F reundlich isotherm constants satisfactorily matched the corresponding experimental breakthrough data. The mobility of P is restricted by the adsorbents and it is proportional to the sorption capacity of them. C opyright (C) 1996 IAWQ.