CLINOPTILOLITE AND MULTIPURPOSE FILTERS FOR UPGRADING EFFLUENT AMMONIA QUALITY UNDER PEAK LOADS

Peak loads of ammonia can not always be handled with success in the bi ological process of nitrification and compliance with standards may be a problem. Ion exchange with clinoptilolite may be used as a second s tage unit to polish the effluent and to assure compliance. Within this context, the use of clinoptilolite in an ion exchange unit or alterna tively in filters together with filter material, without a significant loss of capacity, may be possible, providing substantial reductions i n terms of land requirement for the upgrade. Results from units of cli noptilolite only, and in combination with (i) burned clay and (ii) san d filters have revealed that all configurations are successful as upgr ades for dampening ammonia peaks. Among the configurations investigate d, the combined scheme where clinoptilolite is added to a filter unit which is aerated to enhance biological activity, has given the best re sults, provided that enough time is allowed for the adaptation of the nitrifiers. (C) 1998 IAWQ. Published by Elsevier Science Ltd