Romanian Volcanic Tuffs Exploitation in Environmental Protection

The work presents data concerning genesis and occurrences of Romanian volcanic zeolitic tuffs, specifying a higher frequency of the following zeolitic types: stilbite, laumontite, clinoptilolite, heulandite, natrolite and mesolite. The volcanic tuff from Marsid — county Salaj - is one of the representative species of the volcanic tuff in Romania, having a clinoptilolite content ranging from 60% to 70%. The aim of this paper is the survey of our work on the use of volcanic tuffs from Marsid in environmental protection, which is mainly concentrated in the following areas: increase of the zeolite ion-exchange capacity; the advanced purification of some metallurgical wastewaters; the use of spent zeolites containing metallic cations for obtaining fertilisers of high agrochemical quality containing trace elements; the improvement of the water coagulation process; the improvement of the filtering of drinking water; the use of organoclinoptilolite for wastewater pollution abatement. The obtained results, as well as the availability and low cost of clinoptilolite tuffs, make these materials excellent candidates for environmental protection.