Wastewater Treatment Using Modified Natural Zeolites

Current wastewater treatment processes generally improve the quality of effluent water by enhancing the efficiency of the pollutant reduction process or by increasing the retention time of the wastewater in the treatment facility. The latter approach, however, requires a larger aeration basin and higher operation cost.

One of the most promising approaches to improve the efficiency and increase the capacity of wastewater treatment plants without increasing size is based upon application of natural zeolites in the aeration basin. Zeolite particles are good carriers of bacteria, which adsorb on the zeolite surface resulting in increased sludge activity. There is a significant drawback to the application of the zeolite additive. Formation of the bacteria layer on the zeolite surface is a slow process and becomes effective only after approximately a week.

A new zeolite modification method accelerates the interaction between zeolites and activated sludge, which further increases the sludge activity. The effects of modified zeolites on organic degradation rates have been tested in laboratory and full-scale experiments. Based on the experiments, new industrial technologies for zeolite modification and wastewater treatment have been developed.