Municipal Wastewater

Zeolite as Municipal Water Filter Media

The presence of NH₄+ in waters can become an issue due to:

Toxicity to fish and aquatic life
Contribution to algal eutrophication
Reduction of dissolved oxygen
Detrimental effects on the disinfection of water supplies
Corrosive action on certain metals and constructive materials (mercer et al. 1970)
Zeolite makes an excellent filter media for numerous filter types. Clinoptilolite material has been utilized in two stages of treatment of municipal wastewater in Hungary as reported by M. Pansini, of the University of Napoli, in Italy. (Kallo 1995) the addition of 40-80 mg (567) of Clinoptilolite granules to sewage resulted in the following effects:

30% – 50% increase in the biological activity of the living sludge
50% – 100% increase in the settling rate of suspended solids
Easier dewatering and composting of the dewatered sludge
Reduction in the amount of excess simultaneously added Fe3+ salt for phosphate removal from 2 – 2.5 to 1.2 – 1.8 fold. Subsequently, ammonium was removed by ion-exchange in a column filled with Clinoptilolite Zeolite granules

DeWatered Human Waste

Application of sewage sludge is a common practice in many countries for utilization of the increasing amounts of municipal waste produced by urban populations. Sewage sludge contains significant quantities of organic matter and nutrients such as nitrogen and phosphorus, and therefore increases organic carbon levels in soils and provides readily available nutrients for plants (Weggler and Beaton 2000). The negative aspects of spreading sewage solids are that sludge contains heavy metals such as cadmium, zinc, copper, nickel, and lead. These heavy metals can be taken up by plants through their root system and lead to toxicity in plants or potential implications for food quality (Silveira 2003).

Clinoptilolite Zeolite has proven itself in the capture of heavy metals and prevention of heavy metal uptake by plants. Addition of Zeolite after the de-watering process will allow for use of nutrients in waste sludge while solving the issue of heavy metals. Zeolite will also capture the ammonia ions that cause odors and increase water infiltration to the root system of plants.