Zeolite as 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.
Standalone lagoon systems have been built in North Dakota to handle sewage wastewater generated by thousands of workers at oil rigs, man camps, and worker housing. Lining these ponds with Zeolite or layering Zeolite as the ponds fill would greatly reduce ammonia and methane emissions, along with decreasing of leaching.