The Wetlands as Natural Sewage Treatment Plants for cost-effective water management in peri-urban areas

<p>The city of Hyderabad has a small river, a tributary of Krishna river viz., Musi river and due to huge and unplanned constructions and destruction of the catchment area, the flow in the river has been gradually reducing and at the same time huge sewage water flows in the river due to increasing population living in the peri-urban areas without any infrastructure. Thus, the river in the down-stream carries mostly the sewage water particularly in the non-rainy season.</p> <p>Conveniently, there exist a number of natural wetlands on the bank of the river and they help in purifying the sewage under natural conditions. Therefore, to check the efficacy of this purification an experiment was carried out by allowing the swage water of the river to pass through a designated wetland and it was found that the nitrate was reduced to more than 90% after passing the sewage through the wetland for a time period of 48 hrs. In addition to Nitrate reduction, the phosphate and Sulphate too have been reduced considerably.</p> <p>Based on this experiment, a few schemes of irrigation through the constructed wetlands have been suggested using wastewater.</p>