| Sumario: | Energy efficient wastewater treatment systems are the current environmental concerns which prompted for the applications of natural wetlands as efficient systems at urban areas. However, a detailed investigation is highly desired to determine the efficiency determining factors relevant to structure and functions of natural wetlands for enhanced wastewater treatment. In view of this the wastewater fed natural wetland is examined by hydro-geophysical means, to decipher i) the
effective depth of physico-chemical and microbial reactions, ii) the saturated zone thickness, and iii) hydrogeological attributes enhancing the wastewater quality at Hyderabad city, India. The wetland has been scanned using electrical resistivity tomography (ERT) to decipher its physical structure, and hydrogeological and biogeochemical investigations are performed to understand the dynamics. The low electrical resistivity ( =10.5-34.0 O-m) and moderate hydraulic conductivity (K=2.938 m/d) acquired for saturated zone (10–15 m depth), are found the wastewater enhancing parameters in the wetlands. Geophysically derived laterally constrained inversion (LCI) models explore the maximum saturated zone of wetland up to 25 m as an effective depth for pollutant removal mechanisms. It implies the proportionality between depth to bed rock (confining layer) and wetland efficiency. Further, the bio-geochemical scanning determines the bioremediation, sedimentation, adsorption, redox reactions and ion exchange processes as wetland functions for removing nutrients (77-97%), BOD (78%), COD (76%), and microbes (99.5-99.9%) load with the discharge Q=1812 m3d-1 of treated wastewater. Further, the wetland efficiency integrated with engineered interventions help develop various NTS models with different application scenarios, that are i) constructed wetlands, ii) minimized community wetlands, and iii) single outlet system, suitable for urban, peri-urban and rural areas, respectively. The socio-economic assessment, and farmer-consumers and stakeholders survey suggest that to test and use of wetland systems implementation as a policy guideline under sustainable water management.
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