Municipal Wastewater Treatment uses Vertical Flow Followed by Horizontal Flow in a Two-Stage Hybrid-Constructed Wetland Planted with Calibanus hookeri and Canna indica (Cannaceae).

The utilization of hybrid-constructed wetland systems has recently expanded due to more rigorous municipal wastewater discharge and also complex wastewaters treated in hybrid-constructed wetlands (HCWs). A lab-scale two-stage experimental setup of vertical flow followed by horizontal flow hybrid-constructed wetland (VFHCW-HFHCW) configuration was built. First-stage vertical flow hybrid-constructed wetland reactor with the surface area was 1963.49 cm2 and second-stage horizontal flow hybrid-constructed wetland reactor with the surface area was 2025 cm2. The HCW unit was planted with two type plants: Calibanus hookeri and Canna indica (Cannaceae). Influent Municipal wastewater flow rate 112.32 l/day, hydraulic loading rate (HLR) 0.55 m/day, and hydraulic retention time of 1 day. The efficiency was evaluated in municipal wastewater quality improvement and physico-chemical analysis in our laboratory. The removal rate after the second-stage horizontal flow of BOD3 at 27 °C, COD, TSS, TP, NH3-N, and NO3-N reached 92.75%, 89.90%, 85.45%, 88.83%, 99.09%, and 96.05%, respectively. The results shown after both stage hybrid-constructed wetland VFHCW-HFHCW, treated effluent of Municipal wastewater produced high-quality effluent which may be reused in gardening, agriculture, and flushing in toilet purpose according to Bureau of Indian Standards (BIS) code for practices. However, in the future, hybrid-constructed wetlands could be standards design criteria developing and enhancing the performance standards and economic meets both to make more popular technology of the hybrid-constructed wetland (HCW). Supplementary Information: The online version contains supplementary material available at 10.1007/s11270-022-05984-0.

Batch kinetic modeling of arsenic removal from water by mixed oxide coated sand (mocs).

A new granular media developed by coating of iron and manganese on quartz sand surface proved to be effective for arsenic (III) removal from water. The media has shown alkali resistance. The kinetic and thermodynamic studies data were tested using pseudo-second- order, intraparticle diffusion and Elovich equation models. The rate constants, equilibrium sorption capacity and normalized standard deviations were calculated for all the three models. It was shown that all three models almost accurately predict the sorption capacity with respect to time for whole range of data points. However, sorption kinetic data were better correlated using Elovich equation model based on normalized standard deviation. The Langmuir and Freundlich isotherm equations could be used to describe the partitioning behavior of system at different pH and media size. The results of thermodynamic studies show that the As(III) adsorption on Mixed Oxide Coated Sand (MOCS) was endothermic in nature. Kinetic and isothermal studies data have also been used to obtain thermodynamic parameters of the process.