Integrated Processes of Anoxic/Oxic Bioreactor and Artificial Wetland for Rural Domestic Wastewater Treatment

Abstract

This paper examined the treatment of rural domestic wastewater. Influent and effluent samples were experimented for Chemical oxygen demand (COD), NH4+-N, NO3--N and TP in the Taihu Lake Environmental laboratory of Southeast University in Wuxi. Different hydraulic retention time (HRT) and recycle ratios were applied to appraise their influence on removal efficiency. The wastewater temperature was controlled between 20 to 24°C and pH ranges 7.6 – 8.1. The result revealed average COD, NH4+-N, NO3--N and TP removal efficiencies of 77.2, 74.1, 94 and 83% with optimum HRT of 3hrs and recycle ratio of 2 respectively. The obtained results confirmed that, the integrated processes of anoxic/oxic bioreactor and artificial wetland was viable and proficient in domestic wastewater treatment.

Effects of Hydraulic Retention Time (HRT) on the Performance of a Pilot-Scale Trickling Filter System Treating Low-Strength Domestic Wastewater

“…3. This agreed with the findings of Ladu et al [32], who studied the effects of three different HRTs on the efficiency of anaerobic filters while treating domestic wastewater, and found that the efficiency of the reactor increased by increasing HRT (from one to three days). Furthermore, they observed a 32% reduction in COD values at HRT of one day, 40% at HRT of two days and 44% at HRT of three days.…”

“…5. Different researchers have reported that the efficiency of a reactor for removing TN from wastewater largely depends on the ratio of COD to TN concentrations (COD/TN) along with reactor configuration [32,42]. Ladu et al [32] reported more than 75% TN removal efficiency in a sequencing batch reactor at a COD/ TN ratio of greater than 3.9, while Wang et al [42] reported a 37-41% reduction in TN concentration at a COD/TN ratio of 7.2.…”

“…Different researchers have reported that the efficiency of a reactor for removing TN from wastewater largely depends on the ratio of COD to TN concentrations (COD/TN) along with reactor configuration [32,42]. Ladu et al [32] reported more than 75% TN removal efficiency in a sequencing batch reactor at a COD/ TN ratio of greater than 3.9, while Wang et al [42] reported a 37-41% reduction in TN concentration at a COD/TN ratio of 7.2. In the present study, 5.1-20.3% reduction in TN concentrations at COD/TN ratio of 0.9 were observed at HRT of 24 hrs and during the 2 nd phase of operation (HRT of 48 hrs), 3.1-32.8% reduction in the concentrations of TN at COD/TN ratio of 1.75 while at HRT of 72 hrs, 28.4-87.2% reduction in the concentrations of TN at COD/TN ratio of 2.07 were observed.…”