Determination of regression model parameter for constructed wetland using operating data

Abstract

Seven years of performance data from a free surface flow constructed wetland system receiving agricultural runoff were used to determine treatment performance and to develop regression and wetland design models. Removal rates by the wetland were 21-43.6% for 5-day biochemical oxygen demand (BOD 5 ), 49.0-58.1% for total phosphorous (TP), 24.1-46.0% for total nitrogen (TN), and 57.6-77.8% for total suspended solids (TSS). First-order area-based rate constant (k 20 ) values for BOD 5 were 15.48 m/year in the early stage of observation and decreased to 12.00 m/year for the stable period. Similar results were found for TP, for which k 20 values were 18.72 m/year in the early stage and 14.92 m/year for the stable period. For TN, k 20 values in the early stage (21.32 m/year) were slightly lower than those for the stable period (38.02 m/year). Finally, TSS had values of 132.4 and 172.6 m/year in the early and stable periods, respectively. The low k 20 for BOD 5 was not important for nonpoint source pollution control in the constructed wetland because these kinds of wetlands mainly focus on nitrogen and phosphorus retention. The wetland area and outlet concentration could be approximately predicted using the first-order kinetic model, but the maturity and hydraulic loading rate should be considered for more accurate prediction.

Effectiveness of two-stage horizontal subsurface flow constructed wetland planted with Cyperus alternifolius and Typha latifolia in treating anaerobic reactor brewery effluent at different hydraulic residence times

“…However, Vymazal (2005) reported that nutrient removal is usually insignificant in CW, does not greater than 50%. On the contrary, Son et al (2010) reported a nitrogen removal efficiency of 53%, and overall observed a two-stage vertical subsurface flow constructed wetland (VSSFCW) performed better nitrogen removal as compared to a single-stage VSS-FCW. Accordingly, in the present study, the two-stage HSSFCW treatment achieved over 77.5% of TN removal at higher HRTs.…”

Quantifying the Log Reduction of Pathogenic Microorganisms by Constructed Wetlands: A Review

“…Regarding parameters, the Cin, Cout, HRT, and HLR were assessed since those where the only parameters that were consistently reported in the literature review. The reason behind this preliminary plotting was the fact that multiple studies have been conducted for the removal of pollutants and pathogens from CWs where they perform regression analysis and try to determine if there are significant relationships between the aforementioned parameters [16][17][18][19][20][21][22]. These studies found that there seems to be a linear/nonlinear relationship that is expressed through an equation that is using the Cout as a function of Cin and/or HRT, HLR.…”

PESTIPOND: A descriptive model of pesticide fate in artificial ponds: II. Model application and evaluation

“…Models of varying levels of complexity have been developed and applied to field data to gain insight into the performance of APs. However, many of these models were dedicated to simulating nutrient behavior (Kalin et al, 2013;Son et al, 2010;Sonavane and Munavalli, 2009), and fewer models were assigned to pesticides. Among pesticide fate models are the risk assessment models such as PRZM (Carsel, 1998) and MACRO (Larsbo and Jarvis, 2003;Larsbo et al, 2005), which simulate pesticide fate in the root zone and macro-porous field soils, respectively, and TOXSWA (Adriaanse, 1996) from the FOCUS group (Tooby, 1999), to model pesticide fate in ditches.…”