A hybrid constructed wetland for organic-material and nutrient removal from sewage: Process performance and multi-kinetic models

Abstract

A pilot-scale hybrid constructed wetland with vertical flow and horizontal flow in series was constructed and used to investigate organic material and nutrient removal rate constants for wastewater treatment and establish a practical predictive model for use. For this purpose, the performance of multiple parameters was statistically evaluated during the process and predictive models were suggested. The measurement of the kinetic rate constant was based on the use of the first-order derivation and Monod kinetic derivation (Monod) paired with a plug flow reactor (PFR) and a continuously stirred tank reactor (CSTR). Both the Lindeman, Merenda, and Gold (LMG) analysis and Bayesian model averaging (BMA) method were employed for identifying the relative importance of variables and their optimal multiple regression (MR). The results showed that the first-order-PFR (M) model did not fit the data (P > 0.05, and R < 0.5), whereas the first-order-CSTR (M) model for the chemical oxygen demand (COD) and Monod-CSTR (M) model for the COD and ammonium nitrogen (NH-N) showed a high correlation with the experimental data (R > 0.5). The pollutant removal rates in the case of M were 0.19 m/d (COD) and those for M were 25.2 g/m∙d for COD and 2.63 g/m∙d for NH-N. By applying a multi-variable linear regression method, the optimal empirical models were established for predicting the final effluent concentration of five days' biochemical oxygen demand (BOD) and NH-N. In general, the hydraulic loading rate was considered an important variable having a high value of relative importance, which appeared in all the optimal predictive models.

Removal and monitoring acetaminophen-contaminated hospital wastewater by vertical flow constructed wetland and peroxidase enzymes

“…In essence, the horizontal flow CW conditioned denitrification better than vertical flow pattern. For example, horizontal flow CW removed above 50% TN of initial concentration 50-200 mg/L (Nguyen et al, 2018). Our results agreed with previous findings.…”

Treatment of Wastewater Containing Runway De-Icing Agents in Biofilters as a Part of Airport Environment Management System

“…The second experiment showed that either increasing or decreasing biofilter HL relative to the value of 5.0 L/m 2 •d contributed to only a negligible decrease in nitrogen removal efficiency (Figure 4). [27] presented similar changes in nitrogen removal efficiency, as affected by hydraulic loading. In addition, Wang et al [28] failed to demonstrate a linear correlation between nitrogen removal efficiency and HL values (from 0.5 to 3.0 m 3 •m −2 •d −1 ).…”

Myriophyllum aquaticum-Based Surface Flow Constructed Wetlands for Enhanced Eutrophic Nutrient Removal—A Case Study from Laboratory-Scale up to Pilot-Scale Constructed Wetland

“…A Monod kinetic model was used to describe and evaluate the pollutant removal dynamics in the LSCW. The hydraulic inflow pattern in this LSCW was thought to be similar to that of the plug flow pattern [46]. Therefore, model equations of COD and NH (Table 1).…”

“…The constant C half represents the concentration of the corresponding pollutant when the pollutant removal efficiency reaches half the maximum removal rate. Based on previous studies [45][46][47], the removal dynamics of COD and NH 4 + in the LSCW were used to establish the simulation models and were also used to evaluate the pollutant removal efficiency of the PSCW. The C half values for COD and NH 4 + were taken as 60 mg/L and 0.05 mg/L, respectively, which are the concentrations used for Monod equations in wastewater treatment processes [45][46][47].…”