Influence factors in the adjustment of parameters of the modified first-order kinetics equation used to model constructed wetland systems

Abstract

The aim of the present work was to evaluate the relationship between the hydraulic retention time power parameter (n) of the modified first-order kinetic mathematical model (MFOKM) with the hydraulic dispersion number (d) and the organic matter degradability, obtained from the ratio of chemical and biochemical oxygen demands (COD/BOD) along the length of horizontal subsurface flow constructed wetlands (HSSF-CWs). For this purpose, unplanted HSSF-CWs prototypes of equal volumes and length/width ratios (L W-1) of 1.0, 4.0 and 7.3 were used. All HSSF-CWs were filled with gravel # 0 and received sanitary sewage (SW) during a period of 90 days, in which the BOD and COD, in the total and soluble forms, were monitored in the influent and effluents from the system. These units were subject to tracer tests, before and after the HSSF-CWs received the SW, to obtain d. The MFOKM was adjusted to the COD and BOD experimental data. In all cases, an inverse relation was observed between n and the parameters d or with the organic matter decay rate obtained in the initial part of the HSSF-CWs.

Current Insights into Growing Microalgae for Municipal Wastewater Treatment and Biomass Generation

“…MWW treatment plants are meticulously designed to cater to the level of purification required for the product. As de Matos et al [21] described, these treatments can span multiple stages, including preliminary, primary, secondary, and tertiary.…”

Exploring the Removal of Organic Matter in Constructed Wetlands Using First Order Kinetic Models

“…Matos et al [28] observed graphically and using Pearson's coefficient (−0.985) that Likewise, for low initial concentrations, the degradability would be smaller and the organic material more recalcitrant. This would characterize the conditions of a pre-treated sewage (primary, secondary or tertiary effluent), in which there is remaining material that is more difficult to degrade, i.e., having a k value smaller and more uniform.…”

“…Matos et al [28] observed graphically and using Pearson's coefficient (−0.985) that the value of (n) is strongly associated with the deterioration grade of organic matter (OM). In summary, the greater the magnitude of variation in OM concentrations at the beginning of CWs, the lower the value of n.…”