Novel hybrid models for the design of upflow anaerobic filters separated in phases

Abstract

In this paper, upflow anaerobic filters separated in two (UAF‐2SS) and three phases (UAF‐3SS) were evaluated for treating landfill leachate, varying volumetric organic load (2.25–4.64 kg/m3‐day), temperature (20°C–34°C), and depth ratio in reactors. Eight hybrid models were formulated, obtaining a determination coefficient upper to 0.7.

An approach to models for transport and transformation of organochlorine pesticides in rivers

“…In this study, it is hypothesized that the transport and transformation processes of particulate and soluble substrates, represented as the concentrations of the OCPs dissolved in water and sorbed on sediments $$( {{C_{{\rm{OCP}}}}} ),$$ by autochthonous microorganisms under anaerobic or aerobic conditions in a tropical river are approaches to those that occur in the reactors of biological filters. The substrate is transported and transformed by the innate biological mass $$( X )$$ that inhabits the soil of the riverbed, forming a film known as biofilm (Exhibit 2) (Maldonado‐Maldonado et al., 2018a, 2018b, 2020, 2021; Márquez et al., 2020). The biofilm adheres to the soil solid matrix, for instance, the riverbed (Exhibit 2), at the interface between the aqueous and solid phases within the fluvial environment, similar to the biological filters (Maldonado‐Maldonado et al., 2018a, 2018b, 2020.…”

“…The biofilm adheres to the soil solid matrix, for instance, the riverbed (Exhibit 2), at the interface between the aqueous and solid phases within the fluvial environment, similar to the biological filters (Maldonado‐Maldonado et al., 2018a, 2018b, 2020. 2021; Márquez et al., 2020). The biofilm is assumed to consist of an active part $$( {{X_A}} )$$ and an inactive part, $$( {{X_G}} )$$ (Exhibit 2).…”

“…In this study, the kinetic coefficient is termed as the OCP accumulation–utilization rate $$( {{r_{{\rm{OCP}}}}} )$$ by microorganisms to take into account the inhibition of the microorganisms due to the presence of the recalcitrant matter (Freytez et al., 2019; Maldonado et al., 2021; Márquez et al., 2020), and the potential occurrence of sorption–desorption processes causing accumulation, thus $${r_{{\rm{OCP}}}}$$ is estimated using the modified equation of Monod (Equation 4) that is expressed by Equation (6), which is as follows (Freytez et al., 2019; Maldonado et al., 2021; Márquez et al., 2020): $$\begin{equation}\frac{{d{C_{{\rm{ocp}}}}}}{{dx}} = {\rm{\;}} - {\rm{\;}}\frac{w}{Q}\left[ {\frac{{{\mu _m}X{C_{{\rm{OCP}}}}_e}}{{Y\left( {{C_{{\rm{OCP}}}}_e + {K_s}} \right)}}} \right].\end{equation}$$where $${k_m}$$ is a coefficient that represents the maximum accumulation–utilization rate of $${\rm{OCP}}$$ (mass/volume·length), obtained from Equation (3) and expressed by Equation (7) as follows: $$\begin{equation}{k_m} = {\rm{\;}}\frac{{w{\mu _m}X}}{{QY}}.\end{equation}$$…”

“…Monod's kinetics (Monod, 1949) are widely used to characterize the biodegradation rates of organic contaminants. This expression has been successfully used to describe the rate of removal of organic compounds in laboratory studies where the domestic and industrial wastewater were the sole source of carbon and energy (Freytez et al., 2019; Maldonado et al., 2018a, 2018b, 2020, 2021; Márquez et al., 2020). For instance, for the chemical oxygen demand (COD) removal in an upflow anaerobic filter in two (UAF‐2SS) and three separate (UAF‐3SS) stages, the kinetic parameter$$\;k$$, associated with the maximum substrate utilization rate, varied between 0.04 and 0.83 mg COD/mg biomass‐day for low Volumetric Organic Loads (2–4.64 kg COD/m 3 ‐day) and between 0.52 and 7.12 mg COD/mg biomass‐day, respectively (Maldonado et al., 2021).…”

“…This expression has been successfully used to describe the rate of removal of organic compounds in laboratory studies where the domestic and industrial wastewater were the sole source of carbon and energy (Freytez et al., 2019; Maldonado et al., 2018a, 2018b, 2020, 2021; Márquez et al., 2020). For instance, for the chemical oxygen demand (COD) removal in an upflow anaerobic filter in two (UAF‐2SS) and three separate (UAF‐3SS) stages, the kinetic parameter$$\;k$$, associated with the maximum substrate utilization rate, varied between 0.04 and 0.83 mg COD/mg biomass‐day for low Volumetric Organic Loads (2–4.64 kg COD/m 3 ‐day) and between 0.52 and 7.12 mg COD/mg biomass‐day, respectively (Maldonado et al., 2021). For a modified expression of Monod's equation, it has been determined that $$k$$ varied in an order of 4.8 mg COD/mg biomass‐day and 5.9 mg COD/mg biomass‐day for UAF‐2SS and UAF‐3SS reactors for a microorganisms mass into the reactors of 670 mg (volatile suspended solids)/L (Maldonado‐Maldonado et al., 2018a, 2018b, 2020; Márquez et al., 2020).…”