4-chlorophenol removal by air lift packed bed bioreactor and its modeling by kinetics and numerical model (artificial neural network)

Abstract

Abstract4-chlorophenol (4-CP) is a hazardous contaminant that is hardly removed by some technologies. This study investigated the biodegradation, and physical 4-CP removal by a mixed microbial consortium in the Airlift packed bed bioreactor (ALPBB) and modeling by an artificial neural network (ANN) for first the time. The removal efficiency of ALPBB was investigated at 4-CP(1-1000 mg/L) and hydraulic retention time (HRT)(6-96 hr) by HPLC. The results showed that removal efficiency decreased from 85 at 1 to 0.03% at 1000 mg/L, with increasing 4-CP concentration and HRT decreasing. BOD5/COD increased with increasing exposure time and concentration decreasing, from 0.05 at 1000 to 0.96 at 1 mg/L. With time increasing, the correlation between COD and 4-CP removal increased (R2 = 0.5, HRT = 96 h). There was a positive correlation between the removal of 4-CP and SCOD by curve fitting was R2 = 0.93 and 0.96, respectively. Moreover, the kinetics of 4-CP removal follows the first-order and pseudo-first-order equation at 1 mg/L and other concentrations, respectively. 4-CP removal modeling has shown that the 2:3:1 and 2:4:1 were the best structures (MSE: physical = 0.126 and biological = 0.9)(R2allphysical = 0.999 and R2testphysical = 0.999) and (R2allbiological = 0.71, and R2testbiological = 0.997) for 4-CP removal. Also, the output obtained by the ANN prediction of 4-CP was correlated to the actual data (R2physical = 0.9997 and R2biological = 0.59). Based on the results, ALPBB with up-flow submerged aeration is a suitable option for the lower concentration of 4-CP, but it had less efficiency at high concentrations. So, physical removal of 4-CP was predominant in biological treatment. Therefore, the modification of this reactor for 4-CP removal is suggested at high concentrations.

Modelling of n-Hexadecane bioremediation from soil by slurry bioreactors using artificial neural network method

“…In other studies, it has been predicted that microbial populations with 4-9-1 and 3-25-1 structures were used for the removal of toluene and trichloroethylene. Therefore, the results of this study were confirmed by previous studies 30 , 31 .…”

“…ANN is a powerful modeling method for determining the nonlinear relationship between variables 30 . This study was performed by feed-forward backpropagation and Levenberg–Marquardt using MATLAB 2018 31 , 32 .…”

Influence of Operating Parameters on Photocatalytic Oxidation of 2,4-Dichlorofenol in Aqueous Solution by TiO2/Stainless Steel Photocatalytic Membrane

“…A significant category of these persistent pollutants is represented by refractory organic compounds, which include chlorophenols. They end up in wastewater resulting from the manufacture of pesticides, paints, polymers, cosmetics, etc., and because they cannot be removed by conventional methods in wastewater treatment plants, they arrive in natural water bodies [3,4].…”