Modeling the performance of biodegradation of textile wastewater using polyurethane foam sponge cube as a supporting medium

A pilot-scale fixed-biofilm reactor (FBR) was established to treat textile wastewater to evaluate the feasibility of replacing conventional treatment processes that involve activated sludge and coagulation units. A kinetic model was developed to describe the biodegradation of textile wastewater by FBR. Batch kinetic tests were performed to evaluate the biokinetic parameters that are used in the model. FBR column test was fed with a mean COD of 692 mg/L of textile wastewater from flow equalization unit. The influent flow rate was maintained at 48.4 L/h for FBR column test. Experimental data and model-predicted data for substrate effluent concentration (as COD), concentration of suspended biomass in effluent and the amount of carbon dioxide (CO2) produced in the effluent agree closely with each other. Microscopic observations demonstrated that the biofilm exhibited a uniform distribution on the surface of polyurethane foam sponge. Under a steady-state condition, the effluent COD from FBR was about 14.7 mg COD/L (0.0213 Sb0), meeting the discharge standard (COD < 100 mg/L) that has been set by the government of Taiwan for textile wastewater effluent. The amount of biofilm and suspended biomass reached a maximal value in the steady state when the substrate flux reached a constant value and remained maximal. Approximately 33% of the substrate concentration (as COD) was converted to CO2 during biodegradation in the FBR test. The experimental and modeling schemes proposed in this study could be employed to design a full-scale FBR to treat textile wastewater.

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Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment

Water Science & Technology ◽

10.2166/wst.2006.863 ◽

2006 ◽

Vol 54 (9) ◽

pp. 181-189 ◽

Cited By ~ 18

Author(s):

D.H. Shin ◽

W.S. Shin ◽

Y.-H. Kim ◽

Myung Ho Han ◽

S.J. Choi

Keyword(s):

Wastewater Treatment ◽

Textile Wastewater ◽

Pilot Scale ◽

Biofilm Reactor ◽

Dyeing Wastewater ◽

Moving Bed Biofilm Reactor ◽

Combined Process ◽

Chemical Coagulation ◽

Moving Bed ◽

Textile Wastewater Treatment

A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl2.In the MBBR process, 85% of COD and 70% of color (influent COD=807.5 mg/L and color=3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT=44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl2, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.

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Validation of a multisubstrate mathematical model for the simulation of the denitrification process in fluidized bed biofilm reactors

Water Science & Technology ◽

10.2166/wst.1994.0785 ◽

1994 ◽

Vol 29 (10-11) ◽

pp. 401-408 ◽

Cited By ~ 5

Author(s):

B. Eramo ◽

R. Gavasci ◽

A. Misiti ◽

P. Viotti

Keyword(s):

Mathematical Model ◽

Fluidized Bed ◽

Research Programme ◽

Pilot Scale ◽

Convective Transport ◽

Biofilm Reactor ◽

Steady State Condition ◽

Biofilm Reactors ◽

Numeric Simulation ◽

Particle Bed

The present paper compares the experimental results obtained from a research programme developed on a pilot-scale fluidized bed biofilm reactor and the outputs of a numeric simulation model; the mathematical model can determine the substrate concentration profile within the reactor. The experimental campaign investigated heterotrophic biological denitrification in anoxic conditions. The model is based on multi-substrate Michaelis-Menten kinetics and considers mass transport resistancephenomena within and outside bioparticles. A monodimensional model of the reactor taking into consideration, in steady-state condition, phenomena due to convective transport and turbulent diffusion has been used. The fluidization model applied to describe the behaviour of the biofilm-covered rigid particle bed is based on the Wen and Yu correlation.

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Nitrite and nitrate as electron acceptors for biological sulphide oxidation

Water Science & Technology ◽

10.2166/wst.2015.252 ◽

2015 ◽

Vol 72 (4) ◽

pp. 593-599 ◽

Cited By ~ 3

Author(s):

G. Munz ◽

A. Mannucci ◽

J. Arreola-Vargas ◽

F. Alatriste-Mondragon ◽

F. Giaccherini ◽

...

Keyword(s):

Steady State ◽

Electron Acceptor ◽

Removal Rate ◽

Nitrate Removal ◽

Pilot Scale ◽

Ratio Increase ◽

Steady State Condition ◽

Primary Sludge ◽

Nitrogen Loads ◽

Solids Retention

Autotrophic denitrification with sulphide using nitrate (R1) and nitrite (R2) as electron acceptor was investigated at bench scale. Different solids retention times (SRT) (5 and 20 d) have been tested in R1 while R2 was operated at SRT = 13 d. The results indicated that the process allows complete sulphide removal to be achieved in all tested conditions. Tested sulphide loads were estimated from the H2S produced in a pilot-scale anaerobic digester treating vegetable tannery primary sludge; nitrogen loads originated from the nitrification of the supernatant. Average nitrogen removal efficiencies higher than 80% were observed in all the tested conditions once steady state was reached. A maximum specific nitrate removal rate equal to 0.35 g N-NO3− g VSS−1 d−1 was reached in R1. Due to sulphide limitation, incomplete denitrification was observed and nitrite and thiosulphate tend to accumulate especially in the presence of variable environmental conditions in both R1 and R2. Lower SRT caused higher NO2accumulated/NO3reduced ratios (0.22 and 0.24, with SRT of 5 d and 20 d, respectively) using nitrate as electron acceptor in steady-state condition. Temperature decrease caused sudden NO2accumulated/NO3reduced ratio increase in R1 and NO2− removal decrease in R2.

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Treatability studies of textile wastewater on an aerobic fluidized bed biofilm reactor (FABR): a case study

Water Science & Technology ◽

10.2166/wst.2009.207 ◽

2009 ◽

Vol 59 (9) ◽

pp. 1817-1821 ◽

Cited By ~ 6

Author(s):

Thalla Arun Kumar ◽

S. Saravanan

Keyword(s):

Wastewater Treatment ◽

Fluidized Bed ◽

Removal Efficiency ◽

Textile Wastewater ◽

Pilot Scale ◽

Biofilm Reactor ◽

Combined Process ◽

Biofilm Process ◽

Textile Wastewater Treatment

The performance of a pilot scale aerobic fluidized bed biofilm process and chemical coagulation for textile wastewater treatment was studied. In order to enhance biological treatment efficiency of textile wastewater, poly urethane cubes were incorporated as a supporting media for attached growth. Fenton's reagent was used as a coagulant in the present study. The fluidized bed biofilm process was operated at four HRTs (3, 4.5, 6 and 8 hour) and the results showed that the COD removal efficiency increased from 69% to 94% when the HRT increased from 3 to 4.5 and there of the removal efficiency remained constant around 94%, even though using relatively low MLSS concentration and short sludge retention time. COD and TDS removals of 94.2% and 93.3% were achieved by overall combined process (FABR + Coagulation aided Sedimentation). After the treatment there is remarkable decrease in colour in addition to COD and TDS. This combined process was highly competitive in comparison to the other similar combined systems. It was concluded that this combined process was successfully employed and much effectively decreased they COD, TDS and color of textile wastewater treatment at pilot scale.

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Kinetics of biodegradation of phenolic wastewater in a biofilm reactor

Water Science & Technology ◽

10.2166/wst.2009.203 ◽

2009 ◽

Vol 59 (9) ◽

pp. 1703-1711 ◽

Cited By ~ 5

Author(s):

Yen-Hui Lin ◽

Tzu-Yang Hsien

Keyword(s):

Model Simulation ◽

Pilot Scale ◽

Biofilm Reactor ◽

Oil Refining ◽

Orthogonal Collocation ◽

Steady State Condition ◽

Biofilm Thickness ◽

Phenolic Wastewater ◽

Biokinetic Parameters ◽

Fixed Biofilm

This work presents a mathematical model to describe the biodegradation of phenolic wastewater in a fixed-biofilm process. The model incorporates diffusive mass transport and Haldane kinetics mechanisms. The model was solved using a combination of the orthogonal collocation method and Gear's method. A laboratory-scale column reactor was employed to verify the model. Batch kinetic tests were conducted independently to determine biokinetic parameters for the model simulation with the initial biofilm thickness assumed. The model simulated the phenol effluent concentration results well. Removal efficiency for phenol was approximately 94–96.5% for different hydraulic retention times at a steady-state condition. Model simulations results are in agreement with experimental results. The approaches of model and experiments presented in this paper could be used to design a pilot-scale or full-scale fixed-biofilm reactor system for the biodegradation of phenolic wastewater from petrochemical and oil refining plants.

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Computational Performance of Disparate Lattice Boltzmann Scenarios under Unsteady Thermal Convection Flow and Heat Transfer Simulation

Computation ◽

10.3390/computation9060065 ◽

2021 ◽

Vol 9 (6) ◽

pp. 65

Author(s):

Aditya Dewanto Hartono ◽

Kyuro Sasaki ◽

Yuichi Sugai ◽

Ronald Nguele

Keyword(s):

Heat Transfer ◽

Steady State ◽

Natural Convection ◽

Lattice Boltzmann ◽

Numerical Results ◽

Convection And Heat Transfer ◽

Steady State Condition ◽

Physical Systems ◽

Flow And Heat Transfer ◽

Computational Performance

The present work highlights the capacity of disparate lattice Boltzmann strategies in simulating natural convection and heat transfer phenomena during the unsteady period of the flow. Within the framework of Bhatnagar-Gross-Krook collision operator, diverse lattice Boltzmann schemes emerged from two different embodiments of discrete Boltzmann expression and three distinct forcing models. Subsequently, computational performance of disparate lattice Boltzmann strategies was tested upon two different thermo-hydrodynamics configurations, namely the natural convection in a differentially-heated cavity and the Rayleigh-Bènard convection. For the purposes of exhibition and validation, the steady-state conditions of both physical systems were compared with the established numerical results from the classical computational techniques. Excellent agreements were observed for both thermo-hydrodynamics cases. Numerical results of both physical systems demonstrate the existence of considerable discrepancy in the computational characteristics of different lattice Boltzmann strategies during the unsteady period of the simulation. The corresponding disparity diminished gradually as the simulation proceeded towards a steady-state condition, where the computational profiles became almost equivalent. Variation in the discrete lattice Boltzmann expressions was identified as the primary factor that engenders the prevailed heterogeneity in the computational behaviour. Meanwhile, the contribution of distinct forcing models to the emergence of such diversity was found to be inconsequential. The findings of the present study contribute to the ventures to alleviate contemporary issues regarding proper selection of lattice Boltzmann schemes in modelling fluid flow and heat transfer phenomena.

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