Modelling the Simultaneous Adsorption and Biodegradation of Aromatic Hydrocarbons onto Non-Carbonized Biological Adsorbent in Batch System

In this study, a modified two-site sorption kinetic numerical model that differentiates between the adsorption and biodegradation quantities of a non-carbonized biological activated adsorbent (NCBAA) was developed and validated. Also, the effects of initial naphthalene and phenol concentrations on the simultaneous adsorption-biodegradation performances of orange and pineapple peel immobilized Pseudomonas aeruginosa NCIB 950 in naphthalene and phenol removal was respectively evaluated. Adsorption-biodegradation model was developed from the modification of a two-site kinetic numerical model by combining the elements of adsorption and biodegradation models and validation of the model carried out through the application of batch adsorption-biodegradation equilibrium and kinetic experimental data. Results showed that the model predictions of the naphthalene and phenol concentrations are in good agreement with the experimental data. For simultaneous adsorption-biodegradation of naphthalene by orange peel immobilized Pseudomonas aeruginosa, adsorption rate coefficient increased with initial naphthalene concentration and biodegradation rate coefficient decreased with increased initial concentration; and for phenol simultaneous adsorption-biodegradation by pineapple peel immobilized Pseudomonas aeruginosa, adsorption rate coefficient decreased with increased initial phenol concentration and biodegradation rate coefficient increased with increased initial phenol concentration. Thus, the adsorption-biodegradation model is a reasonable tool for simulating the adsorption-biodegradation behaviors of aromatic hydrocarbons in NCBAA. Keywords: Bacteria; Simultaneous adsorption-biodegradation; Phenol; Naphthalene; Non-carbonized biological activated adsorbent; Numerical model.

Evaluation of Microbial Systems for Biotreatment of Textile Waste Effluents in Nigeria: Biodecolourization and Biodegradation of textile Dye

The evaluation of some microbial species for the decolourization and degradation of textile dye has been investigated. Six microbial strains were isolated from soil contaminated with textile waste effluents using the spread plate technique and the isolates were identified as bacterial isolates ( Pseudomonas fluorescence , Pseudomonas nigificans , and Pseudomonas gellucidium ) and fungal isolates ( Aspergillus niger , Proteus morganii and Fusarium compacticum } based on gram staining, morphological and biochemical tests. They were evaluated for their capability to remove colour and degrade dye, reduce chemical oxygen demand (COD) and biological oxygen demand (BOD) levels of textile waste effluents. The results revealed that all the bacterial and fungal isolates have a good potential to remove colour and degrade dye, reduce the COD and BOD levels of the textile waste effluents with percent colour removal, COD and BOD reductions between 39 and 48%, 74 and 97% and 77 and 95%, respectively. Binary mixed culture of Pseudomonas fluorescence and Aspergillus niger was efficiently utilized for the removal of different initial concentration (10, 15, 20, 25 and 30 mg/l) of dye from textile waste effluents. It had a higher percent decolourization than individual isolates. The stirred tank bioreactor was found to be very effective for efficient biotreatment of textile waste effluents

Selection of Mass Transfer Models for Competitive Adsorption of Antibiotics Mixture from Aqueous Solution on Delonix regia Pod Activated Carbon

The selection of suitable mass transfer models that fit the adsorption of a mixture of antibiotics in aqueous solution onto activated carbon derived from Delonix Regia Pods (DRPs) was examined in this study. The ripe DRPs were cleaned, activated with KOH and then carbonised at 350 °C. The surface chemistry of the raw and the modified DRPs were characterised using Fourier Transform Infrared (FTIR), before being subjected to batch adsorption of a mixture of Amoxicillin (AMO), Tetracycline (TETRA) and Ampicillin (AMP)  under the effect of time (0-240 mins), and concentration (20-100 mg/l). The adsorption diffusion mechanisms of the process were analyzed. The spectra of the raw and modified DRP indicate the existence of hydroxyl groups alkanes, unconjugated ketone, carbonyl, and ester groups.  McKay has the highest  (0.9445) for the mass transfer diffusion model. This indicates that the adsorption rate of the selected antibiotics in the wastewater is regulated and monitored by the internal mass transport processes in accordance with a pore diffusion mechanism

Optimization and Isothermal Studies of Antibiotics Mixture Biosorption From Wastewater Using Palm Kernel, Chrysophyllum albidum, and Coconut Shells Biocomposite

The presence of persistent pharmaceutical products in water bodies is a significant problem that obstructs wastewater reuse. This study investigated the adsorption process for removing the recalcitrant antibiotics, including tetracycline (TC), ampicillin (AMP), and amoxicillin (AMOX) from an aqueous solution using a composite biosorbent made from a mixture of palm kernel shell (PKS), Chrysophyllum albidum (CAS), and coconut shell (CS). Simplex centroid design in the Design of Expert (12.0.1.0) was applied to optimize the percentage composition (20-55%) of the composite biosorbent precursor and to remove TC-AMP-AMOX mixtures from the aqueous solution in a batch study. The equilibrium data were fitted to 12 isotherm models and analyzed statistically. The maximum adsorption capacity of 9.12 mg/g, 8.66 mg/g, and 7.11 mg/g was achieved for TC, AMP, and AMOX, respectively, using the biocomposite biosorbent with an optimal mixture of 55% PKS, 20% CAS, and 25% CS. The adsorption behavior of TC, AMP, and AMOX was well-described by the Langmuir/Elovich isotherm (R2=1.000), Hill-DeBoer (R2=0.9953), and Freundlich/ Halsey (R2=0.9898) models, respectively. The obtained results showed that the biocomposite PKS-CAS-CS leverages the individual adsorptive capacity of each constituent to enhance the adsorption process. Moreover, the composite biosorbent demonstrated excellent potential for removing recalcitrant pharmaceuticals from wastewater effectively

Evaluation of Microbial Systems for Biotreatment of Textile Waste Effluents in Nigeria: Biodecolourization and Biodegradation of textile Dye

The evaluation of some microbial species for the decolourization and degradation of textile dye has been investigated. Six microbial strains were isolated from soil contaminated with textile waste effluents using the spread plate technique and the isolates were identified as bacterial isolates ( Pseudomonas fluorescence , Pseudomonas nigificans , and Pseudomonas gellucidium ) and fungal isolates ( Aspergillus niger , Proteus morganii and Fusarium compacticum } based on gram staining, morphological and biochemical tests. They were evaluated for their capability to remove colour and degrade dye, reduce chemical oxygen demand (COD) and biological oxygen demand (BOD) levels of textile waste effluents. The results revealed that all the bacterial and fungal isolates have a good potential to remove colour and degrade dye, reduce the COD and BOD levels of the textile waste effluents with percent colour removal, COD and BOD reductions between 39 and 48%, 74 and 97% and 77 and 95%, respectively. Binary mixed culture of Pseudomonas fluorescence and Aspergillus niger was efficiently utilized for the removal of different initial concentration (10, 15, 20, 25 and 30 mg/l) of dye from textile waste effluents. It had a higher percent decolourization than individual isolates. The stirred tank bioreactor was found to be very effective for efficient biotreatment of textile waste effluents

Effect of concentration of mixed culture of fungi on the biodegradation of palm oil mill effluent

The performance of mixed culture of isolated fungi on the biodegradation of palm oil mill effluent (POME) was evaluated in this study. Specifically, the effect of effect of dosage of the mixed culture on the degradation of lipid content of the POME was investigated in order to determine the suitable incubation for effective biodegradation. The four mixed cultures, (TRQ1/TRQ2, TRQ2/TRQ3, TRQ1/TRQ3 and TRQ1/TRQ2/TRQ3), developed at equal proportions were dosed at 3%, 4% and 6% respectively in a batch process. The percentages removal of the lipid content ranged from 77.4–81.5%, 77.4–81%, and 75.9–82.3%, for 3%, 4% and 6% dosages respectively. The kinetic parameters were evaluated using Zero Order, First Order and Michaelis-Menten expression for biological systems. The fitness of the data indicates ranges of R2 for Zero Order to be 0.46–0.50, 0.40–0.57 and 0.51–0.55, which are less than R2 (0.61–0.69, 0.53–0.70, 0.63–0.76, respectively) obtained for First Order for 3%, 4% and 6% dosages respectively, while R2 obtained for Michaelis-Menten kinetic expression ranged from 0.79–0.94, 0.68–0.87 and 0.69–0.98, respectively. The study shows that the biodegradation of POME was influenced by increasing dosage of inoculums and the biodegradation rate was well fitted to Michaelis-Menten kinetic expression. The incubation period of effective degradation of POME was found to be 5days