Biodegradation of phenol by bacterial strain isolated from paper sludge

The objective of this project work is to study the degradation of phenol by bacterial strain isolated from paper sludge. Biodegradation is one of the cheapest methods without any production of hazardous by-products. The growth and phenol biodegradation study was carried out in MSM broth with phenol as the sole carbon source and energy. The strains were designated as S1, S2 and S3 and examined for colony morphology, Gram staining and biochemical tests. Phenol degrading performance of all the strains was evaluated initially. One of the strains namely S2 was found to be highly effective for the removal of phenol. The effect of temperature, pH and phenol concentration on the rate of phenol degradation by that particular strain was carried out. Observations revealed that the rate of phenol biodegradation was significantly affected by pH, temperature of incubation and phenol concentration. The optimal conditions for phenol removal were found to be pH of 8, temperature of 30°C and concentration of phenol of 200 ppm

Aerobic Biodegradation of 2, 4 Dichlorophenol In A Spouted Bed Bio-Reactor (Sbbr)

Chlorinated phenolic compounds represent a major class of hazardous pollutants commonly encountered in wastewater generated by the petroleum and petrochemical industries. In this regard, biological treatment, as an economical and green technology, has been shown to be one of the most promising approaches for the removal of many organic water pollutants such as chlorophenols. Under aerobic conditions, bacteria utilize chlorophenols as a source of carbon and energy. This study aimed at developing an integrated system for biodegradation of 2, 4 dichlorophenol (DCP) in a specially designed spouted bed bioreactor (SBBR), characterized by systematic intense mixing, resulting in enhanced biodegradation rates. The system utilizes microbial immobilization of an effective commercial bacterial consortium, consisting mainly of Pseudomonas putida, in order to retain the biomass within the reactor. The bacteria were immobilized in polyvinyl alcohol (PVA) gel particles and used in the SBBR to remove DCP from the wastewater. The role of glucose, which has often been included as a carbon source during initial biomass acclimatization, was investigated and found not to be significant enough to justify its inclusion in the acclimatization process. In addition, the effects of several operating parameters were investigated in the batch mode operation, then modeled and optimized for maximum degradation rate by response surface methodology. The process was further tested in a continuous mode in order to evaluate the SBBR hydrodynamics in terms of stability and sustainability to shock loads. Total removal of the contaminant was achieved in the batch process at every initial concentration up to 200 mg/l, whereas a combined 80% removal at a throughput of 1400 g/m3day was obtained during Continuous operation. Additionally, the process was mathematically modeled using a dynamic modeling approach in order to assess reaction and mass transfer limitations. The results supported the use of the PVA immobilization technique as the most effective decontamination process. Finally, the process was evaluated for the treatment of refinery wastewater and was proven to be very effective

Bioremediation of Phenolic Compounds in Circulating Packed Bed Bioreactor

Wastewaters containing phenolic compounds such as phenol and cresols pose a high risk to human health and natural environment. Compared to physicochemical methods, bioremediation is an attractive alternative for removal of phenolic compounds from contaminated waters. This research aimed to evaluate bioremediation of phenolic compounds in batch systems and in continuously operated circulating packed bed bioreactors (CPBBs). The biodegradation of individual phenol, o-cresol, and p-cresol and mixtures of these compounds (binary and ternary mixtures) were studied. In addition to creating kinetic data on biodegradation of these contaminants, toxicity of the treated effluents generated under various conditions were assessed. Effects of initial concentrations and temperatures were investigated in batch system. Work in continuous flow CPBBs focused on the impact of phenols concentration and loading rate on the removal percentage and removal rate for influents containing individual and mixture of phenols (binary and ternary) for a wide range of conditions. The toxicity of treated effluent samples generated under various conditions was determined and compared with the employed influents to evaluate the potential risk of releasing the effluents into natural water bodies. In batch systems, a linear relationship between biodegradation rate and initial concentration of p-cresol or o-cresol was observed for the range of initial concentrations evaluated. The optimum temperature for biodegradation of p-cresol and o-cresol were 35 and 25 °C, respectively. In a binary mixture, the presence of phenol enhanced p-cresol biodegradation. During both binary- and ternary-biodegradation, p-cresol was the preferred substrate and utilized first, while phenol and o-cresol were used simultaneously (if both were present) upon complete exhaustion of p-cresol. The interaction of phenols in the ternary mixture was more complicated, as a result, polynomial models were used to describe the impact of initial concentration on biodegradation rate. It was shown that increase in p-cresol and o-cresol initial concentrations had positive effects on biodegradation rate of all three phenols, but their interaction appeared to impact the biodegradation rate negatively. In batch system the maximum observed biodegradation rates for phenol, p-cresol, and o-cresol were 17.8, 8.9, and 7.2 mg L-1 h-1, respectively. In continuous flow CPBBs, the maximum removal rates of phenol, p-cresol, and o-cresol were 82.6, 107.2, and 73.8 mg L-1 h-1 at the loading rates of 104.7 (residence time: 4.7 h), 183.9 (residence time: 2.8 h), and 163.9 mg L-1 h-1 (residence time: 1.8 h), respectively under mono-substrate biodegradation. For binary-substrate biodegradation, the presence of o-cresol had a negative impact on phenol removal rate, while p-cresol did not impose the same effect. The maximum removal rates of phenol and p-cresol during binary-substrate biodegradation were 89.2 and 78.4 mg L-1 h-1 at their respective loading rates of 137.9 and 123.9 mg L-1 h-1. The maximum removal rates of phenol and o-cresol during binary-substrate biodegradation were 119.9 and 70.3 mg L-1 h-1 at the respective loading rates of 209.8 and 112.9 mg L-1 h-1. When all three substrates were present in the influent, the maximum removal rates of phenol, p-cresol, and o-cresol were 129.2, 135.3, and 108.0 mg L-1 h-1 at their corresponding loading rates of 179.3, 195.9, and 165.7 mg L-1 h-1. It was also shown that p-cresol was the preferred substrate, followed by phenol and o-cresol. In case of untreated influents, p-cresol presented the most toxicity, followed by o-cresol, with phenol presenting the least toxicity among these three compounds. Toxicity evaluation of effluents obtained under various operating conditions revealed that overall treatment in CPBBs reduced the toxicity of influent containing phenolic compounds, although the decrease in toxicity differed pending on the operating conditions such as nature of phenolic compound, its influent concentration and loading rate

Effect of different concentrations of phenol on growth of some fungi isolated from contaminated soil

Phenol concentration in 25 water samples collected from three Egyptian Governorates (El- Gharbia, Kafer El-Sheik and El-Menofia) was assayed. The wastewater collected from El-Mehalla El-Kobra II (El- Gharbia governorate) was the most polluted sample with phenol and was equal to 0.0 88 mg/L. Czapeks medium was the most suitable among the other tested media for the growth of Hormodendrum bergeri, Fusarium oxysporum and Aspergillus flavus var. coulmnaris. However, where they were able to grow in the media containing 0.1 g/100 ml phenol, they failed to grow in the potato dextrose medium (PDA) with 0.14 g/100 ml phenol. On the other hand, the efficiency of Aspergillus ochroceus to grow on phenol was low when compared with H. bergeri, F. oxysporum and A. flavus var. coulmnaris. The growth of H. bergeri, F. oxysporum and A. flavus var. coulmnaris was optimum on the medium that contained 0.1 g/100 ml phenol after 6 days. The addition of a mixture of vitamins (B1 + B6 + B12) at 0.1% (w/v) to Cazpeks medium enhanced the growth of H. bergeri, F. oxysporum and A. flavus var. coulmnaris in the presence of phenol. Growth in the presence of phenol induced some morphological modification in both F. oxysporum and A. flavus var. coulmnaris.Key words: Phenol, growth, fungi, morphological changes

Biotechnology and Bioengineering

Biotechnology and Bioengineering presents the most up-to-date research on biobased technologies. It is designed to help scientists and researchers deepen their knowledge in this critical knowledge field. This solid resource brings together multidisciplinary research, development, and innovation for a wide study of Biotechnology and Bioengineering

Investigation into the bioremediation and benefication of olive-derived wastewaters from the Western Cape

Includes bibliographical references.Since this was the first research project into olive wastewaters produced in South Africa, the scope of the project was broad, and recommendations were made for further research in several directions. Most importantly, the development of smallscale treatment systems that could be used on site would be of great benefit to olive and olive oil producers, as they are often remote and do not have access to appropriate treatment facilities. In addition, the combination of unit operations, such as an extraction system and a biological degradation system, would allow for the recovery of a valuable product that would offset the cost of producing a treated effluent

Preparation and Characterization of Novel Activated Carbons for Adsorption and Adsorption Assisted Biodegradation of Organic and Inorganic Water Pollutants

The primary sources of water contamination are industrialization, urbanization, and agricultural activities, which are harmful to the environment and the living beings. The wastewater treatment is very necessary for saving the water to emancipate the living organisms. Among various treatment technologies, adsorption and biodegradation are the most efficient methods for removing various pollutants from wastewater. The integration of adsorption and biodegradation processes for the treatment of organic compounds leads to the enhancement of the degradation rate and adsorption capacity. Among various adsorbents used, the activated carbon is one of the most efficient adsorbents due to high surface area and developed pore structures, and a actual support media for microbial growth. In this study, the Fox nutshell has been used as a novel precursor material for the preparation of activated carbons. These are the residue with no commercial value. The Fox nutshell contains low ash (5%) content and high volatile matter (70.1%) that is favorable for activated carbon preparation. Therefore, the Fox nutshell has been a worthwhile material for the preparation of the activated carbon. The activated carbons were prepared by chemical activation method using zinc chloride, orthophosphoric acid, and potassium carbonate. The effect of various process parameters such as heating rate, activation time, carbonization temperature and impregnation ratio on porous characteristics of the prepared activated carbons has been investigated. The proximate and ultimate analyses of the prepared activated carbons was carried out by using standard methods and CHNS analyzer, respectively. The prepared activated carbons were characterized by using N2 adsorption-desorption isotherm at 77 K. The surface functional groups present on the prepared ACs surface were determined by the Fourier Transform Infrared Spectroscopy (FTIR) analysis. The Field Emission Scanning Electron Microscope (FESEM) analysis revealed the surface texture of the ACs while Transmission Electron Microscopy (TEM) analysis is used to visualize the presence of micropores network. The prepared activated carbon with a ZnCl2 activator (ACZC-600-2.0) which has the highest BET surface area of 2869 m2/g and pore volume of 1.96 cm3/g is obtained at the following conditions: 600 ºC carbonization temperature, 2 impregnation ratio and one hr activation time. The prepared activated carbon with an H3PO4 activating agent (ACPA-700-1.5) has the BET surface area of 2636 m2/g and pore volume of 1.53 cm3/g is obtained at 700 ºC carbonization temperature, 1.5 impregnation ratio and one hr activation time. The another prepared activated carbon with a K2CO3 activator (ACKC-800-0.5) has the BET surface area of 1236 m2/g and pore volume of 0.98 cm3/g which has the highest surface area and pore volume is obtained at 800 ºC carbonization temperature, 0.5 impregnation ratio and activation time of one hr. Batch adsorption experiments of phenol, methylene blue (MB) and Cr(VI) onto prepared activated carbons were carried out at various initial concentration. Adsorption kinetics of phenol, MB and Cr(VI) were studied by using different kinetic models, i.e., the pseudo-first-order model, the pseudo-second-order model, and the intraparticle diffusion model. The experimental adsorption isotherms of these adsorbates on the prepared activated carbons were analyzed using the Langmuir, Freundlich, and Temkin isotherm models. adsorption capacity (qe) of 500 mg/L of initial phenol concentration onto ACZC-600-2.0 and ACPA-700-1.5 are 75.37 and 83.21 mg/g, respectively. The equilibrium adsorption capacity (qe) of MB onto ACZC-600-2.0 and ACPA-700-1.5 are 968.74 and 766.53 mg/g, respectively for 500 mg/L of initial concentration. Adsorption capacity (qe) of 10 mg/L of initial Cr(VI) concentration onto ACZC-600-2.0 and ACPA-700-1.5 are 43.45 and 56.31 mg/g, respectively. The potential applications of the prepared activated carbons for removal of adsorbates have been studied in fixed bed column. The effects of the bed height and flow rate of phenol, MB and Cr(VI) adsorption onto prepared activated carbons were also studied. The bacterial strain of Pseudomonas putida (MTCC 1194) has been taken for the phenol biodegradation in both suspended and immobilized phase. The bacterial strain has been acclimatized up to 1000 mg/L of phenol concentration. Biological granular activated carbon (BGAC) shows more efficiency than the free cells for phenol removal due to both adsorption and biodegradation process. The BGAC has been used in fluidized bed bioreactor for treatment of synthetic phenol wastewater. In fluidized bed bioreactor, effects of inlet flow rate of the wastewater, different phenol concentration solutions, and the ratio of bed (settled) volume to bioreactor volume (Vb/VR) on the removal of phenol were studied