Pentachlorophenol and spent engine oil degradation by Mucor ramosissimus

Pentachlorophenol (PCP) has been widely used for many years and belongs to the most toxic pollutants. Spent engine oils enter environment every day in many ways. Both of them cause great environmental concern. In the present work we focused on identifying metabolites of PCP biodegradation formed in the cultures of Mucor ramosissimus IM 6203 and optimizing medium composition to enhance PCP removal in the presence of engine oil acting as a carbon source. Pentachlorophenol (PCP) to tetrachlorohydroquinone (TCHQ) transformation was the most interesting transformation conducted by the tested strain. TCHQ was further transformed to 2,3,5,6-TCP and 2,3,4,6- TCP. Strain IM 6203 is also capable of PCP transformation to corresponding anisoles – pentachloromethoxybenzene (PCMB) and pentachloroethoxybenzene (PCEB). Characterization of enzymatic background involved in PCP to TCHQ transformation showed that TCHQ formation is catalyzed by inductive and cytochrome P-450 dependent enzymatic system. Experiments conducted on mineral medium allowed defining the optimal quantitative and qualitative medium make-up for PCP to TCHQ transformation. Biodegradation of PCP on the optimized synthetic medium X was more efficient than on rich Sabouraud medium. The tested strain is capable of growing in the presence of spent engine oil therefore we checked the ability of PCP transformation on optimized synthetic medium containing oil as a carbon source. The obtained results showed that PCP removal and TCHQ formation occurred were found to be the most efficient on the oil containing medium (OX medium). PCP removal and TCHQ formation after 240 h of culturing reached 1.19 mg/l and 0.89 mg/l, respectively. Additionally, 55.5% of oil introduced to the medium was removed during 10 days of the experiment. PCP biodegradation mechanisms used by Mucor species have not been sufficiently explained. The presented results point to the tested strain as an interesting model for the research on fungal PCP biodegradation in the areas highly contaminated with engine oil and for its future application in PCP and oils removal

Removal of endocrine disrupting chemicals using low pressure reverse osmosis membrane

Endocrine disrupting chemicals (EDCs) are one of the major focuses of contaminants in current environmental issues, as they can cause adverse health effects on animals and human, particularly to endocrine function. The objective of this study was to remove a specific group of EDCs (i.e molecular weight range 228 to 288 g/mol) using low pressure reverse osmosis membrane (LPROM). A multi-layer thin-film composite of aromatic polyamide (ES20) membrane and a C10-T cross flow module of LPROM manufactured by Nitto Denko Company was used in this study. The effects of operating parameters, i.e. pH, operating pressure, concentration and temperature were observed using a design of experiment based on MINITABTM software. The analysis of results was conducted by factorial analysis (FA) and response surface analysis (RSA). It was found that LPROM has been effectively applied to remove pentachlorophenol (PCP) (more than 83%), 17ß-estradiol (more than 87%) and bisphenol-A (BPA) (more than 87%). For permeate flux, both PCP and 17ß-estradiol tests produce excellent flux rate; i.e. 23.8 L/m2.h and 22.9 L/m2.h, respectively. For BPA, the permeate flux produced was slightly lower (19.1 L/m2.h) due to its physical-chemical properties effect at various levels of the recovery rate. In this study, the percentage of rejection was increased with the increased of pH and concentration of compounds. The flux was observed to increase with the increase of operating pressure. This study also investigated the interaction effects between operating parameters involved. In addition, statistical models were developed to represent the performance of LPROM under two response parameters, i.e. percentage of EDCs rejection and permeate flux. Statistical models were then validated using One-Factor-At-a-Time (OFAT) design of experiments and comparisons were made to better understand the trend of EDCs rejection and permeate flux

Insecticide Effects on Normal Development and Hatch of Embryos of \u3ci\u3eParatanytarsus Parthenogeneticus\u3c/i\u3e (Diptera: Chironomidae)

Simple, low cost methods are needed to determine the effect of pesticides on non-target aquatic organisms. In this report, embryos of Paratanytarsus parthenogenetic us were exposed from deposition to hatch to five pesticides. Four of the five pesticides affected development or hatch only at concentrations which exceeded 96-h LC50 values of other non-target invertebrates. One pesticide, fenitrothion, affected hatch at 13 Ilgll which is similar to 96-h LC50 values for other aquatic invertebrates. Because of the low sensitivity of the embryo to pesticides, this method may not be a useful pesticide screening test for non-target invertebrates

Use of Desulfovibrio and Escherichia coli Pd-nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil

BACKGROUND Desulfovibrio spp. biofabricate metallic nanoparticles (e.g. ‘Bio-Pd’) which catalyse the reduction of Cr(VI) to Cr(III) and dehalogenate polychlorinated biphenyls (PCBs). Desulfovibrio spp. are anaerobic and produce H2S, a potent catalyst poison, whereas Escherichia coli can be pre-grown aerobically to high density, has well defined molecular tools, and also makes catalytically-active ‘Bio-Pd’. The first aim was to compare ‘Bio-Pd’ catalysts made by Desulfovibrio spp. and E. coli using suspended and immobilised catalysts. The second aim was to evaluate the potential for Bio-Pd-mediated dehalogenation of PCBs in used transformer oils, which preclude recovery and re-use.\ud RESULTS Catalysis via Bio-PdD. desulfuricans and Bio-PdE. coli was compared at a mass loading of Pd:biomass of 1:3 via reduction of Cr(VI) in aqueous solution (immobilised catalyst) and hydrogenolytic release of Cl- from PCBs and used transformer oil (catalyst suspensions). In both cases Bio-PdD. desulfuricans outperformed Bio-Pd E. coli by ~3.5-fold, attributable to a ~3.5-fold difference in their Pd-nanoparticle surface areas determined by magnetic measurements (Bio-PdD. desulfuricans) and by chemisorption analysis (Bio-PdE. coli). Small Pd particles were confirmed on D. desulfuricans and fewer, larger ones on E. coli via electron microscopy. Bio-PdD. desulfuricans-mediated chloride release from used transformer oil (5.6 $\pm$ 0.8 $\mu$g mL-1 ) was comparable to that observed using several PCB reference materials. \ud CONCLUSIONS At a loading of 1:3 Pd: biomass Bio-PdD. desulfuricans is 3.5-fold more active than Bio-PdE. coli, attributable to the relative catalyst surface areas reflected in the smaller nanoparticle sizes of the former. This study also shows the potential of Bio-PdD. desulfuricans to remediate used transformer oil

Wood Preserving Chemicals and Procedures

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Pollutants Biodegradation by Fungi

Revisión sobre los mecanismos de detoxificación de contaminantes por hongosOne of the major problems facing the industrialized world today is the contamination of soils, ground water, sediments, surfacewater and air with hazardous and toxic chemicals. The application of microorganisms which degrade or transform hazardous organic contaminants to less toxic compounds has become increasingly popular in recent years. This review, with approximately 300 references covering the period 2005-2008, describes the use of fungi as a method of bioremediation to clean up environmental pollutants

Adsorption of pentachlorophenol onto activated carbon in a fixed bed : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Environmental Engineering at Massey University

The adsorption of pentachlorophenol (PCP) from water onto granular activated carbon (GAC) was studied. Equilibrium and kinetic behaviour was studied, and the results used to predict fixed bed adsorber behaviour. Batch equilibrium tests showed that the adsorption capacity of activated carbon for PCP is best represented by the Freundlich isotherm, with constants of K = 95 and 1/n = 0.18. Batch adsorption kinetics experiments were conducted in a spinning basket reactor. Surface diffusion and external film transfer coefficients were determined by fitting the homogeneous surface diffusion model (HSDM) to the experimental batch adsorption data. A surface diffusion coefficient value of 2.26 x 10-9cm/s was calculated using this method, which was similar to surface diffusion coefficients for similar compounds found by other investigators. Using equilibrium and kinetic parameters, the HSDM was used to predict bench scale fixed bed adsorber breakthrough curves at varying flow rates. A correlation was used to calculate the film transfer coefficient. There was a good agreement between the experimental breakthrough curves and those predicted by the model. By varying parameters in the model it was found that the adsorption rate in the PCP-activated carbon system was primarily limited by surface diffusion. The homogeneous surface diffusion model was shown to be effective in predicting breakthrough of PCP and could conceivably be used to predict full scale adsorber performance or to aid pilot plant studies

Surface Fluorescence Studies of Tissue Mitochondrial Redox State in Isolated Perfused Rat Lungs

We designed a fiber-optic-based optoelectronic fluorometer to measure emitted fluorescence from the auto-fluorescent electron carriers NADH and FAD of the mitochondrial electron transport chain (ETC). The ratio of NADH to FAD is called the redox ratio (RR = NADH/FAD) and is an indicator of the oxidoreductive state of tissue. We evaluated the fluorometer by measuring the fluorescence intensities of NADH and FAD at the surface of isolated, perfused rat lungs. Alterations of lung mitochondrial metabolic state were achieved by the addition of rotenone (complex I inhibitor), potassium cyanide (KCN, complex IV inhibitor) and/or pentachlorophenol (PCP, uncoupler) into the perfusate recirculating through the lung. Rotenone- or KCN-containing perfusate increased RR by 21 and 30%, respectively. In contrast, PCP-containing perfusate decreased RR by 27%. These changes are consistent with the established effects of rotenone, KCN, and PCP on the redox status of the ETC. Addition of blood to perfusate quenched NADH and FAD signal, but had no effect on RR. This study demonstrates the capacity of fluorometry to detect a change in mitochondrial redox state in isolated perfused lungs, and suggests the potential of fluorometry for use in in vivo experiments to extract a sensitive measure of lung tissue health in real-time