Biodegradability of imidazolium ionic liquids

Biodegradability of imidazolium ionic liquids

Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576 microorganisms, 2) it is wide-spread in nature and thus it is lowcost. The dimension...

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Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576

microorganisms, 2) it is wide-spread in nature and thus it is lowcost. The dimensionless mathematical model of the process was developed and implemented in the COMSOL Multiphysics programming environment. The model consists of mass balances of a substrate, which enables the fungal growth, and the dye, which is to be degraded, in the fungal biofilm and in the wastewater. The biofilm is modeled as a two dimensional domain while the liquid film is represented by a boundary condition. The biomass growth, decay and erosion are also considered. Numerical results are compared with experimental data measured in a lab-scale trickle-bed bioreactor and the results are discussed. Many various mathematical models of biofilms were created, but they mostly deal with bacterial biofilms. Our mathematical model is endeavoring to describe the performance of the fungal biofilm trickle-bed reactor in such an easy way as possible but keeping the necessary degree of complexity. doi:10.1016/j.jbiotec.2010.09.171 [P-E.150] Evaluation of performance charcteristics in an anaerobic baffled-fixed film reactor (ABFFR) treating palm oil mill effluent Vassanasak Limkhuansuwan 1 , Chinnapong Wangnai 2 , Pawinee Chaiprasert 3,∗ 1 King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand 2 King Mongkut’s University of Technology Thonburi (Bangkhuntien)), Bangkok 10150, Thailand 3 King Mongkut’s University of Technology Thonburi (Bangkhuntien)), Bangkok 10150, Thailand Keywords: Baffle compartment; Hybrid baffled - fixed film reactor; Hydrolysis; Methanogenesis; Palm oil mill effluent

The anaerobic baffled-fixed film reactor (ABFFR) in this study was designed for enhancing the biodegradation of high suspended solid (SS) and organic matter in palm oil mill effluent (POME). An ABFFR was developed by a baffled process combined with plastic nets fitted inside the last fourth compartment of reactor. The most significant advantages of the ABFFR is solid retention time (SRT) longer than hydraulic retention time (HRT) and its ability to separate anaerobic digestion stage in the reactor. POME containing high concentration of COD (65,120 ± 1,000 mgl-1 ) and SS (21,060 ± 550 mgl-1 ) was semi-continuously upflow fed at 1.2 l d-1 . The reactor was operated within ambient temperature at 20 days hydraulic retention time and 3.2 kgCOD m-3 d-1 organic loading rate. The reactor was run to 5 cycles of HRT at 112 d of operation. The performance characteristics in term of hydrolysis of SS, COD reduction, VFA spectrum, biogas and methane production was investigated in each compartment and overall reactor. The overall performance of ABFFR in term of COD and SS removal were 90% and 80%, respectively with methane production of 6.9 l d-1 . The performance characteristics of the first to third baffle compartment act as hydrolysis and fermentation chamber for suspended organic matter at reduction of cellulose 59, 5 and 9%, respectively while that of hemicellulose 55, 4 and 13%, respectively and lignin 38, 5 and 8%, respectively. pH was in acidic range of 4.5-5.0. Acetate was major found and followed by butyrate and propionate in three compartments. The fourth compartment acts as methanogenic chamber with pH of 7.7 and less volatile fatty acids accumulation. The soluble COD removal was 90%. High biogas and methane production was found. Biogas and methane yield were 0.45-0.53 and 0.3-0.38 m3 kg-1 soluble COD removed. These results show

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that ABFFR enhance the SS degradation and biogas production for POME. doi:10.1016/j.jbiotec.2010.09.172 [P-E.151] DNA damage on crocodylus moreletti from an urban lake, exposure to metals at southern gulf of Mexico M.T. Gamboa Rodriguez 1,∗ , J.R. Gamboa Aldeco 1 , L. Saldivar Osorio 1,2 1

Universidad Juarez Autónoma de Tabasco, Mexico Universidad Nacional Autónoma de México, Mexico Keywords: genotoxicity; comet assay; crocodylus; Lead 2

At the southern Gulf of México, some crocodile populations have been decreasing their number due to anthropogenic pressures to their habitat. A continuous inlet of pollutants to their aquatic ecosystems, like municipal waste and pluvial waters carrying particulate and oil deposited by auto motors, with risk to health and reproduction capabilities of individuals. Genotoxic effect of environmental metals (like lead)on the DNA of a wild Crocodylus moreletii population of an urban, in order to establish subpopulations or individuals at risk. In the present study we determined lead concentration in 28 blood samples and 20 dermal plates from crocodiles. Samples, their respective blanks and standards were analyzed by triplicate with an A.A. spectrometer (Perkin Elmer 2380) with graphite furnace. DNA strands brakes were evaluated with the Single cell electrophoresis assay on peripheral blood leucocytes of wild individuals taken from the lake and compared to a control group from a reproduction farm. DNA migration from the nucleus measured in ␮m was from 19.5 up to 49.88 and from 0 up to 35 in the wild and control groups respectively. DNA migration was reported as the Tail/head ratio. Wild group presented a mean value of 1.6 + 0.10, while control group was 0.4 + 0.16.The difference was statistically significant (p < 0.05). Lead in blood samples were from 6.55 up to 15.34 ␮g/dl with a mean of 12.01 ± 1.6 ␮g/dl. Mean Blood Lead concentration was slightly higher in wild organisms (12.01 ± 1.6 ␮g/dl) than organisms from a crocodile farm (8.15 ± 1.7 ␮g/dl),however this was not statistically significative (p < 0.05).Lead concentration in dermal plates was from 4.2 up to 55.29 ppm with a mean value of 22.62 ± 3.2 ppm. level of damage evaluated on wild animals were medium to high. Crocodylus population in this natural habitat is impacted in their genetic material by urban activities. doi:10.1016/j.jbiotec.2010.09.173 [P-E.152] Biodegradability of imidazolium ionic liquids E. Liwarska-Bizukojc ∗ , I. Doniec Technical University of Lodz, Poland Keywords: biodegradability; imidazolium; ionic liquid Introduction: Ionic liquids (ILs) due to their unique physicochemical properties including negligible volatility and nonflammability are believed as potential substitutes of conventional organic solvents. In this study biodegradability of three imidazolium ILs of different length (from C2 to C10) of alkyl chain substituents were tested. Methods: The object of investigation were the following ILs: 1 ethyl-3-methylimidazolium bromide ([C2mim][Br]), 1-hexyl-

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Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576

3-methylimidazolium bromide ([C6mim][Br]) and 1-decyl-3methyimidazolium bromide ([C10mim][Br]). The biodegradability of ILs was evaluated with the use of the Closed Bottle Test (OECD 301D). Two series of this test were performed. In each of them different inocula were applied so as to make the results more reliable. The series were made for each ionic liquid individually in triplicate. Sodium dodecyl sulphate (SDS) was used as a reference substance. Results: All tested ILs occurred to be poorly biodegradable. Their biodegradability increased slightly with time, however it did not reach the required level of 60%. Compounds which exceed this level of biodegradability are classified as readily biodegradable. Finally, after 28 days the degree of biodegradation of two tested ILs, i.e. [C2mim][Br] and [C6mim][Br] was in the range of 8-9%, while for the third one it was higher and equal to 26.4% on average. The degree of biodegradation of SDS was equal to 85% already after 14 days. Discussion: The results of the biodegradability tests indicate that calling ILs as “green solvents” referring to their biodegradability is discussable. Poor biodegradability of ILs has been already found (Gatherhood et al., 2004; Docherty et al., 2007; Romero et al., 2008). However, an influence of alkyl chain length on biodegradability was not thoroughly investigated. The several studies performed in this area led to divergent conclusions. On the one hand, ILs with longer chain length are more toxic to microorganisms, what can inhibit biodegradation processes. On the other hand, the longer alkyl chain can be more accessible to bacteria and as a result of its degradation more acetyl-CoA and subsequently more ATP is formed. The results obtained in this work unequivocally indicate that the longer length of alkyl chain substituent does not decrease the biodegradability of imidazolium ILs with bromide anion. References Docherty, K.M., Dixon, J.k., Kulpa, Ch.F., 2007. Biodegradation of imidazolium and pyridinium ionic liquids by an activated sludge microbial community. Biodegradation 18, 481–493. Gatherhood, N., Garcia, M.T., Scammells, P., 2004. Biodegradable ionic liquids:Part I. conept, preliminary targets and evaluation. Green Chem. 6, 166–175. Romero, A., Santos, A., Tojo, J., Rodriguez, A., 2008. Toxicity and biodegradability of imidazolium ionic liquids. J. Haz. Mat. 151, 268–273.

doi:10.1016/j.jbiotec.2010.09.174 [P-E.153] The effect of the symbiosis between Tagetes erecta L. and Glomus intraradices in copper(II) uptake: the implication for phytoremediation Omar Surisadai Castillo ∗ , Nabanita Dasgupta-Schubert, Carlos Juan Alvarado, Esther Magdalena Zaragoza, Hector Javier Villegas University of Michoacan, Mexico Keywords: Tagetes erecta; Glomus intraradices; Copper; Phytoremediation Excessive use of fertilizers and other anthropogenic activities have gradually accumulated micronutrients such as copper in soils. Phytoremediation is an environmental biotechnology that seeks to remediate pollution caused by bioaccumulative toxins like Cu. It is known that symbiotic mycorrhizal associations can increase the uptake and delivery of low mobility nutrients and micronutrients, to the host plant because they solubilize nutrients and increase their catchment area. To analyze the effect of mycorrhizae on the phytoaccumulation of Cu, we studied their ability to solubilize Cu(II) and enhance its absorption by the plant Tagetes erecta L. colonized with the arbuscular mycorrhizal fungus Glomus intraradices. Plants were grown for 9 weeks in a growth chamber

under controlled conditions of temperature, relative humidity and photoperiod. Cu concentrations in the substrate were 0, 500, 1000, 1500, 2000 and 2500 mg.kg-1 in the insoluble form of CuO to simulate the insoluble Cu-O bonded species in soil. The biotic and abiotic parameters of colonization, foliar area, biomass, pH of lixiviates and plant biometrics were determined as functions of the Cu concentration that was measured in the roots, shoots and lixiviates by Atomic Absorption Spectrometry. The results of Cu absorption showed that colonized plants accumulated more Cu in the roots and all plants displayed the typical behavior of Cu excluders. However in mycorrhizal plants, it appears that G. intraradices increases plant tolerance to Cu(II). On the other hand, the evaluation of the colonization of roots inoculated with G. intraradices showed that with increasing concentration of Cu in the substrate, a proliferation of vesicles develop. These results suggest that G. intraradices possibly accumulates Cu in its vesicles thereby enhancing the Cu tolerance of T. erecta even while increasing root Cu accumulation. Finally the parameters Bioconcentration Factor and Translocation Factor suggest that the system T. erecta-G. intraradices can potentially phytostabilize Cu. doi:10.1016/j.jbiotec.2010.09.175 [P-E.154] Influence of initial C/N ratio on composting of coir pith Sudarut Tripetchkul ∗ , Kanokwan Pundee, Songpon Khunsrisuk, Saengchai Akeprathumchai King Mongkut’s University of Technology Thonburi, Thailand Keywords: Coir pith; composting; C/ N ratio; cow manure; coconut juice Coir pith and coconut juice are produced as by-products in large quantity annually from coconut processing industries of which small portion has been efficiently utilized. This study proposed to add-value to coir pith and coconut juice by composting. Generally, coir pith is a significant source of carbon; however, small amount of nitrogen needs to be supplemented to accelerate biodegradation of organic matter in the compost pile. This study aims at investigating the influence of cow manure addition on coir pith composting together with rice bran and molasses using coconut juice as nutrient supplement and moisture adjusting agent. Three composting experiments designated as Treatment 1, 2 and 3, corresponding to the C/N rations of 30, 25 and 20, respectively, were conducted. Physical and chemical parameters were monitored throughout composting process. Results showed that, for all treatments, physical changes in terms of color, odor and texture, and pH appeared to be of similar trend. Additionally, during a thermophilic phase, the temperature within the compost piles reached the highest value of approximately 56-58 o C remaining for 5-7 days which ensured sanitary, in other words, eliminating pathogenic microorganisms. Considering the chemical changes in terms of organic matter and nitrogen losses, Treatment 2 containing 50% cow manure showed the highest biodegradation rate constant of organic mater (k = 0.309 day-1 ) and the highest N losses (41.9%) whereas Treatment 1 containing 34% cow manure showed the lowest N loss (-7.3%). All treatments appeared to reach maturity after 1 month composting. However, considering the amount of waste to be treated, compost containing higher initial C/N ratio (30) led to the highest amount of coir pith and coconut juice utilized, approximately 60 and 190 kg,