Bioremediation of PAHs - Limitations and soultions

Introduction 1.1 Occurrence of polycyclic aromatic hydrocarbons (PAH) in the environment Worldwide industrial and agricultural developments have released a large number of natural and synthetic hazardous compounds into the environment due to careless waste disposal, illegal waste dumping and accidental spills. As a result, there are numerous sites in the world that require cleanup of soils and groundwater. Polycyclic aromatic hydrocarbons (PAHs) are one of the major groups of these contaminants (Da Silva et al., 2003). PAHs constitute a diverse class of organic compounds consisting of two or more aromatic rings with various structural configurations (Prabhu and Phale, 2003). Being a derivative of benzene, PAHs are thermodynamically stable. In addition, these chemicals tend to adhere to particle surfaces, such as soils, because of their low water solubility and strong hydrophobicity, and this results in greater persistence under natural conditions. This persistence coupled with their potential carcinogenicity makes PAHs problematic environmental contaminants (Cerniglia, 1992; Sutherland, 1992). PAHs are widely found in high concentrations at many industrial sites, particularly those associated with petroleum, gas production and wood preserving industries (Wilson and Jones, 1993). 1.2 Remediation technologies Conventional techniques used for the remediation of soil polluted with organic contaminants include excavation of the contaminated soil and disposal to a landfill or capping - containment - of the contaminated areas of a site. These methods have some drawbacks. The first method simply moves the contamination elsewhere and may create significant risks in the excavation, handling and transport of hazardous material. Additionally, it is very difficult and increasingly expensive to find new landfill sites for the final disposal of the material. The cap and containment method is only an interim solution since the contamination remains on site, requiring monitoring and maintenance of the isolation barriers long into the future, with all the associated costs and potential liability. A better approach than these traditional methods is to completely destroy the pollutants, if possible, or transform them into harmless substances. Some technologies that have been used are high-temperature incineration and various types of chemical decomposition (for example, base-catalyzed dechlorination, UV oxidation). However, these methods have significant disadvantages, principally their technological complexity, high cost , and the lack of public acceptance. Bioremediation, on the contrast, is a promising option for the complete removal and destruction of contaminants. 1.3 Bioremediation of PAH contaminated soil & groundwater Bioremediation is the use of living organisms, primarily microorganisms, to degrade or detoxify hazardous wastes into harmless substances such as carbon dioxide, water and cell biomass Most PAHs are biodegradable unter natural conditions (Da Silva et al., 2003; Meysami and Baheri, 2003) and bioremediation for cleanup of PAH wastes has been extensively studied at both laboratory and commercial levels- It has been implemented at a number of contaminated sites, including the cleanup of the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989, the Mega Borg spill off the Texas coast in 1990 and the Burgan Oil Field, Kuwait in 1994 (Purwaningsih, 2002). Different strategies for PAH bioremediation, such as in situ , ex situ or on site bioremediation were developed in recent years. In situ bioremediation is a technique that is applied to soil and groundwater at the site without removing the contaminated soil or groundwater, based on the provision of optimum conditions for microbiological contaminant breakdown.. Ex situ bioremediation of PAHs, on the other hand, is a technique applied to soil and groundwater which has been removed from the site via excavation (soil) or pumping (water). Hazardous contaminants are converted in controlled bioreactors into harmless compounds in an efficient manner. 1.4 Bioavailability of PAH in the subsurface Frequently, PAH contamination in the environment is occurs as contaminants that are sorbed onto soilparticles rather than in phase (NAPL, non aqueous phase liquids). It is known that the biodegradation rate of most PAHs sorbed onto soil is far lower than rates measured in solution cultures of microorganisms with pure solid pollutants (Alexander and Scow, 1989; Hamaker, 1972). It is generally believed that only that fraction of PAHs dissolved in the solution can be metabolized by microorganisms in soil. The amount of contaminant that can be readily taken up and degraded by microorganisms is defined as bioavailability (Bosma et al., 1997; Maier, 2000). Two phenomena have been suggested to cause the low bioavailability of PAHs in soil (Danielsson, 2000). The first one is strong adsorption of the contaminants to the soil constituents which then leads to very slow release rates of contaminants to the aqueous phase. Sorption is often well correlated with soil organic matter content (Means, 1980) and significantly reduces biodegradation (Manilal and Alexander, 1991). The second phenomenon is slow mass transfer of pollutants, such as pore diffusion in the soil aggregates or diffusion in the organic matter in the soil. The complex set of these physical, chemical and biological processes is schematically illustrated in Figure 1. As shown in Figure 1, biodegradation processes are taking place in the soil solution while diffusion processes occur in the narrow pores in and between soil aggregates (Danielsson, 2000). Seemingly contradictory studies can be found in the literature that indicate the rate and final extent of metabolism may be either lower or higher for sorbed PAHs by soil than those for pure PAHs (Van Loosdrecht et al., 1990). These contrasting results demonstrate that the bioavailability of organic contaminants sorbed onto soil is far from being well understood. Besides bioavailability, there are several other factors influencing the rate and extent of biodegradation of PAHs in soil including microbial population characteristics, physical and chemical properties of PAHs and environmental factors (temperature, moisture, pH, degree of contamination). Figure 1: Schematic diagram showing possible rate-limiting processes during bioremediation of hydrophobic organic contaminants in a contaminated soil-water system (not to scale) (Danielsson, 2000). 1.5 Increasing the bioavailability of PAH in soil Attempts to improve the biodegradation of PAHs in soil by increasing their bioavailability include the use of surfactants , solvents or solubility enhancers.. However, introduction of synthetic surfactant may result in the addition of one more pollutant. (Wang and Brusseau, 1993).A study conducted by Mulder et al. showed that the introduction of hydropropyl-ß-cyclodextrin (HPCD), a well-known PAH solubility enhancer, significantly increased the solubilization of PAHs although it did not improve the biodegradation rate of PAHs (Mulder et al., 1998), indicating that further research is required in order to develop a feasible and efficient remediation method. Enhancing the extent of PAHs mass transfer from the soil phase to the liquid might prove an efficient and environmentally low-risk alternative way of addressing the problem of slow PAH biodegradation in soil.

Analysis of Manganese nodules from Sonne cruises SO06/1 and /2, "Hawaii-Tahiti-Transect", Teilprojekt ICIME

Manganese nodules research has focused on the area between the Clarion Fracture Zone to the North and the Clipperton Fracture Zone to the South where significant concentrations were found ni Ni-Cu. During the CCOP/SOPAC-IOC/IDOE International workshop on the "Geology Mineral Resources and Geophysics of the South Pacific" held in Fiji in September 1975, a working group on manganese nodules was formed by scientists from: CNEXO, Brest, the Institute of Oceanography, New Zealand, Imperial College, London and the Technical University of Aachen. A draft project was presented in July 1976 by J. Andrews, University of Hawaii and G. Pautot, Cnexo on a joint survey under the name of: "Hawaii-Tahiti Transect program". Further details were worked on in September 1976 during the International Geological Congress in Sydney with the participation of D. Cronan, Imperial College, Glasby, New Zealand Geological Survey and G. Friedrich, Aachen TU. The scientific final program was established in July 1977, planning on the participation of three research vessels: the Suroit (CNEXO), the Kana Keoki (U. of Hawaii) and the Sonne (Aachen TU). Several survey areas were selected across the Pacific Ocean (Areas A, B, C, D, E, F, G and H) with about the same crustal age (about 40 million years) and a similar water depths. Being near large fault zones, the ares would be adequate to study the influences of biological productivity, sedimentation rate and possibly volcanic activity on the formation and growth of manganese nodules. The influnece of volcanic activity study would particularly apply to area G being situated near the Marquesas Fracture Zone. The cruise from R/V Sonne started in August 1978 over areas C, D, F, G K. The R/V suroit conducted a similar expedition in 1979 over areas A, B, C, D, E, H and I. Others cruises were planned during the 1979-1980 for the R/V Kana Keoki. The present text relates the R/V Sonne Cruises SO-06/1 and SO-06/2 held within the frame work of this international cooperative project.

[Colección de fotografías sobre la ciudad de Valencia (1914 a 1930) [ [Material gráfico].]

[27]. Pasadizo que une la Catedral con el Palacio Arzobispal de Valencia en la calle de la Barcella, 1917 (1 par estereoscópico) (1 fot.) -- [28]. Puerta románica de la Catedral de Valencia, 1917 (1 par estereoscópico) (1 fot.) -- [29-30]. Fuente monumento al Márques de Campo situado en la plaza Emilio Castelar, 1917 (3 pares estereoscópicos) (2 fot.) -- [31]. Patio interior sin identificar, un hombre y un policia (1 par estereoscópico) (1 fot.) -- [32]. Estatua ecuestre de Don Jaime I El Conquistador en el Parterre, 1917 (1 par estereoscópico) (1 fot.) -- [32 A y B]. Máximo López Roglá en el Parterre (2 par estereoscópico) (2 fot.) -- [33-35]. Nieve en Valencia, en la alameditas de Serranos, niños jugando con la nieve en la Glorieta, 30-12-1917 (3 pares estereoscópicos) (3 fot.) -- [36-38]. Claustro del Patriarca con la escultura del Beato Juan de Ribera, en una de las fotos un grupo de seminaristas, 1917 (5 pares estereoscópicos) (3 fot.) -- [39-40]. Museo del Patriarca de Valencia, relicarios, Cruz Patriarcal (2 pares estereoscópicos) (2 fot.) -- [41-48]. Antiguo Hospital Padre Jofré, acceso desde la calle, patio de entrada y estatua del Padre Jofré, pórtico del Real Monasterio de la Santísima Trinidad, miembros de la Congregación de la Inmaculada y San Luís, los congregantes con los enfermos en el patio del hospital, 1913 (8 pares estereoscópicos) (8 fot.) -- [49]. Estandarte de la Academia Valencianista del Centro Escolar y Mercantil, 1917 (1 par estereoscópico) (1 fot.) -- [50-51].Miembros de la Congregación de la Inmaculada y San Luís y de la Academia Valencianista del Centro Escolar y Mercantil (calle libreros 2) junto a la falla, en una de las fotos llevan el estandarte de la Academia (2 pares estereoscópicos) (2 fot.) -- [52]. Sede de la Academia Valencianista del Centro Escolar y Mercantil (2 pares estereoscópicos) (1 fot.) -- [53-69]. Fallas, año 1917 (21 pares estereoscópicos) (14 fot.) -- [70]. Mercado de Colón, carruaje con caballo junto a la puerta principal, 1917 (1 par estereoscópico) (1 fot.) -- [71]. Palacio de la Exposición, 1917 (1 par estereoscópico) (1 fot.) -- [72-87]. Los Jardines de Viveros: ruinas en primer plano al fondo la torre del Palacio de Ripalda, jaulas de los pájaros, Francisco Roglá López en Viveros, Isabel Orrico Vidal con sus hijos y las niñeras en Viveros en distintos situaciones y contemplando el estanque con el Museo de San Pío V al fondo, 1922 (19 pares estereoscópicos) (17 fot.) -- [88-90]. La Hípica (5 pares estereoscópicos) (3 fot.) -- [91-94]. Jugando al tenis en un campo habilitado para el tenis entre pinos (8 pares estereoscópicos) (4 fot.) -- [95-97]. El Puerto de Valencia, 1921 (4 pares estereoscópicos) (3 fot.) -- [98-104]. Llegada al puerto de Valencia de cuatro submarinos, entre ellos el submarino Monturiol, escoltados por torpederos y acompañados por el buque de salvamento Canguro, 8 de septiembre de 1921 (7 pares estereoscópicos) (7 fot.) -- [105-107A-D]. Playa y Balneario de las Arenas: un hombre y tres mujeres patinando en las Arenas; Isabel Orrico Vidal (izquierda), Ignacio Roglá Orrico (bebe) en brazos de Pilar (la niñera de Chiva), Manolo Orrico Vidal con su mujer Mercedes Gay, la niñera con Luisito Roglá Orrico, los niños más mayores son Merceditas Orrico Gay y Paquito Roglá Orrico; en las Arenas a la izquierda de la foto Ignacio Roglá Orrico (bebe), Ana María Rodríguez Gay, Paquito Roglá Orrico, Manolo Orrico Vidal, Merceditas Orrico Gay, en el centro Mercedes Gay Lloveras (sentada) y Gonzalo Rodríguez Gay, a la derecha Gonzalo Rodríguez, Ana Gay Lloveras, Isabel Orrico Vidal con Luisito Roglá Orrico y Francisco Roglá López (6 pares estereoscópicos) (6 fot.) -- [109]. En la playa de la Malvarrosa barca tirada por bueyes, 1922 (1 pares estereoscópicos) (1 fot.) -- [110-117]. Fiesta de la Virgen de los Desamparados, tapíz de flores con la imagen de la Virgen colocada en el retablo de flor, salida de la Virgen de la Basílica en el traslado a la Catedral, salida de la Virgen de la Catedral para la procesión de la tarde (9 pares estereoscópicos) (7 fot.) -- [118-120]. Carroza del MArqués de Llanera (actualmente en el Museo Nacional de Cerámica y Artes Suntuarias "González Martí" por la calle Carniceros esquina con la calle Arolas, vista lateral de la carroza, procesión del Corpus? (5 pares estereoscópicos) (3 fot.) -- [121-122]. Gigantes y Cabezudos junto a la Catedral, Fiesta del Corpus (2 pares estereoscópicos) (2 fot.) -- [123]. Isabel Orrico Vidal en el balcón del nº 11 de la calle de la Paz (1 par estereoscópico) (1 fot.) -- [124]. Procesión del domingo de Ramos (1 par estereoscópico) (1 fot.) -- [125-136]. Desfile del cortejo fúnebre por la calle (de la Paz?) de los restos de Sorolla el 13 de agosto de 1923 (16 pares estereoscópicos) (10 fot.) -- [137]. Detalle de la fuente de la Alameda (1 par estereoscópico) (1 fot.) -- [138-139]. Francisco Roglá López con su caballo en la Alameda, carruaje por la Alameda (2 pares estereoscópicos) (2 fot.) -- [140-143]. Jura de bandera en la Alameda (4 pares estereoscópicos) (4 fot.) -- [144A, B, C, D, E]. Fuente con estatua de la Alameda, José Roglá López leyendo el periódico junto a la fuente, con un grupo de amigos, grupo de amigos y un barquillero en el Paseo de la Alameda, José Roglá López con unos amigos en una fuente de la Alameda que ahora está en el barrio del Carmen (5 fot.) -- [145]. Grupo de coches de la época en la plaza de la Virgen (1 fot.) -- [146A, B]. Pareja de novios saliendo de la Basílica de la Virgen? (2 pares estereoscópicos) (2 fot.) -- [147-148]. Niños de la Asociación de San Vicente Ferrer que representan los milagros en los altares (2 pares estereoscópicos) (2 fot.) -- [149-150]. Actos festivos, dos mujeres llevando una bandera con gente alrededor (2 fot.) -- [151-152]. Plaza de toros de Valencia, 1930 (2 fot.) -- [153]. Rosalía Roglá López con su abuela materna en el piso de la calle Liñán nº 3, a través de los cristales se ve el edificio de la Lonja (1 par estereoscópico) (1 fot.) -- [154]. Rosalía Roglá López en el balcón de su piso de la calle Liñán nº 3, al fondo a la izquierda se ve la plaza del mercado y la Lonja (1 par estereoscópico) (1 fot.) -- [155]. José Roglá López de pié junto a la ventana leyendo un periódico (1 fot.) -- [156-157]. Isabel Orrico Vidal en la Alameditas de Serranos, al fondo el Museo San Pío V (2 fot.) -- [158-159]. Ignacio Roglá Orrico, Luís Roglá Orrico y Francisco Roglá Orrico sentados en un banco en la Glorieta, los tres niños junto al monumento al Dr. Gómez Ferrer de la Glorieta, 1928 (2 fot.) -- [160-161]. Ignacio Roglá Orrico, Luís Roglá Orrico en el jardín de los Viveros, los dos niños con Paco bebiendo en una fuente de Viveros junto al estanque, 1929 (2 fot.) -- [162]. Grupo familiar sentado en el jardín de los Viveros, Manolo Orrico Gay, Manolo Orrico Vidal, Luís Roglá Orrico, Isabel Orrico Vidal, Mercedes Gay Lloveras y Mercedes Orrico Gay, 1930 (1 par estereoscópico) (1 fot.) -- [163]. Isabel Orrico Vidal junto a Luís Roglá Orrico en bicicleta en el jardín de los Viveros, 1930 (1 par estereoscópico) (1 fot.) -- [164]. Manolo Orrico Gay y Luís Roglá Orrico (detrás) en bicicleta por el jardín de los Viveros (1 par estereoscópico) (1 fot.)

Studia critica in C. Lucilium poetam.

Mode of access: Internet.

C. Lucilii Carminum reliquiae /

Frontispiece of volume 2 is portrait of Janus Dousa.

Coniectanea critica ad C. Lucilii librorum decadem primam /

Mode of access: Internet.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Pseudodifferential operators with C*-algebra-valued symbols: Abstract characterizations

Given a separable unital C*-algebra C with norm parallel to center dot parallel to, let E-n denote the Banach-space completion of the C-valued Schwartz space on R-n with norm parallel to f parallel to(2)=parallel to < f, f >parallel to(1/2), < f, g >=integral f(x)* g(x)dx. The assignment of the pseudodifferential operator A=a(x,D) with C-valued symbol a(x,xi) to each smooth function with bounded derivatives a is an element of B-C(R-2n) defines an injective mapping O, from B-C(R-2n) to the set H of all operators with smooth orbit under the canonical action of the Heisenberg group on the algebra of all adjointable operators on the Hilbert module E-n. In this paper, we construct a left-inverse S for O and prove that S is injective if C is commutative. This generalizes Cordes' description of H in the scalar case. Combined with previous results of the second author, our main theorem implies that, given a skew-symmetric n x n matrix J and if C is commutative, then any A is an element of H which commutes with every pseudodifferential operator with symbol F(x+J xi), F is an element of B-C(R-n), is a pseudodifferential operator with symbol G(x - J xi), for some G is an element of B-C(R-n). That was conjectured by Rieffel.

Structural and physicochemical characterization of RS prepared using hydrolysis and heat treatments of chickpea starch

The aim of this study was to evaluate the production and the structural and physicochemical properties of RS obtained by molecular mass reduction (enzyme or acid) and hydrothermal treatment of chickpea starch. Native and gelatinized starch were submitted to acid (2 M HCl for 2.5 h) or enzymatic hydrolysis (pullulanase, 40 U/g per 10 h), autoclaved (121 degrees C/30 min), stored under refrigeration (4 degrees C/24 h), and lyophilized. The hydrolysis of starch increased the RS content from 16% to values between 20 and 32%, and the enzymatic treatment of the gelatinized starch was the most efficient. RS showed an increase in water absorption and water solubility indexes due to hydrolytic and thermal process. The processes for obtaining RS changed the crystallinity pattern from C to B. Hydrolysis treatments caused an increase in relative crystallinity due to the greater retrogradation caused by the reduction in MW. RS obtained from hydrolysis showed a reduction in viscosity, indicating the rupture of molecules. The viscosity seemed to be inversely proportional to the RS content in the sample.

Preservation of Phakopsora pachyrhizi uredospores

This study compared different temperatures and dormancy-reversion procedures for preservation of Phakopsora pachyrhizi uredospores. The storage temperatures tested were room temperature, 5 degrees C, -20 degrees C and -80 degrees C. Dehydrated and non-dehydrated uredospores were used, and evaluations for germination (%) and infectivity (no. of lesions/cm(2)) were made with fresh harvested spores and after 15, 29 76, 154 and 231 days of storage. The dormancy-reversion procedures evaluated were thermal shock (40 degrees C/5 min) followed or not by hydration (moist chamber,24 h). Uredospores stored at room temperature were viable only up to a month of storage, regardless of their hydration condition. Survival of uredospores increased with storage at lower temperatures. Dehydration of uredospores prior to storage increased their viability, mainly for uredospores stored at 5 degrees C, -20 degrees C and -80 degrees C. At 5 degrees C and -20 degrees C, dehydrated uredospores showed increases in viability of at least 47 and 127 days, respectively, compared to non-dehydrated spores. Uredospore germination and infectivity after storage for 231 days (7.7 months), could only be observed at -80 degrees C, for both hydration conditions. At this storage temperature, dehydrated and non-dehydrated uredospores exhibited 56 and 28% of germination at the end of the experiment, respectively. Storage at -80 degrees C also maintained uredospore infectivity, based upon levels of Infection frequency, for both hydration conditions. Among the dormancy-reversion treatments applied to spores stored at -80 degrees C, those involving hydration allowed recoveries of 85 to 92% of the initial germination.