Estimation of bioavailability of polycyclic aromatic hydrocarbons in river sediments

Froehner, Sandro; Dombroski, Luiz Fernando; Machado, Karina Scurupa; Fernandes, Cristóvão Scapulatempo; Bessa, Marcelo Rodrigues

doi:10.1007/s13762-012-0069-z

Cited by 11 publications

(4 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the investigated soil had a rather high content of organic C (over 5 %), its decontamination by SBO assisted soil washing was rather challenging. According to previous work (Froehner et al 2012b), soil and sediments with high organic carbon content have higher capacity to retain PAHs. Under these circumstances, to accomplish the two above objectives, the reported experimental plan was designed to establish source-product performance relationships and to develop a two steps process, comprising soil washing and secondary treatment of the recovered washing solution.…”

Section: Introductionmentioning

confidence: 80%

Urban wastes to remediate industrial sites: a case of polycyclic aromatic hydrocarbons contamination and a new process

Montoneri

Tomasso

Colajanni

et al. 2013

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

The objective of the present paper was to investigate the potential of urban wastes derived soluble bioorganic substances (SBO) to perform as auxiliaries for enhanced washing of urban soil contaminated by industrial activities. The second objective was to show how the SBO could be used for remediating the environmental impact caused by industrial activities and, at the same time, be compatible with the real-world situation demanding zero waste processes. The SBO, isolated from four urban biowastes, were characterized for their lipophilic/hydrophilic (LH) and aliphatic/aromatic C ratios, and for their surface activity properties. Soil, containing about 0.45 % w/w polycyclic aromatic hydrocarbons (PAHs), was sampled from a dismissed coal gasification site. The efficiency of the SBO for washing the contaminated soil was investigated. The most lipophilic SBO, in spite of the highest surface activity, was the least efficient. The products having lower LH, poorer surface activity, but higher concentration of aromatic C were more efficient. All SBO allowed developing a two steps process. This comprised soil washing, and the recovery and chemical treatment of the washing solution, to yield a PAHs-SBO precipitate and the clean water phase to recycle to further soil washing. Data were obtained under the same experimental conditions using Triton X-100 commercial surfactant. The results indicated that, although the commercial surfactant is the most efficient in the soil washing step, it does not allow removal of PAHs from the recovered washing solution. On the contrary, 95-99 % PAHs removal from the recovered SBO washing solutions is attained.

show abstract

Section: Introductionmentioning

confidence: 80%

Urban wastes to remediate industrial sites: a case of polycyclic aromatic hydrocarbons contamination and a new process

Montoneri

Tomasso

Colajanni

et al. 2013

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Numerous abiotic and biotic factors can influence the biodegradation processes . For example, PAH solubility and bioavailability increase with decreasing logKow and, therefore, PAH with low logKow tend to be removed faster by microorganisms than more hydrophobic ones (Froehner et al, 2012), which is consistent with our observations in the Mediterranean. In addition, higher temperatures increase the solubility of PAH molecules, making them more bioavailable for microbial organisms uptake and metabolism.…”

Section: Pah Biodegradationsupporting

confidence: 92%

Biodegradation of polycyclic aromatic hydrocarbons in the surface ocean

Varela¹

View full text Add to dashboard Cite

Increasing quantities of organic pollutants (OP) are being released to the environment, posing a threat to Earth’s life system. In the marine environment, OP pollution caused by oil spill accidents receives a lot of academic and societal attention. However, the magnitude of semi-volatiles OP introduced by atmospheric deposition and by maritime currents is orders of magnitude larger. Little is known, however, about the cycling of these background OP in the oceans and their effects to marine ecosystems. It is believed that an important sink of OP in the marine environment must be microbial biodegradation, since it is widely recognized their capacity to consume many OPs. However, neither the magnitude of biodegradation, the identity of the main degraders nor OP effects to microorganisms, is known. Polycyclic aromatic hydrocarbons (PAH) and other semi-volatile hydrocarbons are among the most abundant OP in the marine environment. Their wide spectrum of physicochemical properties make PAH family an ideal surrogate to study the biogeochemistry of OP in seawater. This thesis focuses on the biodegradation activities under background concentrations of PAH in the upper ocean, and the co-occurring microbial responses to this exposure. The goals of this work are: 1) to get insights into microbial PAH biodegradation under realistic conditions in different upper ocean environments by means of biogeochemical, molecular and genomic approaches, 2) identify the main players and describe the main metabolisms co-occurring along with biodegradation in the interaction between PAH and microorganisms by means of physiological measurements and metatranscriptomic approaches, and 3) localize marine hot spots of PAH biodegradation and describe some of the main physicochemical influencing factors of biodegradation. For these purposes we did short term incubations with background concentrations of PAH, mimicking those conditions found in the surface ocean in several oceanic provinces with contrasted physicochemical conditions. We used molecular biology and analytical chemistry techniques to calculate biodegradation taxes and evaluate the changes in the composition and genetic expression profiles of microbial communities exposed to PAH ambient levels. We found that PAH microbial metabolic capacity is a widespread trait in the global upper ocean although PAH biodegradation rates span in a wide range of values. These findings strongly suggest a fundamental role of microbial degradation as a relevant driver of PAH fate in the upper ocean. We observed that PAH at background concentrations after short term exposure (24-48 hrs) had an impact on microbial communities compositions and functionality. The main taxa responsible for PAH biodegradation at background concentrations varied depending on the site and the habitat, and included many different groups. The battery of genes expressed during PAH exposure included PAH degrading genes plus genes involved in stress response and detoxifying strategies among others. Comparison of results from the different sites identified new environmental drivers affecting the efficiency of PAH biodegradation in the upper ocean beyond those already described and those that are commonly overlooked: bacterial life-style (PA vs free-living), microbial community pre-exposure history to organic pollutants and the habitat (specially the SML). Overall, this thesis adds new information and field-based evidence regarding the microbial controls over the fate and transport of the background PAH concentrations in the surface ocean. In a context of increasing emissions and global change, it becomes crucial to be able to forecast the fate of OP once in the ocean. This requires understanding at a mechanistic level how do microbial metabolic processes and the pool of OP in the ocean intertwine, in order to elucidate a more updated, and always evolving, global carbon cycle. Quantitats creixents de contaminants orgànics (CO) s’alliberen al medi ambient, cosa que suposa una amenaça per al sistema de vida de la Terra. En el medi marí, la contaminació causada per vessaments de petroli accidentals rep molta atenció tant acadèmica com social. No obstant això, la magnitud de la contaminació per CO semi-volàtils que arriba als oceans de manera difusa és ordres de magnitud més gran en comparació als vessaments accidentals. Actualment hi ha poca informació sobre el cicle d'aquests CO a la columna d’aigua i sobre quins són els efectes que causen sobre els ecosistemes marins. Es creu que un destí important dels CO al medi marí són els processos de biodegradació per part dels microorganismes, ja que és àmpliament reconeguda la seva capacitat per consumir molts CO. Tanmateix, no es coneix ni la magnitud de la biodegradació ni la identitat dels principals degradadors, ni tampoc els efectes dels CO als microorganismes. Els hidrocarburs aromàtics policíclics (HAP) i altres hidrocarburs semi-volàtils es troben entre els CO més abundants en el medi marí. L’ampli espectre de propietats fisicoquímiques dels HAP els converteixen en un model ideal per estudiar la biogeoquímica dels CO a l'aigua de mar. Aquesta tesi es centra en les activitats de biodegradació sota concentracions ambientals realistes de HAP a les aigües marines superficials i les respostes microbianes concomitants a aquesta exposició. Els objectius d'aquest treball són: 1) explorar la biodegradació microbiana de HAP en condicions realistes en diferents entorns d’aigües superficials marines mitjançant tècniques biogeoquímiques, moleculars i genòmiques, 2) identificar els principals actors de la degradació i descriure els principals metabolismes que coexisteixen juntament amb la biodegradació mitjançant mesures fisiològiques i tècniques metatranscriptòmiques i 3) localitzar “punts calents” de biodegradació de HAP en hàbitats marins i descriure alguns dels principals factors fisicoquímics que influeixen en la biodegradació. Per tal d’assolir els objectius, hem realitzat incubacions de curta durada amb aigua superficial marina amb nivells de HAP ambientals, imitant les concentracions que es troben a l'oceà superficial en diverses províncies oceàniques i amb condicions fisicoquímiques contrastades. En particular, el treball de camp es va desenvolupar a l'Antàrtida Marítima, al NE del Pacífic subàrtic i al NO del Mediterrani. Es va utilitzar tècniques de química analítica i biologia molecular per obtenir les taxes de biodegradació i avaluar els canvis en la composició i els perfils d'expressió gènica de les comunitats microbianes exposades a nivells ambientals de HAP. Els resultats indiquen que la capacitat microbiana de biodegradació dels HAP és un tret estès a l'oceà superficial a escala global, tot i que les taxes de biodegradació dels HAP tenen una gran variabilitat. Aquestes troballes suggereixen el paper fonamental de la biodegradació microbiana com a un del principals processos que modulen el destí dels HAP a l'oceà superficial. En els experiments d’incubació vam observar que les exposicions a curt termini (24-48 hores) amb concentracions ambientals de HAP tenen un impacte en la composició i la funcionalitat de les comunitats microbianes. Els principals tàxons responsables de la biodegradació dels HAP a concentracions ambientals variaven segons el lloc i l'hàbitat, i inclouen molts grups diferents. Durant els experiments de curta exposició les poblacions de bacteris hidrocarbonoclàstics (BHC), és a dir, els bacteris especialitzats en l'ús d'hidrocarburs com a font de carboni i energia, van esdevenir actors clau en la biodegradació. La bateria de gens expressats durant l'exposició als HAP inclou gens de degradació de HAP, a banda d’altres gens implicats en donar resposta a l'estrès i altres estratègies de desintoxicació.

show abstract

“…Similar results were obtained by Cuypers et al (1998) with an acetone-water mixture of 0.5 where LMW PAHs were easily extracted but not for HMW PAHs such as 5-ring PAHs. Based on this observation, it is probable that the lower extraction potential of HMW PAHs as compared to LMW PAHs may be similar, to a certain extent, to the biodegradation potential of PAHs in the soil where LMW PAHs are more easily degraded than HMW PAHs (Froehner et al 2012;Juhasz and Naidu 2000;Lu et al 2012). Figure 2 presents the biodegradation results of 16 PAHs for sample S4 using the soil slurry reactor.…”

Section: Solvent-water Extraction Experimentsmentioning

confidence: 88%

Solvent–water extraction method for the evaluation of polycyclic aromatic hydrocarbons bioavailability in coal–tar-contaminated soils

Lee

Chao²,

Ong

2013

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

A solvent-water extraction method was proposed as an assessment tool to estimate the bioavailability of polycyclic aromatic hydrocarbons in coal-tar-contaminated soils. The approach taken was to measure the percent of polycyclic aromatic hydrocarbons extracted by a solvent-water mixture and comparing the results with the percent of polycyclic aromatic hydrocarbons degraded in a soil slurry reactor. Five soil samples from three former manufactured gas plant sites and a coal-tar disposal site which were operated between 1880 and 1947, and 1945 and 1950, respectively, in Iowa, USA were used in this study. Extraction experiments were conducted using acetone-water or ethanol-water mixtures with solvent volume fractions ranging from 1.0 to 0.4 (v/v). The percent of polycyclic aromatic hydrocarbons extracted from the various soils decreased as the volume fraction of the solvent in the solvent-water mixture was reduced. An acetone-water mixture of 0.6 was found to be appropriate in correlating the percent of polycyclic aromatic hydrocarbons degraded to the percent of polycyclic aromatic hydrocarbons extracted. For the first correlation, the percent extracted and the percent biodegraded were modified by using the molecular weights and log K ow of polycyclic aromatic hydrocarbons, respectively. For the second correlation, the equation relating the percent extracted and the percent biodegraded was modified using soil properties such as organic carbon content and percent of clay and silt. Although the experiments were conducted for a limited number of soils, the extraction method appeared to be a good starting point in estimating the bioavailability of polycyclic aromatic hydrocarbons in coal-tar-contaminated soils.

show abstract

Estimation of bioavailability of polycyclic aromatic hydrocarbons in river sediments

Cited by 11 publications

References 31 publications

Urban wastes to remediate industrial sites: a case of polycyclic aromatic hydrocarbons contamination and a new process

Urban wastes to remediate industrial sites: a case of polycyclic aromatic hydrocarbons contamination and a new process

Biodegradation of polycyclic aromatic hydrocarbons in the surface ocean

Solvent–water extraction method for the evaluation of polycyclic aromatic hydrocarbons bioavailability in coal–tar-contaminated soils

Contact Info

Product

Resources

About