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1.
J Environ Manage ; 301: 113933, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731951

RESUMO

The long-alkanes biodegradation rate was generally found slow during widely used pre-oxidation combined with biodegradation for oil contamination treatment, resulting in long and unsustainable removal. In this study, different chitosan content was used to produce iron catalysts for pre-oxidation, and nutrients were added for the long-alkanes biodegradation experiment. Mechanism of Fenton pre-oxidation and improvement in the biodegradation rate of long-alkanes were studied by analyzing the change in organic matter and bacterial community structure, the amount and activity of bacteria in the biological stage, and the degradation amount long-alkanes hydrocarbon before and after pre-oxidation. Results showed that the destruction of bacteria greatly reduced when hydroxyl radical intensity decreased to 4.40 a.u.. Also, the proportion of humic acid-like was high (40.88%), and the community structure was slightly changed with the pre-oxidation for the fast biodegradation (FB) group. In the subsequent biodegradation, it was found that the degradation rate of each long-alkanes in the FB group increased significantly (C30: 4.18-8.32 mg/(kg·d)) with the increase of the degradation of long-alkanes (10-50%). Further studies showed that the high nutrient dynamics (6.05 mg/(kg·d)) of the FB group resulted in high bacteria performance rate (0.53 mol CO2 × log CFU/(104 g2 d)), which further accelerated the substrate transformation(41%). Therefore, the biodegradation rate of long-alkanes was increased (43.8 mg/(kg·d)) with the removal rate of long-alkanes of 76%. The half-life of long-alkanes for the FB group (64 d) was 33 d shorter than the slow biodegradation group (99 d). These results exhibited that pre-oxidation regulation can shorten the bioremediation cycle by improving the biodegradation rate of long-alkanes. This research has good engineering application value.


Assuntos
Alcanos , Petróleo , Bactérias , Biodegradação Ambiental , Hidrocarbonetos
2.
Chemosphere ; 286(Pt 1): 131619, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34346343

RESUMO

For wastewater treatment, sediment microbial fuel cells (SMFCs) have advantages over traditional microbial fuel cells in cost (due to their membrane-less structure) and operation (less intensive maintenance). Nevertheless, the technical obstacles of SMFCs include their high internal electrical resistance due to sediment in the anode chamber and slow oxygen reduction reaction (ORR) in the cathode chamber, which is responsible for their low power density (PD) (0.2-50 mW/m2). This study evaluated several SMFC improvements, including anode and cathode chamber amendment, electrode selection, and scaling the chamber size up to obtain optimally constructed single-chamber SMFCs to treat fat, oil, and grease (FOG) trap effluent. The chemical oxygen demand (COD) removal efficiency, PD, and electrical energy conversion efficiency concerning theoretically available chemical energy from FOG trap effluent treatment (%ECWW) were examined. Packing biochar in the anode chamber reduced its electrical resistance by 5.76 times, but the improvement in PD was trivial. Substantial improvement occurred when packing the cathode chamber with activated carbon (AC), which presumably catalyzed the ORR, yielding a maximum PD of 109.39 mW/m2, 959 times greater than without AC in the cathode chamber. This SMFC configuration resulted in a COD removal efficiency of 85.80 % and a %ECWW of 99.74 % in 30 days. Furthermore, using the most appropriate electrode pair and chamber volume increased the maximum PD to 1787.26 mW/m2, around 1.7 times greater than the maximum PD by SMFCs reported thus far. This optimally constructed SMFC is low cost and applicable for household wastewater treatment.


Assuntos
Fontes de Energia Bioelétrica , Purificação da Água , Eletricidade , Eletrodos , Hidrocarbonetos
3.
Sci Total Environ ; 806(Pt 1): 150316, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34555609

RESUMO

In the last decade, lignin has received much attention as a feedstock to produce bio-based products. This study investigates the potential benefits of using lignin to mitigate the environmental impact of the road construction sector. An environmental life cycle assessment (LCA) of various top-layer bio-based asphalts using kraft lignin was conducted. From a cradle-to-grave perspective, lignin-based asphalts were compared with conventional asphalts. The results of the LCA revealed that the climate change impact of lignin-based asphalts could be 30-75% lower than conventional asphalts. For the other ten impact categories, trade-offs were observed. Overall, two key factors to make the environmental impact of lignin-based asphalts lower than conventional asphalts are 1) increasing the amount of bitumen-substituted and 2) using low-grade biomass fuels for process steam in the pulp mill. The substitution of weak filler with lignin was beneficial only for climate change and could lead to a worse overall environmental performance than conventional asphalts. Similarly, higher environmental impacts for lignin-based asphalts could be obtained if the pulp mill consumed natural gas to complete the energy balance to replace the part of the black liquor from which lignin is extracted. This study also includes an in-depth discussion on methodological choices such as the allocation methods for lignin, functional units, and asphalt layers considered. We believe that such a methodological discussion could be helpful to support future Product Category Rules for asphalt mixtures.


Assuntos
Hidrocarbonetos , Lignina , Biomassa
4.
Environ Pollut ; 292(Pt A): 118271, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34627963

RESUMO

Despite the economic benefits of the oil and gas industry in Northern Alberta, significant concerns exist regarding the impacts of increased oil production on the environment and human health. Several studies have highlighted increases in the concentrations of polycyclic aromatic compounds (PACs) and other hydrocarbons in the atmosphere, water, soil and sediments, plants, wildlife and fish in the Athabasca Oil Sands Region (AOSR) as a result of oil sands industrial activity. Sediment cores can provide information on the temporal trends of contaminants to the environment and provide important baseline information when monitoring data are absent. Here we combined analytical chemistry and a mammalian cell-based bioassay in dated lake sediment cores to assess paleotoxicity in freshwater systems in the AOSR. Sediment intervals were radiometrically dated and subsequently analysed for PACs. PAC extracts from select dated intervals were used in cell-based bioassays to evaluate their endocrine disrupting properties. We demonstrated spatial and temporal variability in the PAC composition of sediment cores around the AOSR with some of the highest concentrations of PACs detected near oil sands industrial activity north of Fort McMurray (AB) in La Saline Natural Area. Recent sediment had positive enrichment factors across most PAC analytes at this site with heavier pyrogenic compounds such as benz(a)anthracene/chrysene and benzofluoranthene/benzopyrene dominating. Our study is the first to link chemical analysis of sediment cores with biological effect assessments of endocrine activity showing feasibility of extending the usefulness of sediment cores in monitoring programs interested in complex mixture assessments. While we observed no spatial or temporal differences in ERα mediated signaling, AhR CALUX results mirrored those of the chemical analysis, demonstrating the utility of coupling biological effects assessments to historical reconstructions of contaminant inputs to the natural environment.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Alberta , Animais , Monitoramento Ambiental , Humanos , Hidrocarbonetos , Campos de Petróleo e Gás , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
5.
Sci Total Environ ; 804: 150194, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798737

RESUMO

Biochar has been utilized as a renewable biomass resource to develop sustainable and eco-friendly pavements. This study focuses on the influence of biochar as an asphalt modifier on the improvement of high-temperature performance of asphalt. A series of tests were performed to comprehensively evaluate the high-temperature performance of the biochar modified binder. The interaction mechanism between the biochar and the binder was explored using scanning electron microscopy and Fourier-transform infrared spectroscopy (FTIR). The results indicated that the complex modulus and penetration of the biochar-modified asphalt binder could be increased by up to 35% and 36.5%, respectively, compared with those in case of the matrix asphalt, thereby improving the deformation resistance. In addition, the observed increase in the complex modulus, rutting factor, and viscosity-temperature index contributed to the improvement of temperature sensitivity and anti-rutting properties. These relationships are attributed to the fact that biochar has a fibrous porous structure and forms a skeleton and stiffening zone in the binder. Although biochar has a negative effect on the low-temperature properties of the binder, this can be alleviated by controlling the biochar content. Moreover, the FTIR results showed that no new chemical functional groups appeared after the incorporation of biochar into the binder. The internal chemical environment of the biochar-modified asphalt binder was different from that of the matrix asphalt. In conclusion, biochar is feasible as a modifier for binders owing to its high-temperature properties.


Assuntos
Carvão Vegetal , Hidrocarbonetos , Temperatura
6.
J Environ Manage ; 301: 113863, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34610558

RESUMO

This study presents the thermo-chemical conversion by means of pyrolysis as a route to valorise end of life tyres (ELTs) in a sustainable manner whilst targeting produced pyrolysis oil (pyro-oil) to replace conventional fossil fuels. The work presented here compares the results of pyro-oil extracted from the pyrolysis of three tyre grades, namely fresh (new) tyres, car and lorry truck ELTs; and investigates the pyro-oil extracted for fuel properties and common fuel hydrocarbon range. A fixed bed reactor system was used to conduct the experimental runs between 500 and 800 °C. The results show that fresh tyres and car ELTs yield some 45% of pyro-oil at an average reactor bed temperature equal to 600 °C which promotes evolution of liquid hydrocarbons via primary route of tyres cracking, hence pyro-oil production to a maximum. Furthermore, and at a similar operating temperature; the diesel range hydrocarbons (C10-C19) were around 66% of the total fuel like chromatograph studied for the pyrolysis oils. The work in this study and based on properties of fuel investigated point towards blending the oil extracted with conventional fuels that could result in lowering dependency on fossil based ones. Further upgrading is also possible whereby desulphurisation could lead to renewable and sustainable fuel source utilising a solid waste feedstock such as ELTs.


Assuntos
Óleos , Pirólise , Temperatura Alta , Hidrocarbonetos , Resíduos Sólidos , Temperatura
7.
J Environ Manage ; 301: 113849, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34619586

RESUMO

Engine oil consists of hazardous substances that adversely affect the environment and soil quality. Bioremediation (employing organisms) is an appropriate technique to mitigate engine oil pollution. In the present study, the earthworm species, Drawida modesta (epigeic) and Lampito mauritii (anecic) were used to restore the soil polluted with polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs) from used engine oil. Four treatments were set up in addition to positive and negative controls. A maximum of 68.6% PAHs and 34.3% TPHs removal in the treatment with soil (1 kg), cow dung (50 g), used engine oil (7.5 mL) and earthworms was recorded after 60 days. Undoubtedly, earthworms effectively removed PAHs and TPHs from the oil-contaminated soil. PAHs were more strongly accumulated in D. modesta (16.25 mg kg-1) than in L. mauritii (13.25 mg kg-1). Further, histological analysis revealed the epidermal surface irregularity, cellular disintegration, and cellular debris in earthworms. The pH (6.3%), electrical conductivity (12.7%), and total organic carbon (35.4%) were significantly (at P < 0.05) decreased after 60 days; while, total nitrogen (62%), total potassium (76.2%), and total phosphorus (19.2%) were substantially increased at the end of the experiment. The seed germination assay with fenugreek indicates that germination percentage (95%), and germination index (179), were dramatically increased in earthworm inoculated treatments when compared to the negative control (without earthworms). The results reveal that there is a great scope for utilizing the earthworms, D. modesta and L. mauritii for the bioremediation of soils contaminated with PAHs and TPHs.


Assuntos
Oligoquetos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Animais , Biodegradação Ambiental , Bovinos , Feminino , Hidrocarbonetos , Solo , Poluentes do Solo/análise
8.
J Environ Manage ; 301: 113826, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34626942

RESUMO

The continuous growth of waste is generating worldwide more and more increasing related environmental concerns. Anything that is not recycled or recuperated from waste represents a loss of raw materials and other production factors used in the manufacture, transport and consumer phases of the product. This research explored the potential of three waste namely Construction and Demolition (CD) waste, Fly Ash (FA), and Jet Grouting (JG) waste as fillers in comparison to the traditional limestone one for making hot asphalt mastics for road pavement, through a rheological analysis and environmental compatibility tests towards the release of potentially toxic elements. A total of eight asphalt mastics were prepared by using two filler-to-binder weight ratios (f/b) of 0.5 and 1 for blending each filler with a neat bitumen 50/70 penetration grade. The Frequency Sweep test and the Multiple Stress Creep and Recovery (MSCR) test were carried out to investigate the rheological properties of the asphalt mastics. Asphalt mastics containing FA and JG fillers were found to be more mechanically and environmentally efficient than traditional limestone mastic in particular by adopting an f/b equal to 1 where it was observed higher complex shear modulus values, G*, (on average 50% compared to the traditional asphalt mastic) and lower non-recoverable creep compliance values, Jnr, (on average 35% compared to the traditional asphalt mastic) at all test temperatures investigated. Based on the suggested ranking methodology, CD emerged as the filler performing in the same way of the traditional one. All the waste containing mastics, showed up noticeable environmental compatibility, being the potentially toxic elements completely immobilized into the mastics' structure e practically not releasable into acidic water, highlighting the waste recycling for road pavements as primary strategy to immobilize hazardous wastes.


Assuntos
Materiais de Construção , Reciclagem , Cinza de Carvão , Hidrocarbonetos
9.
Chemosphere ; 286(Pt 2): 131752, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426136

RESUMO

Over recent decades, hydrocarbon concentrations have been augmented in soil and water, mainly derived from accidents or operations that input crude oil and petroleum into the environment. Different techniques for remediation have been proposed and used to mitigate oil contamination. Among the available environmental recovery approaches, bioremediation stands out since these hydrocarbon compounds can be used as growth substrates for microorganisms. In turn, microorganisms can play an important role with significant contributions to the stabilization of impacted areas. In this review, we present the current knowledge about responses from natural microbial communities (using DNA barcoding, multiomics, and functional gene markers) and bioremediation experiments (microcosm and mesocosm) conducted in the presence of petroleum and chemical dispersants in different samples, including soil, sediment, and water. Additionally, we present metabolic mechanisms for aerobic/anaerobic hydrocarbon degradation and alternative pathways, as well as a summary of studies showing functional genes and other mechanisms involved in petroleum biodegradation processes.


Assuntos
Microbiota , Poluição por Petróleo , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Poluição por Petróleo/análise , Microbiologia do Solo , Poluentes do Solo/análise
10.
J Colloid Interface Sci ; 607(Pt 1): 401-411, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34509114

RESUMO

HYPOTHESIS: Zeta-potential in the presence of brine has been studied for its application within hydrocarbon reservoirs. These studies have shown that sandstone's zeta-potential remains negatively charged, non-zero, and levels-off at salinities > 0.4 mol.dm-3, thus becoming independent of salinity when ionic strength is increased further. However, research conducted to date has not yet considered clay-rich (i.e. clay ≥ 5 wt%) sandstones. EXPERIMENTS: Firstly, streaming potential measurements were conducted on Bandera Gray sandstones (clay-rich and clay-poor) with 0.6 and 2 mol.dm-3 NaCl brine-saturated in pressurised environments (6.895 MPa overburden and 3.447 MPa back-pressure). Secondly, the streaming potential was determined at identical conditions for the effect of two surfactants, SDBS and CTAB, at concentrations of 0.01 and 0.1 wt% on the clay-poor sample in 0.6 mol.dm-3 NaCl. Thirdly, a comparison of zeta potentials determined via electrophoretic and streaming potential was conducted. Accordingly, this work analyses the effects of mineralogy and surfactants within this process. FINDINGS: Clay-rich sandstone possessed lower zeta-potentials than clay-poor sandstone at the two tested salinities. SDBS reduced zeta-potential and yielded higher repulsive forces rendering the rock more hydrophilic. Additionally, electrophoretic zeta-potentials were higher when compared to streaming zeta-potentials. Mechanisms for the observed phenomena are also provided.


Assuntos
Surfactantes Pulmonares , Tensoativos , Argila , Hidrocarbonetos , Interações Hidrofóbicas e Hidrofílicas
11.
Chemosphere ; 286(Pt 2): 131750, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34352537

RESUMO

The remediation effects of hydrogen peroxide (H2O2) oxidation and surfactant-leaching alone or in combination on three typical oilfield sludges were studied. The removal efficiency of total petroleum hydrocarbons (TPHs) of Jidong, Liaohe and Jiangsu oil sludges by hydrogen peroxide oxidation alone was very poor (6.5, 6.8, and 3.4 %, respectively) but increased significantly (p < 0.05), especially of long-chain hydrocarbons, by combining the use of H2O2 with surfactants (80.0, 79.8 and 82.2 %, respectively). Oxidation combined with leaching may impair microbial activity and organic manure was therefore added to the treated sludges for biostimulation and the composition and function of the microbial community were studied. The addition of manure rapidly restored sludge microbial activity and significantly increased the relative abundance of some salt-tolerant and alkali-tolerant petroleum-degrading bacteria such as Corynebacterium, Pseudomonas, Dietzia and Jeotgalicoccus. Moreover, the relative abundance of two classic petroleum-degrading enzyme genes, alkane 1-monooxygenase and catechol 1, 2-dioxygenase, increased significantly.


Assuntos
Microbiota , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Peróxido de Hidrogênio , Petróleo/análise , Esgotos , Microbiologia do Solo , Poluentes do Solo/análise , Tensoativos
12.
Chemosphere ; 286(Pt 2): 131663, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34371357

RESUMO

In this study, an immobilization method for forming and keeping dominant petroleum degradation bacteria was successfully developed by immobilizing Pseudomonas, Acinetobacter, and Sphingobacterium genus bacteria on wheat bran biochar pyrolyzed at 300, 500, and 700 °C. The removal efficiency indicated that the highest TPHs (total petroleum hydrocarbons) removal rate of BC500-4 B (biochar pyrolyzed at 500 °C with four kinds of petroleum bacteria) was 58.31%, which was higher than that of BC500 (36.91%) and 4 B (43.98%) used alone. The soil properties revealed that the application of biochar increased the content of organic matter, available phosphorus, and available potassium, but decreased pH and ammonium nitrogen content in soil. Bacterial community analysis suggested that the formation of dominant degrading community represented by Acinetobacter played key roles in TPHs removal. The removal rate of alkanes was similar to that of TPHs. Besides, biochar and immobilized material can also mediate greenhouse gas emission while removing petroleum, biochar used alone and immobilized all could improve CO2 emission, but decrease N2O emission and had no significant impact on CH4 emission. Furthermore, it was the first time to found the addition of Acinetobacter genus bacteria can accelerate the process of forming a dominant degrading community in wheat bran biochar consortium. This study focused on controlling greenhouse gas emission which provides a wider application of combining biochar and bacteria in petroleum soil remediation.


Assuntos
Gases de Efeito Estufa , Petróleo , Poluentes do Solo , Álcalis , Bactérias , Biodegradação Ambiental , Carvão Vegetal , Fibras na Dieta , Gases de Efeito Estufa/análise , Hidrocarbonetos , Petróleo/análise , Solo , Microbiologia do Solo , Poluentes do Solo/análise
13.
J Hazard Mater ; 421: 126699, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34330075

RESUMO

The present study employed an anoxic packed bed biofilm reactor (AnPBR) inoculated with in-situ biosurfactant-producing bacteria for the biodegradation of petroleum wastewater. Highly acclimated biomass decreased the start-up phase period and with increasing the initial total petroleum hydrocarbon (TPH) concentration from 1.5 to 4 g/L was accompanied by TPH and chemical oxygen demand (COD) removal efficiencies of above 99% and 96%, respectively. Decreasing hydraulic retention time (HRT) from 24 to 6 h caused an increase in the specific hydrocarbon utilization rate value from 0.45 to 1.66 gTPH/gbiomass.d. Moreover, dehydrogenase activity, surfactin, and rhamnolipid reached 31.8 µgTF/gbiomass.d, 95.1, and 27.1 mg/L, respectively. The biodegradation kinetic coefficients such as K, Ks, Kd, Y and µmax were 0.784 (d-1), 0.005 (g/L), 0.138 (d-1), 0.569 (gVSS/gCOD), and 0.446 (d-1), respectively. Dropping of bioreactor performance, especially TPH removal efficiency from 99% to 37.6% in the absence of nitrate after 10 days, indicates anoxic metabolism has been the dominant biodegradation pathway. The effluent chromatogram of gas chromatography/flame ionization detector (GC/FID) showed aliphatic, cyclic aliphatic, and aromatic hydrocarbons efficiently degraded. According to the high degradation rate of AnPBR in different operational parameters, it can be recommended for the treatment of oil-contaminated wastewater.


Assuntos
Petróleo , Bactérias , Biodegradação Ambiental , Biofilmes , Hidrocarbonetos
14.
Chemosphere ; 287(Pt 3): 132220, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34543895

RESUMO

The present study investigated the effects of metal loaded spent adsorbent as catalyst for the catalytic pyrolysis of pine needle biomass. Metal active sites (Ni, Fe, Cu, Zn and Mo) were introduced in alumina matrix by wet impregnation process. Non-catalytic and catalytic semi-batch pyrolysis study was carried out at conditions: 550 °C temperature, 50 °C min-1 heating rate and 200 mL min-1 N2 flow rate. Results indicated significant deoxygenation potential 3.33-35.57% of the applied catalysts towards oxygenated compounds by converting them into their corresponding hydrocarbon (27.70-36.41%) and phenolic (40.41-46.04%) derivatives. Among all the catalysts, Ni/Al and Fe/Al produced the highest quality bio-oil by enriching their carbon content to 62.93 and 60.14% and heating value to 31.41 and 26.86 MJ kg-1, respectively. Moreover, significant enhancement in their hydrocarbons (36.41 and 36.01% for Ni/Al and Fe/Al, respectively) and phenolic compounds (46.04 and 41.67% for Ni/Al and Fe/Al, respectively) from 9.15% hydrocarbons and 13.32% phenols in non-catalytic bio-oil had also been observed. Presence of CO and CO2 in the evolved gases also represented the occurrence of deoxygenation reactions during catalytic breakdown. Hydrocarbon and phenol-rich bio-oil can find its application either as a replacement for petroleum fuel or an industrial-grade chemical. Thus, catalysts derived from spent aluminum hydroxide nanoparticle adsorbent can act as an effective substitute for the currently utilized high-cost catalysts in catalytic pyrolysis of biomass.


Assuntos
Nanopartículas , Pirólise , Hidróxido de Alumínio , Biocombustíveis , Biomassa , Catálise , Temperatura Alta , Hidrocarbonetos , Fenóis , Óleos Vegetais , Polifenóis
15.
Bioresour Technol ; 343: 126127, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34653626

RESUMO

The influence of Pseudomonas putida 7525 strain on the pretreatment of petroleum refinery sludge was optimized at different dosages to maximize solubilization for improved biodegradability. Laccase-producing P. putida strain at a dosage of 108 CFU/mL resulted in 249% and 121.57% increments in soluble chemical oxygen demand and volatile fatty acids production respectively as compared to untreated within 6 days of incubation. 1L biochemical methane potential test conducted for optimization of different inoculum and pretreated substrate ratios (0.3, 0.4, 0.5, 0.7 and 1.0) revealed maximum methane augmentation (62%) and volatile solids degradation (66.7%) at ratio 0.5. Scaled-up study (20L) for ratio 0.5 resulted in 57.07% total petroleum hydrocarbon, 62.98% oil and grease and 91.9% phenol removal within 50 days of digestion of pretreated PS. Kinetic modelling of cumulative methane yield indicated that modified Gompertz model showed the best fit thereby, evincing the potency of bacterial species for bioremediation of PS.


Assuntos
Petróleo , Pseudomonas putida , Anaerobiose , Hidrocarbonetos , Metano , Esgotos
16.
Environ Pollut ; 292(Pt B): 118343, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34662593

RESUMO

The biodegradation of hazardous petroleum hydrocarbons has recently received a lot of attention because of its many possible applications. Bacillus marsiflavi strain was isolated from oil contaminated soil of Rawalpindi, Pakistan. Initial sequencing was done by 16s rRNA sequencing technique. Bac 144 had shown 78% emulsification index and 72% hydrophobicity content. Further, the strain displayed production of 15.5 mg/L phosphate sloubilization and 30.25 µg/ml indole acetic acid (IAA) in vitro assay. The strain showed 65% biodegradation of crude oil within 5 days by using Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Whole Genome analysis of Bac 144 was performed by PacBio sequencing and results indicated that Bacillus marsiflavi Bac144 strain consisted of size of 4,417,505bp with closest neighbor Bacillus cereus ATCC 14579. The number of the coding sequence was 4662 and number of RNAs was 141. The GC content comprised 48.1%. Various genes were detected in genome responsible for hydrocarbon degradation and plant defense mechanism. The toxic effect of petroleum hydrocarbons in soil and its mitigation with Bac 144 was tested by soil experiment with three levels of oil contamination (5%, 10% and 15%). Soil enzymatic activity such as dehydrogenase and fluorescein diacetate (FDA) increased up to 49% and 40% with inoculation of Bac 144, which was considered to be correlated with hydrocarbon degradation recorded as 46%. An increase of 20%, 14% and 9% in shoot length of plant at 5%, 10% and 15% level of oil was recorded treated with Bac 144 as compared to untreated plants. A percent increase of 14.89%, 16.85%, and 13.87% in chlorophyll, carotenoid, and proline content of plant was observed by inoculation with Bac 144 under oil stress. Significant reduction of 14% and 18%, 21% was recorded in the malondialdehyde content of plant due to inoculation of Bac 144. A considerable increase of 21.33%, 19.5%, and 24.5% in super oxide dismutase, catalase, and peroxidase dismutase activity was also observed in plants inoculated with strain Bac 144. These findings suggested that Bac-144 can be considered as efficient candidate for bioremediation of hydrocarbons.


Assuntos
Bacillus , Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Bacillus/genética , Biodegradação Ambiental , Hidrocarbonetos , Petróleo/análise , RNA Ribossômico 16S , Microbiologia do Solo , Poluentes do Solo/análise
17.
Environ Pollut ; 292(Pt B): 118454, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34737024

RESUMO

Measurements of vertical distribution of volatile organic compounds (VOCs) have attracted wide attentions, which could help to understand atmospheric oxidation mechanism and provide implications for VOC control. This study measured the non-methane hydrocarbons (NMHCs) and oxygenated VOCs (OVOCs) simultaneously for the first time at three different heights, namely ground, 118 m and 488 m, in the Canton Tower located in the urban core of the Pearl River Delta (PRD). The results show that NMHCs decreased while some OVOC species such as formaldehyde and acetaldehyde increased with increasing height. It was mainly attributed to the dilution and chemical loss of NMHCs but secondary production of OVOCs during vertical transport. Ratio analysis and receptor modeling indicate that vehicle exhausts (47%) and fuel evaporation (39%) were major sources of the total NMHCs. Interestingly, industry contributed much more at 118 m, probably affected by organic gas discharge from the high chimney of industrial factories. The chemical reactivities in terms of OH radical loss rate (LOH), ozone formation potential (OFP) and secondary organic aerosol potential (SOAP) were lowest at 118 m, smaller than those influenced by high fresh NMHC emissions at ground and strong formation of secondary species (e.g. OVOCs) at 488 m. OH exposure estimated by isoprene and m,p-xylene/ethylbenzene was different depending on their time scale of vertical turbulent mixing and chemical loss. OVOC species measured at different heights were positively correlated with Ox (R = 0.48-0.87), indicating that OVOCs were largely contributed by secondary formation in photochemical process. The tower measurements of NMHCs and OVOCs provided a unique opportunity to investigate the VOC distribution and chemical behaviors, which could give important information for understanding O3 and PM2.5 pollution mechanism in the PRD region with fast developing urban setting and substantially changing air quality.


Assuntos
Poluentes Atmosféricos , Ozônio , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Hidrocarbonetos/análise , Metano , Ozônio/análise , Rios , Compostos Orgânicos Voláteis/análise
18.
Chemosphere ; 286(Pt 2): 131782, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34375825

RESUMO

The current study was dedicated to finding the effect of soil amendments (biochar and compost) on plants belonging to Poaceae and Fabaceae families. Plants selected for the phytoremediation experiment included wheat (Triticum aestivum), maize (Zea mays), white clover (Trifolium repens), alfalfa (Medicago sativa), and ryegrass (Lolium multiflorum). The physiological and microbial parameters of plants and soil were affected negatively by the 4 % TPHs soil contamination. The studied physiological parameters were fresh and dried biomass, root and shoot length, and chlorophyll content. Microbial parameters included root and shoot endophytic count. Soil parameters included rhizospheric CFUs and residual TPHs. Biochar with wheat, maize, and ryegrass (Fabaceae family) and compost with white clover and alfalfa (Poaceae family) improved plant growth parameters and showed better phytoremediation of TPHs. Among different plants, the highest TPH removal (68.5 %) was demonstrated by ryegrass with compost, followed by white clover with biochar (68 %). Without any soil amendment, ryegrass and alfalfa showed 59.55 and 35.21 % degradation of TPHs, respectively. Biochar and compost alone removed 27.24 % and 6.01 % TPHs, respectively. The interactive effect of soil amendment and plant type was also noted for studied parameters and TPHs degradation.


Assuntos
Compostagem , Lolium , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Carvão Vegetal , Humanos , Hidrocarbonetos , Medicago sativa , Poaceae , Solo , Poluentes do Solo/análise
19.
Chemosphere ; 286(Pt 3): 131751, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34399257

RESUMO

Oil spills in Arctic marine environments are expected to increase concurrently with the expansion of shipping routes and petroleum exploitation into previously inaccessible ice-dominated regions. Most research on oil biodegradation focusses on the bulk oil, but the fate of the water-accommodated fraction (WAF), mainly composed of toxic aromatic compounds, is largely underexplored. To evaluate the bacterial degradation capacity of such dissolved aromatics in Greenlandic seawater, microcosms consisting of 0 °C seawater polluted with WAF were investigated over a 3-month period. With a half-life (t1/2) of 26 days, m-xylene was the fastest degraded compound, as measured by gas chromatography - mass spectrometry. Substantial slower degradation was observed for ethylbenzene, naphthalenes, phenanthrene, acenaphthylene, acenaphthene and fluorenes with t1/2 of 40-105 days. Colwellia, identified by 16S rRNA gene sequencing, was the main potential degrader of m-xylene. This genus occupied up to 47 % of the bacterial community until day 10 in the microcosms. Cycloclasticus and Zhongshania aliphaticivorans, potentially utilizing one-to three-ringed aromatics, replaced Colwellia between day 10 and 96 and occupied up to 6 % and 23 % of the community, respectively. Although most of the WAF can ultimately be eliminated in microcosms, our results suggest that the restoration of an oil-impacted Arctic environment may be slow as most analysed compounds had t1/2 of over 2-3 months and the detrimental effects of a spill towards the marine ecosystem likely persist during this time.


Assuntos
Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Regiões Árticas , Biodegradação Ambiental , Ecossistema , Gammaproteobacteria , Hidrocarbonetos , Poluição por Petróleo/análise , RNA Ribossômico 16S/genética , Água do Mar , Água , Poluentes Químicos da Água/análise
20.
An Acad Bras Cienc ; 93(suppl 4): e20201662, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34817036

RESUMO

This manuscript evaluates the technical feasibility of reusing coal ash in the formulation design of dense asphalt mixes. Physicochemical and mineralogical properties of fly and bottom ash matrixes prepared with coal ash were analyzed by scanning electron microscopy (SEM), X-Ray diffraction (XRD), semi-quantitative spectrometry by X-Ray fluorescence (XRF) and surface characterization by Nitrogen (N2) adsorption. Filler fractions under 0.075 mm with 6.0% in weight from an entirely gneissic aggregate gradation curve taken as reference were compared to identical mixes prepared with fly and bottom ashes individually and also to a combined sample with 3.0% of each ash type. Tests on compaction ability with gyratory shear press, resistance to action of water and to rutting were carried out to compare mechanical performance. The results indicate that both gneissic and coal ash fillers do not form dipoles of effective electric attractions to bituminous matrixes, resulting in inert and hydrophilic behavior regarding to action of water, respectively. Despite surface and morphologic characteristics underlying the mechanical performance of gneissic fillers, coal ash matrixes have shown, in general, good technical feasibility to be used in asphalt mixes.


Assuntos
Cinza de Carvão , Hidrocarbonetos , Estudos de Viabilidade , Microscopia Eletrônica de Varredura
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