Evaluation of bioremediation effectiveness on crude oil-contaminated sand

A treatability study was conducted using sea sand spiked with 3% or 6% (w/w) of Arabian light crude oil to determine the most effective bioremediation strategies for different levels of contamination. The sea sand used in the study was composed of gravel (0.1%), sand (89.0%), and silt and clay (10.9%). The water content of the sea sand was adjusted to 12.6% (w/w) for the study. Different combinations of the following treatments were applied to the sand in biometer flasks: the concentration of oil (3% or 6%), the concentration of a mixture of three oil-degrading microorganisms (Corynebacterium sp. IC-10, Sphingomonas sp. KH3-2 and Yarrowia sp. 180, 1x10(6) or 1x10(8) cells g-1 sand), the concentration of the surfactant Tween 80 (1 or 10 times the critical micelle concentration), and the addition of SRIF in a C:N:P ratio of 100:10:3. Three biometer flasks per combination of experimental conditions were incubated, and the performance of each treatment was examined by monitoring CO2 evolution, microbial activity, and oil degradation rate. The results suggest that the addition of inorganic nutrients accelerated the rate of CO2 evolution by a factor of 10. The application of oil-degrading microorganisms in a concentration greater than that of the indigenous population clearly increased biodegradation efficiency. The application of surfactant slightly enhanced the oil degradation rate in the contaminated sand treated with the higher concentration of oil-degrading microorganisms. The initial CO2 evolution rate was shown to efficiently evaluate the treatability test by providing significant data within a short period, which is critical for the rapid determination of the appropriate bioremediation approach. The measurements of microbial activity and crude oil degradation also confirmed the validity of the CO2 evolution rate as an appropriate criterion.     

生物柴油促进原油污染砂粒释放油

对4种生物柴油促进原油污染砂粒释放油的效果进行了研究,并探讨了菜籽生物柴油投加量和砂粒粒径对促进效果的影响。结果表明,菜籽生物柴油的促进效果最好,8 h释放量达到73%,废油脂生物柴油的效果最差,仅为52%;生物柴油的促进效果随着投加量的增大而升高,当投加量超过海水体积的5%时促进效果不再明显增加;在生物柴油作用下,小粒径砂粒上原油的释放效果优于大粒径砂粒。     

Polycyclic aromatic hydrocarbons in crude oil-contaminated soil: A two-step method for the isolation and characterization of PAHs

A two-step analytical method is developed for the isolation and characterization of polycyclic aromatic hydrocarbons (PAHs) in crude oil contaminated soil. In the first step, those crude oil components were isolated which are easily mobilized with water from the contaminated soil (determination of groundwater pollution potential). In the second step, the fraction containing the remaining crude oil compounds was extracted using toluene. After the cleanup of the fractions, both fractions were analyzed using high-performance liquid chromatography (HPLC). The HPLC of the toluene extracted fraction shows that along with the sixteen priority pollutants from the US-EPA list, many other polycyclic aromatic hydrocarbons (PAHs) are present as well. It is evident from the chromatograms that a significant amount of PAHs are present as is also the case in the fractions eluted by water. The described method allows the determination of total organic pollutants from crude oil, some of them being potential groundwater contaminants. The major part of the total pollutants could not be mobilized by water and therefore remains in the soil, which was extracted in the second step.     

Biodegradation of nitrogen- and oxygen-containing aromatic compounds in groundwater from an oil-contaminated aquifer

The aerobic biodegradation of oxygen and nitrogen heterocycles and o-cresol by subsurface bacteria in groundwater from an oil contaminated site at Zealand, Denmark, was compared to the biodegradation of these compounds in laboratory adapted suspended and fixed-film cultures. The aquifer at the abstraction site had a relatively high redox potential, since it contained nitrate. The groundwater (i.e. without the soil phase) had a high biodegradation potential for dibenzofuran, indole, quinoline, flourenone and o-cresol. All the compounds were degraded in groundwater within 5–15 days from an initial concentration of about 0.5 mg L⁻¹ in both mixed substrate and single substrate experiments with an initial ATP concentration of 0.2 ng mL⁻¹. Pyrrole, however, was not degraded in groundwater within 55 days in the mixed substrate experiment and very slowly, after a lag period of 20 days, in the single substrate experiment. The biodegadability picture found for groundwater in the mixed substrate experiment was similar to the results found with laboratory adapted suspended and fixed-film cultures. None of the compounds had any inhibitory effect on the biodegradation of naphthalene.     

Phytoremediation in the tropics--influence of heavy crude oil on root morphological characteristics of graminoids

When studying species for phytoremediation of petroleum-contaminated soils, one of the main traits is the root zone where enhanced petroleum degradation takes place. Root morphological characteristics of three tropical graminoids were studied. Specific root length (SRL), surface area, volume and average root diameter (ARD) of plants grown in crude oil-contaminated and uncontaminated soil were compared. Brachiaria brizantha and Cyperus aggregatus showed coarser roots in polluted soil compared to the control as expressed in an increased ARD. B. brizantha had a significantly larger specific root surface area in contaminated soil. Additionally, a shift of SRL and surface area per diameter class towards higher diameters was found. Oil contamination also caused a significantly smaller SRL and surface area in the finest diameter class of C. aggregatus. The root structure of Eleusine indica was not significantly affected by crude oil. Higher specific root surface area was related to higher degradation of petroleum hydrocarbons found in previous studies.     

Two-year magnetic monitoring in conjunction with geochemical and electron microscopic data of roadside dust in Seoul,Korea

Mineral magnetic properties of roadside dusts in Seoul, Korea, were measured and compared with the results of geochemical analyses in order to investigate the spatio-temporal patterns of urban pollution. Scanning electron microscope (SEM) observations and energy dispersive X-ray spectroscopy (EDS) analyses were carried out to verify the magnetic materials and their potential sources. A total of 1956 dust samples were collected monthly at eight sites, from June 1998 to June 2000. Thermomagnetic data and SEM observations for magnetic extracts indicated that the major magnetic phase was magnetite-like material. In particular, the highest and the lowest magnetic concentrations were observed in industrial areas and a park area, respectively, whereas, heavy traffic areas showed low to intermediate concentration. A linear correlation between enrichment indexes of magnetic susceptibility and heavy metals suggests that magnetic susceptibility can be used as a proxy for heavy metal pollution. The magnetic concentrations and magnetic particle sizes showed systematic seasonal fluctuations (high and large in winter versus low and small in summer) due to the seasonal influx variations of anthropogenic magnetic materials. On the basis of the morphology and elemental composition, the magnetic materials were grouped into three types: magnetic spherules possibly emitted from factories and domestic heating systems, aggregates derived from vehicle emission or motor vehicle brake system, and angular magnetic particles of natural origin.     

Scanning and transmission electron microscope of suspended lead-rich particles in the air of San Luis Potosi,Mexico

In the city of San Luis Potosi exists an important metallurgical plant and is known that in the adjacent urban zone, there is a high concentration of lead in the air, it is also supposed that most of the particles with lead have an anthropogenic origin because these particles show morphological characteristics and chemical composition very different in comparison with common lead minerals. In this work it was proved that most of the airborne particles with lead present in this urban zone, effectively came from the copper smelter. The airborne particles with lead were compared with particles with lead obtained starting from samples of slag and lead calcine of the copper smelter. To perform the comparative study, these particles were studied with energy dispersive X-ray microanalysis (EDS) in conjunction with scanning electron microscope to obtain chemical composition and associated morphological characteristics. Results suggest that these particles, composed of only one phase, are chemically distinct from any crustal lead mineral. Because of the complexity of the chemical composition of these particles (Pb, S, Cu, As, Fe, Zn, Cd, Sb, O), some of the airborne particles were analyzed by transmission microscopy in order to associate crystalline structure with any particular chemical phase.     

Airborne investigations of SO2 oxidation in the plumes from power stations

The Danish contribution to the EUROCOP COST 61a project is described. Work concerned the physical and chemical reactions of sulphur dioxide released from a power station. The investigation was based on the application of two tracers. Inactive, inert SF₆ is used to monitor the dispersion of and deposition from the plume; it was intended to use radioactive ³⁵SO₂ to determine the degree of oxidation of sulphur released from the stack; so far, however, public reaction has prevented the use of a release of activity in field experiments. Some attempts have been made to base the investigations of analyses of inactive samples only. Previously published results obtained at an oil-fired power station suggest a half-life of about 30 min for SO₂ in the first part of the plume. New results obtained at a mainly coal-fired power station give a half-life of about 90 min.     

Validity and uncertainty in the calculation of an emission inventory for ammonia arising from agriculture in Great Britain

Emissions of ammonia have received increasing attention recently, following concern about the environmental consequences, especially in The Netherlands where levels are high due to intensive livestock farming. Direct local effects and more widespread consequences for a range of ecosystems have been attributed to ammonia emissions. As the most prevalent alkaline gas in the atmosphere, ammonia interacts with acidic species, changing their characteristics, chemical and physical behaviour, and enhancing their potential for acidification of soils. Ammonia also forms an important component of the nitrogen cycle and of nitrogen deposition. In the UK, as in many other European countries, there has been a considerable increase in the emission of ammonia within the last 30 years, estimated at about 50%. This results mainly from increases in agricultural production based on the steadily rising number of livestock and increasing fertilizer consumption. This paper discusses the various sources to emissions of ammonia from agricultural sources in the United Kingdom, and some of the uncertainties involved in constructing a national emissions inventory.     

赤泥添加对石灰性土壤中Pb、Cd形态分布及小麦根系的影响

通过田间种植小麦实验,研究添加不同剂量拜耳赤泥（0%、1%、2%、3%、4%和5%）对重金属污染的石灰性土壤Pb、Cd化学形态和小麦幼苗根系的影响。培养1个月,添加赤泥显著地提高了土壤pH值,提高幅度随赤泥投加量增加而增大。培养3个月,添加不同剂量的赤泥均明显降低土壤中可交换态Pb和Cd的含量,赤泥投加量为5%时效果最为显著,分别比对照下降90%和72%。添加赤泥对所种植小麦幼苗的根系也有影响。种植5个月,小麦根系总根长、总表面积和总体积等随添加赤泥的剂量增加呈现先增大后减小的趋势,赤泥投加量为3%时增幅最大,总根长、总表面积和总体积分别比对照增加88.23%、75%和90.32%。研究表明,赤泥可作为重金属污染的石灰性土壤的理想改良剂,但考虑到小剂量赤泥（即1%~3%）促进重金属污染农田中小麦根系的生长,建议在种植区采用小剂量赤泥（即3%）处理的重金属污染修复方案。     

Use of mosses to study atmospheric deposition of trace elements: contributions from investigations in Norway

This paper presents essential features of biomonitoring work carried out in the author's laboratory during more than 25 years using various analytical techniques for the determination of over 50 elements. A substantial part of this work concerns large-scale deposition surveys in Norway using the moss Hylocomium splendens, where five nationwide surveys have been carried out since 1977. Considerable efforts have also been spent on intercalibration of different species of mosses and transformation of concentrations in moss to absolute deposition rates. Other significant activities include establishment of recommended values for moss reference samples, source apportionment of lead in mosses by stable isotope ratios and monitoring of local metal deposition around factories. Experience from this work has facilitated a critical evaluation of the contribution from sources other than atmospheric deposition to the elemental composition of the moss, as well as factors leading to depletion of elements in the moss. Recent work indicates that mosses may also be suitable for the monitoring of persistent halogenated organic pollutants and ¹³⁷Cs deposition.     

In vitro biotransformation of PBDEs by root crude enzyme extracts: Potential role of nitrate reductase (NaR) and glutathione S-transferase (GST) in their debromination

In order to investigate the enzyme transformation of PBDEs and to track the key enzymes involved in PBDE degradation in plants, in vivo exposure of plants of ryegrass, pumpkin and maize and in vitro exposure of their root crude enzyme extracts to PBDEs were conducted. Degradation of PBDEs in the root crude enzyme solutions fit well with the first order kinetics (R² = 0.52–0.97, P < 0.05), and higher PBDEs degraded faster than the lower ones. PBDEs could be transformed to lower brominated PBDEs and hydroxylated-PBDEs by the root crude enzyme extracts with debromination as the main pathway which contributed over 90% of PBDE depletion. In vitro and in vivo exposure to PBDEs produced similar responses in root enzyme activities of which the nitroreductase (NaR) and glutathione-transferase (GST) activities decreased significantly, while the peroxidase, catalase and cytochrome P-450 activities had no significant changes. Furthermore, higher enzyme concentrations of NaR and GST led to higher PBDE debromination rates, and the time-dependent activities of NaR and GST in the root crude enzyme extracts were similar to the trends of PBDE depletion. All these results suggest that NaR and GST were the key enzymes responsible for PBDE degradation. This conclusion was further confirmed by the in vitro debromination of PBDEs with the commercial pure NaR and GST.     

Cation and anion leaching and growth of Acacia saligna in bauxite residue sand amended with residue mud, poultry manure and phosphogypsum

Purpose  

To examine (1) the effect of organic (poultry manure) and inorganic (residue mud and phosphogypsum) amendments on nutrient leaching losses from residue sand and (2) whether amendments improve the growth of plants in residue sand.     

A structural decomposition analysis of air pollution from fossil fuel combustion in India

During the last decade, there has been worldwide concern with global climate change, which has been induced by greenhouse gases (GHGs) due to the use of fossil fuels. The CO₂ emissions from fossil fuel combustion have been identified as the single most significant source of GHG emissions into the atmosphere. Realising the need to control and regulate emissions of pollutants, the objective of the present study estimates the trend of CO₂, SO₂ and NO_x between the periods 1991-92 and 1996-97. An input-output structural decomposition analysis approach is used to determine their sources of change. It also provides a set of alternative scenarios for the year 2001-2 and 2006-7. The sources of changes in the amount of CO₂, SO₂ and NO_x emissions are categorised into four factors: the ecoefficiency, the structure of production, the structure of demand, and the volume of demand. Results indicate that the electricity sector contributes more towards direct, as well as indirect, emission coefficients. The petroleum product sector also contributes more in this respect. The dominant role is played by the structure of demand and the volume of demand.     

The fate and mobility of copper from chemical root control barriers in soil and leachate

The use of copper (Cu)-treated containers is common horticultural practice, though the movement of this Cu to soil and water remains unexplored. Therefore, the fate and quantity of Cu migrating from the fabric of 10 in-ground Cu(OH)(2)-treated root control baskets was studied in the field. After 3 months, 29% of the initial Cu remained on the basket fabric, 71% of the Cu had been deposited in the soil, 0.2% was in the leaves and roots of the maple shrub (Acer ginnala) growing in the basket, and 0.004% was recovered in leachate from the baskets. Soluble Cu concentrations in leachate varied between 0.5 and 8.5 mg l(-1) and exceeded 1 mg l(-1) in 60% of samples. Mycorrhizal inoculation significantly increased the Cu concentration in A. ginnala leaves. Baskets containing no tree had significantly higher soil Cu and leached significantly more Cu over the 3-month period than treed baskets.     

The impact of seasonal variations in DOC arising from a moorland peat catchment on coagulation with iron and aluminium salts

Natural organic matter (NOM) is one of the main sources of environmental pollution to drinking water supplies in much of the UK and the US. Whilst traditional treatment with trivalent coagulants has proven a successful strategy in the past, operational problems are now being reported during periods of elevated organic levels in the water. Characterisation of the pollutants in terms of polarity, molecular weight and charge, provides a method to understand the impact of the observed temporal and spatial variations in terms of a mechanistic parameter relevant to the treatment processes. Results from this study demonstrate that it is not simply the increased organic concentration, but also the change in NOM composition and character, which influences the impact on the treatment processes. Consequently, monitoring of these parameters provides an insight into how to manage the impact caused by environmental changes to the catchments.     

Concentration-dependent enantioselective accumulation of chiral polychlorinated biphenyls in Nelumbo nucifera Gaertn. root from contaminative sediment

Environmental Science and Pollution Research - Nelumbo nucifera Gaertn. (lotus) roots were collected from contaminated sediments which were artificially adding different concentrations of chiral...     

The financial development-environmental degradation nexus in the United Arab Emirates: the importance of growth,globalization and structural breaks

Environmental Science and Pollution Research - This article revisits the nexus between financial development and environmental degradation by incorporating economic growth, electricity consumption...     

Untangling unexpected terrestrial conservation challenges arising from the historical human exploitation of marine mammals in the Atlantic sector of the Southern Ocean

Intensive human exploitation of the Antarctic fur seal (Arctocephalus gazella) in its primary population centre on sub-Antarctic South Georgia, as well as on other sub-Antarctic islands and parts of the South Shetland Islands, in the eighteenth and nineteenth centuries rapidly brought populations to the brink of extinction. The species has now recovered throughout its original distribution. Non-breeding and yearling seals, almost entirely males, from the South Georgia population now disperse in the summer months far more widely and in higher numbers than there is evidence for taking place in the pre-exploitation era. Large numbers now haul out in coastal terrestrial habitats in the South Orkney Islands and also along the north-east and west coast of the Antarctic Peninsula to at least Marguerite Bay. In these previously less- or non-visited areas, the seals cause levels of damage likely never to have been experienced previously to fragile terrestrial habitats through trampling and over-fertilisation, as well as eutrophication of sensitive freshwater ecosystems. This increased area of summer impact is likely to have further synergies with aspects of regional climate change, including reduction in extent and duration of sea ice permitting seals access farther south, and changes in krill abundance and distribution. The extent and conservation value of terrestrial habitats and biodiversity now threatened by fur seal distribution expansion, and the multiple anthropogenic factors acting in synergy both historically and to the present day, present a new and as yet unaddressed challenge to the agencies charged with ensuring the protection and conservation of Antarctica’s unique ecosystems.     

Use of Co speciation and soil properties to explain variation in Co toxicity to root growth of barley (Hordeum vulgare L.) in different soils

The influence of soil properties on the bioavailability and toxicity of Co to barley (Hordeum vulgare L.) root elongation was investigated. Ten soils varying widely in soil properties were amended with seven doses of CoCl₂. Soil properties greatly influenced the expression of Co toxicity. The effective concentration of added Co causing 50% inhibition (EC₅₀) ranged from 45 to 863 mg kg⁻¹, representing almost 20-fold variation among soils. Furthermore, we investigated Co toxicity in relation to Co concentrations and free Co²⁺ activity in soil solution. The EC₅₀ values showed variation among soils of 17- and 29-fold, based on the Co concentration in soil solution and free Co²⁺ activity, respectively. Single regressions were carried out between Co toxicity threshold values and selected soil properties. Models obtained showed that soil effective cation exchange capacity (eCEC) and exchangeable calcium were the most consistent single predictors of the EC₅₀ values based on soil added Co.