Hydrocarbon stress response of four tropical plants in weathered crude oil contaminated soil in microcosms

Responses to hydrocarbon stress of four tropical plants Panicum maximum, Zea mays, Centrosema sp. and Pueraria sp. grown in crude oil contaminated soils (1%, 5% and 10% w/w) were evaluated in a green house. Plants’ percentage survival, shoot heights, biomass development, and phytotoxicity susceptibility were used as indicators of growth, stress response and hydrocarbon tolerance. Relative to control, shoot heights and biomass of plants reduced with increasing hydrocarbon concentration, but 1% w/w oil-in-soil, stimulated shoot heights (5.9% and 6.4%) and weights (21.9% and 2.3%) in P. maximum and Centrosema sp. respectively. P. maximum tolerated the contaminant stress with biomass yields of 113% and 57% of control respectively in 1% and 10% w/w oil-in-soil. All the plants had 100% survival in 1% w/w, but considerably reduced survival in 10% w/w oil-in-soil. These results show that P. maximum has great potential for phytoremediation of petroleum contaminated soil.     

Suspended timber ground floors: measured heat loss compared with models

ABSTRACT

There are approximately 6.6 million dwellings in the UK built before 1919, predominantly constructed with suspended timber ground floors whose thermal performance has not been extensively investigated. The results are presented from an in-situ heat-flow measuring campaign conducted at 27 locations on a suspended timber ground floor, and the estimated whole-floor U-value compared with modelled results. Findings highlight a significant variability in heat flow, with increased heat loss near the external perimeter. In-situ measured-point U-values ranged from 0.54?±?0.09?Wm^?2 K^?1, when away from the external wall perimeter, to nearly four times as high (2.04?±?0.21?Wm^?2 K^?1) when near the perimeter. The results highlight the fact that observing only a few measurements is likely to bias any attempts to derive a whole-floor U-value, which was estimated to be 1.04?±?0.12?Wm^?2 K^?1 and nearly twice that derived from current models. This raises questions about the validity of using such models in housing stock models to inform retrofit decision-making and space-heating-reduction interventions. If this disparity between models and measurements exists in the wider stock, a reappraisal of the performance of suspended timber ground floors and heat-loss-reduction potential through this element will be required to support the UK’s carbon-emission-reduction targets.     

Cold resistance of three species of earthworms (Oligohaeta,Lumbricidae) in Western Siberia

We studied cold resistance of Lumbricus rubellus, Octolasion lacteum, Dendrodrilus rubidus tenuis earthworms of Western Siberia (Tomsk) populations. Worms of these species turned out to be not resistant to low temperatures (100% mortality at ?3?°C), while cocoons, on the contrary, survived ?35?°C (L. rubellus) or below ?40?°C (D. rubidus tenuis). The worms’ populations under study do not have specific cold resistance. Their main characteristics are similar in Western Siberia and other geographically remote areas according to our studies. Due to their very high cold resistance, cocoons are indifferent to winter temperatures. Hibernation of the studied species of worms in the severe conditions of the West Siberian climate is possible only in the warmest habitats where minimum soil temperature in hibernation horizons does not fall below ?2?°C. Apparently, the proportion of such habitats in the region is high as 5 out of 12 surveyed biotopes had minimum temperature above the maximum tolerated by worms at a depth of 15?cm.     

Enhanced growth rate and lipid production of freshwater microalgae by adopting two‐stage cultivation system under diverse light and nutrients conditions

This study aims to investigate the growth behaviour and lipid production of Chlorella vulgaris (a microalga) by manipulating the effect of light and nutrients. In our presumptive two‐staged growth model, C. vulgaris was first grown under low levels of light and nutrients in stage 1 and then in stage 2 under several combinations of light and nutrients, Nt?/Lt? minimum nutrients and minimum light as control; Nt+/Lt+ maximum light and maximum nutrients; Nt+/Lt? maximum nutrients and minimum light, and Nt?/Lt+ minimum nutrients and maximum light. Doubling time reduced from 46.8 ± 02 hours in control (Nt?/Lt?) to 36.1 ± 04 in Nt?/Lt+ and 37.7 ± 0.9 in Nt+/Lt? and further down to 25.2 ± 03 h in Nt+/Lt+. The highest lipid contents were found in Nt?/Lt+ (9.5 ± 0.14%) followed by Nt+/Lt+ (8.6 ± 0.2%), Nt+/Lt? (6.4 ± 0.12%) and Nt?/Lt? (6.1 ± 0.22%), respectively. The maximum biomass (909 mg/L) was found in Nt+/Lt+ likely suggesting that limited growth in control was attributed to the limitation of nutrients and light. Incremental addition of light and nutrients is suggested for enhanced growth rate, biomass and lipid production.     

Comparative effects of biostimulation and phytoremediation on crude oil degradation and absorption by water hyacinth (Eichhornia crassipes [Mart.] Solms)

This study investigated the effects of inorganic fertilizer (urea) amendment on crude oil degradation and uptake by water hyacinth (Eichhornia crasssipes). Experimental units (fresh borehole water) were spiked with crude oil at four different concentrations and then were randomly assigned fertilizer (urea) at three different concentrations. Crude oil degradation and absorption were determined monthly by measuring total petroleum hydrocarbon (TPH) in water column and water hyacinth, respectively. The water hyacinth planted in the control absorbed significantly (p?相似文献   

Extraction of fluoride from soil with water,and with hydrochloric acid solutions simulating predator gastric juices

Fluoride was extracted from two unpolluted soils and three soils polluted by fluoride from an aluminium reduction plant, using different combinations of soil weight, pH and extractant (water or HCl). Equilibrium concentration of fluoride was rapidly attained in the extractant at a soil/ water ratio of 1:10 with unpolluted soils; one polluted soil reached the same equilibrium at 4:10, another at 1.5:10. When shaken with different concentrations of HCl, polluted soils released amounts of fluoride which reached a maximum at pH 1.4. The results of treating different weights of both polluted and unpolluted soils with 0.1 M HCl are described. The results confirm the possibility of efficient uptake of fluoride by predatory animals from soil contained in earthworms.     

Levels of heavy metals in outdoor and indoor dusts in Muscat,Oman

The concentrations of lead, copper, nickel, zinc and chromium in outdoor and indoor dusts collected from different sites in Muscat, Oman, were determined by flame atomic absorption. Results showed a wide range of concentrations, the means in the outdoor dust being, 65?±?50, 124?±?316, 47?±?45, 930?±?666 and 64?±?26 mg kg^??1 for lead, zinc, copper, nickel and chromium, respectively. The 2001 Omani phasing out of leaded fuel resulted in low levels of lead in outdoor dust compared to those reported in the literature. Outstanding was the high nickel concentration in outdoor dust when compared to that in the literature, the reason being natural soil pollution due to the local geology of the northern parts of Oman. The concentrations of chromium, copper and zinc are lower than or comparable to these in other cities around the world. The results also showed that the industrial activities in Muscat do not contribute significantly to metal pollution in street dusts.

On the other hand, the mean concentrations of lead, zinc, copper, nickel and chromium in indoor dust were 108?±?65, 753?±?1162, 108?±?91, 130?±?125 and 34?±?14 mg kg^??1, respectively. In general, zinc and nickel levels are higher than those reported in the literature while lead, copper and chromium levels are lower or comparable.

When outdoor and indoor dusts were correlated, the ratios between indoor–outdoor mean concentrations revealed that lead, zinc, and copper were generated internally, while nickel and chromium were from external sources.     

Instability of petroleum oil degradation by induction of mutation in 45 kb and 60 kb plasmids

A strain of Pseudomonas sp. was isolated from oil‐contaminated soil on petroleum oil agar. This isolate used different alkenes and had two plasmids on gel agarose. These plasmids are probably involved in oil degradation. The mutant strain, which were obtained by sub‐culturing in nutrient broth (oil^?), lost one plasmid (60?Kb) and had deletion in another plasmid (45?Kb). This result suggests that the ability to degrade petroleum oil must depend on these plasmids. The wild isolate has maximum OD of 2.5 for growth on petroleum oil, however the mutant did not have any significant growth on petroleum. GC Profiles of petroleum oil after degradation by wild and mutant were investigated.     

A decade’s (2014–2024) perspective on cassava’s (Manihot esculenta Crantz) contribution to the global hydrogen cyanide load in the environment

In recent years, developing countries have increased their cassava (Manihot esculenta) production for food security. Cassava contains cyanogen glycosides, mainly as linamarin, which through bio-catalysis, i.e. enzyme hydrolysis, results in hydrogen cyanide (HCN). HCN is released into the environment through numerous ways with subsequent volatilisation. Thus, the HCN released during the period 2002–2013 was estimated between 0.025?×?10^?3 to 6.71 ppq (African), 0.012?×?10^?3 to 1.01 ppq (Asian) and 0.007?×?10^?3 to 0.920?×?10^?3 ppq (South American). Furthermore, a decade’s (2014–2024) projection of HCN volatilisation displays increases of 60.5% (Africa), 57.7% (Asia) and 50.5% (South America) when compared with the current production. Furthermore, gas released during cassava plants’ growth, i.e. HCN, NH₃, and NO₂, was quantified in healthy plants. Varying concentrations of HCN were released. These further indicated the presence of a pseudo-halogenic gas in the environment – a contributor to climate change.     

Cyclic threshold shear strain in pore water pressure generation in clay in situ samples

The threshold level of the cyclic shear strain required for pore water pressure generation in clay samples is examined through the results of torsional hollow cylinder cyclic shearing tests according to JGS 0543-2009. The study confirms the previous results, namely, that the threshold cyclic shear strain is dependent on the effective consolidation stress and plasticity index (I_p). The average and standard deviations in the estimated threshold strain levels are 0.038?±?0.023% (I_p?<?30, σ′_c?$\leqq$?100?kN/m²), 0.047?±?0.016% (I_p?<?30, σ′_c?>?100?kN/m²), 0.079?±?0.028% (30?$\leqq$?I_p?<?5?0), and 0.143?±?0.041% (I_p?$\geqq$?50). As was found in past research, the levels of threshold strain for pore water pressure generation for clay are larger than those for clean sand. An increase in pore water pressure is only observed when the stiffness is reduced to around 80% of its initial value. This delay occurs because there is a difference between the cyclic threshold strain of the pore water pressure generation, γ_tp, and the cyclic threshold strain of the stiffness degradation, γ_td. Since the test procedure of JGS 0543-2009 is a standard scheme in the practical design process, it is expected that more data will become available in the near future which will allow for further discussions on threshold strain.     

Ecotoxicological assessment of doxycycline in aged pig manure using multispecies soil systems

This paper assesses the ecotoxicity of the antibiotic doxycycline in aged spiked pig manure using a multispecies soil system (MS 3) covering plants, earthworms and soil microorganisms. The study reproduced realistic exposure conditions, as well as higher exposure doses covering the uncertainty factors typically employed for covering interspecies variability. MS 3, consisting of columns of natural sieved soil assembled with earthworms and seeds from three plant species, were employed. Pig manure was spiked with doxycycline (75 or 7500 microg/ml), aged for 15 days under aerobic/anaerobic conditions and added on top of the soil columns (120 ml/column, equivalent to 220 kgN/ha). Water and doxycycline free manure were used as negative controls. Doxycycline (7500 microg/ml) solution was used as a positive control. No effects on plants or earthworms were observed. Significant effects on soil phosphatase activity, indicating effects on soil microorganisms, were observed at the highest exposure dose, affecting all soil layers in the doxycycline-solution-treated MS 3 (positive control) but only the top layer in the spiked pig manure system. Chemical analysis confirmed the different behavior of doxycycline in both systems (with and without manure) and those effects were observed in soil with measured concentrations over 1 mg/kg soil. The detection of doxycycline in leachates revealed a potential mobility. Leachate concentrations were similar for doxycycline solution and spiked manure treatments.     

The use of indigenous coal reserves for the removal of lead(II) from the aquatic environment by adsorption

Activated carbon was prepared as an adsorbent from low cost Lakhra coal (LC) (Lignite grade) by chemical activation for the removal of Pb(II) from aqueous solution. The variables of pH, adsorbent dose, agitation time, ionic strength and temperature were investigated. The sorption process followed pseudo-first-order kinetics, intra-particle diffusion and Langmuir isotherm models. Evaluation of thermodynamic parameters affirmed the spontaneity of the process. The study also included the surface properties of activated Lakhra coal (ALC) by FTIR, scanning electron microscope and energy dispersive spectroscopy. The maximum Pb(II) removal capacity of ALC was 758?±?8?mg?g^?1 at 32?°C, approximately 300 times higher than without activation. This value was higher than other previously reported values. Thus, this study demonstrated that indigenous LC has excellent potential to be used as an economically feasible adsorbent after activation for the treatment of wastewater bearing Pb(II).     

Diversité des Fougères et leurs alliées le long du gradient altitudinal au sein de l’écosystème forestier des montagnes du Parc National de Kahuzi-Biega (RD CONGO)

Cette étude se focalise sur la vérification de l’hypothèse que l’altitude influence l’occurrence de la flore des Fougères et leurs alliées au sein de l’écosystème forestier des montagnes du Parc National de Kahuzi-Biega. Un échantillonnage de la végétation y a été effectué en considérant 24 parcelles localisées par paires le long de 12 transects installés entre 1278?m et 3123?m d’altitude. Les données obtenues ont été traitées par des méthodes statistiques, principalement la régression et des analyses multivariées. Au total, 157 espèces ont été recensées. Les résultats montrent que la richesse spécifique décroît linéairement avec l’augmentation de l’altitude à partir de 2600?m. Cette tendance prévaut à la fois dans les sites perturbés (R ²?=?0.58; P?R ²?=?0.81; P? This study concerns the hypothesis that altitude influences the occurrence of ferns and their allies in the forest ecosystem of the mountains in Kahuzi-Biega National Park. To obtain an inventory of the ferns and their allies, a sampling of the vegetation was made in 24 squares located in pairs along 12 transects lying between 1278 metres and 3123 metres altitude. The data were statistically analysed, mainly with regression methods and multivariate analysis. A total of 157 species were recorded. Species richness decreases in a linear way with higher altitude from 2600 metres. This tendency is observed in disturbed (R ²?=?0.58; P?R ²?=?0.81; P?相似文献   

Accumulation of gas‐phase methamphetamine on clothing,toy fabrics,and skin oil

To better understand methamphetamine exposure and risk for occupants of former residential clandestine methamphetamine laboratories, we measured the dynamic accumulation of methamphetamine in skin oil, cotton and polyester (PE) clothing, upholstery, and toy fabric (substrates) exposed to 15–30 ppb (91–183 μg/m³) neutral methamphetamine in air for up to 60 days. The average equilibrium partition coefficients at 30% RH, in units of μg of methamphetamine per gram of substrate per ppb, are 3.0 ± 0.2 for a PE baby blanket, 5.6 ± 3.5 for a PE fabric toy, 3.7 ± 0.2 for a PE shirt, 18.3 ± 8.0 for a PE/cotton upholstery fabric, and 1200 ± 570 in skin oil. The partition coefficients at 60% RH are 4.5 ± 0.4, 5.2 ± 2.1, 4.5 ± 0.6, 36.1 ± 3.6, and 1600 ± 1100 μg/(g ppb), respectively. There was no difference in the partition coefficient for a clean and skin‐oil‐soiled cotton shirt [15.3 ± 2.1 μg/(g ppb) @ 42 days]. Partition coefficients for skin oil may be sensitive to composition. ‘Mouthing’ of cloth is predicted to be the dominant exposure pathway [60 μg/(kg body weight*ppb)] for a toddler in former meth lab, and indoor air concentrations would have to be very low (0.001 ppb) to meet the recommended reference dose for children.     

New Approaches to Evaluate the Performance of Firefighter Protective Clothing Materials

This paper presents new proposals in the evaluation and determination of the optimum materials suitable for use in the design and development of firefighter protective clothing by simultaneously addressing the conflicting factors of thermal protection [heat transfer index (HTI), radiant heat transfer index (RHTI) and thermal threshold index (TTI)] and anti-heat stress [water vapor resistance (WVR) and total heat loss (THL)]. To achieve this, this paper proposes new indices for the materials, two types of “total performance” indices, which are defined as the sum and the product of the competing factors of thermal protection and anti-heat stress. The results showed that the candidate materials of firefighter protective clothing were easily rated when the new indices were applied. Of five candidate materials viz. A, B, B₁, B₂ and C, the B sample, with values for HTI₂₄?=?13.2?±?0.2 s, RHTI₂₄?=?18.0?±?0.8 s, TTI?=?1132?±?33 J/m², WVR?=?17.5?±?0.3 m² Pa/W and THL?=?266.2?±?4.1 W/m², was found to exhibit the best total performance. However, the methods proposed to the scientific community in this paper have so far been validated on a limited data set only, and will require further validation by a wider group of researchers and with more samples. Lastly, comments on ISO 11999-3:2015 were also made for the further improvement and development of technical standards.     

Bestimmung thermischer Eigenschaften der Gesteine des Unteren und Mittleren Buntsandsteins

For accurate planning of vertical borehole heat exchanger systems, knowledge of thermo-physical ground parameters is critical. This study reports laboratory-measured thermal conductivity and diffusivity values of Mesozoic sandstones (Lower and Middle Buntsandstein) from four wells. The measurements were made on drill core using an optical scanning method. The mean thermal conductivities of the sandstones range between 2.6?±?0.3 W?/?(m?·?K) and 3.1?±?0.4 W?/?(m?·?K) for dry conditions and between 3.6?±?0.3 W?/?(m?·?K) and 4.1?±?0.6 W?/?(m?·?K) after saturation with water. The mean thermal diffusivity values range between (1.6?±?0.2)?·?10??6 m²?/?s for dry and (2.0?±?0.6)?·?10??6 m²?/?s for water-saturated sandstones. Thermal properties are closely related to the petrography and lithostratigraphy of the sandstones. Additionally, three temperature correction methods were applied for the purpose of evaluating the comparative accuracy and the correction schemes with respect to local in-situ conditions. The results show that the temperature corrections proposed by Somerton (Thermal properties on temperature-related behavior of rock/fluid systems, Elsevier, New York, S 257, 1992) and Sass et al. (J Geophys Res, 97:5017–5030, 1992) are most suited for the respective sandstone data set.     

Determination of oil content of oil contaminated soil

The effectiveness of methylene chloride as an extractant to measure the oil content of oil-contaminated soils was examined. Soil preparation and pretreatment requirements were also studied. The results indicate that methylene chloride extracts topped crude oil efficiently from both mineral and organic soils. About 30% of untopped oils are lost during extraction. This is not considered a problem because normal volatile losses in the field of the light ends normally occurs by the time the soil is sampled. Peat samples should be air dried and mineral soils may be extracted at field capacity ($\text{?}\text{1}\text{3}$ bar water potential) or slightly drier. Complete air drying of mineral soils may reduce recovery of oil. A method of extracting and measuring the quantity of extracted oil is presented.     

Flow behaviours comparison of crude oil–polymer emulsions

The flow characteristics of crude oil–polymer (COPE) emulsions were investigated in terms of viscosity and shear stress. Two commonly used polymers in the enhanced oil recovery were employed. These two different polymers are Alcoflood and Xanthan gum. Rheostress RS100 was used in this study for measuring and analysing the experimental measurements. A cone and plate sensor of RS100 rheometer was utilised for this investigation. The experimental measurements of viscosity and shear stress of different COPE were examined over the shear rate range of 0.1–1000?s^?1. The polymer concentration range of 500–10^4?ppm was examined and two crude oil concentrations of 25% and 75% by volume were tested. A detailed investigation of the flow behaviour of COPE in the presence of two different polymers was completed. The flow behaviour of all COPE exhibit non-Newtonian shear thinning behaviour that can be presented by the power-law model for crude oil-AF1235, however the other types of COPE can be predicted by the Casson model. For a low polymer concentration of 500?ppm, this investigation showed that the flow behaviour of Xanthan emulsions is slightly higher than the Alcoflood emulsions till a shear rate of 100?s^?1. For the higher polymer concentrations, both polymer emulsions exhibited more or less similar flow behaviours till the beginning of the shear thickening for the AF1285 emulsions.     

Matrix versus fracture permeability in a regional sandstone aquifer (Wajid sandstone,SW Saudi Arabia)

Sandstones are often characterized as fractured aquifers. We present a case study of the Wajid sandstone, which forms a regional aquifer system in SW Saudi Arabia, where matrix, fracture, and large-scale hydraulic conductivities are coincident. The measurements deal with different scales and methods and are based on porosity and permeability measurements in the laboratory, as well as pumping tests in the field. Porosities of the sandstone samples in general are high and range between less than 5?% and more than 45?%. Gas permeabilities for strongly cemented samples are <?1 mD, whereas most samples range in between 500 and 5,000 mD. There is only a weak anisotropy with preference of the horizontal x-, y-directions. Hydraulic conductivities of the matrix samples (5.5?·?10^?6 m/s and 1.1?·?10^?5 m/s for the Upper and Lower Wajid sandstone, respectively) were in the same order of magnitude compared to hydraulic conductivities derived from pumping tests (8.3?·?10^?5 m/s and 2.2?·?10^?5 m/s for the Upper and Lower Wajid sandstone, respectively).     

Physico-chemical and biological parameters determine metal bioavailability in soils

The Netherlands Stimulation program on System-oriented Ecotoxicological Research focused on three study areas, including two floodplains and a peaty grassland. All three areas were polluted with metals, with total soil concentrations often exceeding Dutch Intervention Values. The floodplain areas showed a homogeneous distribution of metal pollution, while pollution in the peaty area was more heterogeneous. This study aimed at establishing possible general trends in metal bioavailability by combining results obtained at the three different study sites. Available metal concentrations, measured as pore water or 0.01 M CaCl₂ extractable concentrations in soil, were lowest in the floodplain soils, probably due to the high pH (> 7.0) and high organic matter (8-30%) and clay contents (13-42%). In the peaty soil, having a lower soil pH (4.5-6.5) but higher organic matter contents (38-60%), in some but not all samples Cu concentrations in pore water and Cu and Pb concentrations in 0.01 CaCl₂ extracts were higher than in non-polluted reference areas. Plants in the floodplain areas had only low metal concentrations in their leaves, but soil invertebrates and small mammals did contain elevated concentrations in their body. Cd showed high levels in earthworms, snails and small mammals, while also Cu levels were sometimes increased in earthworms, millipedes and small mammals from the floodplain areas. Earthworms from the peaty area contained increased levels of Cu and Pb. These results suggest that metal bioavailability cannot be predicted from available concentrations in pore water or 0.01 M CaCl₂ soil extracts, but requires measurement of biota and more insight into the biodynamics of metal uptake.