焦化废水中细菌质粒的研究

细菌质粒中常带有一些可编码降解特殊有毒物质酶的基因,为了研究质粒对有毒物质CN^-的降解的意义,主要调查了焦化废水中好氧异养菌的质粒分布特点。从山西省焦化企业公司生化站、太原煤气公司焦化厂生化站中筛选出53株细菌,利用琼脂糖凝胶电泳法,采用GDS-8000型凝胶电泳分析仪进行拍照,同时测定各菌株降氰、降酚能力,CN^-采用异烟酸-毗唑啉酮法,酚采用4-氨基安替比林法测定。结果表明,质粒的存在与降氰力有一定的关系,但对降酚力的影响差异不显著。同时,通过对其中11^*号菌株进行了质粒转化和消除实验,证明质粒稳定,不可用十二烷基磺酸钠(SDS)消除掉,用E．cbli DHI作受体菌,用11^#菌株作供体菌。作转化实验,但由于种种原因,没有筛洗到转化子。     

Managing the relationship with the environment

This article describes the results of a survey carried out by the author's company on behalf of Rank Xerox. The objective was to assess attitudes towards environmental issues in both the public and private sector. Although there were some differences over priorities, both sectors agreed that development of environmental policies was essential to their future.     

Study of the SRF-derived ashes melting behavior and the effects generated by the optimization of their composition on the furnaces energy efficiency in the incineration plants

As regards the incineration process of the urban solid waste, the composition correct management allows not only the valorization of precise civil and industrial groups of waste as alternative fuels but also a considerable increase of the furnace work temperature leading to a remarkable improvement of the related energy efficiency. In this sense, the study of the melting behavior of ashes deriving from several kinds of fuels that have to be processed to heat treatment is really important. This approach, indeed, ensures to know in depth the features defining the melting behavior of these analyzed samples, and as a consequence, gives us the necessary data in order to identify the best mixture of components to be incinerated as a function of the specific working temperatures of the power plant. Firstly, this study aims to find a way to establish the softening and melting temperatures of the ashes because they are those parameters that strongly influence the use of fuels. For this reason, in this work, the fusibility of waste-derived ashes with different composition has been investigated by means of the heating microscope. This instrument is fundamental to prove the strict dependence of the ashes fusion temperature on the heating rate that the samples experienced during the thermal cycle. In addition, in this work, another technological feature of the instrument has been used allowing to set an instantaneous heating directly on the sample in order to accurately reproduce the industrial conditions which characterize the incineration plants. The comparison between the final results shows that, in effect, the achievement of the best performances of the furnace is due to the a priori study of the melting behavior of the single available components.     

Modeling the spill in the Songhua River after the explosion in the petrochemical plant in Jilin

An explosion in a petrochemical plant in Jilin in the northeast of China on 13 November 2005 was responsible for the discharge of large quantities of benzene and nitrobenzene into Songhua River. This endangered the water supply of Harbin city and influenced the daily life for millions of people. The dispersion-advection equation was solved analytically and numerically and used to simulate the concentration of benzene and nitrobenzene in the Songhua River after the accident. Both solutions gave practically identical results. The main elimination process for both compounds was volatilization. The model results are quite close to the results obtained by measurements at monitoring stations. Arrival time of the pollutant wave, peak concentrations and end of the pollutant wave at Harbin and along the river were predicted successfully. The peak concentrations of nitrobenzene at Harbin were more than 30 times above the permissible limits for drinking water.     

Characterization and application of the enzyme peroxidase to the degradation of the mycotoxin DON

Deoxynivalenol (DON), one of the main mycotoxins found in food matrices, has high level of toxicity. This study aimed to characterize the peroxidase enzyme extracted from rice bran to be applied to the biodegradation of DON in order to evaluate the potential peroxidase (PO) from rice bran (RB) has to degrade DON in optimal conditions. Purification and recovery factors of PO extracted from RB and purified by three-phase partitioning were 5.7% and 50%, respectively. PO had the highest level of activity in the phosphate buffer 5 mM pH 5.5 in both crude and purified forms, whose reaction temperatures were 25°C and 10°C. At the end of production, purification and characterization steps, specific activities of the bran were 115.79 U mg^?1 and 4363 U g^?1. Reduction in the mycotoxin DON in optimal conditions determined for PO from RB was 20.3%, a promising result when the aim is to adequate mycotoxicological levels to foods.     

Industrial plastic on the southern beaches of the Arabian Gulf and the western beaches of the Gulf of Oman

The increasing production and use of plastic in the Arabian Gulf combined with shipping and waste disposal practices, have increased the concentration of plastic particles on the sea's surface and beaches. The objective of this investigation was to provide an assessment of the abundance, distribution, potential sources and significance of industrial plastic on the western beaches of the United Arab Emirates on the Arabian Gulf and on the eastern beaches on the Gulf of Oman. The abundance of stranded plastic pellets was highly uneven. By early 1992 alarming levels of fresh plastic pellets were noticed on the Arabian Gulf beaches of the UAE. Large numbers of 25 kg sacks of white plastic spherules manufactured by (SABIC) in Jubail, Saudi Arabia were washed ashore. When compared to the west coast on the Arabian Gulf, the east coast on the Gulf of Oman exhibited much lower levels of plastic pellets. When compared to other parts of the world, the beaches of the UAE on the Arabian Gulf are considered to be heavily polluted with industrial plastic.     

Pursuing the Goals of the Clean Air Act

I am delighted to have this opportunity to address the members attending this 67th annual meeting of the Air Pollution Control Association. Before I came here this morning, I glanced through the pamphlet describing the scheduled technical programs. I was struck by the range and sophistication of the technical sessions that are scheduled for the next three days. Your program makes it very clear that a national program of air quality management requires a large dose of scientific inquiry and engineering know-how. You are the experts who have the training, experience and commitment necessary to provide strong professional leadership in the battle to achieve and maintain clean air for the American people.     

Modelling the behaviour of PAHs during atmospheric transport from the UK to the Arctic

Persistent organic pollutants (POPs) such as PAHs are subject to long-range atmospheric transport, which can result in the contamination of remote areas such as the Arctic. A simple model was developed to describe the removal processes of four PAHs; fluorene (FLU), phenanthrene (PHEN), fluoranthene (FLA) and benzo[a]pyrene (B[a]P) transported over a 5 day period from a source area over the UK to the Russian Arctic. The purpose of this model was to study processes affecting the PAHs within the atmosphere, rather than their interaction with the earth's surface. The components to the model included gas/particle partitioning, reaction with OH radicals and dry and wet deposition (both rain and snow). Atmospheric/meteorological parameters for the geographical region of interest were generated from three-dimensional atmospheric models. Air concentrations were prescribed in the source area with no additional PAH inputs along the transect, both winter and summer scenarios were modelled. Reaction with OH was a major removal mechanism for gas-phase FLU, PHEN and FLA, most notably in the temperate atmosphere. Wet deposition in the form of snow accounted for the majority of PAH loss in the winter, although the gas and particle scavenging ratios used in this model ranged over several orders of magnitude. Using a 5 day transport scenario in a `1-hop’ event, the model predicted that a primary emission of FLA and B[a]P to the atmosphere of the southern UK, would not reach the Russian Arctic at a distance of ∼3500 km, assuming a constant windspeed of 10 m s⁻¹. However, both FLU and PHEN with calculated half-lives of >60 h during the winter could be transported to this area under this scenario.     

Effect of the pesticide lindane on the biomass of the microalgae Nannochloris oculata

This study assesses the growth of the microalgae Nannochloris oculata in the presence of lindane and the ability of N. oculata to remove lindane from media. Algal biomass increased with 0.1 and 0.5 mg L^?1 of lindane, and lindane concentrations in the media decreased. N. oculata removed 73% and 68.2% of lindane in the 0.1 and 0.5 mg L^?1 media concentrations, respectively. Algal biomass decreased to the level of the control at lindane concentrations greater than 2.5 mg L^?1, probably due to toxicity. N. oculata removed lindane from the media at concentrations lower than 1.0 mg L^?1. Thus, N. oculata may be useful for lindane bioremediation in contaminated aquatic systems.     

Investigation of the characteristics of the reflectivity of clouds

This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).     

Atmospheric nitrogen deposition: revisiting the question of the importance of the organic component

The organic component of atmospheric reactive nitrogen plays a role in biogeochemical cycles, climate and ecosystems. Although its deposition has long been known to be quantitatively significant, it is not routinely assessed in deposition studies and monitoring programmes. Excluding this fraction, typically 25-35%, introduces significant uncertainty in the determination of nitrogen deposition, with implications for the critical loads approach. The last decade of rainwater studies substantially expands the worldwide dataset, giving enough global coverage for specific hypotheses to be considered about the distribution, composition, sources and effects of organic-nitrogen deposition. This data collation and meta-analysis highlights knowledge gaps, suggesting where data-gathering efforts and process studies should be focused. New analytical techniques allow long-standing conjectures about the nature and sources of organic N to be investigated, with tantalising indications of the interplay between natural and anthropogenic sources, and between the nitrogen and carbon cycles.     

Evaluation of the available strategies to control the emission of microplastics into the aquatic environment

Environmental Science and Pollution Research - No effective strategy has been found so far to control the emission of microplastics. The purpose of this article is to review the available control...     

Attempts to probe the ozone layer and the ultraviolet-B levels of the past

To get a proper perspective on the current status of atmospheric ozone, which protects the biosphere from ultraviolet-B (UV-B; 280-315 nm) radiation, it would be of value to know how ozone and UV-B radiation have varied in the past. The record of worldwide ozone monitoring goes back only a few decades, and the record of reliable UV-B measurements is even shorter. Here we review indirect methods to assess their status further back in time. These include variations in the Sun's emission and how these affect the atmosphere, changes in the Earth's orbit, geologic imprints of atmospheric ozone, effects of catastrophic events such as volcanic eruptions, biological proxies of UV-B radiation, the spectral signature of terrestrial ozone in old recordings of star spectra, and the modeling of UV-B irradiance from ozone data and meteorological recordings. Although reliable reconstructions do not yet extend far into the past, there is some hope for future progress.     

A multi-step bioassay to assess the effect of the deltamethrin on the parasitic wasp Aphidius ervi

Insecticides are widely used for crop protection. Effectiveness of pesticides and beneficial arthropods in an Integrated Pest Management (IPM) program requires a full understanding of how specific pesticides alter natural enemy effectiveness. This may require evaluation of chemicals at different life stages of the insect considered, on different physiological and behavioural components, and also on population dynamic components such as recolonization capacities after a pesticide treatment. Aphidius ervi Haliday (Hymenoptera: Braconidae) is an aphid parasitoid commonly used for the biological control of aphid populations. In this work, our aim was to assess the effects of deltamethrin (pyrethroid) treatments on this parasitoid using a multi-step bioassay. We evaluated its effects on parasitoid emergence, adult survival and longevity, and host searching. Two exposure methods were used, topical and spray, to evaluate impact of the deltamethrin field rate (6.25ga.i./ha) and also to compare the methods of exposure. A four-armed olfactometer was used to investigate effect of deltamethrin on host searching behaviour. When applied at the rate of field exposure, deltamethrin reduced the adult longevity but not the rate of emergence from mummies. Effects varied between the two exposure methods. Two indices were defined: the "population survival index" to measure capacity of parasitoids to recolonize a treated field and the "reproductive potential" to estimate the reduction in reproduction as a function of longevity decrease. These indices predicted effects of deltamethrin on A. ervi in terms of mortality and reduction of recolonization capacities. However, adults that survived residual exposure to deltamethrin retained their ability to orient to host odours. The implications of results in IPM and interest of the methodology used are both discussed.     

Quality of the surface water of a basin affected by the expansion of the agricultural frontier over the native forest in the Argentine Espinal region

Environmental Science and Pollution Research - Land use changes have led to the degradation of multiple ecosystem services and affected the quality of aquatic ecosystems. The aims of this study...     

Assessment of the effects of the carbamazepine on the endogenous endocrine system of Daphnia magna

In the present study, the endocrine activity of the antiepileptic pharmaceutical carbamazepine (CBZ) in the crustacean Daphnia magna was assessed. To assess the hormonal activity of the drug, we exposed maternal daphnids and embryos to environmental relevant concentrations of CBZ (ranging from 10 to 200 μg/L) and to mixtures of CBZ with fenoxycarb (FEN; 1 μg/L). Chronic exposure to CBZ significantly decreased the reproductive output and the number of molts of D. magna at 200 μg/L. This compound induced the production of male offspring (12?±?1.7 %), in a non-concentration-dependent manner, acting as a weak juvenile hormone analog. Results showed that this substance, at tested concentrations, did not antagonize the juvenoid action of FEN. Further, CBZ has shown to be toxic to daphnid embryos through maternal exposure interfering with their normal gastrulation and organogenesis stages but not producing direct embryo toxicity. These findings suggest that CBZ could act as an endocrine disruptor in D. magna as it decreases the reproductive output, interferes with sex determination, and causes development abnormality in offspring. Therefore, CBZ could directly affect the population sustainability.

     

Scaling DNAPL migration from the laboratory to the field

A particular problem with the release of dense nonaqueous phase liquids (DNAPLs) into the environment is identifying where the DNAPL is and if it is still moving. This question is particularly important at sites where thousands of cubic meters of DNAPLs were disposed of. To date, results from laboratory models have not been scaled to predict analogous migration at the larger length and time scales appropriate for sites where large volumes of DNAPLs were released. Modified inspectional analysis is a technique for developing scaling relationships through nondimensionalizing the governing equations. It was applied in this study to scale observations of DNAPL migration in a laboratory model to four hypothetical scenarios in the field where large volumes of DNAPL were released. One scenario was compared to a large DNAPL spill site. The length and time scales of DNAPL movement predicted from our analysis are consistent with those predicted from a numerical model of this site. To our knowledge, this is the first application of modified inspectional analysis for release of DNAPLs in a laboratory model. This methodology may prove useful for scaling results from other laboratory investigations of DNAPL migration to field-scale systems.     

On the limits of the air pollution predictability: the case of the surface ozone at Athens, Greece

Purpose  

The aim of this study is to investigate the potential effects of increased urbanization in the Athens city, Greece on the intrinsic features of the temporal fluctuations of the surface ozone concentration (SOC).     

An assessment of the aggregate impacts of the proposed reduction in the motor fuels tax in the United States

The analysis in this paper examines the impact of reducing the excise tax on gasoline and diesel fuel on the United States economy. The analytical approach used consists of a computable general equilibrium model composed of fourteen producing sectors, fourteen consuming sectors, six household categories classified by income and the government. The effects of a 4.3 cents per gallon reduction in the excise tax on gasoline and diesel fuel on prices and quantities are examined. The results suggest, for example, that a decrease in the tax would result in higher output by the producing sectors (by about $2.86 billion), and expansion in the consumption of goods and services (by about $3.48 billion), and an increase in welfare (by about $3.59 billion). The government would realise a decrease in revenue of about $2.37 billion. When subjected to a sensitivity analysis, the results are reasonably robust with regard to the assumption of the values of the substitution elasticities.