Sorption of ions of U(VI) and strontium by biosorption based on <Emphasis Type=Italic>Bacillus polymyxa</Emphasis> IMV 8910 in aqueous systems

We have investigated the influence of individual components of waters (humic acids, anions, and cations) on sorption of ions of U(VI) and strontium by the biosorbent based on the Bacillus polymyxa IMV 8919 cells. It is shown that during transition to real aqueous systems there occurs a decrease of the degree of extracting U(VI) and strontium by a microbial sorbent. Extraction of strontium in a great degree depends on the concentration in water of bivalent cations, which may compete with it in the sorption processes. A degree of purification of U(VI) is mainly determined by the pH of the medium. Acidification of aqueous media containing uranium, up to pH 5 makes it possible to raise the degree of extraction of metals by means of a biosorbent     

Biological features of sorption of U(VII) and strontium ions by <Emphasis Type="Italic">Bacillus polymyxa</Emphasis> IMV 8910 cells

It was found that Bacillus polymyxa IMV 8910 bacterium possesses high sorption capacity with respect to U(VI) and strontium ions. We have investigated the impact of the given elements on the rate of the growth and increment of the bacteria biomass. It has been found that sorption capacity of thermoin-activated biomass does not differ from the intact one; maximum sorption constitutes ∼800 and 330 μmol/g of dry matter respectively for U(VI) and strontium. The inhibition analysis and stimulation of the energy exchange of the cell by glucose showed that the processes of sorption of U(VI) and strontium by the biomass of B. polymyxa IMV 8910 did not depend on metabolic activity of the cell, i.e., are implemented by the mechanism of biosorption.     

The effect of carbon dioxide on the viability of bacteria of <Emphasis Type=Italic>Bacillus</Emphasis> and <Emphasis Type=Italic>Diplococcus</Emphasis> genera

The effect of the volume of carbon dioxide gas released from aqueous solution on the reduction of the number of vegetative microorganisms per unit volume of the system has been investigated. A linear relationship between the number of vegetative microorganisms and the volume of released carbon dioxide is observed, when the volume of the released gas does not exceed the level of 0.5 dm³/dm³ of solution. The increasing ratio of the amount of spores to the number of vegetative bacteria of Bacillus genus results in a largely reduced impact of the volume of released carbon dioxide on the microbial viability.     

A method for mapping the spatial distribution of <Emphasis Type=Italic>RockFall</Emphasis> computer program analyses results using <Emphasis Type=Italic>ArcGIS</Emphasis> software

Rockfalls are a natural process of cliff and hillside erosion and can be simulated by computer programs. RocFall is a useful and well-known program which produces envelopes of kinetic energy, velocity, bounce height and fall-out distance for a selected profile. However, with this program it is difficult to record the spatial distribution of the envelopes in their exact coordinates in GIS. In this paper, a method and computer code (FallGIS) written by the authors is proposed for mapping the results obtained from RocFall in ArcGIS. As it is both user-friendly (hence quicker) and does not require any new software, it is hoped it will be a useful tool for engineering geologists, urban planners, etc.      

The <Emphasis Type=Italic>E. coli</Emphasis> dying kinetics under the effect of ozone

The article has investigated the inactivation kinetics of E. coli under the effect of ozone at its different concentrations, pH values, and temperature of a model solution. We have calculated the rate constants of the pseudofirst order and the activation energy of contamination of test organisms with ozone. We have studied the role of free radicals in contamination processes in the presence of traps for radicals: tert-Butanol alcohol and sodium bicarbonate. It has been shown that in the water free of organic matter, contamination takes place mainly by the molecular mechanism of an ozone effect on microorganisms.     

Social housing programme of Selangor <Emphasis Type=Italic>Zakat</Emphasis> Board of Malaysia and housing satisfaction

Social housing in Malaysia is provided through the public and private sectors. Recently, the Selangor Zakat Board (SZB) has started to provide social housing in the state of Selangor, Malaysia. Up to 2007, a total of 906 units have been delivered under its different programmes. This paper evaluates these programmes by adopting the housing satisfaction model which is currently used as a customer satisfaction tool for public/private housing in many local governments in the UK and USA. The main purpose of this paper is to identify the types of housing programmes adopted by SZB and examine beneficiaries’ housing satisfaction in each programme on a comparative plane. In order to examine housing satisfaction, five objective components of satisfaction—housing unit features, housing unit support services, the social environment, public facilities and neighbourhood facilities—were analysed through beneficiaries’ levels of satisfaction which were measured by applying a Likert scale. The findings of the paper indicate that SZB has been successful in providing a moderate level of satisfaction with the housing unit. However, the existence of variable levels of satisfaction with other components implies that there is still scope to enhance residents’ satisfaction with those components.     

The method of eliminating phenol with the use of tyrosinase <Emphasis Type=Italic>Agaricus bisporus</Emphasis> immobilized in alginate

We have considered the method of oxidizing aqueous solutions of phenol (0.25–2.00 mmol/dm³) with the use of a biocatalyst—a partially purified tyrosinase immobilized into calcium alginate. In optimal conditions (pH 7.2, T—25°C, transformation time—one hour, phenoloxidase activity—25–200 unit/cm³) when adding a PEG-6000 stabilizer the preparation stabilized complete oxidation of phenol in a periodic-action reactor during 12 cycles and retained a high degree of transformation of the substrate during the following 16 cycles. The concentrations of coagulants necessary for elimination of transformation products using the immobilized enzyme were reduced 2.5-fold compared with such for a free biocatalyst.     

Heterogeneous rock mass classification by means of the geological strength index: the <Emphasis Type=Italic>San Mauro</Emphasis> formation (Cilento,Italy)

This paper describes an application of the geological strength index (GSI) method to the San Mauro formation, which is characterized by sandstones alternating with argillaceous marls. The Sandstone/Pelite (S/P) ratio and structural complexity were determined. Geo-structural and geo-mechanical surveys were undertaken in situ and rock samples were tested in the laboratory. A map of the S/P ratio was produced showing the bedrock divided in four classes. Three ranges of GSI values were identified. The values of the intact UCS and of the constant m _i were appropriately reduced to reflect the variable presence of sandstone compared with the pelitic fraction. A “weighted average” of the intact strength properties of the hard and weak layers was adopted. The values for the intact materials were reduced from 20 to 60% depending on the GSI categories of the heterogeneous rock mass. In this way, seven classes of rock masses characterized by different values of GSI, reduced UCS and m _i values were identified.     

The Simultaneous Bioremoval of Cr(III) and Dye by Immobilized <Emphasis Type="Italic">Phanerochaete Chrysosporium</Emphasis>

To attain better removal efficiency and higher toxic resistance, the alginate was used to immobilize Phanerochaete chrysosporium BKM-F-1767 in this study. And according to the characteristics of tannery wastewater, inhibitory effect of Cr(III) to the decolorization was investigated and adsorption kinetics of Cr(III) by the immobilized P. chrysosporium had been established. Furthermore, the Acid Violet 7 and Basic Fuchsin contributed as the experimental dyes in the paper, the removal studies were performed at an initial pH of 4.5. The combined effects of Cr and dyes on the simultaneous removal properties were determined in a batch system at different levels of Cr and dyes. Moreover, the dose-response relationship and a kinetic equation describing the simultaneous removal properties had been established. The results have proved that the immobilized P. chrysosporium has the ability to treat the tannery wastewater.     

Purification of radioactively-contaminated waters of <Superscript>90</Superscript>Sr and U(VI) by a ferrite method

We investigated the processes of water purification of ⁹⁰Sr and U(VI) by the ferrite method using the salts FeSO₄ and FeCl₃. It was found that for the formation of a crystalline sediment with magnetic properties there is required a total concentration of iron in the solution ≥150 mg/dm³. Due to partial oxidation of Fe(II) with air oxygen the optimal ratio Fe(II)/Fe(III) in solution should be equal to 6. Alkali concentration for precipitating ferrite under these conditions constitutes 0.01 M. When the alkali concentration is increased further the volume of magnetite sediments does not change, while the values of saturation magnetic induction of ferrite remain maximum. By means of the analysis of phase composition it is shown that the resultant sediment possesses high crystalline property and saturation magnetic induction virtually right after precipitation and has a structure of ferrite. We carried out an assessment of a water purification degree of ⁹⁰Sr and U(VI) by the ferrite method.     

Capacity variation of polymer membranes in biological fouling with <Emphasis Type="Italic">E. Coli</Emphasis> cells

The paper has studied the processes of the biological fouling of UPM-67, UAM-500, and PAN-20 polymer membranes in filtration through them of an E.coli suspension. The paper gives quantitative indicators of the growth of microorganisms on the surface of the membranes depending on a composition of the water being treated. A correlation between membrane capacity and the amount of the E. coli cells that adhered to their surface was conducted.     

Optimierter mikrobiologischer Abbau von Chlorbenzen in <Emphasis Type="Italic">In situ</Emphasis>-Grundwasserreaktoren (SAFIRA)

In two reactors of the SAFIRA pilot plant, the microbial degradation of chlorobenzene (CB) by indigenous bacteria in native aquifer sediment were tested under oxic and anoxic conditions. Under anoxic conditions, no definite degradation was observed. Adding hydrogen peroxide (2.94 mM) and nitrate (2 mM) in one of the two reactors caused the degradation of CB (0.2–0.3 mM) in the lower part of the reactor, accompanied by a clear increase of the number of cultivable aerobic CB-degrading bacteria. After decreasing the hydrogen peroxide concentration to 0.88 mM, the CB concentrations increased in the lower part of the reactor, but decreased later, starting after approximately 100 days, finally under the detection limit again. Less than four mole oxygen were needed for the degradation of one mole CB. No accumulating compounds were determined, which could indicate an incomplete aerobic degradation of CB. These results point out that the oxygen released from hydrogen peroxide was almost completely consumed by bacteria for CB degradation. Nitrate disappeared uniformly during the reactor flow path.     

The combined effect of hydrodynamic cavitation,hydrogen peroxide,and silver ions on the <Emphasis Type="Italic">Escherichia coli</Emphasis> microorganisms

The combined effect of chemical reagents upon sanitary indicator microorganisms of Escherichia coli under conditions of hydrodynamic cavitation was investigated. It was found that the addition of Ag(I) ions or hydrogen peroxide to cavitation units makes it possible to reduce the duration of disinfection due to synergistic effect. The intensifying impact is explained by the physical effects of the cavitation field giving rise to a rapid penetration of chemical reagents into microbial cells and its disintegration. As well as by the chemical processes within the volume of a cavitation bubble accompanied by the formation of strong oxidants: hydroxyl, hydrogen peroxide, and ozone radicals.     

Formation of viable noncultural state of <Emphasis Type="Italic">Candida Albicans</Emphasis>

The paper has investigated the influence of NaOCl on the cells of Candida albicas with the aim of finding viable noncultural state and also conditions of their rehabilitation. Microscopic research of the cells Candida albicans has been given in the indicated state colored with trypan blue.     

An analysis of economic cost minimization and biological invasion damage control using the <Emphasis Type="Italic">AWQ</Emphasis> criterion

DeAngelo et al. (New approaches to the Economics of plant health. Springer, Heidelberg, 2006) have recently used the AWS criterion in a M/G/1 queuing model to show that there is no necessary tension between economic cost minimization and inspection stringency in non-native species management. In this paper, we use an alternate cost criterion (AWQ criterion) to investigate the generality of this central result in DeAngelo et al. (New approaches to the Economics of plant health. Springer, Heidelberg, 2006). Our theoretical analysis shows that there is no unambiguous answer to this question. Therefore, we use numerical methods and our numerical analysis leads to two findings. First, for many values of the model parameters that describe the strictness of inspections, there is a tension between cost minimization and inspection stringency. Second, for most values of the model parameter that depicts the volume of maritime trade handled by the seaport under consideration, there is no tension between cost minimization and inspection stringency.      

Inactivation of <Emphasis Type="Italic">Candida albicans</Emphasis> in the photo-fenton system

The paper has investigated photocatalytic decontamination of the culture of micromycetes Candida albicans in water media depending on the radiation dose (UV-A range), the pH of the medium, the concentration of H₂O₂, ions of iron (II), (III), and phosphate ions. We proposed the interpretation of the impact of the specified factors on the rate of the course of the process being investigated. We showed prospects of using the UV/H₂O₂ and photo-Fenton systems as applied to decontamination of water media from micromycetes Candida albicans.     

Study on the effect of <Emphasis Type="Italic">Artemia franciscana</Emphasis> on the uptake of Zn(II) and Cu(II)

The toxicokinetic study was used to assess the potential of an organism for Zn(II) and Cu(II) bioaccumulation and it was ascertained using a bicompartmental model. The effect of Zn(II) and Cu(II) concentration on the kinetics parameter in Artemia franciscana were determined. In the present investigation, the uptake rate seems to be high with the time period of 72 h for Zn(II) when compared to Cu(II) by the process of bioaccumulation. The bioconcentration factor (BCF) and metal influx rate (I) was also found higher in the Artemia which was exposed to Zn(II) when compared to Cu(II), whereas BCF was inversely related to the concentration. From these parameters, we may predict the effective bioaccumulation of Zn(II) and Cu(II) using Artemia franciscana and whose kinetic parameters were found to be suited to the bicompartmental model.