Adsorption of propisochlor on soils and soil components equation for multi-step isotherms

Static equilibrium measurements were performed for the study of propisochlor on three different kinds of soils at pH = 7.0 at 25 degrees C. The concentration of herbicide was changed from 30 to 300 mumol/l. The obtained two-step adsorption isotherms cannot be evaluated by using the Freundlich or Langmuir equations. New equation has been derived by making use of the usual mass balance and equilibrium relationships of the adsorption and by considering the possibility of the formation of associates of the hydrophobic solute molecules. The characteristic model parameters of each step of the adsorption isotherm were estimated for the studied systems by a non-linear least square regression. The calculated curves fit well to the experimentally obtained two-step isotherms and the parameters of the model can be used for the characterization of the pesticide-soil interactions and consequently the mobility of the propisochlor in soil/water systems.     

Person-based reward systems: A theory of organizational reward practices in reform-communist organizations

A type of organizational reward system based on personal power is described and partially tested. The theory, developed from observations of Hungarian organizations, is grounded in theories of procedural justice and learned helplessness. Person-based organizational reward systems are characterized by highly valued rewards combined with personalistic criteria for reward distribution. Such organizational reward systems were hypothesized to lead to employee perceptions of organizational unfairness; negative evaluations of others; anxiety; and perceptions of self, collegial and organizational inefficacy. These hypotheses were supported in tests in a sample of three Hungarian state-owned organizations classified as having person-based systems and five non-person-based organizations (two Hungarian privately-owned companies, one American state-owned and two American privately-owned organizations). In addition, several behavioral effects of person-based reward systems were proposed: they foster bargaining behavior, withholding of information, avoidance of collaborative tasks, ingratiation and noncompliance with rules.     

Production of surfactin using pentose carbohydrate by Bacillus subtilis

Interest in microbial surfactants has been steadily increasing in recent years due to their diversity, mass production possibility, selectivity, performance under extreme conditions and potential applications in environmental protection. In this study two pentose sugars (xylose and arabinose) were investigated for the submerged fermentation (SmF) of Bacillus subtilis in surfactant production medium for bio-surfactant surfactin production. An excellent vegetative growth of B. subtilis (× 10¹⁰ CFU/mL) was observed for xylose and arabinose containing medium which were comparable to glucose supplemented medium. Low growth (× 10⁸ CFU/mL) was found when medium was not supplemented with any of the sugars. Surfactin production in xylose, arabinose and glucose containing medium was 2700, 2600 and 2000 mg/L, respectively, whereas, medium without any sugar showed low surfactin (700 mg/L) production. These results clearly indicate the effect of pentose sugars on production of surfactin. Gradual depletion of the xylose and arabinose were confirmed by HPLC analysis during the growth phase of the strain that ultimately produced the surfactin.     

Lead- and cadmium-induced histopathological changes in gill,kidney and liver tissue of freshwater climbing perch Anabas testudineus (Bloch, 1792)

The objective of this study was to examine the toxicological effect of two major heavy metal pollutants, lead chloride (PbCl₂) and cadmium chloride (CdCl₂), in the freshwater climbing perch, Anabas testudineus. Fish were exposed to 1.0 and 2.0 mg/L both metals and histopathological changes in gill, kidney and liver tissues were studied. Major changes observed in gill tissue were epithelial lifting, proliferation of epithelial cells, fusion of secondary lamellae, hyperplasia and hypertrophy of mucous cells, and necrosis of epithelial cells. Cell necrosis, degenerated kidney tubules, congestion, lymphocytic infiltration and vacuolation were the major abnormalities observed in kidney tissue. The most conspicuous changes in liver were darker nucleoli, irregularly shaped hepatocytes with dilated blood capillaries, and focal as well as single necrosis. Fish specimens exposed to PbCl₂ exhibited pronounced changes in all tissues examined compared with those exposed to CdCl₂. It is evident from this study that heavy metals can cause significant histopathological changes in fish tissue.     

Co-composting of spent coffee ground with olive mill wastewater sludge and poultry manure and effect of Trametes versicolor inoculation on the compost maturity

The co-composting of spent coffee grounds, olive mill wastewater sludge and poultry manure was investigated on a semi-industrial scale. In order to reduce the toxicity of the phenolic fraction and to improve the degree of composting humification, composts were inoculated with the white-rot fungus Trametes versicolor in the early stages of the maturation phase.During composting, a range of physico-chemical parameters (temperature and both organic matter and C/N reduction), total organic carbon, total nitrogen, elemental composition, lignin degradation and spectroscopic characteristics of the humic acids (HAs) were determined; impacts of the composting process on germination index of Hordeum vulgare and Lactuca sativa were assessed. The coffee waste proved to be a highly compostable feedstock, resulting in mature final compost with a germination index of 120% in less than 5 months composting. In addition, inoculation with T. versicolor led to a greater degree of aromatization of HA than in the control pile. Moreover, in the inoculated mixture, lignin degradation was three times greater and HA increased by 30% (P < 0.05), compared to the control pile. In the T. versicolor inoculated mixture, the averages of C and N were significantly enhanced in the HA molecules (P < 0.05), by 26% and 22%, respectively. This improvement in the degree of humification was confirmed by the ratio of optical densities of HA solutions at 465 and 665 nm which was lower for HA from the treated mixture (4.5) than that from the control pile (5.4).     

Photocatalytic oxidation of organic pollutants on titania-clay composites

TiO2/Ca-montmorillonite composites were prepared by wet grinding in an agate mill. Positively charged TiO2 nanoparticles are bound to the surface of the negatively charged montmorillonite layers via heterocoagulation; the clay mineral is used as adsorbent and support for the photooxidation process. Aquatic solution of 0.5mM phenol was degraded by irradiation with UV-VIS light (lambda=250-440 and 540-590 nm) in suspensions of TiO2-clay composites and significant photodegradation was observed at 40-60% TiO2/Ca-montmorillonite compositions. Synergistic effect was detected at solid/liquid interface for degradation of phenol and at solid/gas interface in the recycling flow reactors for photooxidation of ethanol and toluene vapors.     

THEORY,DEVELOPMENT, AND UTILIZATION POTENTIAL OF THE BIOMILIEU CONCEPT1

The paper presents a quantitative engineering approach to analysis of total environment allowing for simultaneous consideration of a theoretically infinite number of quality indicators and physiological requirements. It discusses theory and fundamentals of a two-dimensional space and time function solution concerning a small estuarine-type environment. A three dimensional solution is indicated. Input data may range from reconnaissance-type to the outputs of mathematical transport models. Applications are discussed with respect to environmental quality problems, availability of suitable data, and some areas of research where results could find immediate application.     

Temperature and extraction methods effects on yields,fatty acids,and tocopherols of prickly pear (Opuntia ficus-indica L.) seed oil of eastern region of Morocco

Environmental Science and Pollution Research - The present study focuses on the effect of temperature and extraction methods on the yields, chemical quality, fatty acids, and tocopherols of the oil...