Bacteria Cell Hydrophobicity and Interfacial Properties Relationships: A New MEOR Approach

For microbial enhanced oil recovery (MEOR), different mechanisms have been introduced. In some of these papers, the phenomena and mechanisms related to biosurfactants produced by certain microorganisms were discussed, while others studied the direct impacts of the properties of microorganisms on the related mechanisms. However, there are only very few papers dealing with the direct impacts of microorganisms on interfacial properties. In the present work, the interfacial properties of three bacteria MJ02 (Bacillus Subtilis type), MJ03 (Pseudomonas Aeruginosa type), and RAG1 (Acinetobacter Calcoaceticus type) with the hydrophobicity factors 2, 34, and 79% were studied, along with their direct impact on the water/heptane interfacial tension (IFT), dilational interfacial visco-elasticity, and emulsion stability. A relationship between the adsorption dynamics and IFT reduction with the hydrophobicity of the bacteria cells is found. The cells with highest hydrophobicity (79%) exhibit a very fast dynamic of adsorption and lead to relatively large interfacial elasticity values at short adsorption time. The maximum elasticity values (at the studied frequencies) are observed for bacteria cells with the intermediate hydrophobicity factor (34%); however, at longer adsorption times. The emulsification studies show that among the three bacteria, just RAG1 provides a good capability to stabilize crude oil in brine emulsions, which correlates with the observed fast dynamics of adsorption and high elasticity values at short times. The salinity of the aqueous phase is also discussed as an important factor for the emulsion formation and stabilization.

A Study of Adsorption Dynamics of Biologically Active Plants

Alstonia scholaris is a biologically active and important Devil tree. The medicinal importance pharmacology importance in particulars antiulcer activity of Alstonic scholaris in albino rats were Analyzed and reported. The juice of Alstona scholaris to rats show a remarkable record with respect to ranitidine tablet (to cure ulcer). This result initiate the author to study chemo mimetic nature of plant material for the removal of heavy metal in synthetic solution also extended studies with modified Alstonia scholaris and Wrichitia Tinctoria. An adsorption of 96% in all the cases was observed. A linear correlation with R2 value of 0.977 was calculated from the linear plot of optical densities of Alstonia Scholaris and modified Alstonia Scholaris similar trend in adsorption was also noted. In the case of Wrightia Tinctoria instead of modified Alstonia Scholaris

Analysis of Selected Methods Use for Calculation of the Coefficients of Adsorption Isotherms and Simplified Equations of Adsorption Dynamics with the Use of IZO Application

The purpose of this paper is to present the IZO application that calculates and visualizes coefficients of adsorption isotherms according to Freundlich, Langmuir, and BET in a classic and linear system, in a simple communicative way. The application also calculates the working time of the adsorption bed based on the transformation of the mass balance equation, and according to the Zuchowicki, Zabieziński, Tichonow, and the Bohart-Adams equations. The laboratory tests of the adsorption process of leachate from a municipal landfill on selected active coals ORGANOSORB 10, DESOTEK, and BA-10, were conducted to check the program for accuracy. Results of tests confirm that the linearization method of the calculation of adsorption isotherms coefficients, used in the IZO application, gives sufficient accuracy and may be used as an alternative of, e.g., the nonlinear estimation method.

ADSORÇÃO DE FÓSFORO EM SOLOS DE REGIÕES TROPICAIS

O fósforo (P) é o nutriente mais limitante ao cultivo nos solos tropicais, que, geralmente, apresentam alta capacidade de adsorção de P. Alguns atributos químicos e físicos do solo como o teor de argila, pH, CTC efetiva e matéria orgânica influenciam na dinâmica de adsorção. O objetivo deste estudo foi avaliar o processo de adsorção do fósforo em um Latossolo Vermelho Amarelo (LVA) e um Neossolo Quartzarênico (RQ) da região de transição Cerrado-Amazônia, e avaliar os atributos dos solos que influenciam na dinâmica de adsorção do P. Os ensaios de sorção foram realizados pelo método “Batch” ou em batelada e à partir dos dados obtidos foram construídas curvas obtendo a equação linearizada de Langmuir, com as quais foram determinados os valores de capacidade máxima de adsorção de P (CMAP), a constante relacionada com a energia de ligação (KL) e o fator capacidade de P máximo (FCPmáx). Houve diferença na CMAP, KL e FCPmáx dos solos estudados, sendo que os maiores valores foram encontrados no LVA, devido principalmente ao maior teor de argila em relação ao RQ. A matéria orgânica foi um dos poucos atributos que tiveram correlação negativa com os atributos de adsorção, ressaltando sua importância no manejo para aumentar a eficiência da adubação fosfatada. Palavras-chave: Latossolo Vermelho Amarelo; Neossolo Quartzarênico; Isotermas de adsorção. Phosphorus adsorption in soils of tropical regions ABSTRACT: Phosphorus (P) is the most limiting nutrient for cultivation in tropical soils, as they generally have high P adsorption capacity. Some chemical and physical attributes of soil such as clay content, pH, effective cation exchange capacity (ECEC) and organic matter influence the adsorption dynamics. The objective of this study was to evaluate the behaviour of the phosphorus adsorption process in a Red-Yellow Latosol and a Quartzarenic Neosol from the Cerrado-Amazon transition region, and to evaluate the soil attributes that influence the adsorption dynamics of the soil of the phosphorus. Sorption tests were performed using the “Bach” method, from the Langmuir linearized equation, the maximum P adsorption capacity (MPAC), the constant with the binding energy (KB) and the maximum capacity factor (PCFmax) were selected. There was a difference in MPAC, KB and PCFmax of the studied soils, and the highest values ​​were found in the Red-Yellow Oxisol, mainly due to the higher clay content in relation to theTypic Quartzipisamment. Organic matter was one of the few attributes that had a negative correlation with the adsorption attributes, highlighting (emphasizing) it’s importance in (soil) management to increase the efficiency of phosphate fertilization. Keywords: Red-Yellow Latosol; Quartzarenic Neosol; adsorption isotherms.