Flocculation of precipitated calcium carbonate (PCC) was monitored using light diffraction spectroscopy (LDS). Four cationic polyacrylamides of high molar mass and with different degrees of branching, all copolymers of acrylamide (AM) and acryloyloxyethyltrimethyl ammonium chloride (Q9), were tested. LDS supplied information about the kinetic curves for flocs growth and also for the flocs struc...

Yeast flocculation is a community-building cell aggregation trait that is an important mechanism of stress resistance and a useful phenotype for brewers; however, it is also a nuisance in many industrial processes, in clinical settings, and in the laboratory. Chemostat-based evolution experiments are impaired by inadvertent selection for aggregation, which we observe in 35% of populations. Thes...

Olive mill wastewater (OMW) was exposed to Fenton treatment and subjected to post Fenton coagulation/flocculation using lime. Several tests were performed for different R = H2O2/COD ratios, from 0.25 to 3.0, promoting the gradual addition of H2O2 and Fe2+, with the original condition of a pH = 3.5 and maintaining a constant relationship H2O2/Fe2+ = 15. A maximum reduction of COD of 96.8% was ob...

Integration of Asphaltenes Flocculation Modeling into Athos Reservoir Simulator — To respond to the ever-growing needs of reservoir simulation studies in a large range of applications, it has been considered necessary to integrate an asphaltenes flocculation model into the Athos software. Athos is a multipurpose simulator which provides a lot of different physical options. Operating companies w...

The flocculation of silica by coagulation with hydrolyzed aluminum salt and the flocculation of aluminum salt in the presence of organic acids at pH 6.5 have been studied by using Small-Angle X-ray Scattering. The flocculation of silica at pH 4.5 by isolated All3 is very similar to its flocculation by nonhydrolyzable salt as Ca++; the fractal dimension Df of the flocs is 2.20. At pH 7.5, Al13 i...

Harvesting of microalgae Scenedesmus sp. (strain A1) using the natural polymer chitosan was investigated. Different chitosan concentrations, i.e., 10, 20, 40, 60 and 80 ppm were used in the pH range 6 to 10 and cultural cell densities values equivalent to 1, 2 and 3 abs680. Without the addition of chitosan, the increase in pH of the culture led to limited cell sedimentation. The addition of chi...

three series of a polydispersed system of sulfadiazine and sulfamerazine mixture were prepared, and effect of three inorganic electrolytes on flocculation of this system was studied. we have found the appropriate flocculating agent and also its necessary concentration. results obtained have shown that there is a relation between flocculation and sedimentation volume, but the hard cake formed wh...

Synthetic high polymer flocculants, frequently utilized for flocculating efficiency and low cost, recently have been discovered as producing increased risk to human health and the environment. Development of a more efficient and environmentally sound alternative flocculant agent is investigated in this paper. Bioflocculants are produced by microorganisms and may exhibit a high rate of flocculat...

A review on the main aspects associated with yeast flocculation and its application in biotechnological processes is presented. This subject is addressed following three main aspects – the basics of yeast flocculation, the development of “new” flocculating yeast strains and bioreactor development. In what concerns the basics of yeast flocculation, the state of the art on the most relevant aspec...

Sludge disposal is one of the most costly and environmentally problematic challenges of modern wastewater treatment worldwide. In this study, a new process was developed, which has a significant potential for lower cost of waste disposal, protection of the environment and public health, and yield of economically useful byproducts. Titanium oxide (TiO2), which is the most widely used metal oxide...