Purification of contaminated water by filtration through porous glass

Method for purifying water that is contaminated with mineral salts and soluble organic compounds is described. Method consists of high pressure filtration of contaminated water through stabilized porous glass membranes. Procedure for conducting filtration is described. Types of materials by percentage amounts removed from the water are identified

The PBW property for associative algebras as an integrability condition

We develop an elementary method for proving the PBW theorem for associative algebras with an ascending filtration. The idea is roughly the following. At first, we deduce a proof of the PBW property for the {\it ascending} filtration (with the filtered degree equal to the total degree in $x_i$'s) to a suitable PBW-like property for the {\it descending} filtration (with the filtered degree equal to the power of a polynomial parameter $\hbar$, introduced to the problem). This PBW property for the descending filtration guarantees the genuine PBW property for the ascending filtration, for almost all specializations of the parameter $\hbar$. At second, we develop some very constructive method for proving this PBW-like property for the descending filtration by powers of $\hbar$, emphasizing its integrability nature. We show how the method works in three examples. As a first example, we give a proof of the classical Poincar\'{e}-Birkhoff-Witt theorem for Lie algebras. As a second, much less trivial example, we present a new proof of a result of Etingof and Ginzburg [EG] on PBW property of algebras with a cyclic non-commutative potential in three variables. Finally, as a third example, we found a criterium, for a general quadratic algebra which is the quotient-algebra of $T(V)[\hbar]$ by the two-sided ideal, generated by $(x_i\otimes x_j-x_j\otimes x_i-\hbar\phi_{ij})_{i,j}$, with $\phi_{ij}$ general quadratic non-commutative polynomials, to be a PBW for generic specialization $\hbar=a$. This result seems to be new.Comment: 19 page

Precoat filtration with body-feed and variable pressure. Part I: Mathematical modelling

The precoat filtration with body-feed is an unit operation of agricultural and food engineering. Mostly it is implemented by using centrifugal pump, which pump curve has a partial horizontal trend. Classically, in filtration theory, this prerogative of the centrifugal pumps leads to the simplifying assumption that filtration occurs with constant pressure. Because of this, it is easy to integrate the Darcy\u2019s differential equation [1, 2 and 3] for the precoat filtration with body-feed, obtaining the well known Carman equation [4]. This is the equation which relates the filtration time with the filtrate volume, the operating pressure, the filter area, and the solid-liquid suspension characteristics. The Carman equation is the start point for the subsequent optimization of the filtration cycles, e.g. by establishing the relationship between the filtration time and the filter cleaning time [5]. A better optimization of the precoat filtration with body-feed could be obtain, with some economic benefits, if an integration of the Darcy ODE was developed starting from actual trend of the pressure produced by the centrifugal pump, that is if a variable pressure was considered, as expected from the pump curve. In this sense a proposal was done by Tiller and Crump [6] many years ago in accordance with a graphic method of integration of the Darcy ODE. However the graphic procedure is tedious since it is iterative and not computerizable. For this reason the aim of this work was to find an analytical solution to the Darcy ODE for the filtration with variable pressure in order to obtain a quick and easy-to-use equation for the subsequent optimization calculations of filtration cycles, even if more complex of the Carman equation

Pretreatment of secondary effluents in view of optimal ozone-based AOP removal of trace organic contaminants : bench-scale comparison of efficiency and energy consumption

This study compares the performance of several ozone-based advanced oxidation processes (AOPs), in combination with filtration, in terms of trace organic contaminant (TrOC) removal efficiency and energy and cost requirement. It was shown that the hydroxyl radical ((OH)-O-center dot) scavenging rate of the secondary wastewater effluent decreased as a result of an additional pretreatment step, leading to an increase of ozone and (OH)-O-center dot exposures at the same ozone dose. Adding filtration such as sand filtration or granular activated carbon filtration (GACF) as a pretreatment increased the removal efficiency of TrOCs by all tested ozone-based AOPs and reduced the minimum effective ozone dose for TrOC elimination. When the applied ozone dose is more than this minimum effective ozone dose, the elimination of TrOCs can be observed. For example, because of the use of anion resin filtration, 17 alpha-ethinylestradiol elimination contributed by the process of ozone-based AOP increased from 34.6 to 42.1% at an ozone dose of 1.0 g O-3/g dissolved organic carbon. Ozone-based AOPs coupled with filtration as a pretreatment were found to be more cost-efficient than the single AOPs at all ozone dose levels. The energy consumption of ozone-based AOPs was decreased by more than 25% when applying GACF as a pretreatment. In comparison with other filtration techniques, the pretreatment of secondary effluents by GACF before ozonation was proven to be the most cost-effective method for TrOC elimination

Gel filtration chromatography

Gel-filtration chromatography is a popular and versatile technique that permits the effective separation of proteins and other biological molecules in high yield. Here, the basis of the method is described and typical matrix types are contrasted. The selection of suitable operating conditions and applications of the method are also discussed

Evaluation of orbits with incomplete knowledge of the mathematical expectancy and the matrix of covariation of errors

The problem of selecting the optimal algorithm of filtration and the optimal composition of the measurements is examined assuming that the precise values of the mathematical expectancy and the matrix of covariation of errors are unknown. It is demonstrated that the optimal algorithm of filtration may be utilized for making some parameters more precise (for example, the parameters of the gravitational fields) after preliminary determination of the elements of the orbit by a simpler method of processing (for example, the method of least squares)