Ya-Ling Cheng

Bio: Ya-Ling Cheng is an academic researcher from National Taiwan University. The author has contributed to research in topics: Geoprofessions & Filtration. The author has an hindex of 3, co-authored 4 publications receiving 62 citations. Previous affiliations of Ya-Ling Cheng include Chung Yuan Christian University.

Filtration blocking laws: Revisited

Abstract: Membrane filtration data are frequently interpreted using membrane blocking laws, with an filtration exponent m = 2, 1.5, 1 and 0, corresponding to complete blocking, standard blocking, intermediate blocking and cake filtration, respectively. Complicated filtration models that are based on combined blocking mechanisms have been discussed in the literature. This study presents a general blocking equation that is based on the Hagen–Poisseuille equation, considering the continuous change of the geometric parameters of the membrane pores and those of the interior of the cake (if it exists) with filtrate volume as those adopted in literature. The proposed blocking model summarized the blocking laws that have been proposed in the literature. Based on the proposed model, the filtration exponent m can be regarded as a continuous function of filtrate volume and can be changed during filtration test. Effects of pore shape and size on blocking behavior were discussed.

Characteristics of natural organic matters in raw and treated drinking water: Comparison study

Abstract: Drinking waterworks provide drinking waters to the public. This study aims at giving a cross-national comparison for the characteristics of natural organic matters (NOM) in raw waters and/or the treated waters collected from 17 waterworks in 8 countries. The NOM of raw waters were of humin-like, protein-like, or mixed type of these two based on the excitation–emission matrix (EEM) fluorescence spectra. Most waterworks efficiently remove turbidities in raw waters; but could only partially remove the NOM from waters. The DOC and size exclusion chromatography area for all collected water samples revealed a linear correlation, indicating that the characteristics of NOM in waters were similar with a universal ratio existing for the DOC and the UV-area. A fraction of non-UV254 organic matters in waters that cannot be removed by the treatment units in waterworks was noted. The water samples collected at two waterworks in Taiwan indicated that the NOM of AMW 200–1500 Da with the second highest estrogenic activities amongst all NOM in the waters can penetrate the existing water treatment chain to the supply system.

The 2008 summary of scientific productivity of chemical engineering, civil engineering and mechanical engineering professionals in Taiwan

Abstract: This report carefully examined the scientific productivity of chemical engineering, civil engineering and mechanical engineering professionals in Taiwan in 2008 by analyzing the authorship for all journal papers listed in the ISI Web of Science from chemical engineering, mechanical engineering, and civil engineering related departments and institutes in Taiwan. The result from analysis of the authorship data still follows a general trend of scientific productivity studied for the three disciplines.

A Review on Modeling of Pore-Blocking Behaviors of Membranes During Pressurized Membrane Filtration

Abstract: Pore blocking is one of the critical factors governing the overall performance of membrane filtration systems. Pore blockage leads to a large resistance to filtration, giving rise to a sharp decline in the filtrate flux rate under constant pressure conditions and a severe increase in the pressure for operation under constant flux conditions during membrane filtration. In membrane filtration work, blocking filtration laws are widely used to interpret the membrane fouling in membrane filtration. This article presents a systematic review on the theoretical developments of mechanistic models related to the blocking filtration laws for describing the membrane fouling in membrane filtration. Equations for constant pressure and constant flux separations in the interstices of a membrane and on the surface are reported for the filtrate flow of Newtonian and power-law non-Newtonian fluids. The blocking filtration laws are useful also in the evaluation of the reduced pore size, maximum filtrate volume, and fouling p...