A review of soluble microbial products (smp) in wastewater treatment systems

https://dr.ntu.edu.sg/bitstream/10356/82800/2/Figures%20_R20151007.pdf

Membrane fouling in osmotically driven membrane processes: A review

Importance of heavy metal-organic matter interactions in natural waters

Organic fouling of reverse osmosis (RO) membranes and its relation to foulant--foulant intermolecular adhesion forces has been investigated. Alginate and Suwannee River natural organic matter were used as model organic foulants. Atomic force microscopy was utilized to determine the adhesion force between bulk organic foulants and foulants deposited on the membrane surface under various solution chemistries. The measured adhesion force was related to the RO fouling rate determined from fouling experiments under solution chemistries similar to those used in the AFM measurements. A remarkable correlation was obtained between the measured adhesion force and the fouling rate under the solution chemistries investigated. Fouling was more severe at solution chemistries that resulted in larger adhesion forces, namely, lower pH, higher ionic strength, presence of calcium ions (but not magnesium ions), and higher mass ratio of alginate to Suwannee River natural organic matter. The significant adhesion force measured with alginate in the presence of calcium ions indicated the formation of a crossed-linked alginate gel layer during fouling through intermolecular bridging among alginate molecules.

Relating organic fouling of reverse osmosis membranes to intermolecular adhesion forces

Chemical and physical aspects of cleaning of organic-fouled reverse osmosis membranes

Characterization of organics in secondary effluents

Elimination of CH3OH under electron impact occurs in trans-1,2- and 1,3-dicarbomethoxycycloalkanes to a greater extent than in the cis-isomers In the trans-diesters, one of the α-hydrogen atoms is abstracted in the course of the elimination In the methyl esters of cyclohexane 1,4-dicarboxylic acids, the elimination of CH3OH is also specific to the trans-isomer, but the abstracted hydrogen atom does not originate at the α-position This result is explained by a stereospecific hidden hydrogen migration step, preceding the elimination

Stereospecific Methanol Elimination and Hidden Hydrogen Transfer in Cyclic Diesters under Electron Impact

Elimination of CH3OH under electron impact occurs in trans-1,2- and 1,3-dicarbomethoxycycloalkanes to a greater extent than in the cis-isomers. In the trans-diesters, one of the α-hydrogen atoms is abstracted in the course of the elimination. In the methyl esters of cyclohexane 1,4-dicarboxylic acids, the elimination of CH3OH is also specific to the trans-isomer, but the abstracted hydrogen atom does not originate at the α-position. This result is explained by a stereospecific hidden hydrogen migration step, preceding the elimination.

Arie Bortinger

Papers

Characterization of organics in secondary effluents

Stereospecific Methanol Elimination and Hidden Hydrogen Transfer in Cyclic Diesters under Electron Impact

Stereospecific methanol elimination and hidden hydrogen transfer in cyclic diesters under electron impact