Determination of the Size Distribution of Dissolved Organics in Effluents

1973 ◽  
Vol 8 (1) ◽  
pp. 1-15 ◽  
Author(s):  
L.A. Addie ◽  
K.L. Murphy ◽  
J.L. Robertson
Keyword(s):  
Size Distribution ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Molecular Size ◽  
Monitoring Systems ◽  
Clean Surface ◽  
Sephadex Column ◽  
Dissolved Organics ◽  
Molecular Size Distribution

Abstract The importance of removing the small amounts of residual organics is increasing as the sources of clean surface water decrease. Knowledge of the nature of these soluble residual organics will be needed in order to assess the type of treatment required for their removal. Residual organics in three different biological treatment plants were analyzed and compared. An attempt was made to characterize these organics by a molecular size distribution on a Sephadex column monitored by differential ultraviolet and refractive index detectors. The organic carbon and chemical oxygen demand of the fractions collected from the column was also determined. An investigation of some of the problems inherent in the monitoring systems was conducted.

Characterization of Landfill Leachates by Molecular Size Distribution, Biodegradability, and Inert Chemical Oxygen Demand

2009 ◽  
Vol 81 (5) ◽  
pp. 499-505 ◽  
Author(s):  
Míriam C. S. Amaral ◽  
Cynthia F. A. Ferreira ◽  
Liséte Celina Lange ◽  
Sérgio F. Aquino
Keyword(s):  
Chemical Oxygen Demand ◽  
Size Distribution ◽  
Oxygen Demand ◽  
Molecular Size ◽  
Landfill Leachates ◽  
Molecular Size Distribution

Pretreatment of concentrated leachate by the combination of coagulation and catalytic ozonation with Ce/AC catalyst

2015 ◽  
Vol 73 (3) ◽  
pp. 511-519 ◽  
Author(s):  
Hangdao Qin ◽  
Honglin Chen
Keyword(s):  
Size Distribution ◽  
Membrane Separation ◽  
Oxygen Demand ◽  
Molecular Size ◽  
Apparent Molecular Weight ◽  
Catalytic Ozonation ◽  
Cod Removal ◽  
Distribution Analysis ◽  
Molecular Size Distribution ◽  
Ozonation Process

A raw concentrated leachate produced from membrane bioreactor-nanofiltration (MBR-NF) was taken from Chengdu Chang'an Waste Landfill Site, China. The major fraction of this concentrated leachate was large refractory humic substances. A coagulation–ozonation process was applied to treat this leachate, aiming at enhancing chemical oxygen demand (COD) removal efficiency and increasing its biodegradability. Meanwhile the molecular size distribution of the leachate, before and after coagulation and ozonation treatment, was analyzed by using ultrafiltration membrane separation. Coagulation pretreatment effectively removed varieties of large molecules in the raw concentrated leachate. The addition of Ce/AC greatly improved the oxidative ability of O3 in COD removal in the ozonation of coagulated leachate. The biochemical oxygen demand (BOD5)/COD ratio increased from 0.011 for the untreated concentrated leachate to 0.30 for the effluent of the coagulation–catalytic ozonation process, which indicated that a subsequent biological treatment could be readily conducted. The stability test demonstrated that the Ce/AC catalyst was effective and stable in the catalytic ozonation process. According to the results of molecular size distribution analysis, a direct correlation was observed between the increase of BOD5/COD and the decrease of apparent molecular weight.

Molecular Size Distribution of Lignin in Wood

Nature ◽  
1967 ◽  
Vol 214 (5086) ◽  
pp. 410-411 ◽  
Author(s):  
W. BROWN ◽  
S. I. FALKEHAG ◽  
E. B. COWLING
Keyword(s):  
Size Distribution ◽  
Molecular Size ◽  
Molecular Size Distribution

A Study of the Malpighian Tubules of the Pill Millipede, Glomeris marginata (Villers)

1974 ◽  
Vol 60 (1) ◽  
pp. 41-51
Author(s):  
PATRICIA ANNE FARQUHARSON
Keyword(s):  
Size Distribution ◽  
Fluid Transport ◽  
Molecular Size ◽  
Malpighian Tubules ◽  
Inverse Relation ◽  
Fluid Production ◽  
Molecular Size Distribution ◽  
Molecular Sieving ◽  
Tubule Fluid ◽  
Tubule Wall

1. Tubule fluid:medium ratios (TF/M) have been measured for inulin, glucose, LMWD and HMWD. These TF/M ratios were surprisingly high. 2. The tubule appears to act as a molecular filter; that is to say, molecules move through the tubule wall in inverse relation to their size. This is best illustrated using polyvinyl pyrrolidone as a tracer. The molecular size distribution of PVP fractions present in tubule fluid differs markedly from the molecular size distribution of PVP in the bathing Ringer. 3. No correlation can be made between the inulin and glucose TF/M and the rate of fluid production. However, the inverse relationship between TF/M and rate of fluid production for dextrans indicates a molecular sieving effect. 4. The significance of these results is discussed with reference to models of fluid transport.

Multidetectors for Analysis of the Composition of Copolymers as a Function of Molecular Size Distribution by Steric Exclusion Chromatography

1973 ◽  
Vol 46 (2) ◽  
pp. 449-463 ◽  
Author(s):  
D. J. Harmon ◽  
V. L. Folt
Keyword(s):  
Liquid Chromatography ◽  
Size Distribution ◽  
Oil Content ◽  
Molecular Size ◽  
The Other ◽  
Additional Information ◽  
Steric Exclusion ◽  
Gel Permeation ◽  
Exclusion Chromatography ◽  
Molecular Size Distribution

Abstract Analysis of molecular size distribution of polymers by steric exclusion liquid chromatography (GPC) is well known. Problems exist, however. These problems involve copolymers and polymer blends. The objectives of the research were to develop methods of analyzing comonomer distribution in copolymers, to study the breakdown of one polymer independent of another in a polymer blend, and to obtain any additional information as might be available. The separations were performed on a Waters Model 200 Gel Permeation Chromatograph. Detectors employed were a Waters R-4 differential refractometer, a Wilks Miran-1 infrared analyzer, and a Beckman Model 144 UV photometer. Examples are given of analysis of average styrene, styrene distribution, and oil content of oil extended SBR. The data is compared with that obtained by other methods. In general the agreement is good. The ability to examine one polymer of a blend independent of the other is also demonstrated. Since elastomers are frequently used as blends, this becomes very important to such studies as milling and extrusion behavior.

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