University of Khartoum

Mobility of Polyacrylamide and Polysaccharide Polymer through Soil Materials

Mobility of Polyacrylamide and Polysaccharide Polymer through Soil Materials

Show full item record

Title: Mobility of Polyacrylamide and Polysaccharide Polymer through Soil Materials
Author: Malik ,Nasr Malik
Abstract: Knowledge of polymer mobility in soil is useful in predicting effective depth of treatment. In this study, solutions con-taining six tritium labeled polymers were flowed through columns of Arlington soil or acid washed quartz sand. The poly-mers were three polyacrylamide (PAM) compounds with negative charge density of 40J > 21J > 2J, and three polysaccha-ride compounds (guar) which had higher positive charge (T-4141), a lower posi-tive charge (CP-14) and negative charge (T-4246). Breakthrough curves were determined in each case. The ratio of leachate con-centration (C) to the of original polymer concentration at the top (Co) did not reach 1 even after more than 20 pore vol-umes (PV) were allowed to flow through. Less than 5 PV were expected to pro-duce C/Co equal to 1 from the calculated retardation factor. The concentration in the effluent dropped to undetectable level within about 1 PV after the solution at the top was replaced with untreated wa-ter which indicated irreversible polymer ISSN 0933-3630 .)1991 by CATENA VERLAG, W-3302 Cremlingen-Destedt, Germany 0933-3630/91/5011851/US$ 2.00 + 0.25 SOIL TECHNOLOGY—A cooperating Journal of CATENA adsorption. Three hypotheses were proposed to ex-plain why C/Co did not reach 1: 1. Slow penetration of polymers into soil aggregates, 2. multi-layer adsoprtion, and 3. polymers consist of two or more molecular groups with varying ad-sorptive capacities. Experiments were designed to support or reject each hypothesis. The first hy-pothesis was conclusively rejected. Al-though the second hypothesis could not be completely rejected, the third hypoth-esis provided the major effects. A frac-tion of the polymers are highly mobile, whereas a fraction had very low mobil-ity. The mobile fraction could be carried about as deep as water flow, whereas the highly adsorbed fraction would be retained very near the soil surface. The effective depth of treatment from a soil physical condition point of view depends on the unknown effectiveness of the mo-bile polymer fraction in altered soil phys-ical conditions.
URI: http://hdl.handle.net/123456789/6854
Date: 1991


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account