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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Cotton Chemistry and Utilization Research » Research » Publications at this Location » Publication #175677
Title: ENHANCEMENT OF CLAY ZETA-POTENTIAL BY CHELATING AGENTS

Author
item POPOV, K. - MOSCOW STATE UNIV.
item KOLOSOV, A. - MENDELEV UNIV.
item ERMAKOV, YU. - FRANKLIN INSTITUTE
item Yachmenev, Valeriy
item YUSIPOVICH, A. - FANKLIN INSTITUTE
item SHABANOVA, N. - FRANKLIN INSTITUTE
item KOGUT, B. - SOIL INSTITUTE
item FRID, A. - SOIL INSTITUTE

Submitted to: Colloids and Surfaces A: Physicochemical and Engineering Aspects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2004
Publication Date: 8/18/2004
Citation: Popov, K., Kolosov, A., Ermakov, Y., Yachmenev, V., Yusipovich, A., Shabanova, N., Kogut, B., Frid, A. 2004. Enhancement of clay zeta-potential by chelating agents. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 244:25-29.

Interpretive Summary: Electrokinetic (EK) technique of soil decontamination is rapidly becoming a very attractive alternative to traditional 'pump and treat' methods for remediation of soils contaminated with a variety of contaminants, including radionuclides and heavy metals. This in-situ extraction technique utilizes a direct current (DC) electric field to transport charged contaminant species throughout the soil pore solution to a collection zone. Likewise, non-charged, organic contaminants could be flushed and extracted from the contaminated soil by exploiting electroosmosis phenomena, which is a flow of pore liquid in soil, induced by an electric field gradient. This effect also opens interesting possibilities for development of new techniques for controlled delivery of nutrients and/or pesticides/fungicides to the plant roots. If enacted, this could decrease the chemical load on fertile soil and also increase crop production as result of more precise delivery of the nutrients to the plant roots. The present paper is exploring the phenomena of the enhancement of zeta-potential by certain chelating agents. Groups benefiting from this development include the agricultural, industrial and academic scientists and the consumer.

Technical Abstract: Significant enhancement of the zeta-potential (' ) in heavy loam type soil samples treated with solutions of 1-hydroxypropane-1,1-bisphosphonic acid (HEDPA), 1,2-Diaminoethane-N,N,N',N'-tetraethanoic acid (EDTA), citric acid, and succinic acid was observed for a relatively broad range of concentrations and pH. An observed increase of zeta-potential in the samples treated with varying concentrations of HEDPA (0.0001 - 0.1 M) revealed a well pronounced broad maximum at 0.05 M. Data also indicates that the enhancement of zeta-potential imparted by HEDPA treatment was not very strongly dependent on the pH of the treated clay suspension, showing only a weakly pronounced maximum at pH 6. It was established that the observed significant increase of zeta-potential, from (-16) up to (-40) mV, qualitatively correlates with a specific complex formation ability of the studied chelating agents. The relative broadness of the maximum of the zeta-potential within a wide concentration range of HEDPA could be associated with an intensive dissolution and complex formation of background cations, such as Fe(III), Al(III), Ca(II), Zn(II), Mg(II), and Mn(II) while observed increase of zeta-potential at pH 6 could be explained by sorption of studied complexing agents on the surface of clay particles.