Attestation committee
Accreditation committee
Expert committee
Dispositions, instructions
Normative acts
Nomenclature
Institutions
Scientific councils
Seminars
Theses
Scientific advisers
Scientists
Doctoral students
Postdoctoral students
CNAA logo

 română | русский | english


The Study of some noxious substances adsorption processes and the elaboration of technological schemes for sewage purification


Author: Ţîmbaliuc Nina
Degree:doctor of chemistry
Speciality: 11.00.11 - Environmental Protection and Rational Utilization of Natural Resources
Year:2009
Scientific adviser: Tudor Lupaşcu
doctor habilitat, professor, Institute of Chemistry, Academy of Sciences of Moldova
Institution:
Scientific council:

Status

The thesis was presented on the 7 November, 2008
Approved by NCAA on the 22 January, 2009

Abstract

Adobe PDF document0.37 Mb / in romanian

Thesis

CZU 661.183.2 + 541.183.5: 628.515 + 628.543+628.3

Adobe PDF document 1.27 Mb / in romanian
121 pages

Keywords

adsorption, activated carbons, dyes, surfactants, aromatic substances, heavy metals ions, sewage, purification, technological schemes

Summary

The thesis comprises fundamental and applied researches regarding the marking out of some noxious substances adsorption processes: surfactants dyes, aromatic substances and heavy metals ions.

The adsorption process of different types of surfactants on industrial activated carbons, obtained and imported from the Russian Federation as well as on activated carbons obtained in pilot and industrial conditions from local annually regenerative material, has been investigated. The influence of solution temperature upon these processes has been established. The sorption processes of surfactants and dyes from individual solutions ant their mixtures have been studied. It has been established that the volume of pores and the specific surface of carbons utilized in the process of adsorption from individual solutions is equal to the sum of these values when these pollutants are adsorbed from be-component mixtures.

It has also been established that the heavy metals ions sorption proceeds via two mechanisms, and namely – through cationic exchange and through the formation of co-ordinative bonds with oxygen atoms from the oxidate groupings modified activated carbon surface. In the process of heavy metals ion and aromatic organic substances sorption from their mixtures, component 1 is immobilized due to acid groupings from oxidized activated carbons; component 2 is retained on the carbon adsorbents due to interaction with adsorbent’s hydrophobic side.

The chemical composition of sewage from JSC “Steaua” has been studied. Coagulation and adsorption procedures, aimed at purifying the above mentioned sewage, have been tested. It has been established that the utilization of the coagulation procedure (using 50 mg/l of aluminum sulphate as coagulant) allows from the 6790 diminution of the organic load from the real sewage. This permits to increase the efficiency of autochthonic activated carbons utilization in the final stage. Sewage can be purified to the extent that would allow for its re-utilization in the technological processes, thus saving the potable water from the pipeline. Based on researches conducted in this thesis, technological schemes for purification of sewage from surfactants, dyes, aromatic substances and heavy metals ions have been elaborated.