Faculty of ecology end chemical technology

Speciality: Ecology of chemical technologies

group OC-08m

"Investigation of the possibility sewage purification
by the soluble polymers"

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ABSTRACT

The purposes and problems:

1. Definition of synthesis conditions of a copolymer on a basis maleic anhydride;

2. Definition of characteristics of the received polymer;

3. Reception of the copolymer soluble form;

4. Research the flocculating abilities of the received copolymers;

5. Research on extraction of heavy metals from sewage by means of the received copolymer.

Theme urgency

Flocculants are high-molecular connections of the organic and inorganic nature. However all of them should be dissolved in water. At the same time overwhelming majority of existing organic polymers don’t dissolve in water. Therefore searching new water-soluble polymers which would be possible to use like flocculants is an actual problem.

Maleic anhydride which is multifunctional organic connection, is widely used in industrial synthesis of organic and high-molecular connections with a wide spectrum of valuable properties. It is one of monomers on which basis reception of soluble polymers is possible. It is among the major monomers, constitutes a basis of the modern industry of synthetic polymeric materials. The chief user of maleic anhydride (to 75% produced) - production of synthetic pitches. Besides, it serves as raw materials for synthesis of additives to oils (9%), insecticide (7%), glues (4%) and other products (5%).

Besides copolymers on a basis of maleic anhydride are used for reception ion-exchanging pitches. Known flocculants of anionic type with carboxylic groups on a basis copolymers of maleic and fumar acids.

The copolymerization mechanism is radical. Radical polymerisation is a process of formation of polymer on free-radical mechanism with consecutive joining of monomer molecules to a macro radical which grows. As chain process radical polymerisation includes following stages:

- chain initiation (origin of free radicals);

- chain growth (joining of monomer molecules to radicals);

- chain breakage.

Macromolecules with anhydride group in a chain are of interest for creation of polymeric film-forming and surface-active substances, ionits, and others technically valuable materials. Also some connections of malein anhydride are soluble in water and can have properties of flocculants.

For acceleration of coagulation process, increases the speed of their sedimentation, improvement the quality of the cleared water, and in some cases for coagulation of colloidal impurity some high-molecular substances named flocculants are use. Usually flocculants apply in addition to mineral coagulants as they promote expansion of optimum areas of temperatures and рН coagulation, reduce the capacity of coagulants, increase density and durability of aggregates which are formed, stabilise work of treatment facilities and increase their productivity.

The basic criteria of quality of polymeric reagents are:

- the chemical nature of polymer and a monomer;

- molecular weight (low 1-3 million; average 3-10 million; high more than 10 million);

- the charge nature (nonionic, anionic, cation, amphoteric);

- size (density) of a charge (low 1-10%, average 10-40%, high 40-80%, very high 80-100%);

- ductility which is advanced by molecular weight and charge;

- the physical form of polymer (amultion, a solution, gel, a powder, granules);

- stability (at storage; temperature influence, pН, ultraviolet, chlorination and ozonization);

- ability to transformation, biotransformation and biodegradation;

- presence of monomers and impurity in dangerous concentration;

- toxicity and danger.

Results and conclusions:

Polymer on a basis of maleic anhydride and styrene, and as two etherified with butyl and heptyl alcohol samples is synthesised today. Now preliminary experiments on selection of an optimum dose of flocculant for a various indicator of waters turbidity are made, experiments on research flocculating abilities of the received polymer are made. The turbidity of investigated water formed with the help of kaolin.

Further planned the realisation of researches on deducing heavy metals from water (Al, Ni, etc.) by means of the synthesised substances.