WO2019051743A1

WO2019051743A1 - Method for preparing polyaluminum chloride-chitosan composite flocculant

Info

Publication number: WO2019051743A1
Application number: PCT/CN2017/101803
Authority: WO
Inventors: 谢超
Original assignee: 谢超
Priority date: 2017-09-14
Filing date: 2017-09-15
Publication date: 2019-03-21

Abstract

Disclosed is a method for preparing a polyaluminum chloride-chitosan composite flocculant, comprising the following steps: dissolving 4-8 parts of aluminum chloride hexahydrate into 80-90 parts of deionized water, slowly dropwise adding 60-70 parts of a 0.5 mol/mL NaOH solution under the conditions of rapid magnetic stirring at 40ºC-50ºC, and 2-4 h after the addition, curing same for 1-2 d, heating and stirring same at 80ºC-90ºC, and condensing and refluxing same for 10-12 h to obtain a PAC solution; adding 10-15 parts of chitosan into 40-50 parts of an acetic acid solution of 2% by volume, and rapidly magnetically stirring same until completely dissolved to obtain an acetic acid solution of CTS; taking 50-60 parts of a PAC solution, slowly dropwise adding 10-20 parts of the acetic acid solution of CTS under the conditions of rapid magnetic stirring, and stirring same until uniform to obtain the polymerized aluminum chloride-chitosan composite flocculant. The method is simple in process and easy to operate, and can quickly prepare a composite flocculant with a strong flocculation capability.

Description

Preparation method of polyaluminum chloride-chitosan composite flocculant

Technical field

The invention relates to a preparation method of a polyaluminum chloride-chitosan composite flocculant.

Background technique

Flocculation is an important part of water treatment. Flocculants can aggregate suspended solids or colloids to form large flocs. Polyaluminium chloride (PAC) is an inorganic flocculant widely used in water plants. Compared with traditional aluminum salts (non-polymerized), it can adapt to more complex water quality, produce less excess sludge and reduce it. The residual aluminum concentration in water has received extensive attention in the field of water treatment in recent years. The hydrolysis capacity of Al in PAC plays an important role in flocculation. The hydrolysis ability and morphology of Al in PAC differs greatly from the hydrolysis of Al in the traditional monomer aluminum salt. In general, the flocculation ability of the latter is weaker than the former because the hydrolysis of the conventional monomer aluminum salt is more difficult to control. The degree of hydrolysis polymerization of Al in different PACs is also different, that is, it will hydrolyze to form aluminum in different forms of polymerized state.

Chitosan (CTS) is approved by the US Environmental Protection Agency as a purifying agent for drinking water because of its natural, non-toxic and safe nature. CTS is a linear polymeric amino sugar substance which is deacetylated by chitin. Obtained, insoluble in water, soluble in acid. CTS is biodegradable, biocompatible and flocculated and can be regenerated after a series of reaction procedures. The high cation concentration produced by the hydrolysis of CTS gives it a strong flocculation capacity, which may be manifested by bridging and electrical neutralization at lower doses. At present, chitosan is often modified or used in combination with other flocculants to improve water treatment.

Summary of the invention

The object of the present invention is to provide a preparation method of a polyaluminum chloride-chitosan composite flocculant.

The invention is achieved by the following technical solutions:

The invention discloses a preparation method of a polyaluminum chloride-chitosan composite flocculant, comprising the following steps: dissolving 4-8 parts of aluminum chloride hexahydrate in 80-90 parts of deionized water, and rapidly magnetic stirring under 40-50 ° C Slowly add 60-70 parts of 0.5mL/mL NaOH solution, 2-4h drop, mature 1-2d, stir at 80-90 °C, condense reflux for 10-12h, get PAC solution; 15 parts of chitosan is added to 40-50 parts of a 2% acetic acid solution, stirred rapidly to complete dissolution to obtain CTS acetic acid solution; 50-60 parts of PAC solution is taken, and slowly added under rapid magnetic stirring conditions. 10-20 parts of CTS acetic acid solution, obtained after stirring uniformly; each raw material is part by weight.

Preferably, in the preparation method, 65 parts of a 0.5 mol/mL NaOH solution is slowly added dropwise under a rapid magnetic stirring condition at 45 °C.

Preferably, in the preparation method, the dropwise addition is carried out for 3 hours.

Preferably, in the preparation method, it is aged for 1.5 days.

Preferably, in the preparation method, the mixture is heated and stirred at 85 ° C, and condensed and refluxed for 11 hours.

The technical effect of the invention:

The method provided by the invention has simple and easy operation, and can quickly produce a composite flocculating agent with strong flocculation ability.

Detailed ways

The substantial content of the present invention will be specifically described below with reference to the embodiments.

Example 1

A preparation method of a polyaluminum chloride-chitosan composite flocculant comprises the following steps: dissolving 6 parts of aluminum chloride hexahydrate in 85 parts of deionized water, and slowly adding 65 parts under rapid magnetic stirring at 45 ° C 0.5moL / mL NaOH solution, 3h drop, after aging for 1.5d, heated and stirred at 85 ° C, condensed and refluxed for 11h, to obtain PAC solution; 12 parts of chitosan was added to 45 parts by volume of 2% acetic acid solution , rapid magnetic stirring until completely dissolved, to obtain CTS acetic acid solution; take 55 parts of PAC solution, slowly add 15 parts of CTS acetic acid solution under rapid magnetic stirring conditions, and stir evenly; each raw material is part by weight.

Example 2

A preparation method of a polyaluminum chloride-chitosan composite flocculant comprises the following steps: dissolving 4 parts of aluminum chloride hexahydrate in 80 parts of deionized water, and slowly adding 60 parts under rapid magnetic stirring at 40 ° C 0.5moL / mL NaOH solution, 2h drop, after aging for 1d, heated at 80 ° C, condensed and refluxed for 10h to obtain PAC solution; 10 parts of chitosan was added to 40 parts by volume of 2% acetic acid solution, Rapid magnetic stirring until completely dissolved, to obtain CTS acetic acid solution; take 50 parts of PAC solution, slowly add 10 parts of CTS acetic acid solution under rapid magnetic stirring conditions, and stir evenly; each raw material is part by weight.

Example 3

A preparation method of a polyaluminum chloride-chitosan composite flocculant comprises the following steps: dissolving 8 parts of aluminum chloride hexahydrate in 90 parts of deionized water, and slowly adding 70 parts under rapid magnetic stirring at 50 ° C 0.5moL / mL NaOH solution, 4h drop, after 2d aging, heated and stirred at 90 ° C, condensed reflux for 12h, to obtain PAC solution; 15 parts of chitosan was added to 50 parts by volume of 2% acetic acid solution, Rapid magnetic stirring until completely dissolved, to obtain CTS acetic acid solution; take 60 parts of PAC solution, slowly add 20 parts of CTS acetic acid solution under rapid magnetic stirring conditions, and stir evenly; each raw material is part by weight.

Claims

The invention discloses a preparation method of polyaluminum chloride-chitosan composite flocculant, which comprises the following steps: dissolving 4-8 parts of aluminum chloride hexahydrate in 80-90 parts of deionized water, 40-50 ° C fast magnetic force 60-70 parts of 0.5 mol/mL NaOH solution was slowly added dropwise under stirring, and the mixture was 2-4 h, and after 1-2 d of aging, the mixture was heated and stirred at 80-90 ° C, and condensed and refluxed for 10-12 h to obtain a PAC solution; Add 10-15 parts of chitosan to 40-50 parts by volume of 2% acetic acid solution, stir rapidly to complete dissolution to obtain CTS acetic acid solution; take 50-60 parts of PAC solution, slow under rapid magnetic stirring conditions 10-20 parts of CTS acetic acid solution was added dropwise, and the mixture was uniformly stirred; each raw material was in parts by weight.
The preparation method according to claim 1, characterized in that 65 parts of a 0.5 mol/mL NaOH solution is slowly added dropwise under a rapid magnetic stirring condition at 45 °C.
The preparation method according to claim 1, wherein the dropping is completed in 3 hours.
The preparation method according to claim 1, wherein the curing is performed for 1.5 days.
The preparation method according to claim 1, wherein the mixture is heated and stirred at 85 ° C, and condensed and refluxed for 11 hours.