Preparation method of loose type polyaluminum ferric chloride flocculants

Abstract

A preparation method of loose type polyaluminum ferric chloride flocculants includes the steps: mixing univalent soluble salt solution serving as loosening agents with polyaluminum chloride solution and ferric trichloride solution, and stirring for continuous reaction for 4h at a rotation speed of 150r / min at the temperature of 40-100 DEG C, so that the loose type polyaluminum ferric chloride flocculants can be obtained. The preparation method has the advantages that the flocculants not only have the excellent flocculation performance and a powerful charge neutralization function of polyaluminum chloride, but also have the advantages of ferric chloride, including high adsorbability, high sedimentation speed, large formed floccules and the like, are better than the ferric chloride in effluent color contamination and have the advantages of good coagulation effects, rapid action, less consumption, wide application range and the like. The base materials of polyaluminum chloride and ferric trichloride used in the method are sufficient in source, so that powerful support is provided for large-scale industrialization. The polyaluminum ferric chloride flocculants are ideal environment-friendly water-treatment flocculants as discharge of waste residues and wastes is basically avoided during production, and environmental pollution is reduced.

Description

technical field [0001] The invention relates to a treatment method for production and domestic water, in particular to a preparation method for a loose polyaluminum ferric chloride flocculant. Background technique [0002] The main treatment method for production and domestic water is to use flocculants, which mainly include aluminum salt series, iron salt series and polyaluminum ferric chloride. [0003] The early flocculants used to treat domestic water were mainly aluminum sulfate, which produced aluminum hydroxide colloids through hydrolysis to absorb suspended substances in water to achieve water purification effects. The water purification effect of aluminum sulfate is not ideal, and the later developed polyaluminum chloride (PAC) has a better flocculation effect. PAC forms alum flowers quickly in water, and the large particles are easier to precipitate, and the flocculation effect is better than that of traditional aluminum salts. PAC, like traditional aluminum salt...

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Problems solved by technology

On the other hand, ferric chloride also has the following disadvantages in use: 1) The dosage of the agent is large, the content of residual iron ions is high, and the low-molecular iron salt is corrosive to the equipment during use, and the chromaticity of the treated water is higher than that of aluminum High salinity; 2) The formation of flocs is less, and the sludge after flocculation cannot be effectively used; 3) Ferric salts are not suitable for treating industrial wastewater containing sulfides, because Fe3+ ions and sulfides will generate iron sulfide or ferrous sulfide 4) When the dosage of iron salt is insufficient, the ferric hydroxide colloid formed by hydrolysis not only does not thresh and destabilize impurities, but becomes a stable system by itself, which increases the turbidity of raw water, and The higher the degree of alkalinity, the greater the residual turbidity

Since these production processes include the process of extracting aluminum and iron, the process is complicated and there are residues discharged, which is not conducive to environmental protection.

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