Method for removing fluorions in drinking water by strengthened magnesium precipitations

A fluoride ion, drinking water technology, applied in the field of water treatment, can solve the problems of complicated operation and high water treatment cost, achieve good removal effect, high fluoride removal efficiency, and promote the effect of magnesium ion precipitation

Inactive Publication Date: 2012-09-12
PEKING UNIV
View PDF5 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, under the condition of normal magnesium ion concentration in natural water, a large amount of Mg(OH) will be formed 2 For precipitation, the pH of the water body must be above 11, and a large amount of alkali needs to be added. The treated water needs to be added with acid to adjust the pH of the water body to neutral. The operation is complicated and the cost of water treatment is high. This method is rarely used.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for removing fluorions in drinking water by strengthened magnesium precipitations
  • Method for removing fluorions in drinking water by strengthened magnesium precipitations
  • Method for removing fluorions in drinking water by strengthened magnesium precipitations

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Embodiment 1. Comprehensive purification method of high hardness shallow water and high fluorine water

[0026] (1) Preparation of a solution containing Al: dissolving solid polyaluminum chloride PACl to prepare an Al solution with an aluminum content of 0.2 mol / L.

[0027] (2) Prepare 1.0mol / L NaOH solution.

[0028] (3) Extract shallow high-hardness groundwater with a magnesium ion concentration of 50mg / L, enter the reaction tank, and put the above-mentioned NaOH and aluminum ion-containing solution into it, so that the pH of the solution is 10.5, and the Al concentration is 0.10mmol / L , rapid stirring, the hydraulic retention time of the reaction tank is controlled at 20 minutes, then it is introduced into the sedimentation tank, and the sedimentation is static for 30 minutes. The effluent of the sedimentation tank is used as industrial and other water. It is discharged from the bottom of the sedimentation tank into the adsorption clarification tank, where it is mix...

Embodiment 2

[0029] Embodiment 2, strengthening co-precipitation purification method:

[0030] (1) Prepare a solution containing Al: dilute the aluminum chloride solution to prepare a 0.2mol / L Al solution.

[0031] (2) Preparation of MgO powder;

[0032] (3) Add MgO powder to the water containing 2.5mg / L of fluoride ion to make the pH of the solution 8.5-11.2. The pH of the solution increases with the increase of the dosage of MgO. At the same time, add 0.2mol / L L Al solution until the Al concentration is 0.06mmol / L, stir rapidly for 10 minutes, form a magnesium-aluminum composite co-precipitation to remove fluoride ions during the strengthening process, precipitate for 1 hour, remove the sediment, and the upper clarified water is purified and treated high-quality drinking water . The relationship curve between fluoride ion removal rate and MgO dosage, such as figure 2 As shown, when the dosage of MgO powder is 200mg / L, the pH of the solution is 10.5, the fluoride ion concentration aft...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
concentrationaaaaaaaaaa
Login to view more

Abstract

The invention relates to a method for removing fluorions in drinking water by strengthened magnesium precipitations. The method includes two means of comprehensive purification of high-hardness superficial water and high-fluorine water and purification of strengthened co-precipitation, and the two means are referred in details in instructions. The method for removing fluorion in drinking water by strengthening magnesium precipitations has the advantages that firstly, in the conventional fluorion removal by neutralizing and softening, fine fluorion removal effect can be realized only by requiring the pH value to be 11 around and a great quantity of magnesium precipitations to be generated; while in the method for removing fluorinion, magnesium ion precipitations can be generated at the lower pH value, and better removal effect of fluorinions is achieved; and secondly, compared with the existing fluorion removal method by the coagulation technology, the method for removing fluorions is high in fluorion removal efficiency. In the existing fluorion removal method by the coagulation technology, fine removal effect can be realized only at the partial acid or neutral pH conditions due to utilization of aluminum stearate and ferric salt type coagulant; coagulation efficiency is limited, feed quantity of the coagulant is large and residual capacity of water outlet coagulant is high due to high alkalinity and pH value of underground water. Besides, the method for removing fluorions in drinking water by strengthened magnesium precipitations can realize better removal effect with the lower chemical feed quantity.

Description

technical field [0001] The invention relates to a water treatment method, in particular to a method for strengthening magnesium precipitation to remove fluoride ions in drinking water at a lower pH. Background technique [0002] Fluorine is one of the essential trace elements for human body. Intake of trace amounts of fluoride is essential for the growth of human bones and teeth, however, excessive intake can lead to fluorosis, which can lead to bone deformation, slow growth, and loss of body weight. The World Health Organization stipulates that the appropriate concentration of fluoride in drinking water is 0.5-1.0mg / L. As the hazards of excessive intake of fluoride have gradually become known to humans, people have begun to explore various methods for defluoridation of drinking water. At present, there are many treatment methods for drinking water with high fluoride content at home and abroad, the main methods are adsorption, ion exchange, reverse osmosis, flocculation pr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C02F5/02C02F1/28C02F1/58C02F101/14
Inventor 晏明全
Owner PEKING UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap