Fluorine-containing wastewater treatment device and process for liquid crystal display panel production plant

Abstract

The invention discloses a fluorine-containing wastewater treatment device and process for a liquid crystal display panel production plant, relates to the field of wastewater treatment, and mainly aimsto solve the problems of an existing fluorine-containing wastewater treatment process. Although the fluoride concentration of the treated concentrated water subjected to reverse osmosis treatment isabout 10mg / L which is as same as that of the existing process, the fluoride concentration in the reverse osmosis produced water is lower than 1mg / L, and the fluoride concentration in the final effluent can reach 5mg / L or below or meet a stricter discharge limit value after the reverse osmosis concentrated water subjected to fluorine removal treatment is mixed with all or part of the reverse osmosis produced water, that is, the effluent quality of the fluorine-containing wastewater treatment is superior to that of a conventional treatment process. According to the method, the fluoride concentration in the fluorine-containing wastewater can be reduced to below 5mg / L or meet a stricter emission limit value only by adopting a conventional fluorine removal agent, and the agent consumption is low although the same fluorine removal effect can also be achieved by adopting a special formula fluorine removal agent.

Description

technical field [0001] The invention relates to the field of waste water treatment, in particular to a device and process for treating fluorine-containing waste water in a liquid crystal panel production plant. Background technique [0002] A large amount of fluorine-containing wastewater is produced during the production of LCD panels. At present, the treatment method for fluorine-containing wastewater in LCD panel production plants is usually calcium salt precipitation to remove fluoride, that is, calcium hydroxide or calcium chloride is added to the wastewater to form fluorine. Calcium chloride precipitation to remove fluoride in wastewater (for the process route, please refer to the attached figure 1 ). [0003] There are two problems in the above process. One is that the calcium salt precipitation method can usually only remove fluoride in wastewater to about 10 mg / L. When it is necessary to further remove fluoride to below 5 mg / L or a stricter discharge limit, calcium...

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Problems solved by technology

[0003] There are two problems in the above process. One is that the calcium salt precipitation method can usually only remove fluoride in wastewater to about 10 mg / L. When it is necessary to further remove fluoride to below 5 mg / L or a stricter discharge limit, calcium The salt precipitation method cannot meet the requirements. At this time, a special formula for defluoridation agent is often used for advanced treatment, but the cost of the agent is relatively high. The hardness is relatively high, and chemical softening (soda ash is used as the softening agent to form calcium carbonate precipitation with calcium ions in the wastewater) and resin softening treatment (see the appendix for the process route) are required before reverse osmosis treatment. figure 2 ), which makes the overall treatment process long and high operating costs

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