Stainless steel cold-rolled acid wastewater denitrification treatment process

A technology of acid wastewater and treatment process, which is applied in the field of water treatment, can solve the problems of high cost of wastewater treatment chemicals, and achieve the effect of solving the high cost of wastewater treatment chemicals, saving costs, and broad market prospects

Inactive Publication Date: 2019-10-11
上海东振环保工程技术有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a stainless steel cold-rolled acid wastewater denitrification treatment process, to solve the existing stainless steel cold-rolled acid wastewater denitrification treatment process proposed in the background technology due to the addition of a large amount of softening agents to bring wastewater treatment agents costly problem

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  • Stainless steel cold-rolled acid wastewater denitrification treatment process
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Examples

Experimental program
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Effect test

Embodiment 1

[0032] A stainless steel cold rolling acid waste water denitrification process, please refer to figure 2 , which includes the following steps:

[0033] 1) Lime neutralization: add milk of lime (5-10% mass concentration) to stainless steel cold-rolled acid wastewater for lime neutralization treatment, and the hydraulic retention time is 0.5h; through lime neutralization treatment, fluoride ions, Sulfate ions react with calcium ions to form calcium fluoride and calcium sulfate precipitates. At the same time, heavy metal ions such as iron, nickel, and chromium in wastewater form hydroxide precipitates under alkaline conditions;

[0034] 2) Primary coagulation and sedimentation: add coagulants and flocculants in turn to the effluent after step 1) lime neutralization for coagulation and sedimentation, the hydraulic retention time is 0.3h; and the produced insoluble matter to form larger dense flocs, and then the sedimentation sludge (that is, dense flocs) is separated from water ...

Embodiment 2

[0042] A stainless steel cold rolling acid waste water denitrification process, please refer to figure 2 , which includes the following steps:

[0043] 1) Lime neutralization: lime milk (5-10% mass concentration) is added to stainless steel cold rolling acid wastewater for lime neutralization treatment, and the hydraulic retention time is 1h; through lime neutralization treatment, fluoride ions and sulfuric acid in wastewater Root ions react with calcium ions to form precipitates of calcium fluoride and calcium sulfate. At the same time, heavy metal ions such as iron, nickel, and chromium in wastewater form hydroxide precipitates under alkaline conditions;

[0044] 2) Primary coagulation and sedimentation: add coagulant and flocculant in sequence to the effluent after lime neutralization in step 1) for coagulation and sedimentation, and the hydraulic retention time is 0.5h; and the produced insoluble matter to form larger dense flocs, and then the sedimentation sludge (that ...

Embodiment 3

[0052] A stainless steel cold rolling acid waste water denitrification process, reference figure 2 , which includes the following steps:

[0053] 1) Lime neutralization: transport the stainless steel cold rolling acid wastewater to the lime neutralization tank, add lime milk (5-10% mass concentration) to the stainless steel cold rolling acid wastewater for lime neutralization treatment; the lime neutralization tank , the hydraulic retention time is 0.5-1h; through lime neutralization treatment, the pH value of the wastewater is adjusted to 9.5-10.5, and the fluoride ions and sulfate ions in the wastewater react with calcium ions to form calcium fluoride and calcium sulfate precipitation. At the same time, the wastewater Iron, nickel, chromium and other heavy metal ions in the solution form hydroxide precipitates under alkaline conditions;

[0054] 2) Primary coagulation and sedimentation: transport the effluent after step 1) lime neutralization to the primary coagulation tan...

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Abstract

The invention relates to the technical field of water treatment, and particularly discloses a stainless steel cold-rolled acid wastewater denitrification treatment process. The process comprises the following steps of 1) lime neutralization, 2) primary coagulation and sedimentation, 3) softening reacting, 4) secondary coagulation and sedimentation, 5) pH adjustment, 6) biological denitrification,7) biochemical precipitation and 8) alkalinity reflux. The problem that in an existing stainless steel cold-rolled acid wastewater denitrification treatment process, a large number of softening agentsare added, so that the wastewater treatment agent cost is high is solved. Accordingly, by making biological denitrification effluent flow back to front-end softening treatment, a large amount of alkalinity generated through a biological denitrification reaction performed by means of high-concentration nitrate nitrogen in stainless steel cold-rolled acid wastewater reacts with excessively added calcium ions in the wastewater to form calcium carbonate precipitation, in the whole softening process, a large number of softening agents do not need to be additionally added, and the stainless steel cold-rolled acid wastewater treatment agent cost can be greatly reduced.

Description

technical field [0001] The invention relates to the technical field of water treatment, in particular to a stainless steel cold-rolled acid wastewater denitrification process. Background technique [0002] The iron and steel industry is a large consumer of water resources, and the treatment of its production wastewater is of great significance to the recycling of water resources and the protection of the environment. Among them, acid wastewater containing hydrofluoric acid, nitric acid, sulfuric acid, and heavy metal ions such as iron, nickel, and chromium generated during the production of stainless steel cold rolling needs to be treated before it can be discharged or recycled. [0003] At present, the conventional treatment process of acid wastewater from stainless steel cold rolling is to add lime milk for lime neutralization. Please refer to figure 1 As shown, it is a flow chart of the conventional treatment process for stainless steel cold rolling acid wastewater, wher...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/14C02F101/16C02F103/16
CPCC02F1/56C02F1/66C02F3/28C02F5/00C02F5/06C02F9/00C02F2101/16C02F2103/16C02F2301/08
Inventor 魏伟肖凡胡伟
Owner 上海东振环保工程技术有限公司
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