CN106746065A - A kind of method for the treatment of electroplating wastewater by microwave - Google Patents

Abstract

The invention discloses a kind of handling process of electroplating wastewater, particularly a kind of Treatment of cyanogen-contained wastewater, the method processes three steps and constitutes by Yin Kefa treatment, coagulating kinetics and UV/ozone oxidation；Cyanide wastewater is first removed tractable cyanide with Yin Kefa in treatment, waste water after treatment carries out coagulating sedimentation by dosing coagulant, heavy metal ion in removal waste water, then under microwave action, the remaining difficult cyanide of waste water, rhodanate and other organic pollutant removals are fallen.The present invention according in cyanide wastewater containing pollutant is complicated, intractable feature, Yin Kefa, coagulant sedimentation and microwave oxidation technology are combined together, collaboration carries out advanced treating to cyanide wastewater, high treating effect, treatment effeciency are high, system run all right, technological process is simple, is easy to implement commercial Application, and the waste water after treatment can return to the technological process of production and be used as recycled water or qualified discharge.

Description

A kind of method for the treatment of electroplating wastewater by microwave

Technical field

The present invention relates to a kind of handling process of electroplating wastewater, particularly a kind of Treatment of cyanogen-contained wastewater.

Background technology

The composition of electroplating wastewater is extremely complex, and cyanide wastewater is main waste water.Electroplating process can produce substantial amounts of cyanide wastewater, this part cyanide wastewater not only contains a certain amount of hypertoxic cyanide, but also containing the heavy metal ion of rhodanate and copper, zinc, lead etc, if cannot effectively process, it will produce great environmentally friendly hidden danger.At present, the method of conventional Treatment of Cyanide-containing Wastewater has acidifying absorption method, Pomolio-Celdecor process, Yin Kefa, sulfur dioxide method etc. both at home and abroad, although a certain amount of cyanide can be reclaimed using acidifying absorption method, but because recovery of cyanide is not thorough, the remaining a certain amount of cyanide of meeting in waste water, while thiocyanate radical and some heavy metal ion are not all removed effectively.After Pomolio-Celdecor process treatment can remaining substantial amounts of chlorine residue, produce ClCN products, secondary pollution problem is caused, while the heavy metal ion such as copper, zinc, lead in waste water fails effectively to be administered.Although Yin Kefa and sulfur dioxide method can make cyanid up to standard, the rhodanate in waste water fails to be processed, additionally, the waste residue produced during treatment heavy metal is also more, easily causes secondary pollution.Therefore, more satisfactory method is also still lacked in terms of to cyanide wastewater treatment, if resolving this problem, there will be important meaning to environmental protection development.For the statistics of the disposal status of electroplating industry waste water and the investigation at present of man of China, the widely used main method for having 7 different classifications：（1）Chemical precipitation method, is divided into neutralization precipitation method and sulphide precipitation again.（2）Redox is processed, and is divided into chemical reduction method, ferrite process and electrolysis.（3）Solvent extraction and separation method.（4）Absorption method.（5）Membrane separation technique.（6）Ion-exchange.（7）Biologic treating technique, including bio-flocculation process, biosorption process, biochemical process, phytoremediation.But the drawbacks of all having certain at present or serious irrationality.

The content of the invention

The above mentioned problem that the purpose of the present invention exists aiming at existing processing method, and provide a kind of technological process simple, high treating effect, treatment effeciency Treatment of cyanogen-contained wastewater high, stable.

Present disclosure includes：

A kind of microwave electroplating processes method for waste water, the method is comprised the following steps：

(1) to adding acid-base reagent, pyrosulfurous acid sodium reagent and catalyst in waste water, it is ensured that the pH value of course of reaction is controlled between 8~10, the reaction time is 60~90 minutes；

(2) reacted waste water adds flocculating agent and flocculant and carries out coagulating sedimentation successively under stirring, and waste water is staticly settled 30~120 minutes into sedimentation basin after coagulation；

(3) waste water after precipitating mixes with microwave catalyst, forms solid-liquid mixed liquor, and irradiation 2-30 minutes is carried out to solid-liquid mixed liquor using microwave, makes solid-liquid mixed liquor that catalytic oxidation to occur；

(4) waste water after oxidation reaction enters in back pool, for returning to the technological process of production or qualified discharge.

Above-mentioned a kind of microwave electroplating processes method for waste water, wherein in the step (1), stirring linear velocity is 0.01m/s~10m/s.

Above-mentioned a kind of microwave electroplating processes method for waste water, wherein in the step (1), the gas liquid ratio that air is passed through during aeration is 3~50:1.

A kind of above-mentioned microwave electroplating processes method for waste water, in wherein described step (1), acid-base reagent is sulfuric acid, hydrochloric acid, sodium hydroxide solution or milk of lime, and pyrosulfurous acid sodium reagent is 5%~30% sodium metabisulfite solution, and catalyst is 5%~30% copper-bath.

Above-mentioned a kind of microwave electroplating processes method for waste water, wherein in the step (2), stirring linear velocity is 0.01m/s~10m/s.Flocculating agent is polymer-inorganic salt flocculating agent, and flocculant is polyacrylamide, and flocculating agent and flocculant are configured to solution state and are added.

A kind of above-mentioned microwave electroplating processes method for waste water, wherein in the step (3), microwave catalyst is one or two in MgFe2O4 or MgFe2O4-Fe2O3.

Above-mentioned a kind of microwave electroplating processes method for waste water, wherein in the step (3), the power of microwave is 200-800 W.

The beneficial effects of the invention are as follows：The present invention according in electroplating cyanic waste water containing pollutant is complicated, intractable feature, Yin Kefa, coagulant sedimentation and microwave oxidation technology are combined together, collaboration carries out advanced treating to cyanide wastewater, high treating effect, treatment effeciency are high, system run all right, technological process is simple, is easy to implement commercial Application, and the waste water after treatment can return to the technological process of production and be used as recycled water or qualified discharge.

Specific embodiment

Instantiation 1：

Certain electroplating cyanic waste water, pH is that 7.8, CNT is 113.47mg/L, SCN-it is 35.24mg/L, Cu2+ is 82.56mg/L, and COD is 187.25mg/L, additionally contains other micro heavy metal ion.3L waste water is taken to be placed in the oxidation reaction groove equipped with stirring system and aerating system,Open stirring system,Under the conditions of being 0.8m/s in stirring linear velocity wastewater pH to 9.0 is adjusted with 1% sodium hydroxide solution,Open aerating system,Aeration rate is adjusted to 1L/min,Slowly add 10% sodium metabisulfite solution 20mL,Reaction 30min,Stop aeration,Add the polymeric aluminum chlorides solution 8mL stirrings 5min of 10g/L,Then 0.5 ‰ PAMA solution 4mL are added,Continue to adjust stirring linear velocity 0.1m/s stirrings 5min after stirring 2min,Stop stirring,Stand 15min,Filtered after precipitation,Take the mL of waste water 100 after precipitation,It is positioned in the conical flask of 500 mL,Microwave power is 600 W,Catalyst MgFe2O4-Fe2O3 consumptions are 1.8 g.The catalytic reaction under microwave condition.The min of microwave irradiation 20, reacted water outlet is through analysis pH between 8~9, CNT ＜ 0.1mg/L, SCN-＜ 0.5mg/L, Cu2+ ＜ 0.5mg/L, COD ＜ 20mg/L, the first pollutant is allowed within concentration of emission limit value in highest, and water quality can reach reuse or discharge standard after treatment.

Instantiation 2：

Certain electroplating cyanic waste water, pH is that 7.5, CNT is 79.58mg/L, SCN-it is 83.45mg/L, Cu2+ is 6.39mg/L, and Zn2+ is 24.25mg/L, and COD is 275.45mg/L, additionally contains other micro heavy metal ion.3L waste water is taken to be placed in the oxidation reaction groove equipped with stirring system and aerating system,Open stirring system,Under the conditions of being 0.8m/s in stirring linear velocity wastewater pH to 9.0 is adjusted with 1% sodium hydroxide solution,Open aerating system,Aeration rate is adjusted to 1L/min,The sodium metabisulfite solution 18mL of slow addition 10% simultaneously,10% copper-bath 1mL,Reaction 30min,Stop aeration,Add the polymeric aluminum chlorides solution 8mL stirrings 5min of 10g/L,Then 0.5 ‰ PAMA solution 4mL are added,Continue to adjust stirring linear velocity 0.1m/s stirrings 5min after stirring 2min,Stop stirring,Stand 15min,Filtered after precipitation,Take the mL of waste water 100 after precipitation,It is positioned in the conical flask of 500 mL,Microwave power is 200 W,Catalyst MgFe2O4 consumptions are 1.8 g.The catalytic reaction under microwave condition.The min of microwave irradiation 20, reaction stops being passed through ozone after terminating, reacted water outlet is through analysis pH between 8~9, CNT ＜ 0.1mg/L, SCN-＜ 0.5mg/L, Cu2+ ＜ 0.5mg/L, COD ＜ 20mg/L, first pollutant is allowed within concentration of emission limit value in highest, and water quality can reach reuse or discharge mark after treatment.

Claims (7)

1. a kind for the treatment of electroplating wastewater by microwave method, the method comprising as follows：

(1) to adding acid-base reagent, pyrosulfurous acid sodium reagent and catalyst in waste water, it is ensured that the pH value of course of reaction is controlled between 8~10, the reaction time is 60~90 minutes；

(2) reacted waste water adds flocculating agent and flocculant and carries out coagulating sedimentation successively under stirring, and waste water is staticly settled 30~120 minutes into sedimentation basin after coagulation；

(3) waste water after precipitating mixes with microwave catalyst, forms solid-liquid mixed liquor, and irradiation 2-30 minutes is carried out to solid-liquid mixed liquor using microwave, makes solid-liquid mixed liquor that catalytic oxidation to occur；

(4) waste water after oxidation reaction enters in back pool, for returning to the technological process of production or qualified discharge.

2. a kind of microwave electroplating processes method for waste water according to claims 1, it is characterised in that：In the step (1), stirring linear velocity is 0.01m/s~10m/s.

3. a kind of microwave electroplating processes method for waste water according to claims 1, it is characterised in that：In the step (1), the gas liquid ratio that air is passed through during aeration is 3~50:1.

4. a kind of microwave electroplating processes method for waste water according to claims 1, it is characterised in that：In the step (1), acid-base reagent is sulfuric acid, hydrochloric acid, sodium hydroxide solution or milk of lime, and pyrosulfurous acid sodium reagent is 5%~30% sodium metabisulfite solution, and catalyst is 5%~30% copper-bath.

5. a kind of microwave electroplating processes method for waste water according to claims 1, it is characterised in that：In the step (2), stirring linear velocity is 0.01m/s~10m/s；Flocculating agent is polymer-inorganic salt flocculating agent, and flocculant is polyacrylamide, and flocculating agent and flocculant are configured to solution state and are added.

6. a kind of microwave electroplating processes method for waste water according to claims 1, it is characterised in that：In the step (3), microwave catalyst is MgFe₂O₄Or MgFe₂O₄-Fe₂O₃In one or two.

7. a kind of microwave electroplating processes method for waste water according to claims 1, it is characterised in that：In the step (3), the power of microwave is 200-800 W.