CN100584771C

CN100584771C - A method for treating heavy metal wastewater

Info

Publication number: CN100584771C
Application number: CN200710048472A
Authority: CN
Inventors: 李福德; 李昕; 吴全珍; 李旭东
Original assignee: Chengdu Institute of Biology of CAS
Current assignee: Chengdu Institute of Biology of CAS
Priority date: 2007-02-13
Filing date: 2007-02-13
Publication date: 2010-01-27
Anticipated expiration: 2027-02-13
Also published as: CN101244859A

Abstract

The invention belongs to the technical field of wastewater treatment, and particularly relates to a method for removing heavy metal ions such as chromium in wastewater. The invention utilizes a composite bacterium consisting of vibrio Desulfovibrio CB1.268(Desulfovibrio Sp.), enterobacter desulfurate CB1.139 (desulfomomaculum Sp.) and bacillus desulfurate CB1.168(Desulfobacter Sp.) to produce nano FeS in a culture medium containing lactate, ferrite and sulfate as well as K, Mg, Ca, Cu, Mn, B, Si and Mo elements under the alkaline condition at the temperature of 30-39 ℃ for anaerobic or facultative culture for 36-72 hours_x(ii) a The nano FeS_xDissociate to S under acidic conditions^2-And Fe²⁺Reduction of Cr⁶⁺Is Cr³⁺With Ni²⁺、Cu²⁺、Zn²⁺And generating insoluble metal sulfide precipitate, and separating the precipitate to remove metal ions in the wastewater. The invention has the advantages of high removing efficiency, low cost and the like.

Description

A kind of method of handling heavy metal wastewater thereby

Technical field

The invention belongs to technical field of waste water processing, be specifically related to the removal method of heavy metal ion such as chromium in the waste water.

Background technology

The method of handling at present both at home and abroad heavy metal wastewater thereby has physics method, chemical method and biological process three major types, kind surplus in the of totally 20, and these methods cut both ways.Seeking more effective treatment process is the target that people yearn for all the time.Chinese patent ZL 93106616.6 " treating electroplating waste water with micro-organism method " has proposed the composite bacteria that four strain bacterium such as Fusobacterium nucleatum, Paracoccus denitrificans, blunt tarda and peptococcus anaerobius are formed first, to lower concentration (≤80mg/L) processing of Cr, Zn, Cu, Ni electroplating wastewater has effect preferably.Chinese patent ZL 96117479.X " administering compound function yeast, its cultural method and the using method thereof of electroplating wastewater " adopts five strain bacterium such as desulfurization bacterium, desulfovibrio, enterobacter cloacae, desulfurization enterobacteria and genus bacillus to form composite bacteria, theoretical basis and the practicality of removing heavy metal in the electroplating wastewater than patent ZL 93106616.6 are greatly improved, but the reaction residence time is long, and the pH value is limit in 5.0～7.5 scopes.Chinese patent ZL00112916.3 " biochemical process is administered the method for metallic wastewater " adopts desulfurization bacterium, enterobacter cloacae, desulfurization enterobacteria to form composite bacteria and proposes: " bacterium and waste water add the reaction tank reaction by 1: 10 volume ratio, add 0.05～5 kilogram of chemical reagent Na by waste water per ton again after the reaction ₂S is or/and FeS removes the heavy metal ion in the waste water, and this method is to rely on to add Na basically ₂S is or/and FeS removes the heavy metal ion in the waste water, its processing cost height, and have the secondary pollution problem of hydrogen sulfide.

Summary of the invention

Big in order to overcome mentioned microorganism method removal heavy metal ions in wastewater long reaction time, baterial cultivation pool and reaction tank volume, also to use Na ₂S and FeS remove the defective of heavy metal ion, the invention provides a kind of by microorganism strains original position generation nanometer iron sulphide (FeS _x) material removes the method for heavy metal ion such as chromium in the waste water.

The present invention realizes in the following way:

On the basis of patent ZL93106616.6 and ZL 96117479.X, work out specific technology, with the composite bacteria that desulfovibrio CB1.268 (Desulfovibrio Sp.), desulfurization intestines shape bacterium CB1.139 (Desulfotomaculum Sp.) and desulfurization bacterium CB1.168 (Desulfobacter Sp.) form, can the many Iron sulfuret (FeS of produced in situ nanometer _x) material, detect FeS through x-electron diffraction energy spectrometer _xIn the formula, x=1.1～1.2, this FeS _xUnder acidic conditions, can remove the heavy metal ion in the waste water well.The bacterial strain ratio of components of this composite bacteria is: desulfovibrio CB1.268 (DesulfovibrioSp.): desulfurization intestines shape bacterium CB1.139 (Desulfotomaculum Sp.): desulfurization bacterium CB1.168 (Desulfobacter Sp.)=1: 1: 1.The condition of this composite bacteria production nanometer iron sulphide is: anaerobism or double oxygen are cultivated, pH7.0～7.4,30～39 ℃ of temperature, contain lactic protein salt, 1%～10% (w/w) ferrous salt of 0.5%～5% (w/w) and 1%～10% (w/w) vitriol and K, Mg, Ca, Cu, Mn, B, Si, Mo element, cultivate and just produced nanometer Fe S in 36～72 hours _xThis nanometer Fe S _xLong 45～the 80nm of material, long-width ratio 15～20 is that bar is thread when amplifying 300,000 times, is lattice fringe and lattice particle when amplifying 400,000 times, dissociates into S under the acidic conditions of pH3～4 ^2-And Fe ²⁺S ^2-And Fe ²⁺Ion all can reduce Cr preferably ⁶⁺Be Cr ³⁺, S ^2-Also with Ni ²⁺, Cu ²⁺, Zn ²⁺Deng the metallic sulfide precipitation that generates indissoluble, through precipitation separation, these ions are removed.

It is as follows that the present invention handles the processing step of heavy metal wastewater thereby method:

In the cultivation device, add the substratum contain lactic protein salt, ferrous salt and vitriol and K, Mg, Ca, Cu, Mn, B, Si, Mo element, regulate pH7.0～7.4, add composite fungus agent, 30～39 ℃ of controlled temperature, anaerobism or double oxygen were cultivated 36～72 hours, contained nanometer Fe S with what generate _xFermented liquid transfer in the reactor, transfer pH3～4, treat nanometer Fe S _xAfter the heavy metal wastewater thereby reaction, add NaOH and transfer pH6～8, the heavy metal ion in the waste water generates the precipitation of indissoluble, through precipitation separation, reaches the purpose of removing metal ion in the waste water.

S ^2-And Fe ²⁺With Cr ⁶⁺, Ni ²⁺, Cu ²⁺, Zn ²⁺Deng reaction see that ionic reaction formula (1) is to (9).

S ^2-With Cr ⁶⁺Reaction as shown in the formula:

FeS _x+H ⁺→Fe ²⁺+S ^2- (1)

HCrO ₄ ^-+S ^2-→S↓+H ₂O+Cr ³⁺?(2)

Cr ₂O ₇ ^2-+S ^2-→S↓+H ₂O+Cr ³⁺(3)

Reaction formula (2), (3) show FeS _xThe S that acidolysis produces ^2-Reduction Cr ⁶⁺Be Cr ³⁺, after reaction finishes, transfer pH6～7, Cr with NaOH ³⁺With OH ^-Generate Cr (OH) ₃Precipitation, through solid-liquid separation, Cr ⁶⁺Be removed.

Fe ²⁺With Cr ⁶⁺Reaction formula as follows:

Fe ²⁺+Cr ₂O ₇ ^2-→Cr ³⁺+Fe ³⁺ (4)

Reaction (4) shows FeS _xThe Fe that acidolysis produces ²⁺Reduction Cr ⁶⁺Be Cr ³⁺, after reaction finishes, transfer pH6～7 with NaOH, generate Cr (OH) ₃Precipitation, through solid-liquid separation, Cr ⁶⁺Be removed.

FeS also can be directly and CrO ₄ ^2-And Cr ₂O ₇ ^2-Reaction makes its Cr ⁶⁺Be reduced to Cr ³⁺:

CrO ₄ ^2-+FeS _x→Cr ³⁺+Fe ³⁺+S↓?(5)

Cr ₂O ₇ ^2-+FeS _x→Cr ³⁺+Fe ³⁺+S↓(6)

After reaction finishes, transfer pH6～7, Cr with NaOH ³⁺Generate Cr (OH) with OH- ₃Precipitation, through solid-liquid separation, Cr ⁶⁺Be removed.

Secondly, nanometer Fe S _xThe S that acidolysis produces ^2-Also with Ni ²⁺, Cu ²⁺, Zn ²⁺Sulfide precipitation Deng generating indissoluble through precipitation separation, makes Ni ²⁺, Cu ²⁺, Zn ²⁺Be removed, reaction formula is as follows:

Ni ²⁺+S ^2-→NiS↓ (7)

Cu ²⁺+S ^2-→CuS↓ (8)

Zn ²⁺+S ^2-→ZnS↓ (9)

From nickelous sulfide solubility product: α 1.6 * 10 ^-24, β 2.5 * 10 ^-22, γ 2 * 10 ^-26With cupric sulfide solubility product: Cu ₂S 6 * 10 ^-48, CuS 6 * 10 ^-36And zinc sulphide solubility product: α 1.6 * 10 ^-24, β 2.5 * 10 ^-22As can be known, the solubleness of these ionic sulfide is very little, and it remains in solution metal ionic concentration all below the GB emission standard after generating sulfide precipitation.

Once more, nanometer Fe S _xIn Fe ²⁺Be oxidized to Fe ³⁺, transferring pH6～7 o'clock with NaOH, Fe ³⁺Generate Fe (OH) ₃Precipitation, Fe (OH) ₃Precipitation has fine absorption and mixes (wadding) and coagulate effect, makes the inorganic and organism of a little be adsorbed removal, makes stable effluent quality up to standard.

Demonstration project shows: nanometer Fe S _xRemoving heavy metal ions in wastewater is that chemical method is (as using chemical reagent Na ₂SO ₃Or FeSO ₄) 2 times of clearance.To Cr ⁶⁺Clearance reach 99.99%, to Ni ²⁺, Cu ²⁺, Zn ²⁺Clearance reach 99.9%.Cr in the treat effluent ⁶⁺＜0.1mg/L, Ni ²⁺, Cu ²⁺＜0.5mg/L, Zn ²⁺＜0.2mg/L.So the inventive method has characteristics such as place to go efficient height, cost be low.

Composite bacteria of the present invention has generated nanometer Fe S after 36～72 hours incubation growth _x, with the nanometer Fe S that is generated _xAnd mixture such as bacterial classification, through concentrate, sealing, packing can be standby.

Description of drawings

Accompanying drawing is the process flow diagram that nanometer Fe S of the present invention handles heavy metal wastewater thereby.

Among the figure: 1,2 are the cultivation device; 3 is the waste liquid equalizing tank; 4,5 is reactor; 6 is strainer; 7 is clean water basin; 8 for cultivating foundation trench; 9 is sludge sump; 10 is the metal recovery device; 11 is innoxious mud cake.

At cultivation device 1, the 2 nanometer Fe S that produce_xMaterial with enter reactor 4 from the waste water of wastewater equalization pond 3, follow into reactor 5 and carry out two-stage reaction, be filtered again rear qualified discharge 7, or reuse 8, add culture medium to recycle-water and enter cultivation device 1 or 2, in pH7.0～7.4,30～39 ℃, cultivate and produced nanometer Fe S in 36～72 hours_xFor using. The mud of filter 6 advances sludge-tank 9, to recover 10 acid addings Crome metal, copper, zinc, nickel are reclaimed in dissolving, and harmless mud cake 11 can be made fertilizer.

Embodiment

Below in conjunction with Figure of description, the invention will be further described.

Embodiment one: certain cold Zha Chang workshop contains the high chromium concentration wastewater treatment

The substratum that in the cultivation device, adds the vitriol contain 0.5% lactic protein salt, 1% ferrous salt and 1% and K, Mg, Ca, Cu, Mn, B, Si, Mo element, regulate pH7.0～7.4, add composite fungus agent, 30 ℃ of controlled temperature, anaerobism or double oxygen were cultivated 36 hours, generated to contain nanometer Fe S _xMixture, for using.

Per hour handle 0.4m ³High chromium concentration waste water, waste water (W) and biological nano FeS _x(BN) ratio is 2: 1, through static mixing, reactor reaction 30min.Add 1 ‰ positively charged ion Polyscrylamide (PAM) flocculation sediment and filtration treatment, measure chromium and sulfide in the water.Total chromium in the water outlet (TCr≤0.17mg/L) and sexavalent chrome (Cr as seen from Table 1 ⁶⁺≤ 0.05mg/L) all be better than first grade discharging mark (TCr1.5mg/L, the Cr of GB ⁶⁺0.5mg/L), do not detect S in the water outlet ^2-The Cr rate of recovery in the mud is greater than 97.0%.

The cold bundle chromate waste water of table 1 result unit: mg/L

Annotate: ND is not for detecting.

Embodiment two: the processing of drop liquid is oozed on certain chromium slag mountain

The substratum that in the cultivation device, adds the vitriol contain 5% lactic protein salt, 10% ferrous salt and 10% and K, Mg, Ca, Cu, Mn, B, Si, Mo element, regulate pH7.0～7.4, add composite fungus agent, 35 ℃ of controlled temperature, anaerobism or double oxygen were cultivated 48 hours, generated to contain nanometer Fe S _xMixture, for using.

This oozes drop liquid and contains Cr ⁶⁺5500mg/L, TCr 5800mg/L, pH14 per hour handles 9m ³Ooze drop liquid, W/BN=1: 1.Through static mixing, reactor reaction, precipitation and filtration treatment the results are shown in table 2.As seen TCr≤0.21mg/L and Cr in the water outlet ⁶⁺≤ 0.05mg/L all is better than the first discharge standard of GB, does not detect S in the water outlet ^2-The Cr rate of recovery in the mud is greater than 97.5%.

Drop liquid result unit: mg/L is oozed on certain chromium slag mountain of table 2

Annotate: ND is not for detecting.

Embodiment three: certain mining industry liquid waste disposal

The substratum that in the cultivation device, adds the vitriol contain 3% lactic protein salt, 6% ferrous salt and 6% and K, Mg, Ca, Cu, Mn, B, Si, Mo element, regulate pH7.0～7.4, add composite fungus agent, 39 ℃ of controlled temperature, anaerobism or double oxygen were cultivated 72 hours, generated to contain nanometer Fe S _xMixture, for using.

This waste liquid contains Cr ⁶⁺1280mg/L, V3800mg/L, 1m is per hour handled in pH2～3 ³Waste liquid, W/BN=1: 3.Through static mixing, reactor reaction, precipitation and filtration treatment the results are shown in table 3.As seen Cr in the water outlet ⁶⁺≤ 0.05mg/L, TCr≤0.15mg/L, V≤0.01mg/L all is better than the first discharge standard in GB and Sichuan Province, does not detect S in the water outlet ^2-The Cr rate of recovery in the mud is greater than 96%, and the rate of recovery of vanadium is greater than 93%.

Annotate: ND is not for detecting; * Sichuan Province's standard.

Claims

1, a kind of method for processing heavy metal waste water, it is characterized in that: utilize desulfovibrio CB1.268 (Desulfovibrio Sp.), desulfurization enteric bacteria CB1.139 (Desulfotomaculum Sp.) and Desulfobacillus CB1.168 (Desulfobacter Sp.) Composite bacteria composed of lactic acid proteinate, ferrous salt and sulfate and K, Mg, Ca, Cu, Mn, B, Si, Mo elements in the culture medium, under alkaline conditions, the temperature is 30 ~ 39 ℃, Anaerobic or facultative culture for 36-72 hours to produce nano-FeS _x , wherein x=1.1-1.2; transfer the fermented liquid containing nano-FeS _x to the reactor, adjust the pH to 3-4, and wait for the nano-FeS _x and After the heavy metal wastewater reacts, add NaOH to adjust the pH to 6-8, and the heavy metal ions in the wastewater form insoluble precipitates, which can be separated and precipitated to achieve the purpose of removing metal ions in the wastewater.

2. A method for treating heavy metal wastewater according to claim 1, characterized in that: the strain composition ratio of the composite bacterial agent is: Desulfovibrio CB 1.268 (DesulfovibrioSp.): Desulfovibrio Sp. CB 1.139 ( Desulfotomaculum Sp.): Desulfobacterium CB1.168 (Desulfobacter Sp.) = 1:1:1; the weight percent of nutrient salt in the culture medium is: lactic acid proteinate 0.5%～5%, ferrous salt 1%～10%, Sulfate 1% ~ 10%; alkaline condition pH 7.0 ~ 7.4.