CN108328800A - A kind of removal waste water of heat-engine plant heavy metal ion method - Google Patents

Abstract

The invention belongs to waste water of heat-engine plant water treatment field more particularly to a kind of removal waste water of heat-engine plant heavy metal ion methods.A kind of removal waste water of heat-engine plant heavy metal ion method, this method are applied to desulfurization wastewater and are completed before entering recovery processing, be as follows：(1) desulfurization wastewater is entered into the first fluidized bed from bottom, is wherein filled with quartz sand filter media in the first fluidized bed, connection NaOH solution tank, KMnO in the bottom of the first fluidized bed₄NaOH solution tank NaOH, while desulfurization wastewater enters the first fluidized bed from bottom, NaOH solution, KMnO₄Solution enters the first fluidized bed together from first fluidized bed bottom；Conventionally the pH in the first fluidized bed is controlled between 7.5~11.The sludge density that the method for the invention enables the technique to generate reaches 2.5~3.0kg/L, and dewatered moisture is less than 20%, and compared with the traditional chemical precipitation method, the sludge quantity that fluidized bed process generates will be less than 25%.

Description

A kind of removal waste water of heat-engine plant heavy metal ion method

Technical field

The invention belongs to waste water of heat-engine plant water treatment field more particularly to a kind of removal waste water of heat-engine plant heavy metal ion sides Method.

Background technology

Heavy metals in industrial wastewater is passing through multiple tracks metallochemistry and electrochemistry to environmental hazard most serious, heavy metal wastewater thereby After process, the metallic elements such as zinc, copper, chromium, nickel, cadmium in water all occur with atomic valence, are directly discharged in environment, can pass through Prolonged cumulative effect endangers the health of people.Minamata disease and bone aching are just respectively by mercurous and contaminated wastewater ring containing cadmium Caused by border.Therefore, it is necessary to processing heavy metal wastewater thereby of adopting an effective measure.

The waste water that heavy metal ion is contained in thermal power plant is mainly desulfurization wastewater, there is plurality of heavy metal element, as Cr, As, Cd, Pb, Hg, Cu etc..

Conventional processing method is exactly：Desulfurization wastewater is directly entered neutralization reaction pond, into reaction tank be added NaOH or Ca(OH)₂Equal alkaline matters, by the Fe in desulfurization wastewater³⁺、Zn²⁺、Ni²⁺、Cu²⁺、Cr³⁺Hydrogen is generated Deng most of heavy metal ion Oxide removal；Organic sulfur, which is added, makes the Hg in waste water²⁺、Pb²⁺Plasma becomes sulfide precipitation；Adding flocculant will give up Thin small and scattered particle and colloidal substance coacervating large particle precipitate in water；Waste water after coagulation enters clarifying basin, into Row sedimentation, discharge after supernatant is up to standard, sludge carry out concentration.

But desulfurization wastewater is handled using above-mentioned method, process route is complicated, is controlled in actual use The desulfurization wastewater operating condition of many power plant and unstable in journey.Therefore, exploitation new process reduces operating cost, improves operation Stability is unavoidable.

Invention content

It is asked for process route is complicated, operating condition is unstable existing for heavy metal ion in current removal desulfurization wastewater The defect of topic and its solution, to effectively remove heavy metal ion in desulfurization wastewater, the present invention provides a kind of removal thermal power plant Desulfurization wastewater heavy metal ion method can easily control process conditions using the method for the invention, and it is useless especially to improve desulfurization The safe and stable operation quality of water process.

A kind of removal waste water of heat-engine plant heavy metal ion method of the present invention, includes the following steps：

A kind of removal waste water of heat-engine plant heavy metal ion method, it is complete before entering recovery processing that this method is applied to desulfurization wastewater At being as follows：

(1) desulfurization wastewater is entered into the first fluidized bed from bottom, wherein quartz sand filter media is filled in the first fluidized bed, first Bottom connection NaOH solution tank, the KMnO of fluid bed₄NaOH solution tank NaOH, while desulfurization wastewater enters the first fluidized bed from bottom, NaOH solution, KMnO₄Solution enters the first fluidized bed together from first fluidized bed bottom；；By the addition for controlling NaOH solution Amount controls the pH in the first fluidized bed between 7.5~11；

(2) treated, and desulfurization wastewater enters second fluidized bed to step (1)；Addition by controlling NaOH solution will be first-class The pH changed in bed is controlled between 4.5~7.0；

(3) treated, and desulfurization wastewater enters buffer pool to step (2), the buffer cycles in buffer pool, while sampling and measuring is through slow Rush pond treated that desulfurization wastewater is recycled if the following conditions meet simultaneously；If being unsatisfactory for any of which When one condition, the circular treatment of next step is carried out；The condition includes：Ni contents are less than 1mg/L；Cd contents are less than 1.5mg/L；Zn contents are less than 1mg/L；Hg contents are less than 0.05mg/L；

(4) desulfurization wastewater that recycling condition is unsatisfactory in step (3) is repeated into step (1)-(3), until sampling and measuring desulfurization is useless Until water meets recycling condition.

Using the method for the invention, when desulfurization wastewater passes through the first fluidized bed, divalent manganesetion and ferrous ion are inhaled It is attached in the heavy metal ion dissolved in desulfurization wastewater, in oxidant KMnO₄Under the action of be oxidized to manganese dioxide and hydrogen-oxygen Change iron, and one layer of coating is formed in metal surface, since manganese dioxide and iron hydroxide have very inorganic dissolved ion Strong characterization of adsorption makes the soluble ion adsorbed be copolymerized into particle and settles down shape by increasing continuously this layer of coating At sludge, the sludge density that the method for the invention enables the technique to generate reaches 2.5~3.0kg/L, and dewatered moisture is low In 20%, compared with the traditional chemical precipitation method, the sludge quantity that fluidized bed process generates is up to 22-25%.

Description of the drawings

Fig. 1 is the attachment structure schematic diagram of equipment involved by the method for the invention.

Fig. 1-the first fluidized bed；2- second fluidized beds；3- buffer pools；4-KMnO₄NaOH solution tank NaOH；5-NaOH NaOH solution tank NaOHs.

Specific implementation mode

A kind of removal waste water of heat-engine plant heavy metal ion method, this method are applied to desulfurization wastewater and are entering recovery processing Preceding completion, is as follows：

(1) desulfurization wastewater is entered into the first fluidized bed 1 from bottom, is wherein filled with quartz sand filter media in the first fluidized bed 1, Bottom connection NaOH solution tank 5, the KMnO4 NaOH solution tank NaOHs 4 of one fluid bed 1, desulfurization wastewater enter the same of the first fluidized bed 1 from bottom When, NaOH solution, KMnO₄Solution enters the first fluidized bed 1 together from 1 bottom of the first fluidized bed；；By controlling NaOH solution Addition controls the pH in the first fluidized bed 1 between 7.5~11；Will be disengaged from waste water the heavy metal ion such as Ni, Cd, Zn into Row removes for the first time；

(2) treated that desulfurization wastewater enters second fluidized bed 2 for step (1),；By controlling the addition of NaOH solution by first PH in fluid bed 1 is controlled between 4.5~7.0；Cl ions are made to form complicated complexing under fluid bed effect with Hg ions Object.

(3) treated that desulfurization wastewater enters buffer pool 3 for step (2), the buffer cycles in buffer pool 3, while sampling survey Measure buffered pond 3 treated that desulfurization wastewater is recycled if the following conditions meet simultaneously；If be unsatisfactory for When one condition of any of which, the circular treatment of next step is carried out；The condition includes：Ni contents are less than 1mg/L；Cd contents Less than 1.5mg/L；Zn contents are less than 1mg/L；Hg contents are less than 0.05mg/L；

(4) desulfurization wastewater that recycling condition is unsatisfactory in step (3) is repeated into step (1)-(3), until sampling and measuring desulfurization is useless Until water meets recycling condition.

After the method for the invention to desulfurization wastewater handle repeatedly, the removal rate point of the heavy metals such as Ni, Cd, Zn Not Wei 99%, 92%, the removal rate of 97% or more, Hg can also reach 96% or more.

The system of removal waste water of heat-engine plant heavy metal ion of the present invention, including the sequentially connected first fluidized bed 1, the Two fluid beds 2 and buffer pool 3, wherein the first fluidized bed 1 equipped with the arrival end being connected with desulfurization wastewater, NaOH solution tank 5, KMnO4 NaOH solution tank NaOHs 4 are connected to 1 bottom of the first fluidized bed by pipeline respectively, and quartz sand filter media is filled in the first fluidized bed 1.

Claims (1)

1. a kind of removal waste water of heat-engine plant heavy metal ion method, it is characterised in that this method is entering back applied to desulfurization wastewater It completes, is as follows before receiving processing：

(1) desulfurization wastewater is entered into the first fluidized bed from bottom, wherein quartz sand filter media is filled in the first fluidized bed, first Bottom connection NaOH solution tank, the KMnO of fluid bed₄NaOH solution tank NaOH, while desulfurization wastewater enters the first fluidized bed from bottom, NaOH solution, KMnO₄Solution enters the first fluidized bed together from first fluidized bed bottom；By the addition for controlling NaOH solution PH in the first fluidized bed is controlled between 7.5~11；

(2) treated, and desulfurization wastewater enters second fluidized bed to step (1),；By controlling the addition of NaOH solution by first PH in fluid bed is controlled between 4.5~7.0；

(3) treated, and desulfurization wastewater enters buffer pool to step (2), the buffer cycles in buffer pool, while sampling and measuring is through slow Rush pond treated that desulfurization wastewater is recycled if the following conditions meet simultaneously；If being unsatisfactory for any of which When one condition, the circular treatment of next step is carried out；The condition includes：Ni contents are less than 1mg/L；Cd contents are less than 1.5mg/L；Zn contents are less than 1mg/L；Hg contents are less than 0.05mg/L；

(4) desulfurization wastewater that recycling condition is unsatisfactory in step (3) is repeated into step (1)-(3), until sampling and measuring desulfurization is useless Until water meets recycling condition.