Sewage treatment equipment > Zl - ddws001 electroplating wastewater treatment equipment
Equipment basic configuration:
Name: electroplating wastewater treatment equipment
Model: zl - ddws001
Sewage quantity 2 (m3 / h)
Model HD - 1
Ozone dosage (20 g/h)
Air quantity (200 m3 / min)
10 air tank volume (m3)
3 meter specifications (m3 / h)
Outlet pipe diameter (200 mm)
Inlet pipe diameter (200 mm)
30 aerator power (kw)
Description of equipment:
1. The source of the electroplating wastewater
Electroplating is a strong commonality, use area wide, cross-trade and cross functional production industry, in the process of production must use large amounts of water to meet the requirements of process, once the water quality more than technology standard for wastewater discharge, electroplate wastewater mainly comes from the early treatment and electroplating rinse water.
2. The characteristics of electroplating wastewater
From the typical production technology of electroplating and construction unit of the actual situation, you can see that many steps in the process of production will produce a lot of waste water, the waste water has the following features:
(1)Complicated composition.Due to the technological requirements for plating pieces of different and use different kinds of plating, when the wastewater containing cyanide and heavy metal ions, should be dealt with separately.
(2)The content is higher.All kinds of heavy metal content in the wastewater generally under 50 mg/L, individual varieties reached more than 100 mg/L, especially the emissions of plating solution are prone to the impact load.
(3)The bigger toxicity.Wastewater containing chromium, nickel, copper and other heavy metal ions and cyanide are toxic, the biochemical treatment of the general microbial activity has certain inhibitory effect, must use the special biological species.
(4)Are mixed.Park or big city it is hard to electroplating points for various kinds of plating wastewater emissions, COD concentration is higher, must consider the comprehensive processing capacity.
(5)The intermittent discharge.According to the production need daily discharge range of water quality and quantity, can only be considered in the design of the largest emissions per hour, increase the one-time investment.
Electroplating is the use of chemical and electrochemical methods in metal or other materials of various kinds of metal surface plating.Plating technology is widely used in machinery manufacturing, light industry, electronics and other industries.
Electroplating wastewater composition is very complicated, in addition to the wastewater containing cyanide (CN) and acid and alkali waste water, heavy metal wastewater is potential harmfulness of electroplating industry a great deal of waste water category.Based on heavy metal in waste water containing heavy metals are classified, in general can be divided into wastewater containing chromium (Cr), nickel (Ni) wastewater and wastewater containing cadmium (Cd), wastewater containing copper (Cu), zinc (zinc) wastewater and wastewater containing gold (Au), silver (Ag) wastewater, etc.
Electroplating wastewater treatment in the widespread attention at home and abroad, developed a variety of management technology, through the use of toxic governance for non-toxic, harmful into harmless and recycling precious metals, water use and other measures to eliminate and reduce the emissions of heavy metals.With the rapid development of electroplating industry and environmental protection requirements is increasing day by day, at present, electroplating wastewater treatment has begun to enter the clean production technology, total amount control and the circulation economic integration stage, resource recycling and closed cycle is the mainstream of development direction.
The present situation of the electroplating heavy metal wastewater treatment technology
According to current situation of electroplating industry wastewater treatment I national statistics and investigation, there are 7 different classification methods widely used in the main:
1. The chemical precipitation, divide again for neutralization precipitation and sulfide precipitation.
2. The REDOX process, divided into chemical reduction method, the ferrite method and electrolysis method.
3. Solvent extraction separation process.
4. The adsorption method.
5. Membrane separation technology.
6. Ion exchange method.
7. Biological treatment techniques, including biological flocculation method, biological adsorption method, chemical method, and the method of phytoremediation.But there are certain defects or serious irrationality.
The disadvantages of traditional electroplating wastewater treatment method
The electroplating wastewater treatment methods commonly used chemical method, the shunt of comprehensive processing two pieces.Chromium in dealing with more than three water: water, cyanide and comprehensive water (water) copper nickel zinc.Chromium in water reducing agent base reduction, with two levels of cyanide water oxidation cyanide, copper nickel zinc water directly with the first two become integrated water confluence of water.After a period of treatment, a comprehensive water is basically with alkali (caustic soda and lime), polyaluminium chloride (PAC) and organic flocculant (PAM), the specific operation is: the comprehensive water pH mentioned 10 ~ 13, alkali concentration of large and forced the alkali and heavy metal reaction to generate hydroxyl direction.Due to pH > 9, outfalls and with acid and pH value to below 9.
The above is the traditional process, there are many serious mistakes in theory and practice:
1. Sewage treatment before three division, do not conform to the actual production, because no matter what the water are sometimes-complex mix-and-match, I have you, is just a chromium water is given priority to with chromium, cyanide water is given priority to with cyanide, copper nickel zinc triad in the majority with 3 elements.The actual situation, we are found in the practice of wastewater treatment, almost every enterprise of electroplating wastewater.We asked for electroplating factory related personnel, they can actually said the cause of this phenomenon is very clear, it is strange that sewage management was taking shunt - comprehensive processing as cannot violate the normative pattern two pieces.Due to the second paragraph of various pollutants in the wastewater treatment of all exists, how is it possible to use simple water treatment reagent and method can make the terminal standards?
2. Many special discourse mentioned, cyanide to separate processing because of cyanide in water will generate toxic acid of HCN (PPG) and its volatility is bound to cause poisoning.This is true in theory, do be very careful.However, we found that the majority of cyanide water itself is pH < 6 liquid, try to be volatile in the workshop, and will not flow to the sewage pool then evaporate.Besides cyanate itself is liquid, only low evaporation temperature (26 ℃), the outside temperature < 26 ℃ when there is no volatile issue.
3. The artificial force with super alkali make generate hydroxide precipitation of heavy metals in the sludge, this is not science:
(1). From the principle of chemical reaction, regardless in what kind of ph conditions, has a balance reaction, that is to say, never do not reach the water does not exist a certain amount of heavy metals.
(2). Different heavy metal hydroxide formed the best pH (pH) is not the same, for the most suitable pH range, a heavy metal of some other metals may have is to dissolve the pH condition.
(3). With so much money two period of treatment is super alkali, the final discharge water must be super alkali, this this in outfalls add acid to water, in order to pH value reached discharge standard.Add acid as a result, the precipitation has not yet subtle hydroxide rapidly decompose, heavy metal back in the water.
(4). Due to shunt - unites two sewage disposal, engineering installation is more complex, naturally caused by large investment, long construction engineering.
Mineral method and treatment of electroplating wastewater
Mineral method is adopted to pure natural mineral as raw material, after a certain special process to the processing and production of patent NMSTA sewage disposal and natural mineral ores in BC, the auxiliary again add some additives to a kind of mixed electroplating wastewater treatment method.Because the method mainly USES the pure natural mineral as the main raw material, it has the characteristics of ion exchange, adsorption, chemical conversion, catalysis, etc.
The main advantage of this method is as follows:
1. Thoroughly change the traditional process, the shunt processing for a long time such as chromium water, cyanide, integrated water mixing process, corrected the shunt processing of some serious mistakes, to make up for the weakness of the traditional process.
2. After a period of treatment can completely solve the problem, changed the traditional model of two pieces of processing.
3. Due to the above two points, sewage treatment engineering device greatly simplified, infrastructure investment and construction time are greatly reduced.
4. The traditional processing method, theoretical analysis is not possible to amount to mark, a lot of practice also proved that the process does not achieve discharge standards.If the treatment of electroplating wastewater by mineral method, from the theory and practical can steadily discharging standard.
5. The traditional process of electroplating wastewater treatment agent costs, mainly used in caustic soda neutralize acid water, usually with a ton of waste caustic soda will 6 ~ 10 yuan fee, plus other drugs, the total agent cost in more than 10 yuan more.Indeed, if just waste water clarification, the cost is difficult to have a standard.Use method of mineral, the premise is the discharging standard.A ton of wastewater treatment medicament cost about 4 ~ 6 yuan.
My company independent research and development of electroplating wastewater treatment process to overcome the traditional chemical method, high energy consumption, sludge production big shortcoming, and electrolytic recovery method, distillation operation cost is high, the shortcomings of dealing with incomplete, retained the original zero emissions technology with physical method for separation of electroplating waste water cleaning strengths, to achieve the high efficiency of metal ion concentration, concentration of metal ions concentrate can reach back to tank work, heavy metal rinse wastewater be totally zero emissions, company research and development at the core of the membrane module long life, low cleaning frequency, replacement cycle for more than two years.[!--temp.fenxiang--]