Prevention and control of cadmium pollution incident in Longjiang, Guangxi

I guess ......First of all, polyaluminum chloride is easily soluble in water, has strong bridging adsorption, and has a higher alkalinity than other aluminum salts and iron salts. Then due to the fact that cadmium hydroxide has very little solubility in water. Therefore, the goal is to convert cadmium ions into cadmium hydroxide, and then complete the precipitation by adsorption of polyaluminum chloride.

1. Polyaluminum chloride is soluble in water: [Al2(OH)NCL6-N]M+H2O [AL2(OH)3(OH)3]+(H+)+Cl-) hydrolysis, untrimmed) ((OH-) in NaOH can promote hydrolysis).

2. It may be (CD2+)+2NaOH=CD(OH)2+2Na+, or (CD2+)+Al2(OH)3(OH)3].

CD(OH)2 + Al3+) (metathesis reaction, unbalanced) (depending on the amount or amount, it may be the latter).

3. Adsorption precipitation.

That's it......

The principle of this technology is to put caustic soda or lime into the river water, increase the pH value to make the water weakly alkaline, so that cadmium is insoluble in water and separated from the water, forming fine particles of cadmium carbonate. The purpose of putting polyaluminum chloride coagulant into the river water is to solidify the fine particles suspended in the water into large particles, and the cadmium that presettles to the bottom of the river will be released slowly, and the cadmium that presides down to the bottom of the river will be released slowly, Zhang Xiaojian said that the problem does exist, but it will not be serious. The expert group has controlled the feeding materials to not raise the pH value of the river water so that cadmium does not precipitate too much.

Zhang Xiaojian said that the research group has been following up on this.

Reproduced in the news above.

CD2+ can be used to produce precipitates at the calcium carbonate-water interface (see Refer to CarbonAus). It seems that the current treatment method does not mainly use the method of forming cadmium hydroxide precipitation, because the optimal condition for cadmium hydroxide production is not weak alkaline. It may be that cadmium carbonate is mainly formed under weak alkaline, and calcium carbonate may also have a certain replenishing effect, and then the basic aluminum chloride flocculates and settles.

Then, we can see that in order to avoid the accumulation of a large amount of cadmium precipitation in the river channel of the polluted watershed, which will cause subsequent treatment problems. Therefore, the expert group used a small amount of precipitation combined with dilution to deal with the cadmium contamination situation.

What do you want the Internet to do if the news has the truth?

What do experts do when they have the truth?

What do experts do if they can write equations?

What do experts want him to do if they don't fool people?

Dozens of tons of water every day, seven or eight processes, 24-hour special supervision and testing, reaction for more than ten hours of heavy metals in the treated wastewater or sometimes exceed the standard and sometimes be fined, and have to go to the system pipe network to reprocess to be able to meet the standard discharge, why experts say that the river pours some medicine or pours more medicine or pours a lot of medicine every day, every minute and every second after the problem will not be serious? Why?

Because experts are redefining the standards for cadmium contamination again!

My guess is that aluminum chloride is produced under alkaline conditions, and the flocculated precipitation has an adsorption effect, similar to the purified water of alum.

Will this increase the pH value of the water, and will the surrounding area become so-called saline-alkali land?

(1) The list gets:

a1，c2a2，c2b1，c2b2，c2c1，c2-a1，c1a2，c1b1，c1b2，c1-c2，c1a1，b2a2，b2b1，b2-c1，b2c2，b2a1，b1a2，b1-b2，b1c1，b1c2，b1a1，a2-b1，a2b2，a2c1，a2c2，a2-a2，a1b1，a1b2，a1c1，a1c2，a1 There were 30 different results, and there were 8 cases for one upper and one lower river sample, p (one upper river sample and one lower river sample) = 8 30 = 4 15;

2）.x=1/6×（；

A: The average level of cadmium metal per 500g of river water samples was;

3) A: The cadmium content in 25 million tons of river water is about 20 tons

(1) The mass ratio of cadmium to chlorine in CDCL2 is: 112:(:71;

2) The mass fraction of cadmium in cadmium chloride is 112

The mass of cadmium in 1l river water is:

Because, the cadmium chloride content in the water of this section of the river exceeds the standard

So the answer is: (1) 112:71;

2) The content of cadmium chloride in the water of this section of the river exceeded the standard

According to the relevant provisions of China's Tort Liability Law and Criminal Law, if environmental pollution constitutes a tort, it shall be liable for no-fault compensation. and where serious consequences are caused, criminal responsibility is to be borne in accordance with law. Victims of infringement may sue in the people's courts. The competent court is in the polluted place.

In criminal proceedings, the public security organs are to file and investigate the case, and in accordance with the legally-prescribed procedures, the procuratorate is to be requested to review and prosecute, and the people's courts are to make a judgment in accordance with law.