How to deal with the problem of iron mud settlement in Fenton?

Due to the large amount of ferrous sulfate added during the oxidation process of Fenton, a large amount of iron ions in ferrous sulfate are precipitated, and a large amount of iron sludge is produced. It can even cause a large amount of sludge suspended solids to be difficult to settle in the wastewater. Most of the reasons for this situation are that the dosing ratio of ferrous sulfate to hydrogen peroxide is not well controlled, or the dosing of hydrogen peroxide is excessive and the reaction is not complete.

When this happens, flocculation can be strengthened by adding a flocculant (polyacrylamide). Or by adding lime powder for pH adjustment and coagulation to coagulate the suspended solids. Generally, in sewage treatment projects, Fenton has special reaction conditions and sufficient reaction time, if it is determined that the Fenton reaction is thorough, non-ionic polyacrylamide can be added to the water, which can help the sludge to accelerate the settlement.

The removal rate of some high-color and high-COD wastewater can be 90%-95% using ferrous sulfate Fenton. As an advanced wastewater treatment technology, the Fenton method uses the chain reaction between Fe2+ and H2O2 to catalyze the generation of hydroxyl radicals (·OH) with strong oxidizing properties, which can oxidize various toxic and refractory organic compounds, and can be used as a biological pretreatment for high-concentration refractory biodegradable wastewater treatment to improve water quality, enhance the biodegradability of wastewater, and create favorable conditions for subsequent advanced treatment. The main agents of Fenton's reagent are ferrous sulfate and hydrogen peroxide and alkali.

The dosing sequence of ferrous sulfate and hydrogen peroxide will affect the treatment effect of wastewater. First, the ratio of ferrous sulfate to hydrogen peroxide was obtained by orthogonal experiments (once it is not well controlled, it is easy to return color). Then add according to the order of adjusting the pH value first, adding ferrous acid, then adding hydrogen peroxide, and then adjusting the pH value.

After the addition of ferrous sulfate, the reaction is about 15 minutes, and then the hydrogen peroxide is added, and the alkali **pH value is added after the reaction is 20 to 40 minutes, and the treatment effect is better. <>

The Fenton reagent method is aimed at some particularly refractory organic pollutants such as high COD, using the strong redox properties of ferrous sulfate and hydrogen peroxide to generate strong oxidizing hydroxyl radicals, and refractory organic matter to generate free radicals, and finally effective oxidative decomposition (Fenton reagent reaction mechanism). The treatment effect of Fenton's reagent is affected by the concentration of wastewater pollutants, the pH value of the reaction, the ratio of ferrous sulfate to hydrogen peroxide, and the dosing concentration of hydrogen peroxide. The first thing to do is to rule out whether hydrogen peroxide is excessive?

What is the pH of the subsequent post-Fenton precipitation? Personal experience ph in 10--11....In addition, the difficulty of sedimentation should be that the anions and cations in the wastewater are relatively balanced, and it is recommended to add cation PAM to destroy the balance.

The first thing to do is to rule out whether hydrogen peroxide is excessive? What is the pH of the subsequent post-Fenton precipitation? Personal experience ph in 10--11....

2.In addition, the difficulty of sedimentation should be the balance of anion and cation in the wastewater, and it is recommended to add cation PAM to destroy the balance.

In a chemical reaction, a substance that can change the chemical reaction rate of reactants (increase or decrease) without changing the chemical equilibrium, and its own quality and chemical properties have not changed before and after the chemical reaction is called a catalyst (solid catalyst is also called a catalyst).

The Fenton catalyst does not produce iron sludge, which replaces the addition of ferrous ions in traditional Fenton, avoids the generation of a large amount of iron sludge, prevents the generation of secondary pollution, and greatly improves the shortcomings of traditional Fenton.

You can try the effect with a multiphase Fenton catalyst.

Compared with a single Fenton catalyst, the Fenton oxidation process composed of a new multiphase Fenton catalyst is not easy to reverse color, because the addition of hydrogen peroxide can be better controlled. Compared with a single Fenton catalyst, the new Fenton catalyst realizes water treatment under neutral conditions, greatly saves the amount of acid added, reduces the generation of acid mist in engineering, and is more environmentally friendly.

Is ferrous sulfate added with Fenton catalyst, and is the sludge yield high?

There is no need to add ferrous sulfate to the Fenton catalyst, but there will still be sludge production, but the sludge production will be greatly reduced compared to the ferrous sulfate in the Fenton reagent.

Fenton catalyst mainly refers to solid multiphase Fenton catalyst. Is it necessary to add ferrous sulfate to the Fenton catalyst used in the Fenton process, and how much sludge is produced? This article answers them one by one.

First of all, taking Senyang Fenton catalyst as an example, it is made of porous composite materials as the carrier, with a variety of rare earth metal oxides and transition metal oxides as the catalytic components, and refined through the processes of carrier doping, extrusion, mixed impregnation, and high-temperature roasting, which has the characteristics of low loss and high mechanical strength.

Fenton catalyst.

Compared with the traditional Fenton reagent, the Fenton catalyst can greatly reduce the amount of chemical sludge produced by the dosage of the traditional Fenton method, and the iron oxide formed on the surface of the carrier has a heterogeneous catalytic effect, which also promotes the chemical oxidation reaction rate and mass transfer effect, so that the removal rate of COD can be effectively increased by 20% to 30%, and the treatment and operation costs are saved by 30% to 50%.

The multiphase Fenton catalyst is not easy to reverse color during the Fenton oxidation process, so the amount of hydrogen peroxide can be better controlled. The new Fenton catalyst realizes water treatment under neutral conditions, greatly saves the amount of acid added, reduces the generation of acid mist in engineering, and is more environmentally friendly.