Treatment method of iron oxide pigment wastewater

Abstract

The invention discloses a treatment method of iron oxide pigment wastewater. The treatment method comprises the following steps: introducing the iron oxide pigment wastewater into a sedimentation tank; adding calcium hydroxide into the sedimentation tank, uniformly stirring, and then precipitating for 24-36 hours; discharging supernatant liquid in the sedimentation tank, introducing sludge in the sedimentation tank into a stirrer, and adding coal and mineral powder into the stirrer according to a ratio of 1: 1: 1 to obtain a mixture; calcining the mixture in a brick kiln to obtain a finished product brick; the discharged clear liquid is introduced into a reaction tank, ozone is injected, and the oxygenation time is 1.5-2 hours; adding a metal salt, uniformly stirring, precipitating, and stirring again to obtain a suspension; and carrying out resin filtration on the suspension. Compared with the prior art, the method has the following advantages that the problem of environmental pollution can be thoroughly solved by firing the residues in the iron oxide pigment wastewater into bricks; harmful ions in the wastewater react into low-toxicity and low-pollution components, and the low-toxicity and low-pollution components can be directly discharged, so that the pollution to the environment is reduced.

Description

【Technical field】 [0001] The invention relates to the technical field of wastewater treatment, in particular to a method for treating iron oxide pigment wastewater. 【Background technique】 [0002] Iron oxide pigments, mainly iron oxide red, iron oxide yellow, iron oxide black, etc. Due to the need for multiple separations and washings in the production process, the discharge water is characterized by a large amount and various pollution indicators seriously exceeding the standard. Every ton of iron oxide red, iron oxide yellow, and iron oxide black produces about 50 tons, 70 tons, and 30 tons of waste water, respectively. Because there are a lot of pigment residues and inorganic substances in the wastewater, the pH value changes greatly, so there are high CODcr (chemical oxygen demand) and SS (suspended solids), and the wastewater pollution lasts for a long time. After entering the water environment, the water body appears different color. At present, there are two common...

AI Technical Summary

Problems solved by technology

At present, there are two commonly used methods for the treatment of iron oxide-based pigment wastewater. The first method is the neutralization method, which is to add alkaline substances to the Fe+2-containing wastewater, neutralize it first, and then discharge it after precipitation. Although a large amount of Fe+2 can be removed, all Fe+2 cannot be completely separated, so there is still a high amount of Fe+2. The discharged water enters the water body, and the Fe+2 is oxidized and hydrolyzed by air to make the river water appear brown. The water environment is polluted; the second method: neutralize and oxidize, after the waste water is added with an alkaline substance, pass into the air to oxidize, and discharge after precipitation. After oxygenation, Fe(OH)2 becomes Fe(OH)3, but Fe(OH)3 is a colloidal solution with a positive charge, so the discharge water is in poor condition and the chromaticity is still high, which still causes harm to the water environment. pollution, moreover, the treatment cost of this method is high, a large amount of sludge is difficult to handle, and it is easy to cause secondary pollution

In addition, sludge landfill will destroy good farmland, and sludge transportation and landfill costs are high