CN103011361A

CN103011361A - Method for removing iron in sewage

Info

Publication number: CN103011361A
Application number: CN2012105955058A
Authority: CN
Inventors: 汪巍
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2012-12-07
Filing date: 2012-12-07
Publication date: 2013-04-03

Abstract

The invention discloses a method for removing iron in sewage and belongs to the field of sewage treatment in environmental protection. The method comprises the following steps of: adding polymerized aluminum chloride, cationic polyacrylamide and sodium nitrite into sewage with the iron ion concentration of 30-300 mg/L; and agitating and aerating to realize the aim of removing the iron. The method disclosed by the invention has the characteristics of wide raw material sources, cheap price, relatively smaller pharmaceutical dosage, low operation cost, no secondary pollution in a treatment process and high iron removing rate, the removing rate can be higher than 99.9%, and so on.

Description

A kind of method of removing iron in the sewage

Technical field

The present invention relates to a kind of method of removing iron in the sewage, belong to field of waste water treatment in the environment protection.

Background technology

Iron is one of essential trace element of human body, and iron ion is compared with heavy metal ion such as mercury, cadmium, arsenic, lead, chromium, although can not cause remarkable harm to human body, also can bring very large impact to environment.When the iron-holder in the water during greater than 0.3mg/L (in Fe) water just become muddy, when surpassing 1mg/L, glassware for drinking water has iron taste.The human body iron deficiency can cause lower immune function, digestive function weakness, a series of diseases such as nervous activity decline; Excessive Intake, unnecessary irony is put aside in liver with the colloidal form of ironic hydroxide, is unfavorable for the movement of blood in liver cell, thus infringement people's health.Therefore, country has done restriction to the iron level in the tap water, and its limit value is 0.3mg/L.

Mainly contain two kinds of natural oxidation method and aeration contact oxidation methods for the tradition removal method of iron ions from drinking water.The natural oxidation method is in the early days of foundation, use more deferrization process from a kind of of external introduction, but operational system is complicated, equipment is huge, and construction investment is high, and treatment effect is unstable, water outlet is often defective, progressively is touched oxidation style and substitutes from the sixties in 20th century.Contact oxidation method is that one of natural oxidation method is improved greatly, simplified the technical process of natural oxidation method, effect and the stability of deironing have been improved, but not every former water all is to use the contact oxidation method deironing, the strong high water of reducing substance concentration, the oxygenizement of iron will be hindered, and ferrous ion is easy to form trickle ironic hydroxide ion in the water layer on filtrate, will affect effluent quality.In addition, utilize in addition the strong oxidizers such as ozone, chlorine, potassium permanganate to carry out water treatment, but easily cause the secondary pollution of water.

Summary of the invention

The objective of the invention is for overcoming the deficiencies in the prior art, a kind of method of removing iron in the sewage is provided, it is extensive that the present invention has raw material sources, cheap, the added amount of chemical less, working cost is low, the treating processes non-secondary pollution, de-ironing efficiency is high, and clearance can reach 99.9% with first-class characteristics.

The technical solution used in the present invention is: the present invention is by adding polymerize aluminum chloride, cationic polyacrylamide and Sodium Nitrite in iron content sewage, thereby stirring, aeration reach the purpose of removing iron.

Iron concentration is 30～300mg/L in the described waste water.

Concrete operation step of the present invention is:

(1) in containing iron waste water, adds respectively polymerize aluminum chloride and cationic polyacrylamide carries out sedimentation to suspended particulate;

(2) add the Sodium Nitrite of 10～20ppm in the sewage after sedimentation, stir;

(3) in aeration tower, water flow mode is flow lifting type to the usefulness pump waste water lifting, and water outlet is at top of tower;

(4) waste water in the tower is carried out aeration, gas-water ratio is 30: 1;

(5) water outlet drains into the whirlwind-type settling tank behind the aeration, and regulating pH value with alkali simultaneously is 8.5～9.5, and constantly stirs, and leaves standstill, precipitation, the outflow of upper strata liquid be deferrization waste water.

The invention has the beneficial effects as follows:

(1) technical process is simple, and running cost is low;

(2) obvious processing effect can obtain removing the sewage of iron after primary treatment;

(3) treating processes non-secondary pollution, de-ironing efficiency is high, and clearance can reach more than 99.9%.

Embodiment

Example 1

(1) in containing iron waste water, adds respectively polymerize aluminum chloride and cationic polyacrylamide carries out sedimentation to suspended particulate; (2) Sodium Nitrite of adding 10ppm in the sewage after sedimentation stirs; (3) in aeration tower, water flow mode is flow lifting type to the usefulness pump waste water lifting, and water outlet is at top of tower; (4) waste water in the tower is carried out aeration, gas-water ratio is 30: 1; (5) water outlet drains into the whirlwind-type settling tank behind the aeration, regulating pH value with alkali simultaneously is 8.5, and constantly stirs, and leaves standstill, precipitation, the outflow of upper strata liquid be deferrization waste water, iron concentration in the waste water drops to 0.26mg/L by 258mg/L, and the iron ion removing rate has reached 99.9%.

Example 2

(1) in containing iron waste water, adds respectively polymerize aluminum chloride and cationic polyacrylamide carries out sedimentation to suspended particulate; (2) Sodium Nitrite of adding 15ppm in the sewage after sedimentation stirs; (3) in aeration tower, water flow mode is flow lifting type to the usefulness pump waste water lifting, and water outlet is at top of tower; (4) waste water in the tower is carried out aeration, gas-water ratio is 30: 1; (5) water outlet drains into the whirlwind-type settling tank behind the aeration, regulating pH value with alkali simultaneously is 9.0, and constantly stirs, and leaves standstill, precipitation, the outflow of upper strata liquid be deferrization waste water, iron concentration in the waste water drops to 0.086mg/L by 172mg/L, and the iron ion removing rate has reached 99.95%.

Example 3

(1) in containing iron waste water, adds respectively polymerize aluminum chloride and cationic polyacrylamide carries out sedimentation to suspended particulate; (2) Sodium Nitrite of adding 20ppm in the sewage after sedimentation stirs; (3) in aeration tower, water flow mode is flow lifting type to the usefulness pump waste water lifting, and water outlet is at top of tower; (4) waste water in the tower is carried out aeration, gas-water ratio is 30: 1; (5) water outlet drains into the whirlwind-type settling tank behind the aeration, regulating pH value with alkali simultaneously is 9.5, and constantly stirs, and leaves standstill, precipitation, the outflow of upper strata liquid be deferrization waste water, iron concentration in the waste water drops to 0.071mg/L by 237mg/L, and the iron ion removing rate has reached 99.97%.

Claims

1. method of removing iron in the sewage is characterized in that:

(4) waste water in the tower is carried out aeration, gas-water ratio is 30: 1;

2. a kind of method of removing iron in the sewage according to claim 1, it is characterized in that: iron concentration is 30～300mg/L in the described waste water.