Product Introduction

The high concentration ammonia nitrogen wastewater from the ammonia nitrogen stripping tower has a wide range of sources and a large discharge volume. Fertilizer, coking, petrochemical, pharmaceutical, food, landfill sites, etc. all produce a large amount of high concentration ammonia nitrogen wastewater. The discharge of a large amount of ammonia nitrogen wastewater into water bodies not only causes eutrophication and black and odorous water, but also increases the difficulty and cost of water treatment, and even has toxic effects on people and organisms.

IIAmmonia nitrogen blow off tower ammonia nitrogen blow off tower blow off technologyThe blow off method is used to remove ammonia nitrogen from water, which involves introducing gas into the water to allow sufficient contact between gas and liquid, allowing the dissolved free ammonia in the water to pass through the gas-liquid interface and transfer to the gas phase, thereby achieving the goal of removing ammonia nitrogen. Air is commonly used as a carrier (if water vapor is used as a carrier, it is called stripping). Ammonia stripping generally uses stripping tanks and stripping towers2Class of equipment, but the stripping tank occupies a large area and is prone to secondary pollution, so tower equipment is often used for ammonia stripping. Blow off towers often use countercurrent operation, with a certain height of packing inside the tower to increase gas flow—The liquid mass transfer area is conducive to the desorption of ammonia from wastewater. Common fillers include Raschig rings, polypropylene ball rings, polypropylene polyhedral hollow spheres, etc. The wastewater is lifted to the top of the packed tower and distributed over the entire surface of the packing. It flows downwards through the packing and flows in reverse with the gas. The partial pressure of ammonia in the air increases with the degree of ammonia removal and decreases with the increase of gas-liquid ratio.

IIIThe ammonia nitrogen treatment system developed by our company combines multiple technologies such as ammonia nitrogen stripping and absorption tower purification to treat ammonia nitrogen wastewater of different concentrations. It can treat ammonia nitrogen wastewater above 10000mg/L to meet discharge requirements. The concentration of ammonia nitrogen after treatment is below 15mg/L, meeting the national first-class emission standard. It is an ammonia nitrogen treatment system that can balance the characteristics of simple process, low investment, mature technology, convenient control, and no secondary pollution. The ammonia gas produced by traditional ammonia nitrogen blowing is still prone to secondary pollution when it enters the atmosphere with the air. Our company has installed an absorption tower after the ammonia nitrogen blowing tower, so that the air discharged into the atmosphere is purified and pollution-free.

Application areas: 1. Pharmaceutical, pesticide and chemical wastewater; 2. Leachate from landfill sites; 3. Wastewater from fertilizer production; 4. Wastewater from coking industry; 5. Rare earth smelting wastewater; 6. Domestic sewage, etc.

2： Design principle explanation

Ammonia nitrogen mainly exists in the form of ammonium ions (NH4+) and free ammonia (NH3) in wastewater, and its equilibrium relationship is as follows: The relationship between NH3+H2O - NH4++OH - is influenced by pH value. When the pH value is high, the equilibrium shifts to the left and the proportion of free ammonia increases. At room temperature, when the pH value is around 7, most of the ammonia nitrogen exists in the form of ammonium ions, while when the pH is around 11, free ammonia accounts for approximately 98%. Free ammonia is easy to escape from water, and if aerated, it can promote the escape of ammonia from water. Among them, pH is the key to the effect.

Dissociation rate of ammonia nitrogen at different pH and temperature (%)

In practical engineering, blow off towers are mostly used. The structure of the blow off tower adopts a gas-liquid contact device, which is filled with packing inside the tower to increase the contact area. adjustpHThe water after the value is sprayed onto the packing from the upper part of the tower to form water droplets, which fall down through the gaps of the packing and come into contact with the air blown up from the bottom of the tower by the fan in reverse flow, completing the mass transfer process and converting ammonia from liquid phase to gas phase. It is discharged with the air, completing the blow off process and achieving a removal rate of75%Above. Low concentration wastewater is usually blown off with air at room temperature, while high concentration wastewater is often blown off under heating.

The blown off ammonia gas then enters the ammonia absorption purification tower, where it undergoes a chemical reaction with the absorption liquid, resulting in gas emissions that meet standards and are pollution-free.

3： System characteristics and process flow

(1) By combining processes, wastewater of different concentrations can be treated with high removal rates of ammonia nitrogen, and the treated wastewater meets the national first-class discharge standard of ≤ 15 mg/L.

(2) Low energy consumption and low cost, the treatment cost per ton of wastewater is 5-10 yuan, far lower than the traditional process's treatment cost of 15-25 yuan/ton.

(3) All the exhaust gas generated by the system enters the ammonia absorption system, making the entire treatment more environmentally friendly.

(4) The internal design of the equipment is more reasonable, which solves the impact of low temperature climate on the blowing efficiency and the problem of packing blockage after long-term operation.

(5) The equipment is processed using fiberglass or carbon steel anti-corrosion materials, which solves the problem of lifespan caused by traditional equipment corrosion caused by sewageShort issues.