Industrial Wastewater Treatment Equipment

Industrial wastewater treatment equipment is used to treat wastewater generated during industrial production, bringing it up to discharge standards or making it reusable. The following are common types of industrial wastewater treatment equipment:

Pretreatment Equipment

1. Mechanical Grid

It is mainly used to intercept large floating debris and suspended solids in wastewater (e.g., leaves, plastic fragments, fibers). This prevents such impurities from entering subsequent treatment equipment (which could cause clogging or damage) and ensures the smooth operation of subsequent treatment processes.

2. Grit Chamber

Based on the principle of gravitational sedimentation, it allows high-density inorganic particles in wastewater (e.g., sand grains, cinder) to settle at the bottom of the tank, thereby removing these impurities. This reduces wear and clogging of subsequent treatment equipment and helps improve the efficiency of subsequent treatment processes.

3. Equalization Tank

The water quality and quantity of industrial wastewater may fluctuate significantly at different times. The function of the equalization tank is to balance the water quality and quantity, buffering and regulating the wastewater. This allows subsequent treatment equipment to operate under relatively stable conditions, enhancing the stability and reliability of treatment efficiency.

Solid-Liquid Separation Equipment

1. Air Flotation Equipment

It is suitable for treating oil-containing wastewater or wastewater with fine suspended particles. Its principle is to inject a large number of micro-bubbles into the wastewater; these bubbles combine with suspended particles or oil pollutants in the wastewater to form air-float aggregates with a density lower than water. The aggregates then float to the water surface, forming a scum layer, which is subsequently removed by slag scraping equipment to achieve solid-liquid separation.

2. Sedimentation Tank

It utilizes gravitational force to make suspended solids in wastewater settle naturally at the bottom of the tank, realizing solid-liquid separation. According to differences in water flow direction and structure, sedimentation tanks can be divided into horizontal flow sedimentation tanks, vertical flow sedimentation tanks, radial flow sedimentation tanks, etc. They are suitable for treating wastewater with high suspended solid content.

3. Screw Press Dehydrator

It adopts a combination of spiral pressure and static-dynamic ring technology to dehydrate sludge. During operation, sludge is pushed by the spiral shaft to move axially from the low-pressure zone to the high-pressure zone. In this process, water in the sludge is gradually squeezed out and discharged through the gaps between the static and dynamic rings. Finally, efficient sludge dehydration is achieved, and the moisture content of the sludge can be reduced to below 50%.

Biological Treatment Equipment

1. Activated Sludge Aeration Tank

It uses aerobic microorganisms to degrade organic pollutants in wastewater. Inside the aeration tank, air is injected into the wastewater to provide sufficient oxygen for microorganisms, enabling them to decompose and metabolize organic matter in the wastewater under aerobic conditions. Organic matter is converted into carbon dioxide, water, microbial cell substances, etc., thereby achieving the goal of removing organic matter. Parameters such as dissolved oxygen and sludge concentration need to be properly controlled.

2. Biological Contact Oxidation Tank

Fillers are installed inside the tank, and microorganisms grow on the surface of the fillers to form a biofilm. When wastewater flows through the fillers, it fully contacts the microorganisms on the biofilm; organic matter in the wastewater is adsorbed, decomposed, and oxidized by the microorganisms, thus being purified. This method is suitable for treating high-concentration organic wastewater and has advantages such as high treatment efficiency, small floor space, and strong shock load resistance.

3. UASB (Upflow Anaerobic Sludge Blanket)

It is a wastewater treatment equipment operating under anaerobic conditions. Wastewater enters from the bottom of the reactor and flows upward through the anaerobic sludge blanket. Under the action of anaerobic microorganisms, organic matter in the wastewater is decomposed into biogas (mainly composed of methane and carbon dioxide) and water. Meanwhile, the biogas generated stirs the mixture during its ascent, promoting full contact between wastewater and sludge and improving treatment efficiency. Sludge loss must be prevented during operation.

Advanced Treatment Equipment

1. Membrane Treatment Systems

Common types include reverse osmosis (RO) and ultrafiltration (UF) systems.

• Reverse Osmosis (RO): Based on the principle of semipermeable membranes, under pressure, water molecules pass through the semipermeable membrane, while small-molecule pollutants in water (e.g., dissolved salts, heavy metal ions, organic matter) are retained. This achieves high-precision filtration and purification of wastewater.
• Ultrafiltration (UF): It mainly uses the sieving effect of ultrafiltration membranes to remove macromolecular organic matter, colloids, bacteria, and other pollutants in wastewater. It is often used as pretreatment for reverse osmosis or in advanced treatment scenarios with relatively low water quality requirements.

2. Fenton Reactor

By adding ferrous ions (Fe²⁺) and hydrogen peroxide (H₂O₂) to wastewater, highly oxidizing hydroxyl radicals (・OH) are generated. These hydroxyl radicals can undergo oxidation reactions with refractory organic pollutants in wastewater, decomposing the organic matter into carbon dioxide, water, and small-molecule organic matter. This achieves the goal of degrading organic pollutants. It is often used to treat refractory organic wastewater such as printing and dyeing wastewater and phenol-containing wastewater.

Other Auxiliary Equipment

1. Chemical Dosing Device

It is used to add various chemical agents to wastewater (e.g., coagulants, flocculants, disinfectants). Adding coagulants and flocculants can make colloidal particles and fine suspended solids in wastewater coagulate into larger particles, facilitating subsequent sedimentation or air flotation separation. Adding disinfectants can kill pathogenic microorganisms in wastewater, ensuring that the treated water quality meets relevant standards.

2. Filters

Examples include fiber disk filters and activated carbon filters. They can further purify wastewater that has undergone preliminary treatment, removing residual trace pollutants, suspended solids, organic matter, etc., from the water. This improves water quality, enabling the treated wastewater to meet higher discharge standards or reuse requirements.