How To Effectively Treat Industrial Wastewater Guide

If industrial wastewater  is not treated before being discharged outside, it can pollute water sources, soil, etc., affecting human health and damaging the environment. 

What is industrial wastewater

Industrial wastewater  is wastewater generated from production activities of industries. The composition of industrial wastewater is diverse, complex and depends on the type of production, raw materials, technology and production process.

Industrial wastewater can contain a variety of contaminants, including heavy metals, organic matter, persistent organic toxins, bacteria, viruses, and radioactive substances. These substances can cause serious pollution to the environment, causing harm to human health and the ecosystem.

Composition of industrial wastewater

Industrial wastewater typically contains organic, inorganic, and microbial contaminants. The main components include:

Organic pollutants

• Grease and lubricant: From the oil and gas, oil refining, and mechanical industries.
• Phenol and aromatic compounds: From chemical industry, dye production.
• Surfactants: From soaps, detergents.
• Persistent organic compounds: From the plastic, rubber, and paint industries.

Inorganic pollutants

• Heavy metals: Iron, copper, zinc, mercury, chromium, lead, cadmium... From mechanical, chemical, and metallurgical industries.
• Acid, alkali: From cleaning process.
• Mineral salts: Sodium, calcium, magnesium... From cooling water, thermal water.
• Suspended solids: From washing, screening, crushing, grinding processes in factories.

Microorganism

• Bacteria, viruses, mold: From workers' household waste.
• Pathogenic bacteria: Salmonella, Shigella... pollute the environment.

Harmful effects of industrial wastewater

Untreated industrial wastewater will cause serious harm:

For the environment

• Pollutes water sources, reduces dissolved oxygen.
• Kills aquatic species due to toxins.
• Soil pollution by heavy metals, grease.

For man

• Causes disease in humans through direct or indirect contact through food and drinking water.
• Causes cancer and birth defects due to toxic compounds.
• Reduced quality of life due to environmental pollution.

Harmful effects of industrial wastewater on the economy

• Waste of natural resources, costly to fix.
• Decreased land and property value due to pollution.
• Impact on local socio-economic development.

That is why  industrial wastewater treatment  is an urgent issue that individuals, businesses and enterprises need to pay attention to.

What chemicals are used to treat industrial wastewater?

Chemicals commonly used in  industrial wastewater treatment :

pH adjustment

• Sulfuric acid, hydrochloric acid: lower pH.
• Lime, soda: raise pH.

Precipitation and sedimentation

• Lime chlorine, iron sulfate: precipitates organic compounds and heavy metals.
• Synthetic polymers: aid in sedimentation.

Sterilize

• Chlorine: kills bacteria.
• Ozone: deodorizing and disinfecting.

Solids handling

• Synthetic polymers: coagulate suspended solids.

Grease treatment

• Detergent: breaks oil particles into smaller droplets.
• Enzymes, microorganisms: decompose grease.

There are also special deodorizing and color-removing chemicals for each industry.

Current advanced industrial wastewater treatment technologies

Industrial wastewater treatment technology using activated sludge

Activated sludge wastewater treatment technology is an aerobic biological process in which bacteria, fungi and other organisms are used to decompose organic substances in wastewater. This process is often carried out in a large tank called a bioreactor or activated sludge basin.

The wastewater is directed into a biological reactor where it is mixed with activated sludge. Activated sludge is a mixture of bacteria, fungi and other organisms capable of decomposing organic matter. These organisms use organic substances as food and produce by-products such as carbon dioxide, water and inorganic substances.

After the organic matter is decomposed, the wastewater is sent to the settling tank. Here, the suspended solids in the wastewater will settle to the bottom of the tank. After settling, the wastewater is taken out of the tank and discharged into the environment.

After settling, the activated sludge is recirculated into the biological reactor to continue the wastewater treatment process. A portion of the excess activated sludge is discharged from the system.

ADVANTAGES OF INDUSTRIAL WASTEWATER TREATMENT TECHNOLOGY USING ACTIVATED SLUDGE

• High treatment efficiency, can treat many different types of wastewater.
• Processing takes place quickly, within a few hours to a few days.
• This technology is quite simple, easy to operate and maintain.

DISADVANTAGES OF WASTEWATER TREATMENT TECHNOLOGY USING ACTIVATED SLUDGE

• High initial investment costs.
• A constant supply of oxygen is required to ensure proper treatment.
• Excess activated sludge must be properly treated and disposed of.
• Activated sludge wastewater treatment technology is widely used around the world to treat wastewater from urban areas, industrial parks, hospitals and other facilities.

Wastewater treatment technology using ion exchange method

Ion exchange wastewater treatment technology is a process that uses charged resin beads to absorb pollutants in water. This process is commonly used to remove heavy metal ions, organic compounds, and other contaminants from water.

Ion exchange technology works on the principle that charged plastic particles will absorb pollutants with reverse charges. For example, positively charged plastic particles will absorb negatively charged heavy metal ions, and negatively charged plastic particles will absorb positively charged organic ions.

Wastewater treatment by ion exchange is often carried out in ion exchange columns. The wastewater is passed through an ion exchange column, and the pollutants are absorbed into the resin beads. After the wastewater has been treated, the plastic particles are regenerated by washing with a special solution. This solution will release contaminants from the plastic beads, and the plastic beads can be reused.

ADVANTAGES OF INDUSTRIAL WASTEWATER TREATMENT TECHNOLOGY USING ION EXCHANGE METHOD

• Highly effective in removing pollutants, including heavy metal ions, organic substances and inorganic substances.
• Can be used to treat many different types of wastewater, including industrial wastewater, domestic wastewater and agricultural wastewater.
• Does not generate hazardous waste.
• Easy to operate and maintain.
• Low investment and operating costs.

DISADVANTAGES  OF INDUSTRIAL WASTEWATER TREATMENT TECHNOLOGY USING ION EXCHANGE METHOD

• High initial investment costs, including the cost of purchasing ion exchange materials and water treatment systems.
• The ion exchange process can produce wastewater with high or low pH, which requires further treatment before being released into the environment.
• Ion exchange materials can become saturated over time, requiring frequent regeneration or replacement, which is costly.
• Ion exchange may not be effective for all types of contaminants, especially organics.

Industrial wastewater treatment technology using reverse osmosis method

Reverse osmosis is a water filtration process that uses a semi-permeable membrane to separate impurities from water. This membrane has an extremely small pore size, allowing only water molecules to pass through, while impurities such as salt, bacteria, viruses and other contaminants are retained.

ADVANTAGES OF REVERSE OSMOSIS TECHNOLOGY

• Removes most impurities, including difficult-to-remove contaminants such as heavy metals, pesticides, bacteria and viruses.
• The water after treatment is of high quality and can be used directly without boiling.
• Simple processing, easy to operate and maintain.
• Can be used for many different water sources, including seawater and surface water.

DISADVANTAGES OF REVERSE OSMOSIS TECHNOLOGY

• High initial investment costs.
• Consumes a lot of energy.
• Generates wastewater with high concentration of impurities, requiring further treatment before being discharged into the environment.
• Some impurities, such as arsenic and fluoride, may not be completely removed.

Measures to prevent industrial wastewater pollution

Some measures to prevent industrial wastewater pollution:

Control and treat wastewater at source

This includes improving manufacturing processes to minimize the amount of wastewater generated from industrial production.

Use an effective wastewater treatment system

Companies need to invest in advanced wastewater treatment systems to remove or reduce toxic substances and pollutants in wastewater before discharging it into the environment.

Promote water reuse

Companies can adopt water reuse techniques to reduce the amount of new wastewater generated and reduce pressure on clean water resources.

Wastewater monitoring and compliance

Strictly manage wastewater treatment process, ensure compliance with environmental and industrial wastewater regulations.

Increase education and awareness

Create employee education and training on the importance of minimizing wastewater pollution and how to take preventative measures.

Together these measures can help reduce the impact of industrial wastewater on the environment and human health.