Industrial wastewater refers to the contaminated water generated from industrial activities. It typically contains a variety of pollutants, such as chemicals, heavy metals, oils, and other harmful substances. The composition of industrial wastewater can v

What is Industrial Wastewater?

Industrial wastewater is wastewater generated from the production processes of factories, manufacturing facilities, industrial zones, etc. The pollution characteristics or concentration in industrial wastewater vary greatly, depending on the type of industry, production lines, or the scale of the enterprise.

Industrial wastewater contains unstable chemical components, depending on various factors. However, most wastewater carries heavy metal ions such as iron (Fe3), lead (Pb2), mercury (Hg2),... and some organic and inorganic compounds, both soluble and insoluble phosphorus, nitrogen, fatty acids, chlorine, grease, oils, etc.

Therefore, to ensure environmental safety and the well-being of people around, businesses need to design solutions and explore effective industrial wastewater treatment technologies tailored to their specific industrial activities, ensuring flexibility and alignment with the production processes.

Origins of Industrial Wastewater

Industrial wastewater is typically classified into two types:

• Dirty industrial wastewater: This type of water is directly generated from production activities such as equipment cleaning, or the daily activities of factory workers.
• Clean industrial wastewater: This type is produced during machine cooling, heat dissipation in cooling stations, or condensed steam during production processes.

According to specific regulations in each country or region, particularly in Vietnam under Article 2 of Decree 154/2016/ND-CP, industrial wastewater originates from the following production activities:

• Production activities of breweries, distilleries, carbonated drinks, and soft drinks.
• Activities from the printing ink industry, dyeing or textile facilities.
• Wastewater from concrete mixing stations, paint production facilities, spray painting.
• Wastewater generated in coffee processing plants.
• Arising from boiler service industries.
• Laundromats and utility service establishments.
• Export processing zones: instant noodles, dairy, paper, agricultural and aquatic products.
• Wastewater from livestock farms, slaughterhouses.
• Electronic component manufacturing plants, metalworking, mechanical or metallurgical processing, etc.
• Chemical plants, pharmaceuticals, fertilizers, plant protection products, or household items, construction materials, stationery, etc.

Components of Industrial Wastewater

The major pollutants in industrial wastewater are mainly inorganic compounds, dissolved organic compounds, trace organic compounds causing unpleasant odors, organic compounds resistant to biological degradation, and various harmful substances for aquatic life.

Additionally, industrial wastewater also includes other pollutants such as grease, suspended solids, heavy metals, nutrients, all present in high concentrations.

Characteristics

1. Physical properties: Industrial wastewater often carries a strong odor, in various solid-liquid-gas states (suspended solids, adhesives, lime, etc., are usually partially removed by sedimentation).
2. Chemical properties: It contains both inorganic components (chlorine, nitrogen, phosphorus, sulfur, heavy metals like iron, lead, toxic substances, or gases like H₂S, CH₄,...) and organic components (carbohydrates, proteins, nitrogen nutrients, fats, engine oils, lubricants, insecticides, herbicides, etc.).
3. Biological properties: It includes pathogens, various microorganisms causing harmful diseases to human health.

Standards for Industrial Wastewater

The Ministry of Natural Resources and Environment has recently issued new regulations on industrial wastewater - QCVN 40, in addition to the 2015 regulations on industrial wastewater (QCVN 14 - MT:2015/BTNMT) applicable to various types of domestic wastewater from production and business establishments and related industries.

It is divided into two types:

• Type A: Maximum limits for pollutants allowed to be discharged into water sources used for domestic purposes.
• Type B: Maximum limits for pollutants not allowed to be discharged into water sources for domestic use without undergoing industrial wastewater treatment processes.

Why Treat Industrial Wastewater?

The presence of industrial wastewater alongside industrial development leads to numerous adverse effects on the environment and human health.

Water Source Pollution

Industrial wastewater significantly impacts aquatic life in water bodies.

The chemicals in the water alter its properties, leading to genetic mutations in aquatic species over time.

Soil Pollution and Impact on Soil Organisms

Industrial wastewater carries various inorganic and organic compounds that seep into the soil, accumulating to cause soil pollution and harm to soil-dwelling organisms.

Air Pollution

Harmful inorganic and organic compounds in industrial wastewater, when released into the air, increase particulate matter density in the air.

Given these hazards, every factory, plant, or company should understand wastewater treatment methods before commencing operations to ensure environmental safety for both the surroundings and people.