Wastewater Treatment Systems: What Solutions?


Why are there Different Treatment Systems?

Wastewater treatment plants can be installed at the production site of a factory. Their objective is to treat the water generated by industrial production, remove the pollution present and reuse it in recycled form or discharge it into the natural environment. Each wastewater treatment plant must evaluate the legislation and comply with the regulations that apply to it in terms of discharges, water quality, standards, etc. (district regulations, environmental and health standards, etc.).

With the development of activities in France, the production of factories becomes more and more important and, at the same time, the volume of water intended for treatment increases, which explains the development of different purification systems and new technologies. . In general, the design of a treatment system for a wastewater treatment plant is based on the needs of your operation. However, the studies reflect the development of the business in the short term, and the structures built may become insufficient over time. More and more treatment plants are also confronted with seasonal peaks and must find suitable solutions quickly and efficiently.

Air Liquide’s solutions for wastewater treatment and technologies adapt to the treatment steps already in place, and to the water recycling circuit for possible reuse of resources after elimination of water contamination.
For some companies, we are talking about a real valorization of industrial water by reuse of these resources which could seem lost.
Air Liquide’s specific water treatment equipment makes it possible to treat a greater volume of water thanks to the use of gas (gas injection into the pool water).

Which treatment system best suits your needs?

Classic water treatment process: In a classic wastewater treatment plant in Pakistan, the operation is carried out in several stages (pretreatment, primary treatment, and secondary treatment). The pretreatment stage filters the water and can include screening, filtration, settling, and degreasing. In this stage, the major wastes are filtered, but it is not a complete purification. The initial treatment corresponds to sedimentation (filtration, membranes). The purpose of this stage is to remove as much organic material as possible. Secondary treatment is the final treatment of the organic bacteria in the wastewater.

This processing system can evolve according to the source industry production chain and standards.

Biological treatment systems for large scale production of chemical wastewater treatment

This treatment is a solution to a one-time or long-term increase inflow, and to the treatment of chemical-type effluents. Its treatment response quickly to your problem and is integrated into your existing installations. It also allows you to save space by avoiding the design of new pools. This technique is inspired by the natural environment. The principle? Use sludge (a mixture between organic matter and earth) that we boost with CO2 so that it absorbs pollution. Then, decantation is necessary in order to separate the treated water and the sludge. It will be carried out in a station or sent for sludge treatment. This water treatment system multiplies the performance of a station by 2.5 / 3.

Treatment system by neutralization of the pH by CO2 for water that hardly meets the discharge standards.
Any water leaving a treatment plant in Europe and being discharged into the natural environment must have a pH lower than 8.5. However, depending on the industrial sector, it may be difficult to meet this threshold. Food industries, for example, often use water to rinse their tank bottoms. We can disinfect this water and reduce its pH simply by injecting CO2 (carbon dioxide). The results of the analyzes are then simple and predictable.

With a network of experts, Air Liquide can help you find the system best suited to your problem, without modifying your existing installations. We provide you with quality solutions, generally requiring simple modifications such as device installation for the electrical connections necessary for the proper functioning of our equipment. We maintain our equipment ourselves and work with a variety of industries to better support your decontamination project.

Expert opinion Air Liquide - Water treatment: what is COD?

Water treatment: what is COD?

Why choose Air Liquide for water treatment?

Increase the treatment capacity of your biological stations, eliminate foaming, odors, and refractory pollution, neutralize alkaline effluents thanks to industrial gases and the expertise of Air Liquide experts.
Your privileged partner in water treatment offers you a global offer of gas, equipment, and services. You have all the solutions to bring into compliance, regulate and boost the productivity of your industrial wastewater treatment plants and municipal (urban) water plants.
Air Liquide works closely with industrial companies, offering to unravel expertise and know-how. Each solution is the result of continuous research to improve wastewater systems and water and sanitation measures.

What types of water can be treated?

All collect municipal water (rainwater, organic and inorganic compounds in wastewater) can be treated directly at the wastewater treatment plant.

Industrial water is often more polluted, whether, for use as cooling water, land application residues, or station rejects present in a waste pit. However, the purification of industrial water is no less effective if the dedicated infrastructures are efficient.

Industrad Group, The decontamination solution at the heart of the crucial issue of water scarcity

Air Liquide offers the most reliable, the most advance, and the most efficient solution for the treatment of wastewater. Industrad Group is part of a specific context where water pollution control has become a priority:

  • 844 million people on earth do not have access to drinking water or 11% of the world population,
  • 30% of the population do not have access to water through a tap, i.e. around 2,500 million people,
  • 60% are not connected to a secure wastewater treatment plant.

The problem of water treatment in factories

This scarcity of water, a source of deficiencies and illnesses among the population’s concerns, is largely due to insufficient or non-existent decontamination actions. This concerns several million inhabitants of the Earth. In fact, companies and communities have an obligation to treat the effluents resulting from their activities. The treatment of this wastewater may involve several stages, which are differentiated according to their position in the overall treatment process (primary, secondary, and sometimes tertiary). The result of the treatments is subject to compliance with increasingly drastic European standards.

Manufacturers, depending on their operating shutdown, can discharge their effluent directly into the network, or have an obligation to carry out pretreatment or complete treatment of their effluent. During a complete treatment, the discharge can be carried out in a natural environment such as a river. The treatment can be carried out by various processes such as physicochemical processes (rather primary), biological treatment (rather secondary), oxidative treatment with Ozone for example, or adsorption on carbon (rather tertiary). All of these treatments make it possible to eliminate the different forms of pollution, mainly carbonaceous forms (hydrocarbons, alcohol, carboxylic acid for example) and nitrogenous forms which may be present in solid, colloidal, or dissolve forms.

And what about domestic water treatment?

There are two modes of sanitation for domestic water. Individual sanitation and collective sanitation. As part of collective sanitation, domestic water relates to activity, and human consumption is collected by networks which are connected to a treatment station. Wastewater corresponds to sanitary water from toilets, and gray water, or gray water, from shower rooms, bathrooms, and kitchens. In the context of urban effluents, the inhabitant equivalent is used to quantify the pollution which is treated in a wastewater treatment plant. The unit: inhabitant equivalent corresponds, in Europe and mainly, to 200 liters of water per day containing about 60 grams of biodegradable pollution (BOD5). For more detailed information, there are water information systems that explain water treatment as well as sewage sludge treatment to consumers. These water information centers regularly publish reports that can be downloaded online.

Industrad Group, the global answer to all needs

With Industrad Group for Biological Treatment, Industrad Group for Advance Oxidation, or Industrad Group for Neutralization of Effluents, you optimize the treatment capacity of your wastewater treatment plant and you control your operating costs.

These water treatment solutions developed by Air Liquide allow optimum control of water quality by you, with ease. You are thus assured of meeting the standards required by the administration, for the benefit of municipalities and communities. If necessary, in the event of exceedances or failure of the reject quality, Industrad Group allows you to take the necessary measures to comply with legal requirements in record time. You also benefit from regular maintenance of treatment facilities, guaranteeing the efficiency of your facilities and the continuity of your activity.

Air Liquide and you, as close as possible to your water treatment needs

The answers to all your questions related to water treatment.

Do you want to save money on your water treatment plant and optimize its efficiency? 

If you notice a pollution peak that is difficult to treat by your current installations, Air Liquide offers you a suitable solution. No need to carry out civil engineering work to expand your station. With Industrad Group for Biological Treatment, you exploit all the advantages of pure oxygen in water treatment. Your wastewater treatment plant will then be able to treat the peaks without major modification and with the additional advantages of reducing energy consumption, foaming problems, odor emissions, anti-foam consumption, and increase flexibility. of your installation to adapt to the incoming pollutant load. This solution avoids heavy reinvestment by boosting the productivity of your wastewater treatment plant.

Do you want to have all the data on the water before making your choices? 

We can quickly assess the relevance of these solutions on the basis of the information you provide to us, in a confidential manner. Our response will integrate the few necessary adaptations of your wastewater treatment plant to the gas solution, the impact of the solution on wastewater treatment plant sludge.

Gases in water treatment

What are industrial gases used in water treatment plants?

  • Nitrogen gas is used for safety inerting for flammable materials such as dried sludge, activated carbon, on drinking water stations, for example.
  • Oxygen is used to boost your biological station, and in some cases to oxidize compounds such as sulfides, sulfites, and other sulfur compounds that can be found in effluents.
  • Carbon dioxide is used in the production of drinking water for the Calco-carbonic balance of water, as well as for the neutralization of alkaline effluents, to replace strong acids, which are always dangerous to handle and store.
  • Ozone, depending on the geographical areas of the globe, is often produced from pure oxygen, and used in water disinfection, as well as in tertiary treatments, in order to remove color, refractory COD, micro-pollutants, etc.