Hydros designs chlorination systems in both liquid and gaseous phases. Generally for reduced flow rates, chlorine in the gas phase is used directly, while on high flow rates it is preferable to use chlorine in the liquid phase which is vaporized and injected into the system through injector device.

Hydros is able to design and build systems for small and big flowrate with particular attention to compliance with the regulations governing the use of chlorine and with particular reference to the provisions of the following institutions / laws:

Cl               The Chlorine lnstitute USA
WCC           World chlorine Council
IS 4263      Code of safety for chlorine

All our systems are designed with the utmost care in the choice of materials and equipment installed in them in order to ensure a long service life, easy maintenance and total safety for the operator.

What is disinfection?

Human exposure to wastewater discharged into the environment has increased in the last 15 to 20 years with the rise in population and the greater demand for water resources for recreation and other purposes. Wastewater is disinfected to prevent the transmission of infectious diseases and to ensure that water is safe for human contact and the environment. There is no perfect disinfectant. However, there are certain characteristics to look for when choosing the most suitable disinfectant: 
• ability to penetrate and destroy infectious agents under normal operating conditions; 
• lack of characteristics that could be harmful to people and the environment; 
• safe and easy handling, shipping, and storage; 
• absence of toxic residuals, such as cancer-causing compounds, after disinfection; and • affordable capital and operation and maintenance (O&M) costs.

What is chlorine disinfection? 
Chlorine is the most widely used wastewater disinfectant in the U.S., and it kills most bacteria, viruses, and other microorganisms that cause disease. Chlorine is introduced to wastewater in the form of gas, hypochlorites (tablets, solutions, or powder), and other compounds. The different forms of chlorine used at wastewater treatment plants are gaseous chlorine, sodium hypochlorite solution, calcium hypochlorite, and bromium chloride. Wastewater and chlorine are first mixed completely in less than 1 second and then enter a baffled contact chamber to allow time for disinfection to occur. The effluent is then discharged to the receiving water. Chlorine residuals can persist in treated wastewater for many hours. To minimize the effect on aquatic life and the environment, most states require that chlorinated wastewater be dechlorinated. Dechlorination is the process of removing the chlorine residual prior to discharge. Some commonly used dechlorinating chemicals are sulfur dioxide, sodium bisulfite, sodium metabisulfite, and activated carbon. See below image for a flowchart of the chlorination process using liquid chlorine and dechlorination using sulfur dioxide.

What are the advantages of using chlorine disinfection? 
• Chlorine is a well-established technology. 
• Presently, chlorine is more cost-effective than other disinfection methods (except when dechlorination is needed and fire code requirements must be met). 
• The chlorine residual that remains in the discharged wastewater can prolong disinfection even after initial treatment and also provides a measure of the effectiveness. 
• Chlorine disinfection is reliable and effective against a wide spectrum of microorganisms. 
• Flexible dosing enables greater control over disinfection since wastewater characteristics vary from time to time. 
• Chlorine can eliminate noxious odors while disinfecting.

What determines the performance of chlorine disinfection? 
The effectiveness of chlorination depends on the dose, the chlorine demand of the wastewater, the chlorine residual, the amount of time the wastewater is in contact with the chlorine, the fecal coliform count in the wastewater, and other wastewater characteristics. The required degree of disinfection can be achieved by varying the dose and the contact time for any chlorine disinfection system. The chlorine dose usually ranges from 5 to 20 milligrams per liter (mg/L).

For optimum performance, the chlorination system must be designed so that the wastewater flows turbulently in a plug flow fashion throughout the contact chamber, ensuring complete mixing. This mixing allows the chlorine to have maximum contact with the wastewater and ensures that there are no dead areas (unused portions) of the tank.

Generiche scheme for chlorination system


Hydros is presented as an EPC for machines, packages and equipements for: 

  • Water treatment plants, waste water and ground water.
  • Plants and machines for waste management, composting and biogas.
  • Air treatment plants and vapours from industrial processes.
  • Special Mechanical Construction
  • We produce fixed and mobile solutions (Containerized, trailers, boxes) for specific requirements such as the treatment of leachate in lanfills or the module systhem Treatment, a service Pump & TAF ground water treatment or generally for pilot plants.

Our projects are characterized by a high degree of personalization. The engineering phase is entireley managed by our technicians ; we provide all the know how , and adequate human and technical resources, to proactiveley follow all stages of the project.

The efficiency of our production and logistics departments enable us to follow the entire project in terms of outputs and mechanical assembies. Most of the construction activities, especially those special ones, are held at home but we also use third part vendors, constantly checked, to realize some workmanships. The know how acquired allows us to detect and intervene before problems with engineering and then with the creation, even in existing plant complexes.The constant effort put at the disposal of the customers has allowed us to expand our business by acquiring expertise and important references in the construction of machines and plants.


We have  faced and successfully solved the problems of all kind, in various productive sectors, from food to oil Gas, always working with the same method and pursuing the same goal: quality and complete customer satisfaction.

For this reason, HYDROS is the ideal partner for the solution of specific problems.








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