The Danger of Incorrect Dosing in Water and Wastewater Treatment

The use of chemicals such as coagulants, flocculants, and disinfectants is essential for the efficiency of water and wastewater treatment. However, incorrect dosing can compromise the entire process, leading to economic losses, environmental risks, and legal liabilities. Achieving the right balance is the key to operational success.

The Impact of Improper Dosing

When overdosing occurs, product waste drives up operational costs. In addition, unreacted chemical residues may be discharged into the environment, increasing toxicity. The treatment process itself is also affected: excessive coagulants or flocculants generate more sludge than anticipated, overloading the dewatering system and raising disposal costs. A common example is the excessive use of coagulants such as PAC or Polydadmac, which, instead of improving results, can cause residual turbidity and instability in the clarifier.

On the other hand, underdosing compromises treatment efficiency, preventing essential parameters such as BOD (Biochemical Oxygen Demand) and TSS (Total Suspended Solids) from meeting regulatory standards. This non-compliance may result in fines, environmental sanctions, or even plant shutdowns. In industries such as food & beverage and pulp & paper, poor-quality treated water directly impacts production processes and brand reputation. For instance, underdosing polymers in dairy flotation systems may lead to carryover of fats and oils into subsequent stages of treatment.

How to Find the Right Balance

Correct dosing is not a matter of trial and error. It must be a controlled, technical process, based on:

• Jar testing: for accurate adjustments.

• Real-time monitoring: of parameters such as pH, turbidity, and color.

• Continuous training: for the operating team.

• Automation and control technologies: to ensure precision and consistency.

Improper use of chemicals poses environmental, economic, and legal risks. Companies that strive for efficiency and sustainability need reliable partners to deliver tailored technical solutions. This is where Ecosign plays a strategic role, providing high-quality products, specialized technical support, and continuous innovation to ensure that your treatment plant operates at peak performance, without waste, and always in compliance with regulations.

Author: Éverton Luiz Petronilho

References   

1. CONAMA – Conselho Nacional do Meio Ambiente. Resolução CONAMA nº 357/2005 – Dispõe sobre a classificação dos corpos de água e diretrizes ambientais para o seu enquadramento, bem como estabelece as condições e padrões de lançamento de efluentes.

2. Metcalf & Eddy; Tchobanoglous, G.; Burton, F.; Stensel, H. (2014). Wastewater Engineering: Treatment and Resource Recovery. 5ª edição. McGraw-Hill.

3. Libânio, M. (2010). Fundamentos de Qualidade e Tratamento de Água. 3ª edição. Editora Átomo.

4. Di Bernardo, L.; Dantas, A. D. B. (2005). Métodos e Técnicas de Tratamento de Água. 2 volumes. Rima Editora.

5. USEPA – United States Environmental Protection Agency. Wastewater Technology Fact Sheets.

6. WHO – World Health Organization (2017). Guidelines for Drinking-water Quality. 4ª edição.