Water scarcity is one of the major challenges that the world must face to solve society’s supply problems for the future. An important fact is that between 300 and 500 million tons of wastewater are dumped in rivers, lagoons and oceans every year.
It is time for the public and private sectors to implement measures, in line with the circular economy paradigm, to mitigate the demands on Earth created by overpopulation and an overconsumption system.said Guillermo Piccardo, Business Line Manager at Atlas Copco Argentina.
Against this background, since 2018 and in line with Goal 6.3 of the Sustainable Development Goals, the World Bank has sought to promote wastewater treatment and resource recovery initiatives in Latin America and the Caribbean, with the aim of increasing the reuse of clean water worldwide by 2030.
In other words, the better the wastewater treatment, the better the quality of water that can be made potable for the daily needs of cities and their residents.
An important fact is that in the region only between 30 and 40% of the waste water collected is treated, which has a negative impact on health and the environment. indicates Piccard.
Residual or black waters are those whose quality is affected by human activities and can be classified into urban, domestic and industrial waters depending on their origin. The productive sectors with the highest consumption include the chemical industry (25%), agri-food industry and animal husbandry (17%), production and processing of metals (e.g. steel) (13%) and mining (7%). In fact, 80% of the water consumed is discharged into the environment without proper treatment.
Investing in sanitation infrastructure and technologies is a priority for smart management, as it not only provides economic benefits, but also by-products such as nutrients and biogas that can be used to generate clean energy. Additionally, the additional revenue generated through this process could help cover operational costs.
Technologies in wastewater treatment
Wastewater treatment plants are responsible for managing, recycling and converting wastewater – municipal and industrial – into valuable social and productive resources. An essential element of these systems are the oil-free blowers, which ensure a continuous supply of oxygen to the bacteria present in the water.
This is to speed up the decomposition process. It then describes the physical, chemical, and biological steps typically performed to treat water.
1. Pre-treatment: The purification begins with a process of separating large and medium-sized solid waste using bars and screens of different thicknesses.
Generally an air blower is used to clean coarse sediment filters using as little water as possible at much higher power. It is worth mentioning that the pressure used to inject pure water consumes more energy. Nowadays there are devices that compress air and are therefore much more efficient. In fact, they can save between 20 and 30% energy compared to a positive displacement blower. In addition, variable speed compressors, also known as VSDs, are an excellent choice for facilities where air demand varies, such as facilities that operate multiple shifts throughout the day and facilities where demand varies throughout the day sways. The speed of the motor is automatically adjusted according to demand and contributes to energy savings of 35 to 50%, avoiding unnecessary waste.
2. Primary treatment: The aim is to remove suspended solids. The water is retained in decanters so that gravity helps to separate these particles. It is also possible to add substances that improve sedimentation and neutralize the pH of the water.
3. Secondary treatment: The aim is to break down and eliminate organic matter through the use of bacteria and microorganisms, as well as nutrients such as nitrogen and phosphorus. The most widespread treatment is the so-called activated sludge treatment. Normally, treatment plants come to an end when the treated water meets the defined discharge requirements and there are no additional quality requirements for its reuse or later use.
4. Tertiary or chemical treatment: it aims to improve the quality of the resource through the use of ultraviolet (UV) rays or chlorine, with the main objective of eliminating bacteria and pathogens before returning the water to the river and nature becomes.
Despite the water challenges Latin America is facing, there are reasons that allow us to glimpse a sustainable future – with greater professionalization of the sector and the application of innovative solutions that help improve water management – and they respond to success stories that going on from Mexico to southern Argentina, recently published by the Inter-American Development Bank.
In this sense, the possibility to modernize infrastructure and the promotion of public-private partnerships are two factors that will make it possible to lay the foundations for a better future.
