Vert Energy Solutions cleans up Mexico with unique technology

The combination of demographic growth and urbanisation has given rise to an increase in domestic, agricultural and industrial water consumption. This in turn has resulted in water shortages and a significant volume of wastewater, which threatens rivers, lakes, seawater and aquifers. The treatment of water – above all, of wastewater – has become an urgent and necessary practice worldwide.

In Mexico, only 47.5 percent of collected wastewater is treated. Official data says the country has an infrastructure comprising 2,342 municipal wastewater treatment plants (WWTP, of which about half are abandoned due to unforeseen high operating costs), with an installed capacity of 12.1 million cubic metres per day. The majority of municipalities in Mexico have opted for conventional treatment methods, in particular that of activated sludge.

Wastewater sludge treatment is a global environmental problem because contaminants in water may end up in the sludge. Sewage sludge treatment and disposal can constitute up to 40 percent of total emissions associated with wastewater treatment.

As regulations regarding the quality
of treated wastewater effluent have become more demanding, there has been
an increase in production of sludge, which 
is eliminated either via land spreading (directly or after composting) or incineration. This process requires intensive use of energy and therefore generates high electrical costs. Sludge management and disposal can account for up to 50 percent of a plant’s operating costs. This is one of the principal problems Mexico is facing in the treatment of wastewater.

Mexico has also set a target of treating 100 percent of all wastewater by 2030

Mexico has also set a target of treating 100 percent of all wastewater by 2030. The goal implies treating 24.7 million cubic metres per day: 16 million cubic metres per day more than what is treated at the moment. Although there would be obvious benefits from meeting this target, there would also be a significant negative impact from the high energy costs and greenhouse gas emissions. This presents us with the challenge of finding solutions that mitigate the adverse effects upon the environment while also delivering favourable financial returns for companies.

Technologies such as those offered by Vert Energy Solutions, in alliance with its strategic partner Applied CleanTech, allow us to respond to this challenge by reducing the triple cost generated by the treatment of water with the activated sludge system: energy costs, financial costs and environmental costs.

The proposed solution
Vert Energy Solutions, a young Mexican company, was set up with the objective of making the best technologies available in order to deliver sustainable and financially viable water treatment solutions to Mexican companies. Its technologies go beyond creating a positive impact on the environment: they also increase the availability of fresh water, and reduce the investment required to implement, maintain and operate such solutions.

In 2012, Vert Energy Solutions entered into a partnership with Applied CleanTech (ACT), an Israeli company, to introduce ACT’s new sewage mining technology throughout Mexico.

Recognising sewage as a valuable resource, ACT developed a groundbreaking system that extracts bio-solids from wastewater before it becomes sludge. Initial sludge formation is reduced by up to 50 percent before applying any chemical or biological treatment. ACT’s patented sewage recycling system (SRS) technology transforms solids in wastewater into a recycled commodity: Recyllose. Due to its high cellulose content, Recyllose is an efficient biofuel and also a raw material useful for the paper, plastic, construction and energy industries, among others.

By trapping the cellulose component inherent in wastewater and returning it to the industrial cycle as raw material, SRS transforms sewage treatment into sewage mining, and introduces a model for sustainable, efficient and environmentally-friendly wastewater management.

Wastewater leaves the SRS, and goes into the WWTP, containing fewer solids. The main burden of the treatment process is thereby removed and operating expenses are cut by 30 percent. As a result, plant capacity is increased by 30 percent and its life span significantly prolonged. In addition, there is a major decrease in the consumption of electricity, fewer chemicals are needed, and there is 50 percent less sludge to deal with. All this adds up to major savings for the WWTP.

Less sludge means less incineration and wetland pollution, and fewer landfills. With less sludge, the water treatment process consumes less energy and the aeration requirements are also decreased. Since we use less electricity and have less methane-containing sludge, greenhouse gas emissions are reduced and the WWTP becomes eligible for valuable carbon credits.

Launched in 2007, this sewage mining technology has since been successfully deployed across the world, and is currently active in Israel, Scotland, the Netherlands and Mexico.

Success in Querétaro
The first implementation of sewage mining technology in the Americas was the result of a successful collaboration between Vert Energy Solutions and Desarrollos Residenciales Turísticos (DRT) in the city of Querétaro, for which Vert has been awarded the 2014 New Economy Award for Best Recycling and Wastewater Solutions.

Querétaro is a city 200km north of Mexico City, and capital of the state of the same name, with a population of approximately 1.1 million. The Querétaro metropolitan area has seen significant growth, which has positioned it among the most attractive and productive cities in the » country, with a high quality of life and a dynamic economy. Though official figures are not yet available, the city was expected to achieve economic growth of 4.3 percent in 2014, placing it as the city with the highest economic activity in Mexico. Its industrial base and culture are attractive and profitable for productive industries, among them the automotive industry, aeronautics and telecommunications.

The authorities are keen that the state capital should be an intelligent city, boasting technological, economic and social development. However, in recent decades Querétaro has seen complex and growing problems related to the distribution of its water resources, a situation that puts at risk the satisfaction of the present and future necessities of the population, and thus the economic development the city seeks. These problems are clearly related to population growth, which places greater demand on water resources.

The biggest aquifer in the state was over-exploited for years, driving a major project in the early 2000s to build the country’s largest aqueduct. This unprecedented project is aligned with the state government’s comprehensive strategy to ease access to water in the metropolitan area of Querétaro. In combination with this, local authorities eliminated all water-related subsidies: this means the population pays a price that reflects the true cost of water services, raising awareness of water’s value.

Among the changes, one that stands out is the adoption of rational consumption and the reuse of treated water. The projects set up included sustainable residential developments with independent waste treatment plants: once it has been treated, the water is reused for irrigating gardens and green areas, and other activities that do not require the use of drinking water. These initiatives have had good results, such as guaranteeing a constant supply of drinking water in residential zones that had previously had a restricted water supply.

El Pozo
As part of its Banco de Tierra (‘Earth Bank’) programme, DRT carries out the purchase, legalisation and urbanisation of large parcels of land in order to sell lots that offer new and expanded opportunities to property developers.

DRT has a WWTP called El Pozo in the El Marques municipality, which serves 2,500 families, representing around 35,000 inhabitants. Operadora Queretaro Moderno (OQM), a subsidiary of DRT, acts as a private water utility serving a good portion of the population.

The El Pozo WWTP has the capacity to treat 5,200 cubic metres of wastewater every day. In order to optimise and increase the efficiency of the plant, OQM, along with Vert Energy, installed the SRS20K Sewage Recycling System in November 2013; it began operating in January 2014. The SRS creates significant savings in energy consumption and maintenance for OQM, adding up to a 28 percent reduction in total operating costs by the end of 2014.

The use of this sewage mining technology means: 250kg of Recyllose is produced each day; sludge generation is reduced by 50 percent; energy and operating costs are each reduced by 30 percent; plant capacity is increased by 30 percent; and the use of polymers if reduced by 30 to 50 percent. SRS technology will also allow a projected 25-30 percent increase in the capacity of the El Pozo plant, due to the fact that it has reduced the organic load going to the reactors. This will imply savings in additional infrastructure when the plant’s maximum capacity is reached.

The results from the El Pozo plant in Querétaro are encouraging, and show sewage mining is a viable solution to achieving Mexico’s wastewater treatment goals, and is an alternative solution to the growing trend of plant abandonment.

Drawing conclusions
The projected outcomes of implementing sewage mining on a large scale demonstrate its potential, which is supported by the results already obtained at the El Pozo water treatment plant. If this technology got implemented at only 10 percent of the wastewater treatment plants needed to treat 100 percent of Mexico’s sewage by 2030, the benefits would be enormous. Wastewater treatment plants would be cleaner, more efficient and cheaper to operate. Treatment capacity at these plants would increase and a sustainable raw material would be produced at a rate of 1.6 million kilograms per day.

Sewage mining could easily become Mexico’s method of responsibly achieving a very aggressive goal – one the global community has seen as a major example-setting exercise for a developing country. This is the time to invest in game-changing technology that will not only solve our biggest environmental challenges but also do it with a clear philosophy based on return on investment.