Jul 05, 2019

The Future of Effluent Treatment

Municipal & industrial organizations face challenges critical to water’s future 

Reusing treated wastewater would aid in the battle against water scarcity.
Reusing treated wastewater would aid in the battle against water scarcity.

Municipalities and industrial organizations alike face a number of challenges both old and new. Many challenges involve the use of water in varied processes and the subsequent water or wastewater treatment. 

 A few of them are typical, everyday things that all these organizations deal with. However, these things are tied to others that will shape the future of effluent treatment, if not the future of the world. It all comes down to how we use and treat water and how that affects the environmental water sources around us. 

There are six challenges shaping the future of effluent treatment.

 

Decreasing Operational Costs

Money always is an issue in any municipality or organization. Organizations typically have to spend money to make money, so many of them find ways to optimize operating costs. 

Reducing those costs could come in the form of lower power usage, fewer or less expensive process materials, or lower labor costs. For an effluent treatment system, this could mean less necessary maintenance and decreased disposal costs on top of the associated operating costs.

 

Optimize to Improve Efficiency

Hand in hand with lower operating costs is the need for efficiency. As with many things in life, there always is room for improvement when it comes to water treatment efficiency. The power consumption could be lower, the removal rates could be higher, or the equipment could run at peak performance for longer periods. If the efficiency of specific water treatment systems is optimized, the efficiency of the entire effluent treatment process could increase and operational costs could decrease. 

 

Stricter Environmental Regulations

Environmental protection is increasingly prioritized, decreasing the volume of harmful pollutants that are discharged into waters around the world. Wastewater regulators are adding contaminants to their list and steadily dropping the acceptable concentrations of these contaminants. This happens as newly built facilities discharge new pollutants into our waterways that are later discovered to be harmful to plant and animal life, as well as human health.

 

Water Scarcity & the Push for Reuse

We are told that water is a renewable resource, but at the rate we use water, it cannot replenish itself fast enough. Even in places with plentiful freshwater sources, this eventually could become an issue. In places where freshwater sources are far and few between, water scarcity is a reality. Therefore, it is important that water reuse becomes more widely used. This aids in the sustainability of our natural resources. 

Reusing treated wastewater would be a big resource in the battle against water scarcity. By treating wastewater and then reusing it either in the same process, in another process, or externally in another place, raw water consumption can decrease overall. This provides the added benefit of lowering costs for industrial and municipal organizations because they can offset the cost of procuring new freshwater sources for non-potable and non-critical applications.

 

Changing Technology

In the effort to improve efficiency and decrease operating costs, water treatment technology is constantly changing. However, most water treatment plants and systems are constructed with the intent of lasting for decades. Having an effluent treatment plant that is made to last long is wise and dependable. However, if the design and engineering of the plant do not allow for retrofiting to optimize operations, it can be difficult and costly to take advantage of new technology.

 

Waste Not, Want Not: Subproduct Recovery

While there certainly are benefits brought on by treating water, there are even more gains to be made by recovering some of the waste products filtered out of the water. Some facilities produce a lot of fat and oil that potentially could be used as an energy source. 

Many facilities produce sludge in their effluent treatment plants as a byproduct. When properly dewatered, it potentially can be used as a soil additive to fertilizer for farms or greenhouses. While some wastewater contaminants can be seen as purely waste by the company or municipality producing them, to someone else it could prove useful.

 

Regulatory Compliance

An expanding municipal landfill operation had issues with handling its landfill leachate wastewater stream. These issues occurred more frequently after times of heavy rains on the landfill site. In particular, treatment was required of this leachate wastewater stream prior to discharge to maintain regulatory compliance. 

The levels of chemical oxygen demand (COD), total suspended solids (TSS), turbidity, Pb, and total kjeldahl nitrogen (TKN), among others, were required to be reduced to allow for sustainable discharge. Initial levels: 

  • PH: 8
  • COD: 6317 mg/L
  • TSS: 295 mg/L
  • TKN: 874 ppm
  • Turbidity: 335 NTU 
  • Phosphorus: 48 mg/L
  • Oil/Grease:  2.5 mg/L
  • Pb: 0.10 mg/L
  • Color: 30 PT

 

Genesis Water Technologies provided process consulting and design, as well as supplied the specified process system solution.

The system included screen filtration, specialized electrocoagulation, followed by dissolved air flotation with a three stage tertiary cartridge filtration system before a membrane treatment system.  

The system solution was installed by a local project management and contracting firm with technical partner scope responsibilities provided by Genesis Water Technologies.

The optimal removal percentage efficiency results include:

  • PH: 8
  • Raw COD levels: 96.5% reduction
  • TSS: >95% reduction
  • Turbidity: 93% reduction
  • Phosphorus: >89% reduction
  • Oil/Grease:  >95% reduction
  • Pb: 67% reduction
  • Color: >90% reduction
  • TKN: 81% reduction

About the author

Nick Nicholas is an application engineer and technical director for Genesis Water Technologies Inc. Nicholas can be reached at [email protected] 

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