BIOBOX sets a new milestone in planning and design with the fabrication in only 6 weeks of a compact, 100% automated plant capable of biologically removing organic load and nutrients above 95% for a mining site in Ecuador.
Background: Lunding Gold mining in Ecuador
The new compact water plant built by BIOBOX for the Zamora-Chinchipe mining operation in Ecuador has a capacity of 150 m3/day.
Lunding Gold is a Canadian mining company, located in southeastern Ecuador, which is among the highest-grade operating gold mines in the world. In September 2021, it entrusted BIOBOX with an exciting new project for the design, construction and commissioning of a biological wastewater treatment plant.
The mining camp had an existing WWTP that treats wastewater from toilets and kitchens. However, the water from the secondary settling of this WWTP contained excess solids, organic load and nutrients.
Challenges and design of the compact plant: removal of COD, Nitrogen and Phosphorus from wastewater.
One of the main design challenges was to be able to build a compact, pre-assembled and fully automated water treatment plant inside a 40-foot container, in the minimum possible time, to remove solids, organic load, nitrates, ammonium and phosphorus so that the end customer could meet the parameters for discharge into public waterways, according to the IFC standard, which is much more restrictive than Ecuador’s own.
The plant was originally designed to treat 250 mg/l of nitrates (NO3-) and 60 mg/l of ammonium (NH4+), in compliance with the 10 mg/l of total nitrogen at the outlet. Finally, 500 mg/l of COD, 400 mg/l of nitrates (NO3-) and 60 mg/l of ammonium (NH4+) were treated and all parameters were met. This process, in turn, eliminates more than 6 mg/l of phosphorus to comply with the IFC standard.
The plant’s treatment line includes three stages: an initial pre-filtration, a first mixed biological denitrification/ COD removal biofilter and a second mixed nitrification/denitrification biofilter.
In the initial pre-filtration, the SS peaks are laminated, followed by intense anoxic denitrification in three pressurized filters that remove COD at the same time. In the last step, the most complex, a mixed biofilter is able to generate an autotrophic nitrifying oxic process and an anoxic heterotrophic denitrifying one.
The whole process is fully automated, with NO3-, ORP, pH, flow rate probes and controlled by a PLC.
One of the key of the plant’s treatment line is automation, since the entire treatment line is sensorized and automated with 4.0 technology for the study and analysis of data on a central server.
Its high level of automation and sensorization means that all key parameters are monitored 24/7. This facilitates self-management, optimizes resources, avoids potential problems and achieves continuous improvement. All this results in minimal intervention by operating personnel.
The equipment integrates a remote access and control system that allows it to be operated remotely and to be alerted in case of any type of warning. However, the plant is completely autonomous and automatically alerts operating personnel of any need.
From an economic point of view, the technology or technologies used are definitely more competitive than traditional solutions offered on the market, both in terms of operating and investment costs. In addition, civil works are avoided and execution and start-up times are minimized.
In addition to the above, an additional advantage is that it requires the use of a much smaller surface area and completely eliminates the costs of continuous operating personnel in the plant. All this allows for a significant reduction of the associated investment and operating costs.
Conclusions
In conclusion, this plant proved to be the best solution for organic load and nutrient removal above 95%, complying with the regulations for discharge into riverbeds. Our client is satisfied with the solution offered, the urgent need for treatment is met and the mining operation continues satisfactorily with its policy of minimizing environmental impact.
Detailed information of the case study:
Technologies used:
- BIOBOX Nitrates (Puremust-sn®).
- BIOBOX Ammonium
- BIOBOX combined pollutants
- Phosphorus elimination treatment.
Characteristics: BIOBOX Ecuador plant - Treated flow: 150 m3/day
- Inlet nitrate concentration: 400 mg/l
- Inlet ammonium concentration: 60 mg/l
- Total Nitrogen output: /<10 mgl complying with IFC regulations for discharge into watercourse.
- COD inlet concentration: ≈ 500 mg/l
- Outlet COD concentration: < 15 mg/l
- Phosphorus inlet concentration: 8 mg/l
- Phosphorus outflow concentration: 2 mg/l
Steps: BIOBOX Ecuador plant
The water treatment line consists of three steps: - Initial pre-filtration
- Biological Denitrification
- Biological Nitrification