Patented Biological Treatment System For Nitrate Removal
BioTreat is a turnkey system that removes nitrate from any water source. The system employs a consortia of nitrate-reducing bacteria that converts nitrate (NO3) into harmless nitrogen gas (N2). The produced gas escapes naturally from the top of the system. The unit produces no brine or other waste. It is capable of reducing almost any concentration of nitrate in water to below 10mg/L – the national standard in the United States.
Innovative Solutions for Irrigation & Drainage Water in Agrluculture
We design, build, and operate systems for wastewater and well-water treatment and reuse. Our patented nitrate removal system is the best in class solution. Our brine reduction system is the lowest cost and most effective method. Our new salt removal system can remove 95% of the chloride.
How Our System Helps You
BioTreat Systems offer a wide range of benefits.
|Reduction||up to 100%|
|pH of Drainage Water||6.8 to 7.5||pH units|
|Carbon-Nitrogen Ratio||6:1||Lbs of carbon per lb|
of nitrate removed
|Oxygen Reduction Potential (ORP)||-50 to 50||mV (see note)1|
Note: Most drainage water contains more than enough phosphorus for denitrification to proceed. It is standard practice to add a small amount of phosphorus to insure we meet the nitrate:phosphorus ratio requirements.
How it Works
Our system is based on an established aerobic treatment system called the moving bed biofilm reactor or (MBBR) invented in the 1990s. Our implementation of this well-established technology uses a set of water tanks, usually plastic, filled with small plastic parts called biofilm carriers. The bacteria we use attaches and grows on these carriers. Because of the very large surface area of the biofilm carriers, we can pack a prodigious amount of bacteria into a single tank.
Inside the bioreactor tanks, we take active and passive measures to reduce the amount of oxygen in the water. During operation, the dissolved oxygen levels are very low – near 1 or 2 mg/L. This insures that the bacteria consume the nitrate molecules preferentially and not the oxygen.
Drainage or tailwater enters the reactor tanks in the bottom, and moves upward through the tank. As the water moves upward, the water mixes with the biofilm carriers where the nitrate molecules come in contact with the biofilm/bacteria. The treated water then exits via gravity flow from the top of the tank. This upward flow ensures uniform (called “plug flow”) flow and results in excellent mixing of the water and the biofilm carriers. This vertical design also helps to reduce the physical footprint of the system.Inside the bioreactor tanks, we take active and passive measures to reduce the amount of oxygen in the water. During operation, the dissolved oxygen levels are very low – near 1 or 2 mg/L. This insures that the bacteria consume the nitrate molecules preferentially and not the oxygen.
No Special Hardware Required
We avoid any custom or “high tech” components in our designs. All of the components we use are often found in standard irrigation systems. We use centrifugal pumps to move the water through our system. Fittings are Schedule 40 and 80 PVC with heavy use of cam-lever (camlock) connectors. This simplifies connections and maintenance. Industry standard variable frequency drives (VFD) are used to control the pumps. The VFDs are enabled and disabled by float switches or sensors. We employ a variety of manual and electronic flow meters to monitor the water and carbon flow.
External Carbon Sources2
Biological denitrification requires a proper ratio of carbon-nitrate-phosphorus (C:N:P) to operate successfully. Most drainage water contains some dissolved carbon and more than enough phosphorus. The supplemental carbon can be supplied by a range of different sources:
- 50% Ethanol
- 50% Acetic Acid
- Sodium Acetate
Of these, we favor the use of ethanol and glycerin. Glycerin is a common by-product of biodiesel refining. Typically, this is the lowest cost source of external carbon. Ethanol can be easily produced by fermenting common sources of sugar (e.g. molasses), then concentrated to the appropriate strength (about 50%).
1 ORP may vary inside the bioreactor tanks. Since this is a “redox” reaction, ORP’s primary use is to monitor the C:N ratio. Changes in ORP over time can indicate that incoming nitrate concentrations are changing.
2 See this USEPA Link for a good discussion of external carbon sources for denitrification
The system has four major components:
The pre-treatment system normally consists of a supply tank to collect drainage from your irrigation sets. This tank provides constant head pressure for our main centrifugal pump. Filters, strainers, and particulate separators are used to keep suspended solids from entering the bioreactor tanks. Alternatively, a reservoir may be used as your pre-treatment or “holding” tank- with some careful consideration.
The pumping and control system utilizes programmable controllers, VFD’s for pump control, and industry standard protocols for controlling our pumps and acquiring data from any sensors or flow meters installed. To keep things simple, we normally design the system to operate from a single external switch. To do routine maintenance or perform other work on the system, technicians simply flip this switch to temporarily disable the system.
Bioreactor tanks are unpressurized, vertical above-ground tanks. Our design calculator tells us how big these tanks need to be and also calculates the amount of nitrate that will be reduced (to a gas). The only inputs we need from you to size the system are the flow rate, the incoming nitrate level, and how much nitrate you want to remove.
Power and communications can vary widely. For some users, the only control system elements are a VFD. For users that need to quantify their nitrate removal to obtain the so-called Rtreat data (California customers), a programmable action controller is used to collect flow rate data from the system automatically and log this data. Additional capabilities include remote operation- the ability to log into the system’s controller from your office and monitor system operation and vary the water flow rate or the amount of external carbon being used.
System Design & Configuration
The design process starts with your proposed location for the treatment system and a recent water quality test of the water that should be treated. Please use an “irrigation suitability analysis” for your test.
Key inputs we need for our design calculator are:
The calculator will then calculate the amount of biofilm carriers required, the size and number of bioreactor tanks, the residence time (how long it takes the water to transit our system), and the amount of carbon required daily.
Other Factors to Consider
Several other factors unique to your site can impact the layout and operation of the bioreactor. These include:
- Source of water to be treated. We prefer to have your premise equipment keep our bioreactor tanks full.
- Using a man-made reservoir/pond to collect drainage from your daily irrigation sets
- Amount of suspended solids (dirt, clay, algae, other organic matter) in the water
- Location of gravity discharge
- pH of the incoming water
- Nitrate removal monitoring
Mostly likely, your team and the local regulatory authorities will want to know how much nitrate is coming into our system and how much is leaving. In general, nitrate monitoring is best done using test strips and/or an ion selective electrode with a handheld meter. There are continuous nitrate monitoring instruments that use specialized optics. But they are prone to interference from any number of ions dissolved in your drainage water. As of 2022, they are also extremely expensive and really don’t provide that much value.
Use a pond or reservoir for higher asset utilization.
When possible, we strongly encourage customers to use a small pond, reservoir or natural impoundment to collect your irrigation drainage. This allows our system to run for long periods of 20-22 hours per day at much lower flow rate. This enables a smaller and less costly system.
Optimizing the System Design
We can help you optimize the system design and operational costs for the most cost-effective
solution. The most important factors for optimization are:
- System flow rate. Using a pond to collect drainage enables us to treat all the water from your daily irrigation sets more at a lower flow rate over 20-24 hours.
- Amount of nitrate to remove. Many customers may be able to add a tertiary treatment to finish removing the criteria pollutants (usually nitrate). Examples are grass buffer strips. This reduces the amount of daily carbon required. Talk to your regulators and ag consultants- there may be other passive measures that you can take.
- Reduce carbon application as input nitrogen falls. Most crops require heavy nitrogen application during their growth phase. As the plants need less nitrate, continue to lower your carbon application so that you maintain your target nitrate concentration in the effluent.
Acquiring Our System
There are three methods for acquiring our systems. These are:
The subscription method has the lowest up front cost to you but requires a monthly payment. It is similar to a lease but a big difference is that we do all maintenance and repairs.
Purchasing a system eliminates the monthly subscription payment but you must choose how you will maintain your system. We can do some of this for you with an extended maintenance contract.
For customers that need to install multiple systems, we can develop a licensing agreement that gives you the right to assemble, build, and operate our Biotreat systems. This is the overall lowest cost of acquisition (CAPEX) and operating costs (OPEX).
Not sure how to start?
We recommend that you begin with a subscription agreement on your first system. This gives you time to learn the ins and outs of Biotreat. At some point you may want to fully acquire the system after 24 months of operation.
A 50 gallon per minute should cost between $40,000 to $50,000 to install. This price can vary however, depending on options and other site-specific challenges. Monthly subscriptions can run from $2000 to $3000 per month.
Contact us to get a quote for your specific site requirements.
Installation & Setup
Once we’ve configured your system, we will have the large or bulky items shipped directly to your location. Our team will come to the site and setup the system for you. We will prepare the inoculum (bacteria culture that will grow in your tanks) and start the process of growing the nitrate reducing bacteria. Smaller systems (< 25 GPM) will be ready to use in about 1 week. Larger systems may take 10-14 days to fully inoculate.
Once the bacteria has had time to fully populate our tanks, we will start the system operating at a reduced flow. As the nitrate concentration in the outlet of the system drops to satisfactory levels, the system is considered fully installed and operational.
We have a few requirements that customers must meet before installation can begin.