New project uses biochar to absorb excess nutrients from tile drainage

In a new $1 million three-year project, Illinois Sustainable Technology Center (ISTC) researchers will develop a bioreactor and biochar-sorption-channel treatment system to remove excess nitrogen and phosphorus from tile drainage water, which will reduce nutrient loss from crop fields to local waterways.

Excess nutrients in surface water contribute to harmful algal blooms that produce toxins and threaten the health of water ecosystems. A variety of treatment techniques have been studied to reduce nutrient losses.

Woodchip bioreactors, which are buried trenches, have proven to be a cost-effective and sustainable solution to reduce nitrate-nitrogen loss from tile-drained crop fields. However, concentrations of ammonium-nitrogen are often elevated after water has flowed through a bioreactor. Also, woodchip bioreactors do not have a significant effect on phosphorus removal.

Principal investigator Wei Zheng and colleagues plan to develop an innovative treatment system by integrating woodchip bioreactor and designer biochar treatment techniques to reduce the losses of both nitrogen and phosphorus nutrients from tile drainage.

Designer biochars are applied in biochar-sorption-channels to capture dissolved phosphorus and ammonium-nitrogen simultaneously. Researchers will seek to produce the most efficient designer biochars by pyrolysis of biomass pretreated with lime sludge.

The U.S. Environmental Protection Agency-funded project will evaluate the new system by conducting a scale-up field study at a commercial corn production farm.

Researchers will also apply the nutrient-captured biochars as a soil amendment and a slow-release fertilizer in fields to improve soil fertility.

The results from this project will help federal and state agencies and farmers evaluate their current nutrient management practices, inform science-based regulatory programs, and offer an innovative, feasible, and cost-effective practice to mitigate the excess nutrient loads to watersheds, prevent and control algal blooms, and improve agricultural sustainability.

Media contact: Wei Zheng, 217-333-7276,,

New project is set to find ways to manage emerging contaminants

Scientists at the Illinois Sustainable Technology Center (ISTC) are tackling the issue of pharmaceutical contaminants from irrigation with rural sewage effluents in a newly funded project.

Collaborating with the Illinois State Water Survey, principal investigator Wei Zheng has begun a three-year study to investigate emerging contaminants, such as pharmaceuticals and personal care products (PPCPs), in fields irrigated with effluents from rural sewage treatment plants and to develop effective strategies to reduce the amount of contaminants transported to surface or groundwater.

Rural sewage effluent has great potential as an alternative to irrigation water, yet there are concerns about possible negative effects. Rural treatment plants are less effective at removing PPCPs compared to municipal wastewater treatment plants. Therefore, the use of effluents might pose a risk to surface and groundwater ecosystems.

Also, field tile drainage systems, which are commonly used in the Midwest, may accelerate the losses of these chemical contaminants from agricultural soils to nearby watersheds. The potential negative effects of using rural sewage effluent to irrigate tile-drained fields are essentially unknown.

In this project, the research team will conduct a series of laboratory, field, and numerical modeling studies to investigate the processes affecting contaminant transport, track the occurrence of PPCPs, and develop two cost-effective control techniques, oil capture and biochar-sorption channels.

The results will help federal and state agencies and farmers evaluate their current nontraditional water-use practices, inform science-based regulatory programs, and suggest best management strategies to minimize risks and promote the safe and beneficial use of nontraditional water in agriculture.

The project is funded by the U.S. Department of Agriculture.

Media contact: Wei Zheng, 217-333-7276,

Biochar project set to improve ag sustainability

A newly developed system in the lab could become a boon for farmers in the field. Illinois Sustainable Technology Center (ISTC) scientist Wei Zheng and colleagues are creating a designer carbon-based biochar that captures phosphorus from tile drain runoff water and recycles it in soils to improve crop growth.

Zheng hypothesizes that this is a win-win strategy that will lead to increased crop yields and less nutrient runoff into water from agricultural fields.

Fertilizer phosphorus applied for plant growth tends to dissolve and leach out through field tile lines, so it promotes algae growth in nearby waterways. Harmful algal blooms (HAB) appear in lakes in the summer and die off once the growing season ends, contributing to oxygen-depleted waters, which result in fish kills and other adverse effects on aquatic life.

The yearly HAB prompted development of Illinois’ Nutrient Loss Reduction Strategy, which aims to reduce phosphorus in Illinois waters by 25 percent by 2025.

A sustainable, novel approach

Zheng and his colleagues at the University of Illinois (U of I), the Illinois Farm Bureau, and other groups believe their strategy will address this problem. By installing a bioreactor in the field with a biochar-sorption filter, water that runs through the tile system is filtered to remove nutrients before it reaches lakes and streams.

The filter holds biochar—a biomass product that looks like charcoal and is made mostly of carbon with high calcium and magnesium—which traps fertilizer nutrients. The biomass is made into small pellets that won’t block water flow.

In the lab, Zheng is studying different types of designer biochars made from sawdust, grasses, or crop residue pretreated with lime sludge, for example, to find the one that is the most effective in capturing phosphorus.

“We have generated some designer biochars that have extremely high capacities for holding dissolved phosphorus,” Zheng said. “Our previous studies have shown that biochar can not only strongly adsorb nutrients such as phosphorus, but also has a high sorption capacity for other contaminants, such as pesticides and antibiotics.”

This year, Zheng and his collaborators will scale up their technology to develop a bioreactor and biochar-sorption-channel system for a field trial on a commercial farm in Fulton County. In the second year of the project, the team will establish a bioreactor system that is able to treat drainage water received from a 12-acre field. Water testing will confirm how successful the system is at reducing phosphorous runoff.

An additional part of the project, also slated for next year, is to remove biochar pellets from the channel after fertilizer season and apply the phosphorus-captured biochars to the fields where they will slowly release phosphorus and other nutrients into the soil. As a result, producers can keep fertilizer costs down and increase crop yields when applying the biochar pellets at optimal times in the growing season.

“The goal in adopting this technique is to keep applied phosphorus in the agricultural loop and prevent it from leaching into waterways,” Zheng said.

Benefits of a research team-organization collaboration

Wei Zheng demonstrates his bioreactor at Fulton County Field Day in July 2019.
Wei Zheng demonstrates his bioreactor to local farmers at Fulton County Field Day in July 2019.

Illinois Farm Bureau is involved in this project at the state and Fulton County level to foster interactions between farmers and U of I researchers. Their participation helps to ensure that the research is focused on applicable, realistic practices for Illinois farmers, according to Lauren Lurkins of the Illinois Farm Bureau.

The Farm Bureau helps identify producers who are willing to participate in research and in funding and outreach opportunities, such as field days.

“Research including Wei’s can help to add practices to or update the science behind existing practices in the Nutrient Loss Reduction Strategy,” Lurkins said. “PRI has a lot of researchers and resources that our farmers utilize. They cover everything from groundwater for rural area consumption to weather monitoring, which are all important to agriculture.”

Results from the project are expected in 2023. It is funded by the Illinois Nutrient Research & Education Council.

In late 2019, Zheng was appointed Vice Leader of the American Society of Agronomy’s Biochar Committee for his research in various projects on biochar. Several project descriptions are available, including: Using Biochar as a Soil Amendment for Sustainable Agriculture,  Sorption Properties of Greenwaste Biochar for Two Triazine Pesticides, and Carbon Sequestration Using Biochar.


Media contacts: Wei Zheng, 217-333-7276,; Lauren Lurkins,; Prairie Research Institute Communications Team,

Institutional Water Treatment program now tests facilities for bacterium causing Legionnaires’ disease

With the start of a new year, ISTC’s Institutional Water Treatment (IWT) program is offering a new service to test water sources for Legionella, the bacterium that causes Legionnaires’ disease, to decrease exposure for clients with weak immune systems.

Legionnaires’ disease is caused by inhaling water mist containing Legionella. The bacterium can grow in showerheads and sink faucets, cooling towers, and large plumbing systems. Legionella is inhaled, most commonly when showering, according to Mike Springman, manager of the IWT program.

“As long as the temperature of the stored water is hot enough, at 140 degrees, and is hot enough when used, at 120 degrees, and the chlorine is adequate, there shouldn’t be a problem,” Springman said. “Older systems and systems that are not well maintained are more at risk.”

Vulnerable populations, including older adults and others with compromised immune systems, are more susceptible to exposure. Legionnaires’ is a serious type of pneumonia, and symptoms include fever, cough, chills, and muscle aches.

The IWT services group gives advice on controlling corrosion, mineral scale formation, and biological growth for facilities with institutional water systems. Most of their clients are state-operated facilities, such as Human Services, Department of Corrections, the Department of Veterans Affairs, and others that often have older facilities that need to be checked periodically and maintained.

Using IDEXX laboratory test kits, IWT field chemists place bottled water samples in sealed trays, minimizing their own exposure to the bacterium. New laboratory testing facilities at the University of Illinois have been equipped specifically to handle water samples to be tested for Legionella.

Previously, Springman received requests from large facilities a few times a year to test for this particular bacterium. Until now, the testing was not cost-effective because it required sending samples to an outside lab.

“I think that Legionnaires’ disease is becoming more prevalent, or at least people are becoming more aware of what it is as time goes on,” Springman said. “The feedback to our announcement of this new service has been positive, and I think it’s going to work well. It’s going to serve our clients, which is what we’re here to do.”

For more information about IWT and to schedule a site visit, view

Solar panel disposal problem surges as solar energy use grows

Solar energy panels can be recycled, but most end up in landfills. How to handle broken or older panels in Illinois is a challenge that takes a statewide collaboration to figure out, according to Jennifer Martin, coordinator of the Solar Module Recycling Initiative at the University of Illinois’ Illinois Sustainable Technology Center (ISTC).

Solar modules used at solar energy farms and in homes are made from different technologies, all with valuable, recoverable, recyclable materials. No national regulations exist on how to discard panels, but some may contain toxic compounds such as arsenic, cadmium, and lead that can leach into the environment if landfilled.

In addition, the large size of solar panels can potentially fill up landfill sites quickly.

Given that solar power is the fastest growing energy source nationwide, and with a lifespan of 25 to 30 years, solar panels installed in the 2000s and before will soon need to be replaced. Also, panels that are broken in shipping or damaged by storms will be disposed of.

With around 360,000 modules currently installed in Illinois, an additional 6 million solar panels will be installed in Illinois by 2025, posing a significant solid waste problem by mid-century.

“Solar energy is a relatively new industry in the Midwest,” Martin said. “There are many factors that make it difficult to predict the number of solar modules that will come offline in Illinois. However, this looming threat is an opportunity to figure out how to prepare now for recycling and reuse options before a plan is urgently needed.”

Through the ISTC initiative, Martin is working with stakeholders in various national and state organizations to find solutions to the solid waste disposal of solar modules. Organizations include the Illinois Environmental Protection Agency, the Solar Energy Industries Association (SEIA), the National Renewable Energy Laboratory, and others. To date, less than 1 percent of decommissioned solar modules are being recycled, according to SEIA.

The collaborators are working to determine the best options for states to prepare for end-of-life solar recycling and reuse. Predicting the amount of waste headed for the landfills is important, as well as finding locations to recycle the waste.

Some of the specific challenges with developing a recycling plan is the lack of publicly available information on recycling and recovery costs and the basic infrastructure necessary to collect and transport the modules to recycling centers once they become obsolete.

Modules that have declined to about 70 percent effectiveness can still have a useful life and be reused for schools, nonprofit agencies, and other users.

Washington State was the first to pass a solar stewardship bill requiring manufacturers selling solar modules to have an end-of-life recycling program for their products. Through this program, regional take-back locations accept panels with no cost to solar panel system owners.

New Jersey’s recently established Solar Panel Recycling Commission has been tasked to investigate options on recycling and other end-of-life management recommendations for the state.

In Illinois, collaborators hope to have a system in place before millions of panels are ready for disposal in the near future.

“The Midwest is a little behind other regions in the U.S. on adopting solar energy,” Martin said. “With this and other initiatives, the Midwest is forging ahead on finding solutions to a problem that will only become more pressing with time.”

Visit the ISTC website to learn more about the initiative and solar energy disposal in Illinois.

Media contacts

  • Jennifer Martin, Environmental Program Development Specialist, 217-300-3593;
  • Tricia Barker, Associate Director for Strategic Communications, 217-300-2327,

Composting food waste is localized strategy for landfill diversion

Encouraging homeowners to compost their food waste locally yields numerous economic and environmental benefits for communities. University of Illinois researchers have developed a framework to help city planners and community organizations estimate potential cost savings if they can get residents on board.

Almost all food waste generated in the United States ends up in landfills. Until now, most food waste recovery efforts have been focused on business and industry. In a recent case study, Shantanu Pai at the Illinois Sustainable Technology Center (ISTC) and co-authors calculated household-generated food waste for each of the 77 community areas in the city of Chicago.

“Using a very conservative estimate, a 10 percent participation rate, we found that composting for Chicago had the capacity to divert 27 percent of food waste generated by residents away from landfills,” Pai said. “This was shocking to us as we weren’t expecting the diversion rate to be that high.”

The benefits of community composting in neighborhoods and backyards include lowering the overall cost of solid waste collection, reducing greenhouse gas emissions, decreasing transportation of waste for processing and treatment, and helping extend the life of landfills so that new facilities don’t have to be built.

Yet, technology is geared toward larger systems. Also, a location and pick-up services would have to be determined, and participation rates may remain low in certain areas.

“Like recycling, with composting it’s all about personal choice and the choices that are made in households,” Pai said. “The decision to participate in a composting initiative may have nothing to do with economics or other factors.”

Participation in composting programs has been shown to increase when planners engage residents. The more homeowners know about composting and the benefits, the more likely they are to become involved. Past composting initiatives that provided free composting units and training to residents had high participation rates.

For planners and organizations, the framework consists of several steps. The volume of food waste generated from households can be calculated using the framework tool and U.S. Census data to identify households, housing types, and associated income levels, as higher income households tend to generate more food waste.

A composting plan requires identifying an acceptable location for composting. In most cases, individual composting would be in backyards, but in the Chicago community composting study, for example, compost sites were in parks. Other locations could be urban gardens or farms.

The framework also recommends using a 10 percent participation rate for single households, though local data from solid waste management programs will provide a more accurate estimate.

Finally, planners estimate the effort’s impact, which can be a selling point for local composting. The framework is designed for its ease in calculating impacts.

“In this framework, we’ve used only data that are publicly available,” Pai said. “As long as city and community planners have access to the Internet and to GIS, they should be able to calculate the amount of food waste that can be diverted from landfills. The math is easy.”

Pai noted that localized composting is not preferable to larger-scale waste management efforts. Instead, the framework can be used for information gathering to consider composting a complementary strategy as part of the entire solid waste management plan.

Communities interested in receiving planning support can contact the ISTC’s Technical Assistance Program at 217-333-8940 or via the ISTC web site.

This study was published in the journal Sustainable Cities and Society.

Media contact: Tricia Barker, Associate Director for Strategic Communications, 217-300-2327,


Mud to Parks project reuses lost soil from lakes and rivers

This is the first post in ISTC Impact, an occasional series highlighting the effect of some of ISTC’s long-running projects on the environment and economy of the state, region, and nation.

With one fresh idea and buy-in from state politicians and organizations, researchers in the Illinois Sustainable Technology Center (ISTC) found a way to address the growing river sedimentation problem in Illinois, while also restoring waterways and habitat and moving healthy topsoil into cities.

The ISTC Mud to Parks project developed a blueprint for successfully recapturing one of Illinois’ finest resources: its soil.

“Soil is more valuable than oil,” said John Marlin, ISTC research affiliate, who originated the Mud to Parks idea and directed the project. “Yet we are treating soil today like it’s an unlimited resource, even as it erodes away.”

A crane removes sediment from Lower Peoria Lake during spring 2004. The dredging deepened a recreational boat channel at East Peoria. Care was taken to minimize water to reduce shipping costs. The barges traveled 165 miles to Chicago and were unloaded into trucks at the old US Steel South Works site.
A crane removes sediment from Lower Peoria Lake during spring 2004. The dredging deepened a recreational boat channel at East Peoria. Care was taken to minimize water to reduce shipping costs. The barges traveled 165 miles to Chicago and were unloaded into trucks at the old US Steel South Works site.



Trucks place the dredged material on a slag covered field that had no topsoil. It was spread to dry and temporarily seeded with grass.
Trucks place the dredged material on a slag covered field that had no topsoil. It was spread to dry and temporarily seeded with grass.

Soil from rural and urban areas washes into rivers and accumulates in backwaters and behind dams. Water levels in backwaters and side channels are becoming shallower as habitats deteriorate and areas can no longer be used for transportation and recreation. In the Illinois River’s Peoria Lake, levels have declined from 6 to 8 feet in the 1960s to 2 feet in recent years.

ISTC initiated a pilot project in 2004 after Marlin considered the sediment problem in Peoria Lake.  Sediment storage areas were scarce in Peoria, but the material could be deposited on a 500-acre U.S. Steel South Works redevelopment site to create a park.

“Engineers told me that it couldn’t be done,” Marlin said. “It would be too expensive to truck sediment 165 miles from Peoria to Chicago. It occurred to me that barges could be loaded directly from the lake, and using the river system, we could take the barges right to the site, which borders Lake Michigan.”

Most sediment was easily handled by trucks and bulldozers, although some was sticky and did not flow smoothly.
Most sediment was easily handled by trucks and bulldozers, although some was sticky and did not flow smoothly.
During the summer of 2004, botanists from the Illinois Natural History Survey identified plants growing in the placed sediment to determine if any non-native (invasive) species had been transported. The plants were all common to Illinois.
During the summer of 2004, botanists from the Illinois Natural History Survey identified plants growing in the placed sediment to determine if any non-native (invasive) species had been transported. The plants were all common to Illinois.

But first, many agencies and organizations had to come on board. At that time, Lt. Governor Pat Quinn coordinated their participation in an “unbelievable political operation,” Marlin said. Representatives and senators from the Democratic and Republican parties supported the project, along with the Illinois Department of Natural Resources, U.S. Army Corps of Engineers, ISTC, the Illinois State Water Survey, the City of Chicago, the Chicago Park District, the City of East Peoria, and others.

Barges transported more than 80 loads of sediment to the Chicago site that summer. Once the sediment was removed from the barges, it was spread by bulldozer over 15 acres “like icing on a cake,” Marlin said. Over the winter, the sediment weathered to become loose soil, and eventually was used to plant grass, prairie vegetation and trees.

Two of the biggest advantages of the Mud to Parks initiative are the ability to help restore the aquatic habitat in Peoria Lake and to reclaim the sediment for use at restoration and construction sites.  This prevents native soil from being taken from farmland and suburban developments for new projects.

“This project provided a way to take Illinois soil that was washed off the land through erosion and reuse the soil by putting it back on the land,” Marlin said. “Once the sediment is washed into the Gulf of Mexico, it’s gone.”

Dr. Robert Darmody, a soil scientist at the University of Illinois, inspects sediment derived topsoil one year after removal from the lake.
Dr. Robert Darmody, a soil scientist at the University of Illinois, inspects sediment derived topsoil one year after removal from the lake.
Grass covered the sediment on the slag field by 2005. This 2013 photo shows grass and prairie plants thriving. This site, located at the end of 87th St. on Lake Michigan, also supports trees and paths in what is now called Steelworkers Park.
Grass covered the sediment on the slag field by 2005. This 2013 photo shows grass and prairie plants thriving. This site, located at the end of 87th St. on Lake Michigan, also supports trees and paths in what is now called Steelworkers Park.

The process that was developed through the Mud to Parks project proved to be successful, but also difficult to continue. There needs to be a dredging project at one end of the journey and both an operation and a space to place and reuse the sediment at the other end.  If commercial operations coordinated efforts to transport the sediment using barges and stockpile and dry the sediment-derived topsoil, they could mix in biosolids or compost for added nutrients if desired, then sell the topsoil at a profit, particularly in Chicago and St. Louis, where topsoil is expensive.

Mud to Parks project details are available in the ISTC Technical Report 068, Beneficial Use of Illinois River for Agricultural and Landscaping Applications and on the ISTC web site.


Advancing carbon capture technology

Research is progressing on a novel biphasic solvent absorption method that holds promise as an innovative, cost-saving alternative to the conventional CO2 capture process in power plants. ISTC researchers have been assisting the Illinois State Geological Survey (ISGS) on a lab-scale (10KWe) project developing a biphasic CO2 absorption process (BiCAP) with multiple stages of liquid-liquid solvent phase separation, which improves CO2 absorption kinetics and increases the carbon capture capacity.

“And, more importantly,” explained Wei Zheng, senior research chemist at ISTC who is working on the project, “this new technology can also significantly reduce both the energy use and equipment cost for CO2 capture compared to the conventional amine-based process.”

The lab-scale research is being led by ISGS, supported by a grant from U.S Department of Energy (DOE).

Currently, the team has evaluated the corrosive properties of solvents on carbon and stainless steel, which are main materials used for CO2 absorbers and strippers. “Corrosion is not a concern,” said ISTC senior research engineer Brajendra Sharma. “We’re moving forward with the project and are on track with all our milestones.”

Now the research efforts are ready for the next step.  Recently U.S. DOE announced $3M of additional funding for ISGS and ISTC to conduct a three-year bench-scale (40KWe) study of their BiCAP technology.

The primary goal of this new project is to leverage the BiCAP process and validate its technical advantages through a fully-integrated bench-scale testing in a relevant flue gas environment. The proposed technology is aimed at achieving a CO2 capture cost of $30/tonne and >95% CO2 purity to meet DOE’s Transformational CO2 Capture goals.

Read more about the biphasic project on ISTC’s website.