Biochar – ISTC blog

February 6, 2023

ISTC scientist is set to develop technology addressing water contaminated with PFAS

Man-made per- and polyfluorinated substances (PFAS), known as “forever chemicals,” withstand many treatment options and bioaccumulate in the environment, posing serious environmental and health concerns. With a three-year, nearly $1 million grant from the U.S. Department of Defense (DOD) Strategic Environmental Research and Development Program (SERDP), Illinois Sustainable Technology Center (ISTC) scientists are developing a new technology to remove and destroy PFAS from contaminated water using a designer biochar produced from woody biomass or agricultural residues such as corn stalks and cobs.

PFAS are a widely used class of chemicals found in many different consumer, commercial, and industrial products, including non-stick coatings and textiles. Since the 1970s, PFAS have also been used in firefighting foam, which is why the DOD is interested in finding new solutions to clean up contaminated sites where firefighters have trained, according to Wei Zheng, principal investigator of the project at ISTC, a unit of the Prairie Research Institute at the University of Illinois Urbana-Champaign.

Activated carbon, as a most common adsorbent, is typically used to treat PFAS-containing water. Once the activated carbon is saturated with the contaminants, the spent adsorbent is incinerated. However, incineration, even done at sufficiently high temperatures, cannot completely destruct PFAS and will create some hazardous and toxic byproducts. In 2022, the Office of the Assistant Secretary for Defense placed a temporary ban on incineration of materials containing PFAS until safe guidance for disposal of PFAS is issued.

“If incineration is not an option, the spent adsorbent ends up in the landfill where PFAS can leach to water sources and evaporate to air because they won’t degrade,” Zheng said. “So, PFAS will go back to the environment. In this way we just solve one issue but generate a new problem.”

In addition, wastewater treatment plants can’t solve the PFAS issue because these contaminants are never destroyed by conventional treatment techniques. That is why they are called forever chemicals.

In the new project, Zheng will develop a hydrothermal technology, likened to pressure cooking, that will destroy PFAS absorbed on low-cost designer biochar created at ISTC, and at the same time reactivate the biochar that has reached its sorption capacity for reuse. Thus, the designer biochar will act a double role as an adsorbent to remove PFAS from contaminated water and as a catalyst to destroy these compounds under a hydrothermal system.

“The most important and innovative aspect of the project will be the complete destruction of PFAS once they are removed from the water,” Zheng said. “PFAS are widely detected in the environment and in the atmosphere. Our project is designed to mitigate human exposure to PFAS, helping to find ways to indeed solve this problem.”

ISTC is collaborating with researchers at the U.S. Army Corps of Engineers Construction Engineering Research Laboratory on this project.

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Media contact: Wei Zheng, 217-333-7276, weizheng@illinois.edu
news@prairie.illinois.edu

January 18, 2022January 18, 2022

Scientists study ways to reduce PPCPs transferred from soils to food plants

Plant growing in soil

The debate continues: how much risk to human health is the transfer of pharmaceuticals and personal care products (PPCPs) through soils to food plants when biosolids, sewage effluents, and animal wastes are applied to fields? As scientists speculate and study the factors that affect risk, researchers at the Illinois Sustainable Technology Center (ISTC) are finding innovative solutions to remove PPCPs before they contaminate the vegetables and fruits we consume.

PPCPs are the chemicals that make up fragrances, cosmetics, over-the-counter drugs, and veterinary medicines. These chemical residues in the environments are considered emerging contaminants because they are not yet regulated by state and federal agencies.

Organic wastes like biosolids, sewage effluent, and animal waste contain PPCP residues. When these are applied to farm fields, some of the chemicals may degrade, while others may transfer from soils to roots of vegetables and fruits, and then possibly accumulate in edible plant tissues.

Field studies have shown that pharmaceutical concentrations in soils were lower than predicted because PPCPs may degrade in soils, latch on to soil particles, or run off/leach into surface and groundwater. Yet continued and long-term application of PPCP-containing biosolids, animal wastes, and wastewater effluents may increase their concentration levels in plants, according to Wei Zheng, ISTC scientist.

“There has been much argument and debate if PPCPs derived from organic waste application in crop fields can cause risks on public health,” Zheng said. “This issue will become even more at the forefront as the use of biosolids and sewage effluents in crop production systems increases. More studies are necessary because PPCPs vary in their toxicity and physicochemical properties in the environment. In particular, the compounds that are highly persistent and toxic will be a concern.”

Zheng reviewed the literature, summarized the research findings, and made recommendations for future research in a recent article published in Current Pollution Reports.

Factors affecting PPCP transfer

In his review, Zheng reiterated that the factors that have the greatest effect on PPCP transfer are the properties of the PPCPs and soils as well as plant species. Plants grown in sandy soils have higher levels of PPCPs than those grown in high organic matter and clay soils. For certain PPCPs that are destroyed in soils, the process breaks down the original compound into metabolites that may be more toxic and mobile. Metabolites with lower molecular weights could be taken up by plant roots more readily.

Studies have also found that leafy vegetables, such as lettuce and cabbage, tend to have a higher potential to take in PPCPs than root vegetables. Furthermore, certain chemicals accumulate in the roots and have little effect on human health, while others can be transferred to leaves. Further research is needed to develop thresholds for accumulations of PPCPs in food crops when biosolids, effluents, and animal manure are used on fields.

Mitigation efforts

At ISTC, Wei and colleagues are studying several technologies to remove PPCPs, either before they reach the soils or after sewage waste application. The study is being supported by a project funded by the U.S. Department of Agriculture (USDA).

In the project, Wei is studying the feasibility of using inexpensive oils to capture hydrophobic PPCPs from wastewater effluents. The treatment, which would be used at water treatment plants, is especially low cost when applying used cooking oils, such as those from restaurants.

One advantage of this process is that oils remove PPCPs from rural sewage water while leaving behind the nutrients that fertilize crops. After capturing PPCPs, the spent oils can be used as fuel for diesel engines. The process can eliminate the captured contaminants.

Carbon-rich biochar produced from forest and agricultural residues can be used as a filter to absorb PPCPs from sewage water. Biochar can also be directly applied to soils.

Studies found that the average PPCP concentrations in lettuce leaves decreased by 23 to 55 percent when biochar was used in the soil compared with the soils without biochar. Biochar can also be composted with solid waste to immobilize PPCPs and reduce their transfer in soil-plant systems.

In the USDA project, scientists will conduct laboratory, field, and numerical modeling studies to better understand the transfer of PPCPs to crops when rural sewage effluents are applied to agricultural lands. The results will help federal and state agencies and farmers evaluate their current nutrient management and 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.

Media contact: Wei Zheng, 217-333-7276, weizheng@illinois.edu
news@prairie.illinois.edu

This story originally appeared on the PRI News Blog. Read the original story.

January 6, 2021January 6, 2021

Rural-urban collaboration yields alternative solutions to improve state water quality

The Metropolitan Water Reclamation District of Greater Chicago has published a story about their water quality projects in Fulton County. ISTC researcher Wei Zheng is one of the researchers involved in this collaborative effort.

From the article:

In addition to deploying new nutrient recovery technology, the MWRD voluntarily established a program at its Fulton County site to foster collaboration with the agricultural sector to develop and expedite nutrient reduction practices in non-point source areas.

The 13,500-acre property, located in Fulton County between Canton and Cuba, Illinois, was originally purchased in 1970 to restore strip-mined land and approximately 4,000 acres were converted to productive farmland. Years later it became the ideal site to use some of the farm fields to develop and test best management practices to reduce non-point source nutrients.

Since 2015, research and demonstration projects have been established at the site in collaboration with many partners such as the University of Illinois at Urbana-Champaign (UIUC) Crop Science Department, UIUC Department of Agricultural and Biological Engineering, Illinois Sustainable Technology Center, Illinois Central College, Ecosystem Exchange, IFB, and Fulton County Farm Bureau. The projects established include inter-seeded cover cropping, riparian grass buffer, denitrifying bioreactors, runoff irrigation, subirrigation, drainage water managements, designer biochar, and watershed-scale nutrient reduction demonstration.

August 18, 2020August 27, 2021

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, weizheng@illinois.edu, news@prairie.illinois.edu

February 27, 2020August 27, 2021

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.

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Media contacts: Wei Zheng, 217-333-7276, weizheng@illinois.edu; Lauren Lurkins, llurkins@ilfb.org; Prairie Research Institute Communications Team, news@prairie.illinois.edu

July 12, 2019July 12, 2019

ISTC will feature biochar research at Fulton County Field Day

ISTC’s Wei Zheng will showcase his research project “Designer Biochar to Capture and Recycle Phosphorous from Tile Drainage Systems” at the Illinois Farm Bureau’s Fulton County Field Day on July 16.

Zheng and team have proposed to combine a woodchip bioreactor with designer biochar at the tile drain outlet to capture phosphorus within the biochar. The biochar can be removed from the bioreactor system periodically and spread over the field as a form of slow release phosphorus fertilizer. They predict that the system will prevent excess nutrients from the phosphorus from entering local waterways and, if used throughout Illinois farmlands, will help reduce Illinois nutrient load to the Mississippi River and Gulf of Mexico.

Besides an inside look at Zheng’s research, the Field Day will feature additional research tours on vegetative buffer strips and drainage water recycling at the MWRD site, 15779 County Road 5, Cuba, IL. Registration starts at 11 a.m., followed by the tours from 12:30 to 2 p.m. Attendance is free, and lunch will be provided. Pre-registration is still available by calling the Fulton County Farm Bureau at 309-547-3011 or emailing at fultonfb@att.net.

June 19, 2019

Biochar may boost carbon storage, but benefits to germination and growth appear scant

By Lois Yoksoulian, University of Illinois News Bureau

Biochar may not be the miracle soil additive that many farmers and researchers hoped it to be, according to a new University of Illinois study. Biochar may boost the agricultural yield of some soils – especially poor quality ones – but there is no consensus on its effectiveness. Researchers tested different soils’ responses to multiple biochar types and were unable to verify their ability to increase plant growth. However, the study did show biochar’s ability to affect soil greenhouse gas emissions. The new findings are published in the journal Chemosphere.

ISTC researchers Elizabeth Meschewski, left, and Nancy Holm and collaborators developed a systematic study to test the effectiveness of the soil additive biochar and found that it may not be as effective as previously thought.

Biochar additives – particles of organic material burned in a controlled oxygen-free process – provide soil with a form of carbon that is more resistant to microbial action than traditional, uncharred biomass additives. In theory, this property should allow soil to hold onto carbon for long-term storage, the researchers said, because it does not degrade as rapidly as other forms of carbon.

“There are conflicting reports on the effectiveness of biochar for use to increase crop production as well as its potential as a carbon-storage reservoir,” said Nancy Holm, an Illinois Sustainable Technology Centerresearcher and study co-author. “We came into this study suspecting that variations in types of biochar feedstock, preparation methods and soil composition were the cause of the conflicting results.”

Addressing past research inconsistencies, the team designed a systematic study using 10 common Illinois soil types to test the effects of mixing in varying concentrations of biochars from three different feedstocks – corn, Miscanthus and hardwood.

To add a dimension to the study that is common in real-world agricultural settings, the team also examined how two other sources of carbon – plant material burned in an uncontrolled open-atmosphere setting and corn stover – affect soils. Corn stover is composed of raw stalks, leaves and cobs that remain in the field after harvest.

Factoring in each scenario, triplicate analysis and control samples, the experiment produced 429 soil samples in which the researchers planted two corn seeds each.

After a 14-day germination period, the study showed that adding biochar from any of the feedstocks or production techniques had no substantial influence on the output of greenhouse gas production, plant growth dynamics or microbial community activity. However, the researchers did see some important differences in the soils that included corn stover and burnt plant material.

“The addition of corn stover – which simulates actual field conditions – led to a dramatic increase in greenhouse gas emissions, as well as a change in the soil microbial community,” said Elizabeth Meschewski, an ISTC researcher and lead author of the study. “But, initial seedling growth was not affected when comparing these results to the soils with no additives. Addition of burnt plant material did show reduced plant biomass above ground, increased production of the greenhouse gas nitrogen oxide and altered soil microbial community.”

The team concluded that biochar might improve the quality of highly degraded or poor quality soils, but does not appear to provide any quality benefit to the soils used in this study. However, the researchers said that using biochar as an additive instead of raw biomass or burnt plant material could prevent microbe-generated greenhouse gas emissions.

The team acknowledges that a longer-period study is needed for a more comprehensive understanding of how biochar may benefit agriculture.

“For future studies, we recommend performing a similar study in many different soil types for the whole growing season for corn – not just 14 days – and possibly over several growing seasons,” said ISTC researcher and study co-author B.K. Sharma.

Kurt Spokas of the USDA-Agricultural Research Service and Nicole Minalt and John Kelly of Loyola University Chicago also contributed to this study.

The Russell and Helen Dilworth Memorial Fund at the U. of I. supported this study.

March 25, 2019November 16, 2021

Scientist seeks to capture, recycle phosphorus from tile drainage

ISTC researcher Wei Zheng recently received a grant from the Illinois Nutrient Research and Education Council (NREC) to develop specially designed biochar to capture and recycle phosphorus. Read FarmWeek’s story about the project.

Specially designed biochar, seen lower right, would absorb phosphorus from tile drainage water filtered by a woodchip bioreactor. ISTC researcher Wei Zheng is studying special biochar as a water filter, which could be used as slow-release fertilizer. (Illustration by Wei Zheng, ISTC)

February 22, 2019February 25, 2019

ISTC receives grant to create biochars to reduce nutrient runoff from agricultural land

Midwestern farms use subsurface drainage to manage water on their fields. The process uses perforated conduits to remove excess water from soil, which increases crop production and promotes soil conservation. However, these drainage systems can also transport large quantities of nutrients like nitrogen and phosphorus from agricultural fields to surrounding watersheds.

ISTC researchers Wei Zheng and BK Sharma have received a $414,380 grant from the Illinois Nutrient Research and Education Council to develop designer biochars that will capture and recycle phosphorus from tile drainage systems. The project will run from January 1, 2019 – February 28, 2023.

The objectives of this project are to:

create designer biochars to effectively adsorb phosphorus,
construct refillable biochar-sorption-channels to capture phosphorus from subsurface tile drainage, and
recycle phosphorus-captured biochars as a slow-released fertilizer.

The overall project goal is to develop a method that will minimize nutrient losses, keep phosphorus in the closed agricultural loop, and improve crop yields by enhancing nutrient use efficiency.

The research team will conduct laboratory experiments to produce designer biochars by pyrolysis of biomass pre-treated with lime sludge, evaluate their sorption capacities on phosphorus, and optimize their production conditions.

The team will also complete a field study to capture phosphorus losses from subsurface drainage systems via biochar-sorption-channels. The field study will be performed at the Metropolitan Water Reclamation District’s Nutrient Loss Reduction Research site in Fulton County. Furthermore, they will conduct a greenhouse experiment to use phosphorus-captured biochars as a slow-released fertilizer to improve crop yields.

Finally, they will perform a cost-benefit analysis and compare their technique with other best management practices (BMPs) on phosphorus removal studied at the same field location.

The successful completion of this project will offer an innovative, feasible, and cost-effective method for enhancing nutrient utilization, which will increase crop production and protect water quality in the Midwest.

February 19, 2019

Registration is Open for Emerging Contaminants Conference

Join us on May 21-22 for the 2019 Emerging Contaminants in the Environment Conference (ECEC19). Registration will be open until May 3. View the draft agenda on the ECEC19 website.

About the Conference

ECEC19 will be held on May 21-22, 2019, at the Hilton Garden Inn in Champaign, IL. This year the conference will expand beyond the aquatic environment to also include air and soil studies along with effects on human and animal health.

The conference will feature presentations and posters on the latest in emerging contaminant research, policies, and outreach. In addition, there will be plenty of opportunities for discussion and networking with those interested in all aspects of emerging contaminants in the environment.

Researchers, educators, businesses, government officials, regulatory agencies, policy makers, outreach and extension professionals, environmental groups, members of the general public, and medical, veterinary, and public health professionals are encouraged to attend the conference.

The Illinois Sustainable Technology Center and the Illinois-Indiana Sea Grant are cohosting this conference.

Keynote Speakers

Thomas Bruton – PFAS Research and Policy Lead, Green Science Policy Institute
Robert C. Hale – Professor of Marine Science, Virginia Institute of Marine Science
Susan D. Richardson – Arthur Sease Williams Professor of Chemistry, University of South Carolina