Demonstrate an integrated biological system for animal wastewater treatment through utilization

Investigators: Roger Ruan, Paul Chen, Neil Anderson
Funding agency: MNDrive
Description: Minnesota dairy cows, hogs, and poultry production ranks 6^th, 3^rd, and 12^th (1^st in turkey though), respectively in the nation. Animal wastes from these industries have caused great environmental stress. Traditional waste management practice, such as land application as fertilizer for crops production or using manure lagoons for natural digestion and storage, can no longer meet the growing environment protection requirements. A major issue for land application is the loss of nitrogen either through volatilization, nitrification and denitrification, or ground runoff. Strategies of confining nutrient of manure in a relative closed system and strip nutrient out of system may be an applicable solution for the manure management. In this project, we will demonstrate a technology that will mitigate the environmental problems faced by animal production facilities in Minnesota by reducing water pollution and producing value-added products and energy. The technology is intended to completely treat and utilize animal manures using a multi-stage approach consisting of following processes: (1) novel thermophilic anaerobic digestion with ammonia and hydrogen sulfide reduction to improve methane and nitrogen fertilizer production, (2) advanced microalgae cultivation to reduce nitrogen, phosphorus, and COD in the manure and at the same time produce algal biomass as animal and fish feed or for biofuels production, (3) hydroponics to further remove nutrients and pollutants in the post-microalgae culture broth. Additional biochar filtration steps may be added to clean the water and clarity for algae and hydroponic vegetable growth or for use as wash water on farm or direct discharge. Through the systematic and comprehensive utilization/treatment approach, the nearly closed system will not only treat the manure wastes but also produce animal and fish feed, biofuels, nitrogen fertilizer, and green vegetables, all of which sequester carbons, nitrogen, and phosphorus biologically.

The system developed as a result of the project was capable of reducing the key nutrient parameters (COD, TN, ammonia, TP) to a large degree (>98%) Ozone treatment was evaluated and while it had positive effects on hydroponic growth and nutrient removal, it is likely to0 energy intensive to be a viable part of the system, especially considering the nutrients removed are lost without utilization.. The co cultivation of microalgae and activated sludge bacteria was found to improve nutrient removal. While the nutrient reductions achieved are significant, improvements to the system can be made in terms of both nutrient removal and chemical requirements. All of the nutrient levels exiting hydroponic cultivation were under 20 ppm with the exception of potassium. Methods for further reducing potassium should be evaluated. Additionally, using increased temperature for vacuum stripping pretreatment may be able to achieve similar hydrolysis and ammonia removal at a lower pH (with lower chemical requirements). The magnesium addition for struvite precipitation can be optimized to target a specific nutrient ratio for algae cultivation. Additionally, laboratory adaptive evolution may be an effective method of increasing algae tolerance to ammonia and COD and could allow for less fresh water usage for dilution. The addition of trace nutrients in algae cultivation may improve nutrient reductions as well. Further study can improve and optimize the integrated biological system and increase its economic viability.

Destruct Per/Polyfluoroalkyl Substances (PFAS) in Landfill Leachates

Investigators: Roger Ruan, Paul Chen
Funding agency: LCCMR
Description:Per- and polyfluoroalkyl substances (PFAS) have been manufactured and used in a variety of industries in the United States and around the globe. They have broad applications in industry and society, such as food packaging, non-stick stain repellent, waterproof products, industrial applications, and firefighting chemicals. PFAS can enter the environment through production or waste streams and can be very persistent in the environment and the human body because they resist heat, harsh chemical conditions, or moisture, creating a challenge when it comes time for disposal. EPA guidance on PFAS management recommends three disposal methods, namely, incineration, landfill, and injection into deep wells. However, all these methods have many significant unknowns and facilities with these required capabilities are lacking. As PFAS is becoming more and more problematic with increasing awareness, it has recently been the focus of regulatory attention. There is a significant need to develop effective methods to treat PFAS in waste streams.

We propose to develop and study processes to treat leachate from landfill. The landfill method recommended by EPA is only effective if leachate is properly treated to prevent PFAS from entering the surface and ground water and atmosphere. Four different approaches will be investigated: 1) separation: ion exchange and membranes will be used to separate and remove PFAS from the leachate; 2) filtration/absorption, resin, biochar, or other absorbents will be used to filter leachate and retain PFAS; 3) degrading: breaking down PFAS through photocatalysis; and 4) flocculation: growing algae on leachate, flocculating to remove algal biomass and PFAS, and converting harvested mass to biofuel and biochar.

Development Of Continuous Intense Pulsed Light Technology For Non-Thermal Pasteurization Of Powdered Foods

Investigators: Roger Ruan, Paul Chen, David Baumler, Chi Chen, Joellen Feirtag, Zata Vicker
Funding agency: USDA NIFA
Description: Powdered foods are widely used as ingredients in manufacturing processed foods or are consumed directly by humans and animals for their energy and nutrient contents. Inappropriate and insufficient decontamination have led to numerous outbreaks of foodborne diseases in recent years. Different physical and chemical processes have been used to decontaminate powdered foods. However, these processes have various defects, making their application ineffective and sometimes impractical. IPL is an emerging technology for overcoming these defects. The project was aimed to develop an intense pulsed light (IPL) based technology for non-thermal pasteurization of powdered foods. The supporting objectives were: (1) to develop and construct an experimental continuous IPL apparatus; (2) to understand the contributions of variables to the performance of IPL process in terms of bactericidal effects and shelf-life stability; (3) to evaluate the effects of IPL process on nutritional values and sensory quality; (4) to optimize the process and develop a prototype system for field demonstration; (5) to introduce the technology and educate suitable industrial users about the advantages of using IPL to ensure safer powdered foods. The project began in February 2016. The 4-year project has been extended to 5 years at no cost. The extended period was requested for the team to explore the potential applications of the intense pulsed light (IPL) technology. Highlights of accomplishments:

1. In the first year, we successfully developed and constructed a continuous IPL system which was subsequently used for a wide range of experiments that followed in the next two years. This accomplishment ensured that our researchers had the necessary processing capability to treat samples under different conditions including energy level, residence time, temperature, and RH. In the later part of third year and fourth year, we redesigned the system based on our experience with the first system and experimental data, and were able to construct two versions of IPL systems. The latest system enables us to control treatment environments and one-pass process.
2. Our team developed and compared several bacteria inoculation protocols for powdered foods. Validated methods were subsequently used for all the experiments conducted in the project.
3. We conducted a series of experiments to evaluate the bactericidal effects of IPL treatments of numerous powdered samples under different processing conditions. Process improvement and optimization and system development led to bacterial reduction as high as 5 logs. We also conducted research to shed lights on the bactericidal mechanisms of IPL treatment using multiple techniques such as molecular biology, microscopy, high resolution NMR, chemometrics, and metabolomic analysis.
4. Instrumental and sensory evaluation of the quality of the treated products was carried out. Physical and chemical changes were characterized and quantified. Sensory attributes were also quantified and related to instrumentally measured parameters.
5. We interacted with the industry through annual industry advisory committee meetings, workshop in industry setting, testing samples provided by interested companies, and discussion on potential implementation of the technology in current production facilities.
6. Over the past 4 years, we showcased the technology and facility to the stakeholders through onsite tours, workshop, and conferences. Scientific findings were also published on peer reviewed journals.

Catalytic microwave assisted pyrolysis and gasification of solid wastes

Investigators: Roger Ruan, Paul Chen
Funding agency: Xcel Energy, Sun Grants, USDA, DOE, and private companies
Description: The major challenges for thermochemical conversion are the poor quality and stability of the products, and costs associated with feedstock collection, handling, transportation and storage. We focus on development of continuous fast conversion processes and equipment and catalytic upgrading and reforming.  Bench and a pilot scale microwave assisted conversion systems have been developed. Bench system is used for in-depth study of conversion processes while the pilot scale is for demonstration and system analysis. Different feedstocks including algae, wood, lignin, plastics, and sludge have been studied.  A sequential two-step fast microwave-assisted pyrolysis (fMAP) for high quality bio-oil production was investigated. In the process, fMAP was followed by catalytic cracking and upgrading using a packed bed catalyst reactor with HZSM-5 as the catalyst. Results showed that maximum bio-oil and aromatic hydrocarbons yields were obtained when pyrolysis temperature reached 550 ℃. With the increase in the catalyst loading, the bio-oil yield decreased linearly while the aromatic hydrocarbons yield increased. The catalyst bed temperature also has a significant effect on the product chemical profiles. The aromatic hydrocarbons proportion of the bio-oil was found to increase with increasing catalyst bed temperature and reached its maximum of 26.20 % at 425 ℃. In addition, coke yield increased with increasing catalyst to biomass ratio and decreasing catalyst bed temperature. 

Effective Process and System for Inactivation of Avian Influenza Viruses

Investigators: Roger Ruan, Paul Chen
Funding agency: MAES, Avian Influenza Grant Program
Description: The poultry industry currently lacks an efficient and cost effective means of controlling airborne pathogen transmission. The proposed project is intended to demonstrate the feasibility of non-thermal plasma (NTP) and microwave (MW) technologies for effective air sanitation of poultry facilities.  The systems are expected to eliminate avian influenza virus (AIV) from air entering poultry barns and therefore prevent airborne infection incidents. They are also expected to operate continuously with minimal energy use and maintenance. This project is built on the outcome from two recent projects, which have successfully proven the concept of air sanitation using NTP and MW processes, and generated preliminary data showing a great potential for practical implementation. The goal of the proposed project is to advance the technology readiness level (TRL) from the current TRL 2-3 (concept formulated/proven) to TRL 5-6 (components or model validated/demonstrated in a relevant environment). Specifically, we will address the issues identified in the previous research, compare the two technologies, and optimize and further develop the better of the two methods for validation, and demonstrate on a small scale, in a poultry barn.

Improving Food Safety of Pork Supply Chain In China

Investigators: Yanbin Li, Roger Ruan, Paul Chen, etc.
Funding agency: Walmart Foundation
Description: Achieving global food security, sustainability, and One Health in pork production systems continue to be more challenging than ever before. The covid-19 pandemic has created numerous unexpected disruptions of feed, pork, and food supply chains, which have been largely driven by immobilization of the workforce causing reduced ability to conduct essential functions and devastated economies. At the same time, African Swine Fever in China has also created major supply and demand, trade, and agricultural and food supply chain disruptions throughout the world. While pork safety is expected by consumers, it is one of many important components of the supply chain. Development and implementation of more coordinated, collaborative, and holistic systems approaches are needed to improve pork production efficiency, sustainability, and safety in China. The objective of the project is to develop a food safety monitoring and risk assessment integrated system for pork supply chain. With international collaboration and systematic approaches by our multi-institutional, multidisciplinary team, to integrate innovative rapid detection methods, dynamic risk assessment, and big data analytics on foodborne pathogens and antibiotics residues in pork supply chain with blockchain and machine learning technologies into a food safety monitoring and risk analysis system on a cloud platform. The target audience are consumers, swine farms, pork processing plants, wholesale and retail markets, and food safety inspection agencies.

Control of fusarium seedling blight in wheat through fast physical seed treatment

Investigators: Roger Ruan, Paul Chen, Ruth Dill Macky
Funding agency: Small Grain Initiative, Minnesota Agricultural Experiment Station
Description: The goal of the project is to evaluate the effectiveness of non-chemical seed treatment methods on disinfection of wheat seeds as a disease management practice. These new methods, which are based on catalytic intense pulsed light (IPL) and non-heating catalytic microwave processes, have the potential to treat seeds at high throughput without leaving chemical residues and the need to dry while maintaining satisfactory germination rate and reducing seed decay, seedling blight, and root rot by inactivating a broad spectrum of phytopathogens in addition to fungi. The treatments have the potential to be applied broadly to other small grains and other pathogens. The specific objective of the project are: (1) to develop apparatuses and processes for seed treatments, (2) to evaluate the effectiveness of the treatments on pathogen inactivation and impact on germination, and (3) to optimize the processes for best disinfection, germination, and seedling development. 

Safety Assessment of Almond Hull as a Novel Food and Food Ingredient

Investigators: Roger Ruan, Yanling Cheng
Funding agency: Almond Board of California
Description: The Center has developed processes to convert almond hull to functional ingredients and products for human consumption.To obtain safety data for FDA application of GRAS status for almond hulls, animal study of the resultant products is being conducted by Dr. Yanling Cheng at the Beijing Union University. 

Fungal-woodchips Filtering System for PFAS Remediation

Investigators: Jiwei Zhang, Roger Ruan
Funding agency: LCCMR
Description: This project, led by Dr. Jiwei Zhang, is intended to investigate fungal-woodchips filtering systems for PFAS remediation. The Center is tasked with manufacturing the fungal-woodchips biochar filtering system and full destruction of PFAS contained in the filtering materials using microwave assisted pyrolysis.