Progress 10/01/00 to 09/30/06
Outputs
During this five year project we focused first on particle separation and chemical analysis of organic matter for different sources of wastewater (Sophonsiri and Morgenroth, 2004). Starting in the third year, we developed methods to evaluate the microbial biodegradation of different size particles (Dimock and Morgenroth, 2006; Michaud and Morgenroth, 2003). During the last two years we also operated a treatment process to treat swine manure. Swine manure was sampled from the UIUC South Farms. The treatment process used anaerobic digestion combined with membrane separation. One key question in this process was to evaluate the utilization of particulate organic matter in the swine manure. Progress in the application of the treatment process has been described in two conference presentations (Padmasiri et al., 2004; Zhang et al., 2004) and two publications in peer reviewed journals (Padmasiri et al., 2007; Zhang et al., 2007). One of our findings was that the hydrolysis
of particulate matter has a significant influence on the production of volatile fatty acids and subsequently the production of biogas. Thus, the process of hydrolysis influences both system reliability and process efficiency. We have expanded the scope of our work to evaluate the potential hydrogen production from coproducts generated during ethanol fermentation. Key for this hydrogen fermentation is the hydrolysis of slowly biodegradable organic matter. Initial tests were performed to evaluate the feasibility of using a mixed microbial culture to further hydrolyze and degrade thin and whole stillage - a coproduct from corn based ethanol production. We used activated sludge from a municipal wastewater treatment plant as an inoculum that is characterized by a high microbial diversity of hydrolytic bacteria. Thin stillage, whole stillage, and centrifuged particles from whole stillage were tested, and it was shown that of the organic matter in these substrates 98%, 71%, and 58% were
hydrolyzed and degraded, respectively. These results confirm reports in the literature that a diverse mixed culture can be advantageous over the application of isolated microorganisms or pure enzymes to grade compounds such as cellulose, proteins, arabinose, and xylose. Overall, this five year project provided valuable insight into the hydrolysis of particulate organic matter in aerobic wastewater treatment and anaerobic production of energy (e.g., in the form of methane) for agricultural waste streams.
Impacts
Results from our study revealed the overall importance of particulate organic matter for the treatment of agricultural, municipal, and industrial wastes. Wastewater treatment systems operated for biological nutrient removal require the availability of sufficient biodegradable organic matter. Particle size and particle characteristics (i.e., chemical composition and surface characteristics) are major factors influencing hydrolysis rates and therefore the bioavailability of organic matter. Our fundamental understanding of the influence of particle size on bioavailability will help us optimize methods for particle separation in agricultural waste treatment systems. The goal of particle separation should be to remove all these particles that have only a minor benefit as a carbon source for nutrient removal (i.e., large and slowly biodegradable particles) while keeping the readily biodegradable particles as a valuable source of organic carbon. The development of hydrogen
fermentation using coproducts and agricultural wastes can help to improve overall economics of agricultural production.
Publications
- Dimock, R. and Morgenroth, E. 2006. The influence of particle size on microbial hydrolysis of protein particles in activated sludge. Water Res., 40 (10), 2064-2074.
- Padmasiri, S.I., Zhang, A., Fitch, M., Norddahl, B., Morgenroth, E. and Raskin, L. 2007. Methanogenic population dynamics in an anaerobic membrane bioreactor (AnMBR) treating swine manure. Water Res., 41 (1), 134-144.
- Zhang, J., Padmasiri, S.I., Fitch, M., Norddahl, B., Raskin, L. and Morgenroth, E. 2007. Influence of cleaning frequency and membrane history on fouling in an anaerobic membrane bioreactor. Desalination, 207, 153-166.
|
Progress 10/01/04 to 09/30/05
Outputs
During the first four years of this project we focused first on particle separation and chemical analysis of organic matter for different sources of wastewater (Sophonsiri and Morgenroth, 2004). Then during the third year, we focused on developing methods to evaluate the microbial biodegradation of different size particles (Dimock and Morgenroth, 2005; Michaud and Morgenroth, 2003). We are now operating a treatment process that is used to treat swine manure. Swine manure is sampled from the UIUC South Farms. The treatment process uses anaerobic digestion combined with membrane separation. One key question in this process is to evaluate the utilization of particulate organic matter in the swine manure. Progress in the application of the treatment process has been described in two conference presentations (Padmasiri et al., 2004; Zhang et al., 2004; Zhang et al., 2005). One of the findings was that the hydrolysis of particulate matter has a significant influence on the
production of volatile fatty acids and subsequently the production of biogas. Thus, the process of hydrolysis influences both system reliability and process efficiency. We are currently expanding the scope of our work where we are evaluating the potential hydrogen production from coproducts generated during ethanol fermentation. Key for this hydrogen fermentation is the hydrolysis of slowly biodegradable organic matter. Initial tests have been performed to evaluate the feasibility of using a mixed microbial culture to further hydrolyze and degrade thin and whole stillage - a coproduct from corn based ethanol production. We used activated sludge from a municipal wastewater treatment plant as an inoculum that is characterized by a high microbial diversity of hydrolytic bacteria. Thin stillage, whole stillage, and centrifuged particles from whole stillage were tested, and it was shown that of the organic matter in these substrates 98%, 71%, and 58% were hydrolyzed and degraded,
respectively. These results confirm reports in the literature that a diverse mixed culture can be advantageous over the application of isolated microorganisms or pure enzymes to grade compounds such as cellulose, proteins, arabinose, and xylose.
Impacts
Results from our study revealed the overall importance of particulate organic matter for the treatment of agricultural, municipal, and industrial wastes. Wastewater treatment systems operated for biological nutrient removal require the availability of sufficient biodegradable organic matter. Particle size and particle characteristics (i.e., chemical composition and surface characteristics) are major factors influencing hydrolysis rates and therefore the bioavailability of organic matter. Our fundamental understanding of the influence of particle size on bioavailability will help us optimize methods for particle separation in agricultural waste treatment systems. The goal of particle separation should be to remove all these particles that have only a minor benefit as a carbon source for nutrient removal (i.e., large and slowly biodegradable particles) while keeping the readily biodegradable particles as a valuable source of organic carbon. The development of hydrogen
fermentation using coproducts and agricultural wastes can help to improve overall economics of agricultural production.
Publications
- Dimock, R. and Morgenroth, E. 2005. The influence of particle size on microbial hydrolysis of protein particles in activated sludge (Submitted).
- Zhang, J., Padmasiri, S.I., Fitch, M., Norddahl, B., Raskin, L. and Morgenroth, E. 2005 Influence of cleaning frequency and membrane history on fouling in an anaerobic membrane bioreactor (Submitted).
|
Progress 10/01/03 to 09/30/04
Outputs
During the first three years of this project we focused first on particle separation and chemical analysis of organic matter for different sources of wastewater (Sophonsiri and Morgenroth, 2004). Then during the third year, we focused on developing methods to evaluate the microbial biodegradation of different size particles (Michaud and Morgenroth, 2003). We are now operating a treatment process that is used to treat swine manure. Swine manure is sampled from the UIUC South Farms. The treatment process uses anaerobic digestion combined with membrane separation. One key question in this process is to evaluate the utilization of particulate organic matter in the swine manure. Progress in the application of the treatment process has been described in two conference presentations (Padmasiri et al., 2004; Zhang et al., 2004). One of the findings was that the hydrolysis of particulate matter has a significant influence on the production of volatile fatty acids and
subsequently the production of biogas. Thus, the process of hydrolysis influences both system reliability and process efficiency.
Impacts
Results from our study revealed the overall importance of particulate organic matter for the treatment of agricultural, municipal, and industrial wastes. Wastewater treatment systems operated for biological nutrient removal require the availability of sufficient biodegradable organic matter. Particle size and particle characteristics (i.e., chemical composition and surface characteristics) are major factors influencing hydrolysis rates and therefore the bioavailability of organic matter. Our fundamental understanding of the influence of particle size on bioavailability will help us optimize methods for particle separation in agricultural waste treatment systems. The goal of particle separation should be to remove all these particles that have only a minor benefit as a carbon source for nutrient removal (i.e., large and slowly biodegradable particles) while keeping the readily biodegradable particles as a valuable source of organic carbon.
Publications
- Michaud, R. and Morgenroth, E. 2003. The influence of particle size on microbial hydrolysis of particulate organic matter. In: IWA Conference on Nano- and Microparticles in Water and Wastewater Treatment, Zurich, Switzerland, 22 - 24 September 2003.
- Padmasiri, S., Zhang, A., Fitch, M., Norddahl, B., Morgenroth, E. and Raskin, L. 2004. Startup of anaerobic membrane bioreactor treating swine waste. In: 10th IWA World Congress on Anaerobic Digestion 2004, August 29th to September 2nd, 2004.
- Sophonsiri, C. and Morgenroth, E. 2004. Chemical composition associated with different particle size fractions in municipal, industrial, and agricultural wastewaters. Chemosphere, 55, (5), 691-703.
- Zhang, A., Padmasiri, S., Fitch, M., Raskin, L. and Morgenroth, E. 2004. Membrane fouling in anaerobic membrane bioreactor (AMBR) treating swine manure. In: Oral presentation at the 77th Annual conference of the Water Environment Federation (WEFTEC), October 2-6, 2004.
|
Progress 10/01/02 to 09/30/03
Outputs
During the first two years of this project we focused on particle separation and chemical analysis of organic matter for different sources of wastewater. During the third year, we focused on developing methods to evaluate the microbial biodegradation of different size particles. The following conclusions were drawn from our investigation (Michaud and Morgenroth, 2003): 1. Efficient nutrient removal from wastewater requires the availability of a sufficient supply of organic carbon as an electron donor for denitrification and biological phosphorous removal. The majority of the organic matter in raw municipal wastewater is in the particulate form. The availability of particulate organic matter from wastewater as an electron donor is limited by the rate of hydrolysis and many treatment plants are required to purchase external organic carbon sources. 2. Particle size influences hydrolysis rates. Smaller particles have a larger specific surface area and are hydrolyzed
faster. 3. Hydrolysis can result in a breakup of large particles combined with the production of soluble substrate. Hydrolysis of large particles derived from egg whites could best be described using surface based kinetics, where the available surface area increased as a result of hydrolysis. 4. Other approaches were examined including surface-based kinetics without particle breakup and particle adsorption models. These modeling approaches failed to describe the slow increase of OUR after the addition of particles.
Impacts
Results from our study revealed the overall importance of particulate organic matter for the treatment of agricultural, municipal, and industrial wastes. Wastewater treatment systems operated for biological nutrient removal require the availability of sufficient biodegradable organic matter. Particle size and particle characteristics (i.e., chemical composition and surface characteristics) are major factors influencing hydrolysis rates and therefore the bioavailability of organic matter. Our fundamental understanding of the influence of particle size on bioavailability will help us optimize methods for particle separation in agricultural waste treatment systems. The goal of particle separation should be to remove all these particles that have only a minor benefit as a carbon source for nutrient removal (i.e., large and slowly biodegradable particles) while keeping the readily biodegradable particles as a valuable source of organic carbon.
Publications
- Michaud, R. and Morgenroth, E. 2003. The influence of particle size on microbial hydrolysis of particulate organic matter. Wat. Sci. Tech (Submitted).
- Sophonsiri, C. and Morgenroth, E. 2003. Chemical composition of different size organic particles in municipal, industrial, and agricultural wastewater. Chemosphere (In Press).
|
Progress 12/01/01 to 11/30/02
Outputs
During the second year of our project, we applied the developed tools for particle separation and chemical analysis of organic matter for different sources of wastewater. We evaluated influent and effluent samples from treatment plants for municipal and industrial wastewater treatment plants in addition to a lagoon system for swine manure. The following conclusions were drawn from our investigation: 1. Composition of municipal wastewater is independent of particle size. In food processing wastewater and swine manure, particle composition varies with size. 2. Significance of particle varies for different sources. Organic matter in food processing wastewater and swine manure is mainly particulate. 78% of the chemical oxygen demand (COD) in swine manure is associated with particles larger than 10 micrometer and 70% of COD in food processing wastewater is associated with particles larger than 1.2 micrometer. For municipal wastewater, only 45% of COD is larger than 1.2
micrometer. 3. Measured COD could not be completely accounted for by measured proteins, carbohydrates and lipids. An unidentified fraction is defined as a difference between the total COD concentration and sum of the proteins, carbohydrates and lipids converted to COD unit. This unidentified fraction is less than 10% in primary effluent but accounts for approximately 40% and 80% of a total COD in the food processing effluent of equalization tank and a swine manure from a shallow hog pit, respectively. This significant contribution of unidentified fraction implies that global organic parameter such as COD should always be included for wastewater characterization. 4. Particle separation can be used to modify chemical composition. The results of a food processing wastewater show that a physical separation unit effectively removed particles larger than 1.2 micrometer and also raised a protein/carbohydrate ratio of wastewater.
Impacts
Results from our study revealed the overall importance of particulate organic matter for the treatment of agricultural, municipal, and industrial wastes. Particle size distributions were significantly different for the different waste sources tested. The specific size ranges of particles are important as particle size (1) determines rates of hydrolysis and biodegradation, (2) influence solid-liquid separation, and (3) influences the applicability of chemical analysis methods. For the agricultural waste it was found that most of the organic matter was associated with particles larger 10 mm. We are currently evaluating efficient removal mechanisms for these large particles.
Publications
- Sophonsiri, C. 2002. Wastewater characterization: Particle size distribution and organic composition. M.S. thesis, Univ. of Illinois.
|
Progress 10/01/00 to 09/30/01
Outputs
The overall objectives of this project were to develop procedures for a physical and chemical characterization of particulate organic matter in swine manure and subsequently to evaluate hydrolysis and biodegradation of particulate organic matter in manure treatment processes. During this first year, we focused on developing and testing of procedures for physical and chemical testing. Physical separation was done using three different techniques that were applied sequentially. First, large particles were removed using test sieves with 63 and 38 micrometer mesh sizes. Second, microfiltration using polycarbonate filters (Millipore, Bedford, MA) with pore sizes of 10, 1.2 and 0.2 micrometer were used to remove smaller particulate matter. Third, ultrafiltration in stirred cells (Amicon 8200, Millipore, Bedford, MA) with cutoff sizes of 100,000 and 1,000 amu were used to separate colloidal matter and macromolecules. Samples were filtered sequentially resulting in eight size
classes that were analyzed. For each sample we measured chemical oxygen demand (COD), carbohydrate, protein, and total phosphorus. Lipids were measured only for raw samples before filtration. COD was measured using a closed reflux digestion method. Proteins were measured according to the Lowry method using bovine serum albumin as a standard solution and measuring absorbance at 750 nm. Carbohydrates were measurement according to the Anthrone method using glucose as a standard and measuring absorbance at 625 nm. To measure total phosphorus, the samples were digested and ortho phosphate was measured using the molybdovanadate method. Lipids were extracted from samples using trichlorotrifluoroethane and quantified using an infrared spectrophotometer at 2960 cm-1 using corn oil as a standard. The described methods were tested using standard solution and environmental samples and were all shown to work reliably. Unfortunately, the determination of lipids requires a large sample volume (1
liter) and could not be modified to smaller sample volumes obtained from the sequential filtration (typically about 20 ml). Swine manure samples were collected from the University of Illinois Swine Research Center facilities. Fresh manure samples were taken directly from the pit. Initial results showed that the majority of organic matter in fresh manure was in the size fraction between 38 and 0.2 micrometer. The sampled pit was not completely mixed and samples were taken above the sediment layer. Consequently, particles larger than 38 micrometers must have settled in the pit. What is surprising is the low concentration of organic matter in the colloidal fraction (below 0.2 micrometers). Results obtained from swine manure samples were compared to samples collected from municipal and industrial wastewater. Both for the municipal and the industrial wastewater a significant fraction of the organic matter was found in the colloidal fraction. Thus, particle characteristics in swine manure
are significantly different from particle characteristics in municipal and industrial wastewater.
Impacts
Based on preliminary physical and chemical characteristics of particles in swine manure, the availability of particulate organic matter as a carbon source for denitrification and biological phosphorus removal must be further evaluated. It is expected that hydrolysis rates for colloidal matter are significantly faster compared to hydrolysis rates for larger particles found in the swine manure. Thus, it can be speculated that treatment technologies developed for municipal or industrial wastewater cannot directly be applied for the treatment of swine waste, as slower hydrolysis rates for particulate organic matter have to be taken into account. In the second objective of this project we will evaluate hydrolysis rates for different particle size classes to confirm these speculations.
Publications
- No publications reported this period
|
|