Progress 10/01/01 to 09/30/07

Outputs
Dilute milk parlor wastewater (liquid part from the solid/liquid separation device) was investigated using EMMC technology. Both anaerobically treated and raw milk wastewaters were fed to EMMC reactor at different HRT and aeration conditions. Results show that treating raw wastewater at HRT 12 hours and 1 hour on/ 1 hour off aeration condition provides the best removal efficiency and better effluent quality for carbon and nitrogen. The overall removal efficiencies for TCOD, SCOD, TN, and NH3-N are 78%, 63%, 65%, and 96%, respectively. The solids generated from the solid/liquid separation device can be further processed bypassing the existing composting facilities. The treated liquid part effluent form EMMC reactor finally goes to the existing lagoon for further treatment and can be discharged or reuse of floor flushing. With this proposed option, the cost of system operation is $68.62 per dairy cow per year and $88.10 per ton of removal TCOD for the operation of 960 cows. Various treatment alternatives for the dilute milk parlor wastewater were also evaluated, and it was concluded that the aerobic EMMC process only could provide effective removal of organics and nitrogen in order to be able to reuse the treated wastewater. This is very important for the location where land and water resources are limited.

Impacts
The dairy producers have an alternative to separate solid/liquid for their wastewater that can be received an effective EMMC treatment for removal of carbon and nitrogen pollutant. This can provide more effective way for treated wastewater reuse. The solid portion in the wastewater can be further processed into composting product or bioenergy (methane gas) production. This important impact is to provide the producers to have their own selection of treatment alternative to meet the regulatory requirement, achieve the byproduct recovery in the form of reuse of treated wastewater, and cut down the energy bill.

Publications

• Lin, Lao-Ting (2007) Comparison of different technology for dilute milk parlor wastewater treatment and reuse, Master Thesis, University of Hawaii at Manoa, Honolulu, Hawaii, 127 pp.

Progress 10/01/05 to 09/30/06

Outputs
A project entitled "Polluted runoff control for Waialee livestock Farm" was funded through US EPA Clean Water Act Section 319(h) Grants and Department of Health, State of Hawaii. This project involves both point source and non-point source pollution control. The point source pollution includes mainly the milk parlor wastewater and some domestic sewage. The non-point source pollution includes the run off from beef/ dairy feedlots. The treatment system includes two of anaerobic Bio-nest (10 m3 each), one aerobic biopottery (5m3) and a windmill for aeration. After half year of the operation of this integrated treatment system, removal efficiency of TCOD (Total Chemical Oxygen Demand), TSS (Total Suspended Solids) and ammonia nitrogen are 93%, 92% and 60%, respectively. This integrated treatment system makes both point source and non-point sources pollution controllable. It is simple, reliable and low cost. This project has been progressed as proposed. A CD entitled "Animal Waste Management and Pollutant Runoff Control" has been prepared for the distribution of the interested persons and agencies.

Impacts
Because of the strict environmental regulation will be implemented by USEPA, both the problems of point and non-point sources are remained unsolved in the US. The success of this treatment system is able to provide the animal producers to manage their pollution problems. More importantly, this pre-treatment system provides very effectively for the animal problems to be able to integrate this pre-treatment system to their existing lagoon system for treated wastewater reuse and bioenergy (as methane gas) production and utilization.

Publications

• Dong, Lianggie and Yang, P. Y. (2006). An Innovative system integrated Bio-nest, Bio-pottery and windmill aeration. Presented at Hawaii Water Environment Association, 28th Annual Conference, February 9-10, 2006, Honolulu, Hawaii.
• Yang, P. Y. (2006). Polluted runoff control for Wailee Livestock Farm. Final Report to DOH, State of Hawaii, March 2006, 22pp.

Progress 10/01/04 to 09/30/05

Outputs
The result generated from the laboratory study on the Bio-nest reactor for milk parlor wastewater treatment has been filed for the application of patent in U.S. under 35 U.S.C. #119 to U.S. Provisional Application No. 60/480,085 Filing Date: 06/19/03. This invention relates to the field of wastewater treatment. This is a method of treating wastewater using an anaerobic bioreactor which contains a "Bio-nest" structure to retain the microbial content and improve the treatment efficiency. The system is particularly useful for treatment of lipid rich wastewater. This technology has been scaled up for two pilot plants for the application of treatment/reuse of milk parlor wastewater on the island of Oahu, Hawaii, i.e., Mountain View Dairy Inc. and UH-Livestock Research Farm. These two projects are still in progress.

Impacts
The improvement of the wastewater treatment process, and in particular dairy and agricultural wastewater treatment, is an important goal. This is particularly important since the U.S. EPA (Environmental Protection Agency) is putting new rules into place regarding agricultural waste. All large Concentrated Animal Feeding Operations (CAFOs) will soon be required to obtain permits that will ensure they protect America's water by keeping wastewater and manure out of the nation's water ways. This new method for cleaning the pollutants can be effective for agricultural facilities to be compliant with the new ruling.

Publications

• Liangjie Dong and P.Y. Yang (2006) Bionest reactor for the application of anaerobic wastewater treatment and bioenergy recovery. U.S. Parent App. No. 60/480,085. Filing Date: 06/19/03, Status: Pending.

Progress 10/01/03 to 09/30/04

Outputs
A laboratory scale of 2-stage bioreactor for the anaerobic treatment of milk parlor wastewater was investigated. It was found that it proves an effective reactor for the biological treatment of high lipid/fat content of milk parlor wastewater at lower temperature of 22 Centigrade. The advantages of operating this reactor (Bio-nest) include high biomass contact, best application of EMT (Effective Mixing Time) and EBRP (Effective Biomass Reaction Process), less dead zone, providing stable operation conditions regarding for COD removal and methane gas production, combing the advantage of UASB (Upflow anaerobic sludge blank) and anaerobic filter design/operation and correct the disadvantage of UASB and anaerobic filter process. This bioreactor design/operation is in the process of filing the US patent now. A pilot plant with two stages of bioreactor (10m3 each) is under construction now. Monitoring the results will be followed. On-line monitoring of oxidation reduction potential (ORP) was conducted at the full-scale aeration basin operated with intermittent aeration schedule and fed with wastewater generation from fruit fly facility owned by the California Department of Food and Agriculture in Hawaii. It was found that 25% of energy cost for aeration can be saved. From the result of real time monitoring of ORP response and water quality analysis of nitrogen, the behaviors of nitrogen are closely related to the ORP response.

Impacts
Success of integrating the Bionest reactor with existing lagoon system will certainly provide the farmers to improve their environmental pollution problems and to be able to reuse the treated wastewater for floor flushing and irrigation of crop production without deteriorating the environmental quality. The ORP monitoring can provide a practical and easy tool for the evaluation of the degree of nitrification and denitrification condition and reduce the energy cost for the biological wastewater treatment system.

Publications

• Dong, L. and Yang, P.Y. 2003. Design and analysis of an anaerobic bio-nest reactor for treatment of wastewater with high lipids content. Presented at IWA-Asia Pacific Regional Conference, Oct 19-23, 2003, Bangkok, Thailand.
• Shimabukuro, M., Yang, P.Y. and Kim, S. J. 2004. Applicability of ORP respose on a full scale intermittently aerated suspended culture system. Practice Periodical of Hazardous, Toxic, Radioactive, Waste Management, ASCE. 8:19-25.

Progress 10/01/02 to 09/30/03

Outputs
A bioreactor, with simple design and operation with high treatment efficiency, was developed. This is the modification of design and operation of upflow anaerobic sludge blanket (UASB) and anaerobic biofilter reactor. A two-stage of bioreactor (10 L each), were operated for six months. They are filled with two layers of media which is 98% of void volume in the reactor. The reactors were operated in the ambient room of 22,b2 ,aC. A loading rate ranged from 2.68 to 36 g/L/d of total COD (TCOD) using milk parlor wastewater was investigated. At organic loading rate of 36 COD g/L/d, the removal efficiency of total TCOD, soluble COD (SCOD) and total suspended (TSS) are 52%, 28.9% and 62% respectively. Methane gas production rate was 2.17 L/L/d with 57% methane content. If the recovery of methane gas and COD removal efficiency are the main objectives, the organic loading rate needs to be maintained at lower range. At organic loading rate of 3-4 g TCOD/L/d, the removal efficiency of TCOD, SCOD and TSS are 81.8%, 59% and 79.9% respectively. Biogas production rate 2.6 L/L/d with methane content 73% can be achieved. The unique operation of the bio-nest reactor is to achieve a higher COD removal efficiency with high organic loading rate by simple design and operation. This unique bioreactor could provide better sludge distribution, less dead zone and higher TCOD loading rate than conventional UASB does. Especially, the high fat content of milk wastewater was used in this study.

Impacts
An anaerobic bio-nest reactor was designed and investigated for the treatment of milk parlor wastewater. The unique design of this bioreactor provides a high COD removal efficiency with high organic loading rate even the reactor is operated at 22,b2 ,aC. This is due to high SRT, better sludge distribution, less dead zone provided by this unique bioreactor. The shortcoming occurred in the anaerobic filter and UASB are corrected and made-up to design this bio-nest reactor. This bio-nest reactor achieves a comparable or better performance, measured as TCOD removal and methane production, than the anaerobic filter and UASB. Simple design and operation for the application of this bioreactor can be easily integrated into the existing lagoon system (popularly in the United States) or integrated to the aerobic and intermittent aerobic treatment unit (e.g. EMMC, entrapped mixed microbial cell developed at UH) for further removal of carbon and nitrogen in order to dispose, discharge or reuse.

Publications

• Yang, P.Y., Chen, H.J. and Kim, S.J. 2003. Integrating EMMC process for biological removal of carbon and nitrogen for diluted swine wastewater for agriculture reuse. Bioresource Technology. 86:245-252.
• Dong, L. and Yang, P.T. 2003. Design and analysis of an anaerobic bio-nest reactor. Presented at the Anaerobic Digester Summit, Raleigh, North Carolina, June 2-4, 2003.

Progress 10/01/01 to 09/30/02

Outputs
Prior to the evaluation of activated thermophilic aerobic digestion of liquid dairy wastewater for further mesophilic anaerobic digestion and a dual biological fixed bed reactors, an existing wastewater management system located in Honolulu, Hawaii was evaluated for its wastewater treatment and reuse potentials. This dairy farm is currently operating with 1600 dairy cows and practiced three times a day for flushing the floors with about 300,000 gallons of wastewater produced per day. Current problems include: odor generation, contamination of groundwater, surface water pollution, land wastage, not able to recover bio-energy, not able to reuse the wastewater for floor flushing, and labor intensive for cleaning up the lagoon content. It is, therefore, an evaluation/investigation potential pretreatment alternatives prior to the existing lagoon systems is urgently required. In this study, laboratory experimental set up for the two bio-nest reactors (9.5 L each with 8.4 L of effective volume) were installed and treated at ambient temperature of 25 degree centigrade for their process performance regarding removal of COD (Chemical Oxygen Demand), reduction of SS (suspended solids), and production of bioenergy in the form of methane gas. The bio-nest reactors were filled with a certain media for preventing the wash-out of biomass in order to improve anaerobic treatment efficiency and biogas production. For the influent TCOD (Total COD) concentration of 5,000-8,500 mg/L, HRTs of 3.4 days, 2.5 days, and 1.7 days were investigated for the potential TCOD removal, SS reduction and biogas production. It was found that TCOD and TSS removal efficiency of 70-80 percent and 84 percent, respectively. The biogas production rate is about 1.5 L/L/day. The methane content of the biogas was about 75 percent. In order to improve the reuse potential of anaerobically treated wastewater, an aerobic bioreactor filled with bio-activated media was evaluated for the effluent quality. The HRT (Hydraulic Retention Time) of 17.3 hours was operated. It was found that about 53 percent of TCOD removal efficiency from the anaerobically treated effluent was able to achieve. Further optimization of these bioreactors is in progress. Also, an activated thermophilic aerobic digestion and dual biological fixed bed reactors are initiating now.

Impacts
Based on the current finding, it is possible that the existing wastewater management systems can be improved by integrating the bio-nest reactors to achieve the odor reduction, prevention of groundwater contaminating, elimination of clean-out lagoon content, reuse of treated wastewater and recovery of bioenergy. This may provide an effective and simple treatment alternatives to improve the existing lagoon systems for land limited condition and tropical environment.

Publications

• Yang, P.Y. 2001. (a) Pig waste treatment alternatives for land limited condition, (b) Biological and physical-chemical nutrient removal, (c) Economic evaluation. Presented at the Taiwan EPA-US EPA Bilateral Cooperation Workshop for River Basin and Water Quality Management, December 4-7, Kaohsiung, Taiwan. Proceedings, 87-99, 125-132, 217-225, and 245-257.
• Yang, P.Y., Chen, H.J. and Kim, S.J. 2002. Integrating EMMC process for biological removal of carbon and nitrogen from dilute swine wastewater for Agricultural Reuse. Bioresource Technology. (In Press).