S-1000
Regional Project
Animal
Manure and Waste Utilization, Treatment and Nuisance Avoidance for a Sustainable
Agriculture
2003
Station Reports
Reporting scientist:
P.Y. Yang Location: Department of Molecular Bioscience and Bioengineering
University of Hawaii at Manoa,
Honolulu, HI, 96822.
Summary of Work by Objectives and Task
Project Period: October 1, 2001- September 30, 2006.
Report Period: October 1, 2002- September 30, 2003. Objective2: Develop, evaluate,
and refine physical, chemical and biological treatment processes in engineered
and natural systems for management of manures and other wastes.
Task1: Develop and evaluate innovative application of engineered biological
treatment process to stabilize waste, reduce odor, and manage nutrients.
Progress and Accomplishment:
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±2 0C. 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 solids (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 3-4gTCOD /l/d, the removal efficiency
of TCOD, SCOD and TSS are 81.8%, 59% and 79.9% respectively. Biogas production
rate 2.6l/l/d with methane content of 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.
Usefulness of Findings
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±20C. 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 exiting 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.
Plan of work
Based on the results generated from the laboratory studies on the anaerobic
bio-nest reactor and EMMC (Entrapped Mixed Microbial Cell) reactor, a pilot
plant includes two steps of anaerobic reactors (each 10 m3) with two layers
of plastic string and aerobic EMMC unit (10m3) with entrapped mixed microbial
cell to increase the retention of biomass will be installed and investigated
at the Mountain View Dairy Farm on the island of Oahu. They will be operated
in the ambient temperature of 20~27 0C in the field. Optimization of the
organic loading rate and hydraulic retention time for these bioreactors in
order to achieve the maximum treatment efficiency will be developed. This
project will be funded by the Tropical and Subtropical Agriculture Research
(T-SAR), the University of Hawaii during of October 1, 2003 and September
30, 2005.
Publication and Presentations
1. Dong, Liangjie and Yang, P.Y. Dairy farm wastewater treatment and
reuse- A case study in Hawaii. Presented at Scientific, Regulatory and Cultural
Factors Influencing Water and Environmental Issues in Tropical Pacific Islands
Conference, Honolulu, Hawaii. January 15-16, 2003.
2. 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. Bioresouce Technology. 86, Page 245-252.
3. Dong, Liangjie and Yang, P.Y. Design and analysis of an anaerobic bio-nest
reactor. Presented at the Anaerobic Digester Summit, Raleigh, North Carolina,
June 2-4, 2003.