Progress 09/01/08 to 08/31/11
Outputs
OUTPUTS: The outputs from this project included the following: 1) Analysis of laboratory batch sorption experiments of two antibiotics (chloramphenicol sulfamethazine), two hormones (17-beta estradiol and estrone), and two bacteria viruses (MS-2 and phi-x 174) in three tropical soils from Hawaii, 2) Analysis of column leaching experiments of the antibiotics in three soils, hormones in three soils, and viruses in two soils, and 3)Evaluation of abiotic degradation of hormones (because of the reactive manganese present in these soils). Effects of total organic carbon (TOC) on the column transport of hormones and the effect of buffers and TOC on the column transport of viruses were evaluated. The product of the work was a master's thesis and one student graduated so far. The project also partially supported the salary of another student, a visiting Ph.D. student from Korea, and two undergraduate researchers. Two conference papers and one poster were prepared from this work. 1). D'Alessio, M. and C. Ray. 2011. Fate and transport of endocrine disruptive chemicals into Hawaiian soils, American Chemical Society, National Meeting in Anaheim, CA, March 27-31. 2). D'Alessio, M. 2010. Fate and transport of EDCs in Hawaii soils, Hawaii Water Environment Federation Annual Meeting, Honolulu, Hawaii, March 15-17. 3). Ray, C. 2009. Leaching assessment of pathogen indicators in the tropical soils of Hawaii, Indo-US Science Technology Forum, January 12-16, 2009. PARTICIPANTS: Chittaranjan Ray, Principal Investigator; Roger Fujioka, Co-PI; Pratibha Nerurkar, Co-PI; Bunnie Yoneyama, Microbiologist; Joseph Lichwa, Chemist; Matteo D'Alessio, Graduate Student; Seojin Ki, Visiting Graduate Student. TARGET AUDIENCES: Regulatory agencies, producers, academic community, researchers in state and federal labs. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
One of the major outcomes of this project was the recognition of abiotic degradation of hormones as a significant pathway for their losses in the environment. The presence of manganese oxides in soil was attributed to be a key player in abiotic degradation. Among the three soils tested, the volcanic ash (in cinder form) contributed to the maximum transport of these chemicals and viruses. People living in areas dominated by such soils may experience ground water contamination problems if they use shallow wells for drinking water and septic tanks/cesspools for waste disposal. If treated wastewater or lagoon effluent is used for agricultural irrigation, the total organic carbon in the water can enhance the mobility of some of these chemicals and viruses in Hawaii soils.
Publications
- Matteo DAlessio, Lichwa, J., Vasudevan, D., Mohanty, S. K., and Ray, C. 2012. Fate and transport of selected endocrine disrupting chemicals in Hawaiian soils, Water Research (in press)
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: Effect of plastic mulch on the transport of herbicides in pineapple fields was evaluated. Soil water dynamics and herbicide concentrations in the root zone soil were simulated with time as the crop grew. In a large field study, we evaluated the field leaching behavior of several pesticides at five locations in Hawaii -- three on Oahu, one on Maui and one on Kauai representing the diversity of soil and climatic conditions. Although the same amounts of chemicals and appropriate amounts irrigation water were applied to each of the five sites, leaching profiles of the chemicals varied. For some chemicals, leaching was pronounced in field conditions, although in laboratory settings they showed relatively short half-life. More recently, evaluated the leaching and runoff loss of fipronil, a commonly used termite control chemical in Hawaii. We observed much high loss to leaching than to runoff. PARTICIPANTS: Besides the PI (Chittaranjan Ray), two post-doctoral researchers (Xiufu Shuai and Jaromir Dusek) worked on this project. This project provided appropriate exposure to conducting and field and laboratory studies to these two post-doctoral researchers. Also, they were responsible for preparing the manuscripts for peer-reviewed journals. TARGET AUDIENCES: The targeted audience for this research are (a) the pesticide program staff of the Department of Agriculture, State of Hawaii, (b) researchers investigating the fate and transport of pesticides (Hawaii hosted the W-1082/2082 meeting in January 2011), (c) agricultural producers (such as plantation owners/managers), and (b) pesticide producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Hawaii is one of the few states in the union that does not automatically accept the registration of a given chemical issued by USEPA. If the compound is going to be used over a large area and has the potential to leach to ground water, the state conducts an in-house evaluation of its environmental impact. If the impact exceeds a pre-judged score, the University of Hawaii is asked to complete a detailed assessment of its potential to leach to ground water. For this purpose, the registrant provides copies of all fate and transport studies used in EPA's registration process. We used data from these studies to evaluate leaching, potential loss to runoff water, and ecotoxicological impacts. If the compound appears to have significant impact to the local environment, it may be registered as a "restricted use" compound or the state requires that a certified applicator be responsible for its use. Our study helped the state in managing its pesticide registration/regulation program.
Publications
- Dusek, J., M. Sanda, B. Loo, and C. Ray. 2010. Field leaching of pesticides at five test sites in Hawaii: study description and results, Pest Management Science, 66(6): 596-611
- Dusek, J., Alavi, G., T. Vogel, and C. Ray. 2010. Effect of plastic mulch on water flow and herbicide transport in soil cultivated with pineapple crop: A modeling study, Agric. Water Management, 97: 1637-1645.
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Progress 09/01/08 to 08/31/09
Outputs
OUTPUTS: Work for this year included additional experiments to study the mobility of two bacteria viruses (phiX-174 and MS-2) in three tropical soils from Hawaii. These soils are classified as Oxisols, Mollisols, and Andisols and they represent diversity of soils encountered in the islands of Hawaii. The Oxisol and the Mollisol were collected from two depths each (0.6 m and 2.5 m) from the Poamoho and the Waimanalo Experiment Stations of the University of Hawaii on Oahu. The Andisol cinder was collected from the Tantalus area on Oahu. The Poamoho and the Waimanalo were sieved with a 2-mm sieve after drying and were used for the batch sorption and column leaching experiments. The cinder was kept in the refrigerator in moist condition. The soils were characterized for the presence of metal oxides using an electron microscope with energy dispersive X-ray (EDX) spectrometer. The physical and chemical properties of the three soils were characterized. The deeper soil sample from Waimanalo (Mollisol) showed low soil solution pH in several incidences. It was unclear if the fertilization of the farms had any effect on altering the soil pH. Samples were retaken from different location in the same field where the pH matched that of the original samples. Batch sorption and transport experiments for the two viruses were conducted by varying the pH and ionic strengths of the buffer solutions. Several buffers were selected for the experiments. Initially, a salt buffer (potassium dihydrogen phosphate along with magnesium chloride) was used for pH 5. Later an organic buffer (MES, chemical formula C6H13NO4S, CAS number 4432-31-9) was used for the same pH. The organic buffer TRIS (tris(hydroxymethyl)aminomethane) was used for pH 8. In addition, effluent from a cattle farm lagoon was used in the column experiments to provide natural organic matter (NOM) which often enhances transport of pathogens. The pH of the effluent was around 8 (similar to TRIS). The column effluents were monitored for pH, various cations and anions, and dissolved organic carbon. As expected, higher removal of viruses was observed for low pH and high ionic strength conditions. The cinder and the soils from the deeper depths exhibited low sorption compared to surface soils. Breakthrough of phiX-174 occurred in the Waimanalo Mollisol after 5 pore volumes with lagoon effluent compared to MS-2, which needed a minimum of 20 pore volumes to initiate breakthrough. With TRIS buffer, there was no breakthrough of MS-2 in this soil. However, a breakthrough of phiX-174 occurred after 20 pore volumes. With the MES buffer, there was a breakthrough of phiX-174 in this soil after 30 pore volumes; but no breakthrough occurred for MS-2. For cinder, rapid breakthrough of phiX-174 occurred using the MES or the salt buffer (pH 5.5), but not for MS-2. PARTICIPANTS: Chittaranjan Ray, Principal investigator; Roger Fujioka, Co-PI; Pratibha Nerurkar, Co-PI; Seojin Ki, Visiting Graduate Student; and Bunnie Yoneyama, Microbiologist. TARGET AUDIENCES: 1) Regulatory agencies 2) producer, and 3) Research scientists and state and federal organizations PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Leaching studies of pathogen indicators, such ad bacteriaphage are quite important to Hawaii as they simulate leaching behavior of viruses from septic tanks. The primary source of drinking water in the state is ground water. There are many septic systems and large-capacity cesspools located overlying drinking water aquifers. Thus, the knowledge of the leachability of these pathogen indicators provides valuable information for planners, regulators, and cities. The current study is limited in scope in terms of the indicators chosen. Additional studies on the transport of pathogens and ions are warranted.
Publications
- Ray, C. 2009. Leaching assessment of pathogen indicators in the tropical soils of Hawaii, Indo-US Science Technology Forum, January 12-16, 2009.
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