Title page for ETD etd-110198-185033


Type of Document Master's Thesis
Author Leland, Jarrod Ethan
Author's Email Address smeagle@vt.edu
URN etd-110198-185033
Title Evaluating the Hazard of Land Applying Composted Diazinon Waste Using Earthworm Biomonitoring
Degree Master of Science
Department Entomology
Advisory Committee
Advisor Name Title
Mullins, Donald E. Committee Chair
Berry, Duane F. Committee Member
Bloomquist, Jeffrey R. Committee Member
Keywords
  • Composting
  • Diazinon
  • Ecotoxicology
  • Earthworms
  • Bioremediation
  • Pesticides
Date of Defense 1998-07-14
Availability unrestricted
Abstract
A process for disposing of pesticide rinsewater generated from the rinsing of application equipment is being developed at Virginia Polytechnic Institute and State University. This process involves the sorption of pesticides onto an organic matrix followed by degradation in a composting environment. We are now evaluating the hazards that might be associated with land-applying composted pesticide waste. Diazinon was the first pesticide selected for evaluation, which consisted of two studies. The first used the earthworm species Eisenia foetida to evaluate the toxicity of soil amended with composted diazinon waste. The second study determined the bioavailability of delta-2-14C-diazinon and its degradation products to E. foetida in soil amended with composted delta-2-14C-diazinon.

Results from the first study indicate that uncomposted diazinon sorbent and 30-day composted diazinon sorbent were toxic to E. foetida at sublethal and lethal levels. However, E. foetida exposed 60-day composted diazinon sorbent did not experience mortality or demostrate sublethal effects commonly associated with acetylcholinesterase inhibition.

Earthworms exposed to diazinon that was uncomposted or composted for 30 days in the radiolabelled study experienced higher mortality than in the field study. After 30 and 60 days of composting 14C-diazinon became unextractably incorporated into organic matter and very little was mineralized. Earthworms were shown to accumulate radioactivity when exposed to soil amended with 60- day composted delta-2-14C-diazinon. The majority of this radioactivity was unextractably bound to earthworm tissue and that which was extractable contained only trace levels of delta-2-14C-diazinon. Based on the absence of toxicity in the field study and the low levels of 14C-diazinon present in earthworm tissues, 60 days of composting appears to greatly reduce the hazard that diazinon rinsate poses to E. foetida.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  30control.mov 873.56 Kb 00:04:02 00:02:04 00:01:49 00:00:54 00:00:04
  30diaz.mov 654.67 Kb 00:03:01 00:01:33 00:01:21 00:00:40 00:00:03
  60control.mov 733.79 Kb 00:03:23 00:01:44 00:01:31 00:00:45 00:00:03
  60diaz.mov 750.39 Kb 00:03:28 00:01:47 00:01:33 00:00:46 00:00:04
  controlinit.mov 851.40 Kb 00:03:56 00:02:01 00:01:46 00:00:53 00:00:04
  diazinit.mov 635.20 Kb 00:02:56 00:01:30 00:01:19 00:00:39 00:00:03
  thesisleland2.pdf 3.71 Mb 00:17:10 00:08:49 00:07:43 00:03:51 00:00:19

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