Search Results

You are looking at 1 - 10 of 2,606 items for :

Clear All
Free access

Timothy L. Grey, Glenn R. Wehtje, Ben F. Hajek, Charles H. Gilliam, Gary J. Keever and Patrick Pace

Adsorption, mobility, and filtration ability of organic media toward metolachlor were evaluated in a series of laboratory experiments. Experimental variables included media type, metolachlor concentration, and equilibration time. Adsorption isotherms were determined by applying the log form of the Freundlich equation. Mobility was evaluated using glass columns filled with media, which were then surface spiked with metolachlor and then leached daily for 10 consecutive days. Peat, pine bark, combinations of these two media and a mixture of pine bark and sand adsorbed >90% of the 14C metolachlor. Freundlich sorption coefficients were 10.9, 18.2, 13.4, 14.2, and 11.0 for pine bark, peat, 5 pine bark: 1 peat, 3 pine bark: 1 peat, and 5 pine bark: 1 sand, respectively. In a timed exposure experiment using bark, minimum metolachlor adsorption (57%) was at 90 seconds and maximum adsorption (82%) required at least 1440 minutes. In column leaching studies, data for all media indicate that metolachlor is relatively immobile through these substrates. An initial pulse of metolachlor (<1.0 μg·liter-1) was detected with each medium up to the third wetting event with a subsequent decline (>0.5 μg·liter-1 for each medium) in the metolachlor recovered. Filtration efficiency of commercially formulated metolachlor from water passed through different lengths of pine bark filled filters was 0%, 17%, 20%, 22%, 23%, and 29% for filters 4, 20, 12, 8, 16, and 24 cm in length, respectively. These results support the contention that such filtration would be effective provided the residence time of water within the filter was sufficient for adsorption of the contaminant by the media to occur.

Free access

Wallace G. Pill

Growth Media

Free access

Bing Shi and Wallace Pill

Growth Media

Free access

Todd A. Russell, Joseph B. Morton and Bradford Bearce

Growth Media

Free access

Carinne Peters and Marla S. McIntosh

Oral Session 22—Floriculture–Nutrition/Media/Pest Management Moderator: Carinne Peters 20 July 2005, 8:00–9:30 a.m. Room 105

Full access

Mary A. Rogers

maintained through inputs such as composts, cover crops, and commercially available organic fertilizers ( Montri and Biernbaum, 2009 ). In aquaponics, wastewater from fish production provides nutrients to crops in a media-filled raised bed or floating system

Free access

Alan W. Meerow

74 ORAL SESSION 23 (Abstr. 161-167) Floriculture: Media and Nutrition

Free access

Tom A. Street, Richard B. Doyle and Dugald C. Close

grown for 5 months (15 Oct. 2009 to 8 Mar. 2010) in soil and sand media, with and without biochar, under a range of irrigation, fertilization, and biological treatments. Glass house temperature ranged between 18 and 26 °C. Soil and biochar treatments

Free access

Jianjun Chen, Yingfeng Huang, Zhen Yang, Russell D. Caldwell and Cynthia A. Robinson

99 ORAL SESSION 19 (Abstr. 558–564) Floriculture/Foliage: Nutrition/Media Tuesday, 25 July, 2:00–3:45 p.m