Search Results

You are looking at 1 - 10 of 65 items for :

  • "hydrocarbons" x
  • User-accessible content x
Clear All
Free access

Alejandro Alarcon, Frederick T. Davies Jr., Robin L. Autenrieth, David Wm. Reed and David A. Zuberer

A phytoremediation study in a 3 × 3 × 2 factorial experimental design was conducted to determine the effect of Glomus intraradices (AMF) inoculation and inorganic fertilization on the growth and development of Lolium multiflorum cv. Passarel Plus, and on the degradation of total petroleum hydrocarbons (TPH). The 80-day study was done with pots containing sandy soil. Seedlings of L. multiflorum were transplanted to uncontaminated or soil contaminated with Arabian crude oil (ACO) at concentrations of 3000 and 15,000 mg·kg-1. Half of the seedlings were inoculated with 500 spores of AMF. Plants were fertilized with Long Ashton Nutrient Solution (LANS) at 0.5×, 1.0×, or 2.0× strength, modified to supply 30 μg·mL-1 P to maximize the AMF establishment. Total plant dry weight and leaf antioxidant activity were reduced by ACO when compared to control plants. The LANS fertilization enhanced plant growth under ACO-contamination, and allowed similar antioxidant activity in plants exposed to 15,000 mg·kg-1. Soil rhizosphere respiration was increased by LANS, particularly with 15,000 mg·kg-1 ACO. AMF inoculation did not enhance plant growth, antioxidant activity, or microbial respiration. The average root colonization was around 30% in contaminated and uncontaminated rhizospheres, indicating that the tolerance of AMF symbiosis to ACO. Greater TPH degradation was achieved in non-AMF plants at 3000 mg·kg-1 ACO in combination with 0.5× LANS. LANS-fertilization with 1.0× or 2.0× did not enhance TPH-degradation when compared to 0.5× LANS.

Free access

John F. Karlik and Arthur M. Winer

More than 70 biogenic hydrocarbon (BHC) compounds are known to be emitted by plants, but only a few are emitted in relatively large quantities. The magnitude of BHC emissions from individual trees is affected by ambient light and temperature, species-specific emissions rates, and leafmass. Like other volatile organic compounds (VOC), BHC emissions react with oxides of nitrogen (NOx) to form ozone and, thus, can contribute to urban air pollution. On average, BHC emissions are as reactive or more reactive than the VOC emissions from automobiles and can have higher ozone-forming potential. An accurate estimate of the overall magnitude of BHC contributions is important in formulating strategies to reduce peak ozone concentrations because an effective strategy will take into account the relative strengths of NOx and VOC emissions. The choice between NOx and VOC controls is crucial since an incorrect emphasis may result in non-attainment of ozone-reduction goals and control measures for either NOx or VOC involve enormous costs. As part of a program to develop a reliable BHC emission inventory for the Central Valley of California, a quantitative investigation of the leafmass of urban trees was conducted. Twenty-one trees in Bakersfield, Calif., were harvested and leaves removed, dried, and weighed. Leaf masses per tree ranged from 1.5 to 89.6 kg. Leaf mass densities (dry leaf mass per area of crown projection) ranged from 150 to 3200 g·m-2, as much as eight times greater than leaf mass densities for deciduous forests and more than twice those for coniferous forests. These data suggest the BHC contributions of urban trees may be underestimated if their foliar masses are calculated using forest-based leaf mass density data.

Full access

Longyi Yuan, Yang Gao and Deying Li

Spills of petroleum-based products on turfgrass happen primarily because of equipment failure or improper refueling. Hydrocarbons are a major component of fuels and hydraulic fluids, and are hazardous to the environment ( Aislabie et al., 2006

Full access

Ruiqin Bai and Deying Li

of equipment failure, careless refueling over turfgrass, or improperly connected hoses. Hydrocarbons are a major component of petroleum-based fuels and hydraulic fluids and are hazardous to the environment and toxic to plants and animals. Damage

Free access

Dong Sik Yang, Svoboda V. Pennisi, Ki-Cheol Son and Stanley J. Kays

negative effect on indoor air quality ( Darlington et al., 2000 ). VOCs are generally classified as aromatic hydrocarbons (e.g., benzene, toluene, ethylbenzene, xylene), aliphatic hydrocarbons (e.g., hexane, heptane, octane, decane), halogenated

Free access

Chunyu Zhang, Xuesen Chen, Hongwei Song, Yinghai Liang, Chenhui Zhao and Honglian Li

volatile compounds released by M. baccata and M. prunifolia fruit. We identified 58 and 54 volatile compounds, including alcohols, esters, aldehydes, terpenes, hydrocarbons, ethers, heterocycles, carboxylic acids, and ketones, in 10 M. baccata

Free access

Valtcho D. Zheljazkov, Tess Astatkie, Santosh Shiwakoti, Shital Poudyal, Thomas Horgan, Natasha Kovatcheva and Anna Dobreva

-caryophyllene, α-humulene, veridifloral, humulene epoxide II, and manool (in % of the total oil) obtained from eight (for EO) and seven (for the constituents) distillation times (DTs). All of the monoterpene hydrocarbons (α- pinene, camphene, β-pinene, myrcene, and

Free access

Libin Wang, Elizabeth A. Baldwin, Zhifang Yu and Jinhe Bai

-SPME-GC-MS, belonging to eight chemical classes, including 17 aldehydes, 11 alcohols, 4 ketones, 4 hydrocarbons, 2 oxygen-containing heterocyclic compounds, 2 sulfur compounds, 1 ester, and 1 nitrogen- and oxygen-containing heterocyclic compound ( Table 1 ). The most

Full access

Feras Almasri, Husein A. Ajwa, Sanjai J. Parikh and Kassim Al-Khatib

Inc. (Hollister, CA) comprising hydrocarbons, C9 aromatics, and calcium alkylarylsuphonate; it is referred to here as nonionic-2. Potassium bromide was used as a tracer for fumigant mobility. Research showed that bromide is the tracer least adsorbed on

Free access

Jinhe Bai, Elizabeth Baldwin, Jack Hearn, Randy Driggers and Ed Stover

( Auvray and Spence, 2008 ; Baldwin et al., 2008 ; Frank and Byram, 1988 ). The major monoterpene hydrocarbons were d -limonene, β-myrcene, and α-pinene ( Table 2 ), which are mainly contributed from peel oil of citrus fruit ( Dugo et al., 2011