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Alkanes, Isomers, and Nomenclature
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
Alkanes can exist as cyclic molecules, where the carbons form a ring. In other words, the continuous chain of carbon atoms forms a ring, which is a cyclic structure. These compounds are known as cyclic alkanes, or cycloalkanes. What is the general formula for a cyclic alkane?
Engineering Application of Biooxidation Processes for Treating Petroleum-Contaminated Soil
Published in Donald L. Wise, Debra J. Trantolo, Remediation of Hazardous Waste Contaminated Soils, 2018
Chi-Yuan Fan, Anthony N. Tafuri
Cycloalkanes. Cycloalkanes are hydrocarbon rings joined by single carbon-carbon bonds. Single-ring cycloalkanes are somewhat volatile; however, the volatility decreases as the size of the ring and number of rings increase. Cycloalkanes can be biodegraded, but at a slower rate than linear alkanes.
Temporal effect of phytoremediation on the bacterial community in petroleum-contaminated soil
Published in Human and Ecological Risk Assessment: An International Journal, 2023
Yuanyuan Shen, Yu Ji, Wenke Wang, Tianpeng Gao, Haijuan Li, Mingyan Xiao
The soil used in this experiment was a sandy-loam alluvial collected from Xi’an University campus, Shannxi Province, China(Xi'an, 34°16′N 108°56′E, China). The soil samples were collected from the surface to a depth of 20 cm. Large particles, stones, gravel and plant residue were removed by sifting through a 2 mm sieve. Soil pH values were measured by a pH meter (PHS-3E) (w/v ratio of soil and water was set at 1:2.5). Soil organic matter (SOM) was measured by titration with oxygen butyrate; total nitrogen (TN) was determined by Kjeldahl digestion method. Available P was determined by sodium bicarbonate extraction-molybdenum antimony resistance method. Available K was determined by Ammonium acetate flame photometry method. Soil nitrate nitrogen (NO3−-N) and ammonium nitrogen (NH4+-N) were extracted by 2 M KCl solution (1:5 w/v) for 30 min, and the concentrations were measured using a flow injection auto-analyzer. The basic physical and chemical properties of the soil were as follows: pH 8.07, soil organic matter content 1.29 g/kg, available nitrogen 31.34 mg/kg, available phosphorus 8.96 g/kg, and available phosphorus 32.85 mg/kg. The composition of sand, silt and clay particles were 66.3%, 24.7% and 8.9%, respectively. Soil bulk density was 1.23 g/cm3. The petroleum used in the experiment was obtained from the Yanchang oil field in Yan’an, China. Its ground relative density was 871.4 kg/m3 (25 °C), the water content was 0.8%. The petroleum components were analyzed and determined by Gas-chromatography Mass-spectrometer (GC-MS). GC–MS analysis was performed using an Agilent 7890 GC-5975 MSD fitted with a capillary column (RESTEK, USA) DB-5 ms (30 m × 0.25 mm i.d., 0.25 μm). The test results showed that the proportions of n-alkanes, isomeric alkanes, aromatic hydrocarbons and cycloalkanes were 70.42%, 12.35%, 10.31% and 2.67%, respectively. N-alkanes are mainly C5-C19. The content of isomeric alkanes with three branched chains is higher. Cycloalkanes include cyclopentane and cyclohexane series. In cyclohexane series, the content of polycyclohexane containing branch chain is the highest. The main aromatic hydrocarbons are benzene and naphthalene with branched chain, and the content of branched naphthalene is higher than that of benzene.