Organic pollutants in the coastal environment off San Diego, California. 2. Petrogenic and biogenic sources of aliphatic hydrocarbons

Abstract

Abstract-The results from the measurements of aliphatic hydrocarbons suggest that hydrocarbons in the Point Loma Wastewater Treatment Plant (PLWTP) effluents are mainly petroleum derived; those in the Tijuana River runoff have largely originated from terrestrial plants with visible petroleum contamination; and those in the sea surface microlayer, sediment traps, and sediments at various coastal locations off San Diego have mostly resulted from biogenic contributions with enhanced microbial products in the summer season. Rainfall in the winter season appeared to amplify the inputs from terrestrial higher plants to the coastal areas. The PLWTP discharged approximately 3.85 metric tons of n-alkanes (C 10 -C 35 ) in 1994, well below the level (136 metric tons) estimated in 1979. The input of aliphatic hydrocarbons from the Tijuana River was about 0.101 metric tons in 1994. Diffusion, solubilization, evaporation, and microbial degradation seemed partially responsible for the difference in the concentrations and compositions of aliphatic hydrocarbons in different sample media, although the relative importance of each mechanism cannot be readily discerned from the available data. The results from analyses of aliphatic hydrocarbon compositional indices are generally consistent with those of polycyclic aromatic hydrocarbons.

Organic pollutants in the coastal marine environment off San Diego, California. 3. Using linear alkylbenzenes to trace sewage‐derived organic materials

“…In contrast, the A-17 sediments contained the highest amounts of LABs (35.3 ng/g in January and 39.2 ng/g in June) as compared to those from other stations. The low LAB concentrations in the MTR sediments were consistent with the low PAH and AH concentrations in the same samples [17,18].…”

Organic Contaminants in Riverine and Groundwater Systems

“…Appropriate compounds are n-alkanes, steranes, hopanes and acyclic isoprenoids (e.g. Jovancicevic et al 1997;Jovancicevic et al 1998, Kaplan et al 1997Tran et al 1997;Volkmann et al 1997, Wehner et al 1998: Faure et al 2000Jovancicevic et al 2003 ).…”

“…These UCMs and high amounts of alkylated cyclohexanes and benzenes also reflect the contribution of petrogenic emissions, whereas the petrogenic n-alkanes were superposed by biogenic contributions indicated by an odd-over-even carbon chain length predominance. A successful differentation of aliphatic hydrocarbons from both biogenic and petrogenic sources in coastal sediments is rather difficult (Fernandes et al, 1997;Tran et al, 1997).…”

Persistent organic pollutants in sediment cores from the southern region of the Bight of the Californias

“…Los HAP pueden originarse por pirólisis, petrogénesis o por diagénesis temprana (aromatización in situ). En contraste, los hidrocarburos alifáticos (HA) no han mostrado efectos adversos sobre la biota, pero su estudio ha sido utilizado ampliamente para diferenciar entre fuentes biogénicas (marinas o terrestres) y petrogénicas de la materia orgánica (Blumer et al, 1971;Venkatesan et al, 1980;Wakeham, 1996;Tran et al, 1997) Los hidrocarburos clorados son compuestos sintéticos químicamente estables e hidrofóbicos. Aunque en este grupo se incluyen los compuestos más tóxicos conocidos por el hombre, como dioxinas y dibenzofuranos, debido a su uso y su amplia distribución en el medio los bifenilos policlorados (BPCs) y los pesticidas organoclorados son más importantes desde el punto de vista ambiental.…”

“…The most environmentally significant are the polynuclear aromatic hydrocarbons, as some of them have proven to be toxic, mutagenic and carcinogenic; they can originate from pyrolisis, petrogenesis or early diagenesis (in situ aromatization). In contrast, aliphatic hydrocarbons have not been found to adversely affect the biota; however, they have been widely studied to differentiate between biogenic (marine or terrestrial) and petrogenic sources of organic matter (Blumer et al, 1971;Venkatesan et al, 1980;Wakeham, 1996;Tran et al, 1997).…”