N-alkanes distributions and stable isotopic compositions (δ13C and δ15N) in the lacustrine sediments of Shijiu lake were measured to assess whether biological source information was recorded in the molecular biomarker. Results showed regular unimodal n-alkanes distribution in range of C16–C33 with strong predominance of odd-numbered n-alkanes, maximizing at C29. The δ15N for SON were uniformly low, ranging from −6.7‰ to 3.8‰ and C/N ratios ranged from 6.6 to 10.0, suggesting that most of organic matter was influenced by terrestrial characteristics of the watershed. The δ13C for C27 to C31n-alkanes and for SOC varied from −32.9‰ to −26.6‰ and −23.4‰ to −21.6‰, respectively, falling within the range of corresponding n-alkanes in leaves mainly from C3 land plants. The values of C/N, CPI, OEP, ACL and C27/C31 exhibit similar temporal changes with the primary production, showing enhanced eutrophication resulted from increased anthropogenic activities in Shijiu lake from 1852 to 2010.

Sediment samples from a salt marsh habitat in the vicinity of Linden Chemical Plant (LCP) Superfund site in Brunswick Georgia, USA, were analyzed for the composition of total solvent extracts and sources of lipid compounds. Stable isotope analysis of carbon and nitrogen and gas chromatography-mass spectrometry analysis infer past multiple sources of organic matter (OM) from aquatic and terrestrial origin, e.g., phytoplankton, bacteria, and land plants, as well as anthropogenic contamination. The n-alkane and n-alkanol distributions in the sediment samples were dominated by long-chain homologues maximizing at C₂₅–C₂₇ for alkanes (carbon preference index (CPI) ∼1) and C₃₂ for n-alkanols indicating inputs from higher plants, but also microbial and petroleum-related sources. Fatty acid distribution was characterized by short-chain (< C₁₈) and branched homologues indicative of bacterial origin. The high abundance of dehydroabietic acid and anthropogenic contaminants, including alkylphenols, are indicative of the effects of past industrial activities in the LCP marsh area in Brunswick, Georgia.

The ability of aquatic (Juncus effusus L., Scirpus holoschoenus L., Thypha latifolia L. and Juncus sp.) and land (Cistus ladanifer L., Erica andevalensis C.-R., Nerium oleander L., Isatis tinctoria L., Rosmarinus officinalis L., Cynodon dactylon L. and Hordeum murinum L.) plants from Portugal (Aljustrel, Lousal and São Domingos) and Morocco (Tighza and Zeida) mining areas to uptake, translocate and tolerate heavy metals (Cu, Zn and Pb) was evaluated. The soils (rhizosphere) of the first mining area are characterized by high acidity conditions (pH 2–5), whereas from the second area, by alkaline conditions (pH 7.0–8.5). Physicochemical parameters and mineralogy of the rhizosphere were determined from both areas. Chemical analysis of plants and the rhizosphere was carried out by inductively coupled plasma emission spectrometry. The sequential chemical extraction procedure was applied for rhizosphere samples collected from both mining areas. In the acid conditions, the aquatic plants show a high capacity for Zn bioaccumulation and translocation and less for Pb, reflecting the following metal mobility sequence: Zn > Cu > Pb. Kaolinite detected in the roots by infrared spectroscopy (IR) contributed to metal fixation (i.e. Cu), reducing its translocation to the aerial parts. Lead identified in the roots of land plants (e.g. E. andevalensis) was probably adsorbed by C–H functional groups identified by IR, being easily translocated to the aerial parts. It was found that aquatic plants are more efficient for phytostabilization than bioaccumulation. Lead is more bioavailable in the rhizosphere from Morocco mining areas due to scarcity of minerals with high adsorption ability, being absorbed and translocated by both aquatic and land plants.