Polycyclic aromatic hydrocarbons (PAH) consist of three or more fused benzene rings in linear, angular, or cluster arrangements. Substitution of carbon in the benzene ring with nitrogen, sulfur, oxygen, or other elements creates heterocyclic aromatic compounds (Blumer 1976). Excluding diphenyl types there are some 70 possible isomers of 4-6 fused rings. Additionally these isomers may be substituted by a variety of substituents (Erskine and Whitehead 1975). The aromatic hydrocarbons and heterocycles, unsubstituted and substituted, are referred to alternatively as polynuclear aromatics (PNAs), polycyclic aromatic compounds (PCAs), and polycyclic organic matter (POM) (NAS 1972, U.S. EPA 1975 b).

Fate of polynuclear aromatic compounds (PNAs) in soil-plant systems

Polynuclear aromatic hydrocarbons in raw, potable and waste waters

The paper presents the first document to identify the enrichment pattern of acid leachable trace metals (ALTMs) such as Fe, Mn, Cr, Cu, Ni, Pb, Cd, Co, Mo, Ag, As and Ba and their relationship with sediment quality parameters (pH, organic carbon, carbonates and texture) in core sediments (<63 μm particle size) from Indian Sunderban mangrove wetland, formed at the estuarine phase of the river Hugli (Ganges) Textural analysis reveals an overall predominance of mud The results indicate that the change in pH values causes coagulation and precipitation of ALTMs Fe and Mn have fairly close distribution patterns of enrichment in surface layers which might be ascribed to early diagnetic processes The most prominent feature of ALTMs is the enrichment of Fe, Mn, Cr, Cu, Ni, Pb, and Ba in the surface–subsurface layers in the sediment cores, which is mainly attributed to the intense industrial and agricultural activities as well as drainage of untreated domestic sewage to this coastal region The ALTMs also indicate their association with organic carbon and Fe–Mn oxyhydroxides The enrichment is well—supported by the correlation, grouping and clustering of ALTMs in statistical analyses Anthropogenic Factor values indicated ALTMs enrichment for all trace metals due to intense anthropogenic activities Overall higher values of ALTMs in sediments in comparison to other Indian coastal regions indicate that they are mainly due to the uncontrolled anthropogenic activities in this mangrove estuarine complex Statistical analyses suggest that five ALTMs (Cu, Pb, As, Mo, Ba) are attached to the organic particles and the clustering of elements separately also indicates that they are from external source The result of the present study suggests the need for a regular monitoring program which will help to improve the quality of this potential wetland

Acid leachable trace metals in sediment cores from Sunderban Mangrove Wetland, India: an approach towards regular monitoring.

Metal concentrations in water and sediments from tourist beaches of Acapulco, Mexico

This article presents the result of the geochemical analysis of sediment from Pulicat lake, India. The analysis consists of textural composition, CaCO3, organic carbon, total phosphorus, metals such as Cr, Ni, Cu, Pb, Zn, Cd, Fe and Mn of the sediments collected. Multivariate analysis is performed on the dataset and the interpretations are used as pointers to the origin of the composition of sediment components. Analysis shows a strong intermetal relationship, with lesser correlation with sand or mud which indicates that the metals have a common origin and they were already agglomerated before reaching the lake. Contamination Factor and Geoaccumulation Index demonstrated that the sediments were moderately contaminated with Cd. The Pollution Load Index for the Cd, Cr, Cu and Pb were greater than 1, whereby a Pollution Load Index greater than 1 indicates that the system under study is undergoing progressive deterioration representing Cd>Cu>Pb>Cr>Ni>Mn>Zn. Hierarchy of EF for metals in sediments is Cd > Cu > Pb > Cr > Ni > Mn > Zn with average of 3.6 > 2.1 > 1.8 > 1.4 > 1.0 > 0.8 > 0.7, respectively. Cd concentration varies from a minimum of 0.01–1.5 mg kg−1 with a mean of 0.77 mg kg−1. Cu concentration ranges from 25 mg kg−1 and maximum of 81 mg kg−1 with a mean of 50 mg kg−1. Most of the metals are concentrated in the stations near the eastern part, which lie parallel to the sea and these regions act as hot spots for metal accumulation.

M.J. Suess

Papers

Aqueous solutions of 3,4-benzpyrene