Estuaries suspended particulate matter

Luo X-J, Chen S-J, Mai B-X, Yang Q-S, Sheng G-Y, Fu J-M (2006) Polycyclic aromatic hydrocarbons in suspended particulate matter and sediments from the Pearl River Estuary and adjacent coastal areas, China. Environ Pollut 139(1) 9—20... 

Figure 11.9 Negative correlations between particulate P and suspended particulate matter (SPM) and the partition coefficient (Aj) for orthophosphate (Aj = [TPP [mg kg- /[orthophosphate [mg L-1]]) and (SPM) in the Galveston estuary (USA). (Modified from Santschi, 1995.)...

Figure 13.6 Vertical profiles of suspended particulate matter (SPM), oxygen, total alkalinity (TAIk), pH, calculated DIC, and pC02, NC>3, NC>2, and NH4+ in bottom water and fluid muds in the Gironde estuary. (Modified from Abril et al., 1999.)...

Figure 14.5 Particle concentration effect showing negative relationship between particle/solution partition coefficient (X,j) of selected trace metal ions and suspended particulate matter (SPM). Data are from six Texas estuaries (USA). (Modified from Benoit et al., 1994.)...

Estuarine turbidity maximum a region where the suspended particulate matter (SPM) concentrations are considerably higher (10-100 times) than in adjacent river or coastal end-members in estuaries. 

Three minerals (montmorillonite, aluminium oxide and kaolinite) of known particle size and specific surface areas (Zhou et al., 1994) and a sterilised silty clay loam (Champaign, USA) were used as sorbents, along with suspended particulate matter (SPM) collected in polythene carboys from several sites in the Tees Estuary, UK. SPM was collected by high speed continuous flow centrifugation and stored in O.IM NaHCOj at 4 °C. Traces of organics were removed from the three minerals by washing with 0.01 M NaOH. 

A well known Elbe-specific compound is tetrabutyl tin, the parent substance for the synthesis of mono- to tributyl tin compounds widely used as antifoulants, stabilizers in poly(vinyl chloride)s (PVC) and industrial as well as agricultural biocides. The origin of tetrabutyl tin in sediments and suspended particulate matter of the Elbe river can be linked to an industrial point source situated near the confluence of the Mulde and the Elbe rivers (Wilken et al. 1994, Schwarzbauer, 1997). The occurence of tetrabutyl tin not only at sample sites mainly influenced by the Elbe river (sample sites A,B and C), but also in sediments situated farer from the Elbe estuary (sample sites E,F) indicates a wide spatial distribution of Elbe-derived organic matter in the German Bight. 

The sources and pathways of metals through the coastal environment are complex (see Figure 1). Interfacial processes play a key role in their passage from the land to the sea. In estuaries the composition of river water may be modified by physicochemical processes at the fresh water-brackish water interface (FBI), where strong gradients of salinity, temperature, concentration and type of suspended particulate matter (SPM), pH and dissolved oxygen exist. Metal... 

In total mercury determinations, filtration of seawater samples has been found to be a serious source of contamination (see also Chapter 2). Hierefore, filtration should only be considered in cases where the suspended particulate matter (SPM) needs to be investigated separately and/or when the particulate fraction of Hgr is >20% and expected to fluctuate strongly as, e.g., in estuaries and other coastal zones. 

In seawater, most TE occur primarily as dissolved including colloidal species (< 0.45 or <0.4 pm see Chapter 2). Therefore, in the analysis of TE filtration is often avoided, to minimize contamination or losses due to adsorption. Exceptions are made, however, when the suspended particulate matter (SPM) itself or selected elements are studied for which the particulate species constitute a significant fraction of the total concentration in seawater (c.g., Fe, Pb). The SPM should also be separated when its concentration increases to 1 mg/L and thus impacts the accuracy and precision of the methods used to determine the dissolved TE fractions. Higher SPM concentrations are often observed in mixing zones of estuaries, in coastal waters, in the euphotic layer during plankton blooms or in intermediate turbidity layers and close to the bottom. Particle fluxes of TE in the ocean are best measured directly" with sediment traps deployed at different water depths (see Chapter 1). 

Sorption to suspended particulate matter and eventual deposition on the shores of rivers and estuaries, along with other natural physico-chemical processes, tend to remove the oil introduced into surface waters (Levy,... 

Figure 9.50a Compound-specific isotope analysis (CSIA) of suspended particulate organic matter (SPOM), lipids, and plant pigments in several estuaries on the Texas coast (USA). The range of 513C in these estuaries was —18 %o to —22 %o. (Modified from Qian et al., 1996.)...

Qian, Y., Kennicutt, M.C., Svalberg, J., Macko, S.A., Bidigare, R.R., and Walker, J. (1996) Suspended particulate organic matter (SPOM) in Gulf of Mexico estuaries compound-specific isotope analysis and plant pigment compositions. Org. Geochem. 24, 875-888. 

The wetland/stream/river/estuary/shelf region provides a continuum with substantial capacity for denitrification. Nitrate is commonly found, there is abundant organic matter, and sediments and suspended particulate microsites offer anoxic environments. In this section we discuss denitrification in the stream/river/estuary/shelf continuum. Although there are several specific studies of denitrification in wetlands, the role of wetlands in Nr removal at the watershed scale needs to be better understood. 

Physical and chemical erosion of continental rocks, represented by the arrow labeled "1" on Fig. 14-4, introduces particulate and dissolved P to the soil system. The majority (90%) of the P eroded from rocks remains trapped in the mineral lattices of the particulate matter. This P will be transported with the suspended material or bedload downstream until it eventually reaches the estuaries and the oceans, never having entered the biological cycles. The small proportion of the P that is leached from the minerals into solution, however, is readily available to enter biological cycles (2) and to react with inorganic soil particles (3). 

Most kinds of waste now being produced carry a burden of metal contamination and it is evident that the primary step associated with the dispersion of trace elements in the environment is usually the disposal of some kind of waste. This can take the form of gases or particulate matter discharged into the atmosphere, substances dissolved or suspended in liquid effluents, or solid wastes. The disposal of the various kinds of wastes produced can therefore give rise to pollution of the atmosphere, or of rivers, lakes, estuaries and coastal waters, or of the exposed soil surface. The whole biosphere is affected. 

Reactions of dissolved species with particulate and colloidal suspended matter include adsorption/desorption, complexation, ion-exchange, precipitation/dissolution, coprecipitation during coagulation and flocculation (Morgan, 1966 Stumm and Morgan, 1981 Parks, 1975). These processes are particularly important at the land-sea boundary in estuaries (Duinker, 1980 Martin et al., this volume). The interaction with particles > 0.45 ym is not discussed here. 

Keefe, C.W. (1994) The contribution of inorganic compounds to the particulate carbon, nitrogen, and phosphorus in suspended matter and surface sediments of Chesapeake Bay. Estuaries 17, 122-130. 

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