Assessment of MSWI bottom ash organic carbon behavior: a biophysicochemical approach

In order to understand the influence of organic components on the behavior of municipal solid waste incinerator bottom ash, samples from five French incinerators have been analyzed and compared. Biological and physico-chemical experiments were coupled with a view to developing a new rapid assessment method of bottom ash quality. Bottom ash had different total organic carbon contents ranging from 8.8 g kg(-1) to 37.4 g kg(-1). A part of this organic carbon can be leached into the environment or provide a substrate for microbial activity. Samples showed really different behaviors regarding these processes. Comparative results of leaching tests and biodegradation experiments showed a positive correlation between dissolved organic carbon and microbial activity. However, quantities of biodegraded or leached carbon are not representative of the samples' total organic carbon content. Thermal analyses in oxidizing conditions have revealed the presence of two fractions of organic components, showing different thermal behaviors. The associated mass losses were measured and compared to dissolved organic carbon. One of the two fractions can be directly linked to the leachable and easily biodegradable organic matter fraction. Calorimetric test is then presented as a novel analysis method that allows to provide rapid and global information concerning the characteristics of organic matter in bottom ash and its possible short and long-term evolution.     

Headspace solid phase microextraction method for determination of triazine and organophosphorus pesticides in soil

A headspace solid phase microextraction method (HS-SPME) for simultaneous determination of five pesticides belonging to triazine and organophosphorus pesticide groups in soil samples was developed. Microextraction conditions, such as temperature, extraction time and sodium chloride (NaCl) content were investigated and optimized using 100 μ m polydimethyl-siloxane (PDMS) fiber. Detection and quantification were done by gas chromatography-mass spectrometry (GC-MS). Relative standard deviation (RSD) and recovery values for multiple analysis of soil samples fortified at 30 μ g kg^{? 1} of each pesticide were below 13 % and higher than 70 %, respectively. Limits of detection (LOD) for all the compounds studied were less than 3.2 μ g kg^{? 1}. The proposed method was applied in the analysis of some agricultural soil samples.     

Influence of organic matter on municipal solid waste incinerator bottom ash carbonation

The biodegradation of organic matter in municipal solid waste incinerator (MSWI) bottom ash was studied in order to investigate the interaction between the CO(2) produced by microbial respiration and bottom ash. Respiration tests were performed on bottom ash at different moisture contents in an incubator at 30 degrees C. O(2) consumption and CO(2) production were monitored and quantified. Leaching tests were carried out at the end of the experiments. Total organic carbon (TOC) leaching had decreased. Over a period of three weeks, pH decreased from 10.7 to 8.2 and bottom ash was considered to be fully carbonated. This showed that the organic matter found in bottom ash can provide a substrate for microbial activity. The CO(2) produced by microbial respiration was directly dissolved in bottom ash pore water in order to be mineralized in carbonate form. The origin of the carbon dioxide which induces maturation of bottom ash on weathering areas has never been really discussed and is often presumed to be atmospheric CO(2). However, biodegradation of organic matter could contribute for a large part to this phenomenon, depending on field-scale physico-chemical weathering conditions.     

Precipitation of liquid swine manure phosphates using magnesium smelting by-products

Swine manure contains considerable amounts of total (P) and soluble phosphorus (PO(4)-P) which may increase the soil P content when applied in excess to crop requirements and, consequently, risk water eutrophication. The feasibility of using magnesium (Mg) from the by-product of electrolysis and foundries (BPEF) for the removal of P from liquid swine manure was studied by adding up to 3 g of Mg as BPEF per liter of nursery (NU) and grower-finisher (GF) swine manure in 25-L plastic buckets. Changes in P and other elements were monitored for up to 360 h. Small amounts of Mg as BPEF (0.5 and 1.0 g Mg L(-1) manure) reduced the total P concentration of the liquid fraction by 70 to 95% of both manure types with respect to the control treatment of mixed raw manure. A settling period of 8 h or more was necessary to significantly reduce the liquid fraction's total P concentration for both manure types. Reduction of PO(4)-P varied from 96 to 100% in the liquid fractions for both manure types, which along with natural settling, explains most of the total P reduction in that fraction. The addition of BPEF did not influence the N content of manure. The low P liquid fraction can be safely applied to saturated P soils whereas the high P solid fraction offers the opportunity of transporting manure to agricultural soils deficient in P. Since N is conserved, both liquid and solid fractions could be valuable fertilizer manure by-products.     

Polynuclear aromatic hydrocarbons,phenols, and trace metals in selected soil profiles and plant bioindicators in the Holy Cross Mountains,south-central Poland

This report presents the results of PAH, phenol, and selected trace element (Cd, Cu, Hg, Pb, S, and Zn) determinations on detailed soil profiles and associated plant bioindicators (including lichen Hypogymnia physodes, moss Hylocomium splendens, pine Pinus sylvetris) from the three most representative habitats in the Holy Cross Mts, south-central Poland. This study is only part of a larger ongoing environmental study that includes complex sulfur isotope and element determinations in three national parks in N, central and S parts of Poland. The highest concentrations of PAHs (1887 ppb) and numerous trace elements are found in the organic horizon-O and humic horizon-A of each soil type. Different plant species and their individual tissues reveal considerable variability in the concentration of PAHs, phenols and elements examined. Most of the H. physodes thalli also reveal higher concentrations of individual hydrocarbons and some elements (including S and Zn) than their host bark. The highest concentration levels of phenols (1217 ppb) are noted in the 1-year pine needles. Most of the PAHs and elements examined seem to be of anthropogenic origin. The only exception is the distribution pattern of elements in southwestern part of the study area, which is linked to the local bedrock geochemical anomaly. The results of this study indicate that the content of PAHs, Cd, Cu, Hg, Pb, S and Zn in the soils and plant bioindicators examined has not changed considerably since 1998.     

Adsorption anionischer Azofarbstoffe an Boden/Sediment

The adsorption behavior of three anionic azo dyes (Acid Orange 6, Acid Orange 10 andAcid Orange 12) on different soil/sediment components (quartz sand, clay and organic matter) was investigated with a flow-through method using a simplified HPLC apparatus. Organic matter had the highest adsorption capacity for all three dyes, followed by clay and sand. The adsorption on different components in mixtures was not additive. The adsorption of similar aniomic azo dyes decreased with increasing negative charge. The affinity of equally charged dye molecules to the adsorbents was also strongly influenced by the remaining chemical structure. While adsorption on organic matter could always be described by Freundlich isotherms, S-shaped isotherms were often measured with quartz sand and clay. For that reason one must assume different adsorption mechanisms for organic matter and mineral adsorbens. Lower pH values always led to stronger adsorption of the anionic azo dyes. On the other hand, ionic strength effects cannot be characterized so clearly. Adsorption was generally lowered by decreasing ionic strengths but sometimes the opposite effect was observed. Moreover, there were some unusual cases of partly irreversible adsorption on quartz sand and organic matter when the dyes were not dissolved in an aqueous solution containing additional inorganic ions but in double distilled water. The adsorption of anionic azo dyes on soil and sediment materials turned out to be a very complex process. Although some interesting coherences could be pointed out, much more research is required to recognize general principles, concerning for example the influence of the chemical structure or the surrounding aqueous solution.     

Identifying the sources and timing of ancient and medieval atmospheric lead pollution in England using a peat profile from Lindow bog, Manchester

A peat core from Lindow bog near Manchester, England, was precisely cut into 2 cm slices to provide a high-resolution reconstruction of atmospheric Pb deposition. Radiocarbon and (210)Pb age dates show that the peat core represents the period ca. 2000 BC to AD 1800. Eleven radiocarbon age dates of bulk peat samples reveal a linear age-depth relationship with an average temporal resolution of 18.5 years per cm, or 37 years per sample. Using the Pb/Ti ratio to calculate the rates of anthropogenic, atmospheric Pb deposition, the profile reveals Pb contamination first appearing in peat samples dating from ca. 900 BC which clearly pre-date Roman mining activities. Using TIMS, MC-ICP-MS, and SF-ICP-MS to measure the isotopic composition of Pb, the (208)Pb/(206)Pb and (206)Pb/(207)Pb data indicate that English ores were the predominant sources during the pre-Roman, Roman, and Medieval Periods. The study shows that detailed studies of peat profiles from ombrotrophic bogs, using appropriate preparatory and analytical methods, can provide new insight into the timing, intensity, and predominant sources of atmospheric Pb contamination, even in samples dating from ancient times.