粉煤灰和钢渣处理多种金属污染的酸性土壤，金属有效性的衰减研究

The objectives of this work were to determine the potential mineralization of various organic pollutants that are likely found in compostable materials during composting, and to evaluate the participation of the microflora of the thermophilic and maturation composting phases in pollutant mineralization. Four composts were used: a biowaste compost (BioW), a municipal solid waste compost (MSW), a green waste compost (GW) and a co-compost of green waste and sludge (GW+S). In each composting plant, two samples were withdrawn: one in the thermophilic phase (fresh compost) and one in the maturation phase (mature compost) to have the microflora of thermophilic and maturation phases active, respectively. The mineralization of 5 organic pollutants, 3 polycyclic aromatic hydrocarbons (PAHs) (i.e., phenanthrene, fluoranthene and benzo(a)pyrene), 1 herbicide (dicamba) and 1 polychlorinated biphenyl (PCB, congener 52), was measured in a laboratory setting during incubations at 60 ℃ in fresh composts and at 28 ℃ in mature composts. All molecules were 14 C-labeled, which allowed the mineralization of the molecules to be measured by trapping of produced 14CO2 in NaOH. Their volatilization was also measured by trapping molecules on glass wool impregnated with paraffin oil. Mineralization of the organic molecules was only observed when the maturation microflora was present in the mature composts or when it was inoculated into the fresh compost. Phenanthrene mineralization of up to 60% in the fresh GW+S compost was the only exception. Mineralization of PAH decreased when the complexity of the PAH molecules increased. Mineralization of phenanthrene and fluoranthene reached 50%-70% in all mature composts. Benzo(a)pyrene was mineralized (30%) only in the MSW mature compost. Dicamba was moderately mineralized (30%-40%). Finally, no PCB mineralization was detected, but 20% of the PCB had volatilized after 12 d at 60 ℃. No clear difference was observed in the degrading capacity of the different composts, and the major difference was the larger mineralizing capacity of the maturation microflora compared with the thermophilic microflora.     

Schwermetallgehalte im Kultursubstrat und Erntegut des Champignons,Agaricus bisporus (Lange) Singer,beim Einsatz von Müllklärschlammkompost

Heavy metal contents in the culture substrate and in the mushroom, Agaricus bisporus, grown in composts mixed with municipal waste and sewage The addition of increasing quantities of municipal waste compost to conventional horse manure compost resulted in a proportional increase in the heavy metal content of the mixture. The increases ranged between 250% (zinc) and 900% (mercury). Ninety-four to ninety-nine percent of the heavy metals in municipal waste compost are bound in compounds from which they can not be extracted using CaCl₂ solution. The amounts extractable from horse manure compost with CaCl2₂ solution are from 1.5 (zinc)- to 33 (mercury)-times higher. The influences of the increasing quantities of heavy metals in municipal waste — horse manure composts are demonstrable in the content of these metals in harvested mushroom. This, in turn, corresponds to the availability of the metals. The relative enrichment is greatest with mercury, and least with cadmium. The quantities found in mushrooms, with the exception of mercury, fall within the normal range detected in vegetable crops.     

Biological Quality of Potting Media Based on MSW Composts: A Comparative Study

Municipal solid waste (MSW) compost from aerobic or anaerobic bioprocesses was evaluated as components of substrates for potted plant production. Experiments were conducted with potted media consisting of MSW compost mixed with other conventional substrates (peat or composted pine bark). Spring barley (Hordeum vulgare L.) and cress (Lepidium sativum L.) were used to evaluate the biological quality of composts. Higher germination rates of spring barley were obtained when MSW compost from aerobic treatment was employed as compared with MSW compost from the anaerobic bioprocess. Improved biological indices were observed when MSW composts were mixed with composted pine bark rather than with peat. Mixtures of 75% aerobic MSW compost and 25% composted pine bark were more favorable for cress growth than peat as sole substrate.     

Influence of origin and properties of dissolved organic matter on the partition of polycyclic aromatic hydrocarbons (PAHs)

We investigated dissolved organic matter (DOM) from soil, sewage sludges, water from waste disposal sites, and composts as sorbents and potential carriers for hydrophobic polycyclic aromatic hydrocarbons (PAHs) in soil. Partition coefficients (expressed log K_DOC) for two 5-ring compounds were 4·8–4·9 for DOM from soil, 4·5–47 from composts, and 4·3–4·4 from sewage sludges. The DOM from compost and sewage sludge can influence the transport of non-ionic organic contaminants because of the large concentrations of dissolved organic carbon (DOC) released from these materials. Leachates from waste disposal sites did not sorb PAHs. The DOM from compost contained a large percentage of organic molecules > 14 000 Da (32–46%), whereas DOM from waste disposal leachates contained only 7-lo%, and so bound less PAHs. The percentage of total hydrophobic components, as characterized by XAD-8 chromatography, was 50 ± 9% for most of the DOM solutions and did not express the differences in affinity of the organic sorbents to PAHs in the same way as the K_DOC values. Isolated molecular-weight fractions of DOM from composts sorbed benzo(k)fluoranthene in each fraction. The log K_DOC values were 4·1–4·3 for both fractions, < 1000 and 1000–14 000 Da, and 4·8–5·0 for the fraction > 14 000 Da. The interaction of PAHs with DOM < 1000 Da cannot be explained by partitioning within intramolecular nonpolar environments of dissolved macromolecules; rather it seems to be due to the amphoteric properties of DOM. This type of interaction of PAHs with small DOM molecules might affect the mobility of hydrophobic organic chemicals in soils.     

Prediction of Polycyclic Aromatic Hydrocarbon Bioaccessibility to Earthworms in Spiked Soils by Composite Extraction with Hydroxypropyl-β-Cyclodextrin and Organic Acids

Traditional exhaustive extraction methods often overestimate the risk of polycyclic aromatic hydrocarbon(PAH) bioaccessibility to biota. Therefore, reliable assessment methods need to be established. In this study, a composite extraction with hydroxypropyl-β-cyclodextrin(HPCD) and three low-molecular-weight organic acids, oxalic acid(OA), malic acid(MA), and citric acid(CA), was used to predict the PAH bioaccessibility to earthworms, subjecting to two soils(red soil and yellow soil) spiked with selected PAHs,phenanthrene, pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene. For both soils,concentrations of PAHs by composite extraction using HPCD-OA(R~2= 0.89–0.92, slope = 1.89–2.03; n = 35), HPCD-MA(R~2=0.92–0.96, slope = 1.43–1.67; n = 35), and HPCD-CA(R~2= 0.92–0.96, slope = 1.26–1.56; n = 35) were significantly correlated with PAH accumulation in the Eisenia fetida earthworms. Moreover, the HPCD-CA-and HPCD-MA-extracted PAH concentrations were closer to the earthworm-accumulated PAH concentration than the extraction using just HPCD. The results indicated that the composite extraction could improve the prediction of PAH bioaccessibility, and therefore can serve as a reliable chemical method to predict PAH bioaccessibility to earthworms in contaminated soils.     

Growth of Impatiens ‘Accent Red’ In Three Compost Products

Growth of Impatiens wallerana Hook. ‘Accent Red’ was evaluated in three composted urban waste materials (composted biosolids and yard trash (SYT): 20 percent biosolids/sewage sludge, 44 percent yard trimmings, and 36 percent mixed paper; composted refuse fuel residues with biosolids and yard trash (RYT): 74 percent refuse-derived fuel residuals, 10 percent biosolids/sewage sludge, and 16 percent yard trimmings; and composted municipal solid waste (MSW): 100 percent municipal solid waste). Treatments consisted of 100 percent composted waste and media in which the composted wastes were combined with control medium components at 60 percent, 30 percent, or 0 percent composted waste, by volume. Shoot dry mass of plants grown in SYT increased as the percentage of SYT in the medium increased, while shoot dry mass of plants grown in MSW linearly decreased from 1.24 g to 0.15 g. There were no significant differences in shoot dry mass of plants grown in different percentages of RYT. Initial medium soluble salt concentrations in MSW media were more than double concentrations measured in SYT and RYT media. Soluble salt concentrations in both the 100 percent and 60 percent MSW media exceeded 1.75 dS.m^?1, while the soluble salt concentrations in 100 percent SYT and 100 percent RYT were 0.50 dS.m^?1 and 0.61 dS.m^?1, respectively. The C:N ratios in 100 percent SYT and RYT were 17 and 15, respectively, while 100 percent MSW had a C:N ratio of 29. The relatively higher level of compost maturity as indicated by lower C:N and soluble salt concentrations contributed to superior growth of impatiens plants in 100 percent SYT and RYT compared to 100 percent MSW.     

Evaluation of Seed Germination and Growth Tests for Assessing Compost Maturity

Experiments involved the comparison of three procedures used to determine compost maturity/phytotoxicity. The three tests evaluated were the CCME germination test (1996), a modified Zucconi et al. (1981) extract and a direct seed procedure. Three different plant species and seven types of ‘composts’ were used. The species were cress (Lepidium sativum), radish (Raphanus sativus), and Chinese cabbage (Brassica chinensis). Germination and growth experiments were performed on three types of mature composts: 1) racetrack manure-food waste; 2) two different samples of municipal solid waste; and 3) racetrack manure-sewage sludge), two types of immature composts (farmyard manure-food waste and farmyard manure-yard waste-food waste], and a control (soil or water). Four replicates for each species, ‘compost’ and test procedure were evaluated. The study concluded that the commonly used compost extract test and the compost-soil germination and growth tests were not sensitive enough to detect differences between mature and immature ‘composts’, that other test(s) must be used to evaluate compost maturity.     

PAH and PCB removal efficiencies in Umeå (Sweden) and Šiauliai (Lithuania) municipal wastewater treatment plants

Dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the influents and effluents of two municipal sewage treatment plants (STPs) were monitored over 16- (Umeå, Sweden) and 22- (?iauliai, Lithuania) day sampling periods. Sampling was performed using a passive sampling technique (semipermeable membrane devices; SPMDs) for sequestration of the dissolved (readily bioavailable) fraction of persistent organic pollutants (POPs). Removal efficiencies for individual low molecular weight (LMW) PAH compounds varied from 84% to levels at which the compounds were not detected in effluents from Umeå. The corresponding efficiencies of the ?iauliai plant were 33–95%. Measurements revealed that dissolved concentrations of most of the PCBs and some of the high molecular weight (HMW) PAHs increased during the conventional wastewater treatment at both plants. The release of dissolved PAHs and PCBs in the effluents from municipal wastewater treatment plants might increase the environmental contamination by readily bioavailable pollutants in the recipient waters; the rivers Umeälven and Kulpè. SPMDs were found to be suitable sampling tools for long-term (weeks-month) integrative monitoring of trace concentrations of the dissolved fraction of hydrophobic pollutants in the wastewater process, since the sampling and clean-up steps were easy to perform.     

Heavy metal levels in apple orchards after the application of two composts

Abstract

Two composts were tested in eleven different Malus domestica orchards: one was a sewage sludge and bark compost with a low heavy metal content, the other was a municipal solid waste compost with a higher concentration of metals. For six years the zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), cadmium (Cd), and chromium (Cr) content were monitored in the soil, both in ‘total’ and EDTA extractable form, and in leaves and fruits. The resulting data demonstrate clearly that the sewage sludge and bark compost did not cause any significant increase of heavy metal levels in soil and plants; this compost can thus be used to fertilize the soil with no danger either to the environment or to crops. In contrast, the municipal solid waste compost led to a notable accumulation of all the metals examined in the soil and, above all in the case of Pb and Cd, also in the vegetation and the fruits.     

Growth of Hedera helix L. Container Plants in Compost Substrates Made with Miscanthus ogiformis Honda Straw and Various N-Sources

Ammonium sulfate or urea were added as N-source to shredded straw of Miscanthus ogiformis ‘Giganteus’ and water was included as control. The combined materials were composted for seven months, and the resulting composts were tested as growth substrates for nursery container plants and compared with fertilized and unfertilized peat substrates. The pH was below recommended level for the compost substrate made with ammonium sulfate and for the unfertilized peat substrate throughout the experiment. Electrical conductivity and concentrations of most nutrients were low and decreased throughout the experiment for all growth substrates. Shrinking of the growth substrates after 4, 12 or 17 months was larger for compost substrates than for peat substrates. Bulk density increased in compost substrates and decreased in peat substrates, while the total loss of C was greater in compost substrates than in peat. Water retention was lower and air volume greater for compost substrate made with ammonium sulfate than for fertilized peat. Algae and mosses did not occur on Miscanthus compost growth substrates in contrast to peat substrates. The shoot length and dry matter of Hedera helix, produced after four and 12 months of growth, and five months following cut back, showed that plants can grow well in compost substrates made of Miscanthus straw and ammonium sulfate or urea. However, the compost substrates could not fully substitute for fertilized or unfertilized peat substrate with respect to dry matter production.     

Characterization and Sources of PAHs and Potentially Toxic Metals in Urban Environments of Sevilla (Southern Spain)

The purpose of this study was to determine the degree of PAH contamination and the association of PAHs with metals in urban soil samples from Sevilla (Spain). Fifteen polycyclic aromatic hydrocarbons-PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, indeno[1,2,3-c,d]pyrene) and seven metals (Cd, Cr, Cu, Mn, Ni, Pb, Zn) have been evaluated in representative urban soil samples. Forty-one top soils (0–10 cm) under different land use (garden, roadside, riverbank and agricultural allotment) were selected. PAHs from soil samples were extracted by sonication using dichloromethane. The simultaneous quantification of 15 different PAH compounds were carried out by HPLC using multiple wavelength shift in the fluorescence detector. For qualitative analysis a photo diode-array detector was used. Metal (pseudo-total) analysis was carried out by digestion of the soils with aqua regia in microwave oven. The mean concentration of each PAH in urban soils of Sevilla showed a wide range, they are not considered highly contaminated. The results of the sum of 15 PAHs in Sevilla soils are in the range 89.5–4004.2 μg kg^?1, but there seems not to be a correlation between the concentration of PAHs and the land use. Of the 15 PAHs examined, phenanthrene, fluoranthene and pyrene were present at the highest concentrations, being the sum of these PAHs about 40% of the total content. Although metal content were not especially high in most soils, there are significant hints of moderate pollution in some particular spots. Such spots are mainly related with some gardens within the historic quarters of the city. The associations among metals and PAHs content in the soil samples was checked by principal components analysis (PCA). The largest values both for ‘urban’ metals (Pb, Cu and Zn) and for PAHs were mainly found in sites close to the historic quarters of the city in which a heavy traffic of motor vehicles is suffered from years.     

Comparisons of Composts with Low or High Nutrient Status for Growth of Plants in Containers

Abstract

Composts may be incorporated into container mixes for several purposes, including to supply nutrients, add organic matter, or suppress plant diseases. The objective of this research was to assess the nutritional benefits of two composts derived in common from composted chicken manure and used in formulation of container media for growth of tomato (Lycopersicon esculentum Mill.). The composts differed in extractable and total plant nutrients so that one of the composts was considered a nutrient‐rich material and the other a nutrient‐poor material. Media were formulated from soil or peat with the composts added in a progressive array of concentrations from a medium with no compost addition to a medium that was all compost. Half of the media were treated with a water‐soluble, complete fertilizer and half were left unfertilized. Optimum growth occurred in media in which compost did not exceed 25% of the volume. The beneficial effects of the composts on plant growth were associated with increased supply of nutrients for the plants. The suppressive effects were attributed to restricted accumulation of nutrients with the nutrient‐poor compost and to excessive potassium supply and accumulation with the nutrient‐rich compost. Fertilization was beneficial in increasing plant growth with the nutrient‐rich compost and was essential for plant growth with the nutrient‐poor compost. The research demonstrated that composts can be used in formulation of media for container growth of plants.     

Detection of polycyclic aromatic hydrocarbon levels in milk collected near potential contamination sources

Polycyclic aromatic hydrocarbons (PAHs), mainly formed by incomplete anthropogenic organic matter combustion, are ubiquitous in the environment. To assess milk PAH contamination sources, milk samples were collected from the tank milk at farms located near potential contaminating emission sources such as cementworks, steelworks, and motorways. PAH analyses were carried out by gas chromatography coupled to mass spectrometry. Eight PAHs were identified in milk: naphthalene, acenaphthylene, acenaphthene, fluorene, anthracene, fluoranthene, pyrene, and benzo[a]anthracene. For all potential contaminating sources, these eight PAHs were detected with similar profiles and at low concentrations except for fluorene and naphthalene, for which source-molecule interaction is pointed out.     

Wood Ash as an Amendment in Municipal Sludge And Yard Waste Composting Processes

Wood ash from a wood-fired, electrical generating plant was examined as a potential amendment in municipal biosolids and yard waste composting applications. The rate of composting and the final compost quality (chemical, physical, and plant growth characteristics) were examined. Yard waste (leaves, grass, and wood chips) and a municipal biosolids-chip mixture were either not amended or amended with wood ash at eight percent or five percent by weight, respectively, and then composted outdoors in insulated, 1700L, aerated reactors. Yard waste piles heated rapidly to 60°C within six to seven days, whereas biosolid piles heated more slowly to a maximum of 52 to 57°C within nine to 11 days. Ash had little, if any, effect on the time-temperature response. In general, ash-amended compost had higher pi I, plant nutrient, and salt contents. Tomato plants (Lycopersicum esculentum) produced 100 percent more shoot biomass in biosolids than in yard waste compost media. Poor plant growth in the yard waste compost was likely due to the high initial pH and salt content of the growth medium. In yard waste media, tomato plants germinated and produced more shoot biomass in the control compost than in the ash-amended compost.

A pH neutralization study indicated that wood fly ash could be used as an economical substitute for lime which is commonly used to stabilize municipal biosolids prior to land filling or land application. Wood fly ash (pH = 13.2-13.4), when added to biosolids at a 2 to 1 ratio by weight, raised the pH of the mixture to 12.0.     

Input and behavior of polycyclic aromatic hydrocarbons in arable,fallow, and forest soils of the taiga zone (Tver oblast)

Contents of 11 most prevalent polycyclic aromatic hydrocarbons (PAHs) in snow and soils of arable, fallow, and forest areas significantly remote from impact technogenic sources of polyarenes have been examined in the Torzhok district of Tver oblast. From the analysis of snow samples, the volumes and composition of PAHs coming from the atmosphere onto the areas of different land use have been determined. Light hydrocarbons prevail in PAHs. They make up 65–70% of total PAHs; their share in soils reaches almost 95%. An increase in the content of PAHs is revealed in fallow soils compared to arable and afforested areas. A direct relationship is revealed between the lateral distribution of total PAHs and the content of organic carbon. The distribution of total PAHs is surface-accumulative in forest soils, mainly uniform in arable soils, and deepaccumulative in fallow soils. PAH groups characterized by similar radial distributions and ratios between their reserves in snow and soils are distinguished: (1) fluorene and phenanthrene, (2) biphenyl and naphthalene, (3) benzo(a)anthracene, chrysene, perylene, and benzo[a]pyrene, and (4) anthracene and benzo[ghi]pyrene.     

Gehalte an Polycyclischen Aromatischen Kohlenwasserstoffen (PAK) und deren Verteilungsmuster in unterschiedlich belasteten Böden

Contents of polycyclic aromatic hydrocarbons (PAH) and their distribution pattern in soils with different contamination levels In order to study the PAH-contamination of soils in North Rhine Westfalia, soil samples were taken at different sites and analysed for six PAH. The sites were selected with regard to different forms of land use such as arable land and pastures in rural areas and gardens in urban areas and with regard to varying immission situations. The results are valued according to reference (RW) and test values (PW) of the Netherlands Guidelines for soil restoration. The reference values of these guidelines characterizing normal contents are regularly and in part distinctly exceeded for fluoranthene and benzo(a)pyrene at some sites (coking plant, alluvial meadow soils, allotment gardens, close to a highway). The check values which imply more exact investigations are only exceeded at the most contaminated site, a coking plant. The PAH patterns at the different sites investigated depend on the number and kind of PAH sources. PAH typical for motor vehicle emission (benzo(b)fluoranthene, benzo(g,h,i)perylene) are dominating in soils close to a highway, whereas at the cokery site fluoranthene can be found in higher concentrations than the other PAH. In alluvial river soils and in soils of allotment gardens the pattern is more uniform because of diffuse sources with decreasing contents in the order fluoranthene > benzo(a)anthracene > benzo(b) fluoranthene > benzo(g,h,i)perylene > benzo(a)pyrene > benzo(k)fluoranthene. As a guide substance for a first risk assessment benzo(a)pyrene is suitable, since its content shows a strong correlation to the sum of five other PAH. In order to characterize the background contamination of soils with PAH new reference values are proposed.     

Decomposition of peat,biogenic municipal waste compost,and shrub/grass compost added in different rates to a silt loam

An incubation experiment was carried out to test the effects of biogenic municipal waste (compost I) and shrub/grass (compost II) composts in comparison to peat on respiration and microbial biomass in soil. The amounts of these three substrates added were linearly increased in the range of field application rates (0.5%, 1.0%, 1.5%, 2.0%). The sum of CO₂ evolved during the incubation was markedly raised by the three substrates and increased with the rate of substrate concentration. However, the percentage of substrate mineralized to CO₂ decreased with the addition rate from 103 to 56% for compost I, from 81 to 56% for compost II, and from 21 to 8% for peat. During the first 25 days of incubation, compost I enlarged the biomass C content, which remained constant until the end. In contrast, compost II did not raise biomass C initially. But at the end of the incubation, the biomass C content of all 4 compost II treatments almost reached the level of the respective compost I treatment. The increase was significantly larger the more of the two composts was added. In contrast to the two composts, the addition of peat did not have any significant effect on microbial biomass C. The average qCO₂ values at day 25 declined in the order compost I > compost II > peat, at day 92 the order was changed to compost II > peat > compost 1. This change in the order was caused by a significant decrease in qCO₂ values of the compost I treatments, a significant increase in qCO₂ values of the peat treatments and constant qCO₂ values in the compost II treatments.     

Polycyclic aromatic hydrocarbons in soils of Vasilievsky Island (St. Petersburg)

The composition and accumulation patterns of priority polycyclic aromatic hydrocarbons (PAHs) in soils of Vasilievsky Island in Saint Petersburg were studied. Concentrations of benzo[a]pyrene were found to exceed maximum permissible concentrations in all the samples, and the maximum recorded concentration exceeded the MPC by 50 times. Concentrations of other PAHs also exceeded the background values. The main soil pollutants were found to be fluoranthene, pyrene, benzo[b]fluoranthene, benzo[a]pyrene, and benzo[g, h, i] perylene, the part of which in the total content of PAHs was 65–80%.     

Heavy Metals in Water Percolating Through Soil Fertilized with Biodegradable Waste Materials

The influence of manure and composts on the leaching of heavy metals from soil was evaluated in a model lysimeter experiment under controlled conditions. Soil samples were collected from experimental fields, from 0- to 90-cm layers retaining the layout of the soil profile layers, after the second crop rotation cycle with the following plant species: potatoes, spring barley, winter rapeseed, and winter wheat. During the field experiment, 20 t DM/ha of manure, municipal sewage sludge composted with straw (SSCS), composted sewage sludge (SSC), dried granular sewage sludge (DGSS), “Dano” compost made from non-segregated municipal waste (CMMW), and compost made from municipal green waste (CUGW) was applied, i.e., 10 t DM/ha per crop rotation cycle. The concentrations (μg/dm³) of heavy metals in the leachate were as follows: Cd (3.6–11.5)?<?Mn (4.8–15.4)?<?Cu (13.4–35.5)?<?Zn (27.5–48.0)?<?Cr (36.7–96.5)?<?Ni (24.4–165.8)?<?Pb (113.8–187.7). Soil fertilization with organic waste materials did not contaminate the percolating water with manganese or zinc, whereas the concentrations of the other metals increased to the levels characteristic of unsatisfactory water quality and poor water quality classes. The copper and nickel content of percolating water depended on the concentration of those metals introduced into the soil with organic waste materials. The concentrations of Cd in the leachate increased, whereas the concentrations of Cu and Ni decreased with increasing organic C content of organic fertilizers. The widening of the C/N ratio contributed to Mn leaching. The concentrations of Pb, Cr, and Mn in the percolating water were positively correlated with the organic C content of soil.