Ecotoxicological assessment of organic wastes using the soil collembolan Folsomia candida     

《Applied soil ecology》2007,35(3):461-472

The reproduction test with the collembolan Folsomia candida is used as a tool to evaluate the ecotoxicological potential of organic wastes currently applied to soil. Seven organic wastes (dewatered sewage sludges, thermally dried sewage sludges, composted sewage sludges, and a thermally dried pig slurry) were tested. These wastes had different origins, treatments, and pollutant burdens, and were selected as a representative sample of the wide variety of wastes currently generated. F. candida showed varied sensitivity depending on the waste, but also depending on the endpoint assessed. Reproduction was more sensitive than survival, although no correlations between reproduction and physico-chemical parameters and pollutant burden could be found. On the other hand, mortality was directly related to the lack of stability of wastes, probably reflecting the toxicity of end-products such as ammonium. Body length was not shown to be a sensitive endpoint for waste testing, as it was neither affected nor even stimulated by waste concentrations.Organic matter, pH, and electrical conductivity varied with waste concentration in soil-waste mixtures, although their effect on collembolan performance was expected to be low and part of the complex effect exerted by wastes when applied to real soils. Selection of the water content is the most problematic aspect in waste testing, as it may affect the performance of test organisms. In this study, a qualitative approach for water content selection in waste testing was considered to be the most suitable.Treatment of wastes affected composition and toxicity. Composting of sewage sludge increased its stability, compared to the initial sludge, but decreased its non-persistent organic pollutant burden and toxicity. On the other hand, thermally dried wastes from sludge and pig slurry displayed high toxicity, mainly attributable to their low stability. The results from the study indicate the inability of chemical methods to predict the effects of complex mixtures on living organisms with respect to ecotoxicity bioassays, but also the need for stabilization treatments of organic wastes prior to their reuse in soils.  相似文献   

Toxicity reduction of Ontario hydro radioactive liquid waste     

D. W. Rodgers  D. W. Evans  L. Vereecken Sheehan 《Water, air, and soil pollution》1996,90(1-2):219-229

The radioactive liquid waste (RLW) system in Ontario Hydro's pressurised heavy water reactors collects drainage from a variety of sources ranging from floor drains to laundry waste. RLW effluent was intermittently toxic to rainbow trout andDaphnia magna during the first phase of Ontario's Municipal Industrial Strategy for Abatement (MISA) Program, apparently as a result of the interaction of a variety of known and unknown organic and inorganic compounds. Accordingly, we employed a tmatment-based approach to reducing its toxicity, supplemented by chemical analysis. Two series of toxicity reduction tests were conducted. The fast series explored the potential for sorption of the possible toxicants, while the accord series incorporated a wider variety of treatments. Of the 24 samples in the first test series, 17 were toxic (D. magna mortality ≥ 50%). Of the toxic samples, only 7 of 17 were still toxic after passage through an activated carbon column, but 5 of 6 samples tested remained toxic after passage through a metal chelating resin column. In the second series, at least one of the treatments was effective in reducing toxicity of all samples which were initially toxic (16 of 24 samples), but no one treatment was effective for all toxic samples. Three treatments (UV/H₂O₂ photo-oxidation with prior pH adjustment, or passage through a column of either a non-functioalized (N-F) resin or a mixture of N-F resin and a weak base (W-B) anion exchange rain), were effective in reducing the toxicity of more than 50% of the toxic samples; yet roughly 25% of these samples remained toxic after treatment O₂ sparging, UV/H₂O₂ photo-oxidation without prior pH adjustment, and passage through a column of the W-B Resin were less effective, as more than 50% of the samples remained toxic after treatment. Filtering was not effective, as all of the treated samples (9/9) retained their toxicity. There was no obvious correspondence between toxicity and the concentrations of metals (Cu, Zn, Fe, Al and Cd) nor were any simple relationships apparent between toxicity and Total Organic Carbon or NH₃ concentrations. At stations where radioactive liquid wastes are segregated, toxicity was also segregated, suggesting that we may be able to address the problem at source through a combination of Best Management Practices and smaller scale treatment facilities.  相似文献   

Escherichia coli O157 survival following the surface and sub-surface application of human pathogen contaminated organic waste to soil     

Lisa M. Avery  Ken Killham 《Soil biology & biochemistry》2004,36(12):2101-2103

Escherichia coli O157:H7 contaminated wastes such as animal manures and abattoir wastes, may be applied directly onto vegetation, the soil surface, or injected deep into the soil. Our aim was to determine the influence of method of waste application to land on E. coli O157:H7 survival. Bovine slurry and ovine stomach contents containing E. coli O157:H7 were applied to the surface vegetation or sub-surface injected at 25 cm below the soil surface. E. coli O157 survived but did not proliferate on grassland vegetation for up to 6 weeks and in the underlying soil for 8 weeks. Our results suggest that sub-surface injection of organic wastes into soil may reduce the risk of pathogen persistence in the environment.  相似文献   

Influence of animal wastes on growth and reproduction of the African earthworm species Eudrilus eugeniae (Oligochaeta)     

Sifolo Seydou Coulibaly  Irié Arsène Zoro Bi 《European Journal of Soil Biology》2010,46(3-4):225-229

The growth and reproduction of Eudrilus eugeniae were evaluated in four animal species wastes under laboratory conditions. Two hatchlings were introduced in 100 g of each animal waste i.e. cow, sheep, pig, and chicken after 15 days of pre-composting. Biomass gain, mortality, sexual maturity, and cocoons production were monitored periodically for 21 weeks. No mortality was observed in any waste. The maximum weight gain per worm and the highest growth rate per worm per week were obtained in chicken waste. Net biomass gain per worm were 1.01 ± 0.52 g, 1.318 ± 0.07 g, 0.87 ± 0.1 g, and 1.69 ± 0.15 g respectively for cow, sheep, pig, and chicken wastes. The highest number of cocoons produced per worm per day was obtained in chicken waste followed in decreasing order by sheep, cow, and pig waste. The mean number of cocoons produced per worm per day in chicken waste was 40.87% greater than these produced per day in pig waste.Among the four animal species, chicken, sheep, and cow were the most favourable wastes for the growth and reproduction of E. eugeniae, and hence can be recommended as feed materials in large scale vermicomposting facilities.  相似文献   

The use of Folsomia candida (Collembola,Isotomidae) in bioassays of waste     

《Applied soil ecology》2002,19(1):65-70

There is a high probability that urban compost, sewage sludge and ash will come in contact with natural terrestrial ecosystems. The present paper investigates the extent to which the Folsomia candida population development test (now a standardised ecotoxicological test, ISO 11267, for testing the impact of pure chemicals on soil fauna) can be applied to the detection of the toxicity of these wastes, the goal being to evaluate ecotoxicity of wastes before they are spread on land. We show that some potentially useful information on waste toxicity can be obtained with this test, but the results must be interpreting with caution, indeed, problems can arise from differences in pH, humidity and organic matter content of the waste relative to the characteristics of the dilution soil. On the basis of the results of these assays, we propose a classification of the toxicity of seven wastes.  相似文献   

Effects of cadmium,mercury and lead on the survival and instantaneous rate of increase of Paronychiurus kimi (Lee) (Collembola)     

《Applied soil ecology》2007,35(2):404-411

The invertebrate springtail species Paronychiurus kimi (Lee) was selected for use in toxicity testing because it is more ecologically relevant to Korean soils than Folsomia candida Willem, which is the standard animal for toxicity tests. Responses of P. kimi to cadmium, mercury and lead were evaluated in artificial soils following the standardized ISO protocol. Although, reproduction of P. kimi was not as high as that of F. candida, 30 adults produced at least 200 juveniles over 28 days. For each of the three heavy metals, LC₅₀ and EC₅₀ for reproduction and NOEC and LOEC for the effect on reproduction and instantaneous rate of population increase (r_i) were also estimated. The 7 days LC₅₀ was 532, 3.9 and 1322 mg/kg dry soil for cadmium, mercury and lead, respectively. As exposure time increased from 7 to 28 days, the LC₅₀ values decreased for cadmium but not or only slightly for mercury and lead. The 28 days EC₅₀ was 60.0 for cadmium, 0.23 for mercury and 428 mg/kg for lead. Significant changes in r_i of P. kimi were closely followed by the changes in the sublethal endpoint measured (reproduction) and populations were heading toward extinction (r_i = 0) at concentration of 129, 2.0 and 1312 mg/kg dry soil for cadmium, mercury and lead, respectively. P. kimi was found to be more sensitive to all heavy metals tested than F. candida, confirming its suitability as a bioindicator species for soil toxicological testing in Korea.  相似文献   

Factors Associated with Well-to-Well Variation in Nitrate Concentration of Groundwater in a Nitrate-Polluted District in Miyakonojo Basin, Southern Kyushu, Japan     

Yasuhiro Sugimoto  Yukio Toyomitsu  Isao Muto  Masahiko Hirata 《Water, air, and soil pollution》2009,199(1-4):23-32

This study monitored nitrate levels in well water and analyzed their association with well attributes (physicochemical parameters of water, location, livestock farming conditions) in a nitrate-polluted, animal industry district in central Miyakonojo Basin, southern Kyushu, Japan, to characterize the nitrate status of groundwater in the district. Water quality varied considerably among the wells, with nitrate-N concentration and natural nitrogen-15 abundance in nitrate-N (δ¹⁵N-NO₃) ranging from 1.1–44.6 mg L^?1 and 4.2–17.8‰, respectively. There was a significant positive correlation between nitrate-N concentration and δ¹⁵N-NO₃. Nitrate-N concentration was higher in wells located at higher elevations, having larger areas of livestock barns within a 100-m radius and with higher animal populations. Wells in pig farms showed a higher nitrate tendency than those in the other situations (cattle farm, poultry farm, non-livestock farm and non-farmer). The results show that the nitrate status of groundwater in the district has not been drastically changed since 1996, and the nitrate in the wells is of multiple origins (e.g. chemical fertilizer, animal wastes) with a tendency for higher contribution of animal wastes in more heavily polluted wells. The results also highlight a need for further regular monitoring of groundwater quality in the district particularly for wells; (1) located at higher elevations, (2) with a large area of livestock barns nearby, (3) in farms with a high animal population and/or (4) in pig farms.  相似文献   

Kinetics of C and N mineralization, N immobilization and N volatilization of organic inputs in soil     

M Pansu  L Thuriès 《Soil biology & biochemistry》2003,35(1):37-48

C and N mineralization data for 17 different added organic materials (AOM) in a sandy soil were collected from an incubation experiment conducted under controlled laboratory conditions. The AOM originated from plants, animal wastes, manures, composts, and organic fertilizers. The C-to-N_AOM ratios (η_AOM) ranged from 1.1 to 27.1. Sequential fibre analyses gave C-to-N ratios of soluble (η_Sol), holocellulosic (η_Hol) and ligneous compounds (η_Lig) ranging from 1.1 to 57.2, 0.8 to 65.2, and 3.5 to 25.3, respectively. Very different patterns of net AOM-N mineralization were observed: (i) immobilization for four plant AOM; (ii) moderate mineralization (4-15% AOM-N) for composts; (iii) marked mineralization (11-27% AOM-N) for 1 animal AOM, 1 manure and 2 organic fertilizers; and (iv) high rates of transformations with possible gaseous losses for some N-rich AOM.The Transformation of Added Organics (TAO) model proposed here, described AOM-C mineralization (28 °C, 75% WHC) from three labile (L′), resistant (R) and stable (S) compartments with the sole parameters P′_L and P_S=fractions of very labile and stable compounds of AOM, respectively. Dividing the C-compartments by their C-to-N estimates supplied the remaining N_AOM fraction (RAONF). A P_im parameter split the TAO nitrogen fraction (TAONF=added N-RAONF) into two compartments, immobilized (imN) and inorganic (inorgN) N. A P_im>0 value meant that all the TAONF plus a fraction (P_im−1) of native soil inorganic N was immobilized. Additional N mineralization was predicted when necessary from imN by first order kinetics (constant k_remin). The TAO version with two parameters P_im and k_remin allowed us to predict very different patterns of N mineralization and N immobilization. In a few cases, a further first order kinetic law (constant k_v) was added to predict N volatilization from inorgN. Two hypotheses were tested: (i) η_L′, η_R, η_S (C-to-N of L′, R and S)=η_Sol, η_Hol, η_Lig, respectively, (ii) η_L′=η_R=η_S=η_AOM. The first hypothesis was validated by these data, and the second was a good approximation of the former one. In all the cases, predictions were in good agreement with measured values.  相似文献   

Phosphorus Source Effects on Soil Organic Phosphorus: A 31P NMR Study     

《Communications in Soil Science and Plant Analysis》2012,43(11-12):1722-1746

The nature of organic phosphorus (P_o) in animal waste and in soil is important from both plant nutrition and environmental perspectives. The objectives of this study were (1) to monitor the nature of P_o in different animal wastes and biosolids using solution state ³¹P NMR spectroscopy and (2) to understand the nature of P_o as affected by crop P removal in soil amended with different animal wastes and biosolids under greenhouse conditions. Two types of stockpiled cattle (Bos taurus) manure (CM1 and CM2), solid turkey (Meleagris gallopava) litter (TL), solid hog (Sus scrofa) manure (HM), and aerobically digested biosolids (SS) were used. Two kg of Wabash silt loam soil was amended with 0 or 150 mg P kg^?1 from the P sources. Seven harvests of corn (Zea mays L.) were collected, each 35 days after sowing. Organic P was extracted with 0.4 M NaOH from soil samples collected before cropping and after the seventh harvest, as well as from each P source. ³¹P NMR analysis suggested that sugar phosphomonoester was present in all P sources and was the dominant constituent of both CM1 and CM2. Phosphomonoester was detected in large amounts in TL, HM, and SS. Prior to crop P removal, the application of all P sources caused the relative content of sugar phosphomonoester to be greater than the control. Crop P removal resulted in reductions in the relative content of sugar phosphodiesters and phosphodiester in CM1‐ and CM2‐amended soils, respectively. Phosphomonoester was also decreased in TL‐, HM‐, and SS‐amended soils in response to cropping.  相似文献   

Aggregation and availability of phosphorus in a Technosol constructed from urban wastes     

Laure Vidal-Beaudet  Sarah Rokia  Thomas Nehls  Christophe Schwartz 《Journal of Soils and Sediments》2018,18(2):456-466

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Using the Caenorhabditis elegans soil toxicity test to identify factors affecting toxicity of four metal ions in intact soil     

Steven G. Donkin  David B. Dusenbery 《Water, air, and soil pollution》1994,78(3-4):359-373

A previously developed soil toxicity test for rapidly determining the toxicity of chemicals to the soil-dwelling nematode Caenorhabditis elegans (Donkin and Dusenbery, 1993) was used to measure the toxicity of four metals (Zn²⁺, Cd²⁺, Cu²⁺, and Pb²⁺) added to four soils common to the southeastern United States. Nematode survival after a 24-hour exposure in the presence of a bacterial food source was assessed. All soils reduced the toxicity of most metal ions compared to solutions without soil. Pb was the most strongly affected, while Cd toxicity was not much influenced by the soils. Correlations between the LC₅₀S and various soil or metal characteristics were determined. No significant correlation was found between LC₅₀s and many soil characteristics commonly cited as having large effects on soil bioavailability of metals. Although sample size was limited, the indication was that bioavailability of metals to nematodes is determined by a complex array of many interacting soil, as well as metal, properties. Comparison of the relative mobilities of these ions in other soils with the relative toxicity measured here suggests that mobility may be a good predictor of toxicity. The C. elegans soil toxicity test is shown to be as sensitive and more rapid than the commonly used earthworm soil toxicity test.  相似文献   

Biodegradation of estrone and 17 β-estradiol in grassland soils amended with animal wastes     

Sophie D. Lucas 《Soil biology & biochemistry》2006,38(9):2803-2815

The release of endocrine disrupting chemicals into the environment is of increasing concern due to the formation of an intersex state in freshwater organisms and potential risks to human health. The aim of this study was to investigate the persistence of the naturally occurring hormones, estrone and 17 β-estradiol in three agricultural grassland soils in the presence and absence of cattle and sheep wastes (urine and manure). Biodegradation was investigated using ¹⁴C-labelled hormones which were applied to soil in three different solvents (water, artificial urine and natural sheep urine). When applied directly to soil the two hormones degraded at a similar rate, however, the speed of mineralization was soil type and solvent dependant. The half-life (t_1/2) of the hormones in soils ranged from 5 to 25 d. The hormones were also applied to the soils in sheep and cattle manure of different ages (7 d to 2 yr). Generally, the rate of degradation in the animal manure amended soils was more rapid than in the unamended soils (t_1/2=1-9 d), with mineralization being largely independent of manure age and type. We conclude that in comparison to many xenobiotics, estrogens are not persistent in agricultural soils. However, our calculations suggest that if they are lost to freshwater via runoff or leaching then they may have an appreciable effect on freshwater organisms. Assuming normal landspreading rates our results suggest that the risk of estrogen contamination of freshwater associated with manure spreading is very low.  相似文献   

Effects of aeration and moisture during windrow composting on the nitrogen fertilizer values of dairy waste composts     

《Applied soil ecology》1999,11(1):17-28

The objective of this work was to evaluate the effects of turning and moisture addition during windrow composting on the N fertilizer values of dairy waste composts. Composted-dairy wastes were sampled from windrow piles, which received four treatments in a 2×2 factorial of turning (turning vs. no turning) and moisture addition (watering vs. no watering) at two stages of maturity (mature vs. immature). Composts were characterized for their chemical properties. An 84-day laboratory incubation of soils with addition of the composts at two levels was conducted to evaluate the inorganic N accumulation patterns from the variously treated composts. Chemical analyses of variously treated composts did not differ between compost treatments or maturity. In contrast, the inorganic N accumulation patterns differed between soils that received immature versus mature turned composted-dairy wastes. The results suggested that turning was a more important factor than moisture addition affecting the composting process. There was no significant difference in inorganic N accumulation patterns among soils that received different immature composts, while the N accumulation patterns observed for soils that received different mature composts depended on compost treatments. Soils amended with mature composts treated by frequent turning had higher N mineralization potentials (N₀), mineralization rate constants (K), and initial potential rates (N₀K) in comparison to soils with composts that had not been turned. Soils with mature composts treated by watering had a higher N₀, lower K, and therefore similar N₀K when compared to soils with composts that had not been watered. Soils that received mature composts treated by watering and frequent turning had higher N mineralization potentials and N₀ to total organic N ratios than soil alone, which suggested that intensive management of composting would ensure positive N fertilizer values of dairy waste composts, if the appropriate composting duration is completed.  相似文献   

Kinetics of added organic matter decomposition in a Mediterranean sandy soil     

《Soil biology & biochemistry》2001,33(7-8):997-1010

Carbon mineralization kinetics of 17 organic materials were studied in a Mediterranean sandy soil. These added organic matters (AOM) used in the organic fertilizer industry differed in their origin and composition: plant residues from the agri-food industry, animal wastes, manures (plant and animal origin), composts at different composting times and organic fertilizers. The mixtures AOM-soils were incubated under aerobic conditions at 28°C during 6 months. Soil moisture was maintained at 75% water holding capacity and respired-CO₂ was regularly trapped into alkali media in closed chambers, then checked by HCl titration. Analyses of CO₂ were performed in triplicate at 17 sampling occasions. The mineralized AOM fraction (MAOMF) varied according to the AOM origin: from 12–33% of added C for composts, to 65–90% for animal-originated AOM, with many intermediate patterns for plant-originated AOM.Seven decomposition models from the literature were fitted to actual MAOMF: (a) three consecutive models with two 1st-order-kinetic compartments and three parameters (m1, humification; m2, exchange; m3, decomposition), (b) three parallel models (m4, with two compartments and three parameters; m8, a 1st-order plus 0-order model with three parameters; m5, a three-compartment model with four parameters), and (c) m7, a model with one 2nd-order-kinetic compartment and two parameters. Additionally, m6, a simplified version of m5 was proposed. Models m2 and m7 did not match with actual data or gave a poor fit. By the correlation parameters, the most simple model m4 was chosen instead of the consecutive models m1 and m3. Residual sums of squares were always greater—but not significantly—in m8 than in m4, which confirmed the superiority of the models with two 1st-order compartments against 1st-order plus 0-order models for incubation times higher than 100 days. Model m5 (most of its parameters being not correlated) gave the best predictions of our data. The proposed m6 version gave predictions with similar precision as m4 and appeared powerful with only two parameters (very labile and stable fractions of the AOM). A compromise between the precision of the predictions and the simplicity of the formulae allowed the recommendation of the well-known m4 model, and above all the simpler m6 model.  相似文献   

Effect of fulvic acids on lead-induced oxidative stress to metal sensitive Vicia faba L. plant   总被引：2，自引：0，他引：2  

Muhammad Shahid  Camille Dumat  Jér?me Silvestre  Eric Pinelli 《Biology and Fertility of Soils》2012,48(6):689-697

Lead (Pb) is a ubiquitous environmental pollutant capable to induce various morphological, physiological, and biochemical functions in plants. Only few publications focus on the influence of Pb speciation both on its phytoavailability and phytotoxicity. Therefore, Pb toxicity (in terms of lipid peroxidation, hydrogen peroxide induction, and photosynthetic pigments contents) was studied in Vicia faba plants in relation with Pb uptake and speciation. V. faba seedlings were exposed to Pb supplied as Pb(NO₃)₂ or complexed by two fulvic acids (FAs), i.e. Suwannee River fulvic acid (SRFA) and Elliott Soil fulvic acid (ESFA), for 1, 12, and 24?h under controlled hydroponic conditions. For both FAs, Pb uptake and translocation by Vicia faba increased at low level (5?mg?l^?1), whereas decreased at high level of application (25?mg?l^?1). Despite the increased Pb uptake with FAs at low concentrations, there was no influence on the Pb toxicity to the plants. However, at high concentrations, FAs reduced Pb toxicity by reducing its uptake. These results highlighted the role of the dilution factor for FAs reactivity in relation with structure; SRFA was more effective than ESFA in reducing Pb uptake and alleviating Pb toxicity to V. faba due to comparatively strong binding affinity for the heavy metal.  相似文献   

Copper Sorption Characteristics and Activity In a Savanna Acid Soil From Nigeria     

J. O. Agbenin  A. M. Atin 《Water, air, and soil pollution》2003,150(1-4):43-58

The adsorption-desorption, chemical fraction and solubility relations of Cu in a typical savanna soil from Nigeria were studied with a view to elucidating the factors which govern the retention and release of Cu added to the soil as fertilizers and contaminants. Copper adsorption was performed in a KCl medium, and at a pH range of 3.0 to 8.5, using surface and subsurface soil samples of an Alfisol. Copper adsorption curve had a steep slope at low concentration of applied Cu, and a gentle slope at high concentration. Two successive desorptions with 0.01 M KCl recovered between 0 and 6% of sorbed Cu in the surface soil, and between 0 and 3% in the subsurface soil. Fractionation of sorbed Cu showed that between 51 and 62% of the sorbed Cu was in a residual form, whereas the organically-bound form was, on the average, less than 20% of sorbed Cu. Copper sorption increased with increasing pH, which could not simply be explained by pH-dependent charges per se. More than 65% of applied Cu was sorbed at pH ≥ 3.0, far below the point of zero net charge of the soil. The log Cu²⁺-pH activity diagrams showed that Cu²⁺ activities in soil solution were undersaturated with respect to tenorite (CuO) and Cu(OH)_2(c) solubility at the pH range of 4.0 to 7.5, but were supersaturated with respect to cupric ferrite (CuFe₂O₄) solubility except at pH ≤ 4.5. Precipitation of Cu compounds with solubility similar to CuFe₂O₄ might partly account for increasing Cu retention with pH. The strong retention of applied Cu by the soil and its low solubility in the soil solution suggested that the risks of Cu toxicity, and leaching to contaminate ground water and food chain, were Cu-rich wastes to be disposed through this soil, are quite minimal.  相似文献   

Short-term effects of dairy slurry amendment on carbon sequestration and enzyme activities in a temperate grassland     

R. Bol  E. KandelerW. Amelung  B. GlaserM.C. Marx  N. PreedyK. Lorenz 《Soil biology & biochemistry》2003,35(11):1411-1421

Land application of animal wastes from intensive grassland farming has resulted in growing environmental problems relating to greenhouse gas emissions, ammonia volatilisation, and nitrate and phosphorus leaching into surface and groundwater. We examined the short-term effects of dairy slurry amendment on carbon sequestration and enzyme activities in a temperate grassland (Southwest England). Slurry was collected from cows fed either on perennial ryegrass (C₃) or maize (C₄) silages. Fifty m³ ha⁻¹ of each of the obtained C₃ or C₄ slurries (δ¹³C=−30.7 and −21.3‰, respectively) were applied to a C₃ pasture soil with δ¹³C of −30.0±0.2‰. We found that water soluble organic carbon (WSOC) content was two to three times higher in the slurry amended plots compared with the unamended control. No significant change in the soil microbial biomass (SMB) carbon content was observed in the four weeks (772 h) following slurry application. Natural abundance ¹³C isotope analysis suggested a rapid initial incorporation (>25% within 2 h of application) of slurry-derived C in the SMB-C and WSOC pools of the 0-2 cm layer. Linear relationships were found between slurry-derived C in the whole soil, SMB, and WSOC for the 0-2 cm depth in the soil. Applied slurry-derived C was sequestered in the SMB pool in two phases. The first phase (0-48 h) was dominated by the incorporation of labile slurry C from the liquid phase, whereas beyond 48 h slurry-derived C was mainly from less mobile particulate C. No significant differences between treatments were found for invertase and xylanase. Urease activity was always higher in slurry treatments. Cellobiohydrolase, β-N-acetyl-glucosamidase, β-glucosidase and acid phosphatase activities became significantly higher in slurry treatments after 336 h. However, the observed temporal changes in enzyme activities were not correlated with the amounts of slurry-C incorporated in the SMB and WSOC pool.  相似文献   

Tiber River Quality in the Stretch of a Sewage Treatment Plant: Effects of River Water or Disinfectants to Daphnia and Structure of Benthic Macroinvertebrates Community     

Daniela Mattei  Stefano Cataudella  Laura Mancini  Lorenzo Tancioni  Luciana Migliore 《Water, air, and soil pollution》2006,177(1-4):441-455

The evaluation of Tiber River quality, in a stretch including a sewage treatment plant, has been carried out by the contemporary evaluation of water effect on Daphnia and benthic macroinvertebrates community structure. To achieve a good status of a river water by the end of 2015, as provided in the Water Framework Directive (WFD) 2000/60/EC, is necessary to know the quality starting point. To this end, several endpoints are expected by the WFD, including Daphnia toxicity test and macroinvertebrate community analysis. River water sampling was conducted in the four seasons, from upstream to downstream a sewage treatment plant. I endpoint. At the outfall of the sewage treatment plant, river water showed very high acute toxicity to Daphnia only in summer; some toxic effect can be found also upstream in spring. Results at the outfall were consistent with the hypothesis that disinfectants, mainly used in summer to treat discharging waters, are responsible of river water acute toxicity: Daphnia tests with each disinfectant (NaClO, PAA, ClO₂) showed high toxicity. River waters were also utilized in Daphnia reproduction tests. Samples at the outfall (excluding the summer one, undoubtedly toxic) caused slight reduction in survival and fecundity. Disinfectants were also checked in reproduction tests. Still at NOEC_24h, they caused a significant toxicity on both death rate and reproduction. II endpoint. Macroinvertebrate benthic community composition was evaluated upstream and downstream the sewage treatment plant, on these data Extended Biotic Index (EBI), was determined to get a score as quality class. A reduction of water quality score was found downstream the plant, one season delayed (autumn) respect the acute test on Daphnia. Effect of disinfectant discharge, river dilution capability on a short spatial scale and use of different endpoints are discussed in term of river stretch quality.  相似文献   

Nitrogen Isotope Ratios of Synthetic and Organic Sources of Nitrate Water Contamination in Spain     

Curt  M. D.  Aguado  P.  Sánchez  G.  Bigeriego  M.  Fernández  J. 《Water, air, and soil pollution》2004,151(1-4):135-142

This work aims to identify the sources of nitrogencontamination in nitrate vulnerable zones (NVZs) of Spain by means of the nitrogen isotope method. Three categories of nitrogen sources (synthetic fertilisers, animal wastes, and sludges and effluents from waste-water treatment plants) from three NVZs were analysed for their nitrogen isotopic composition (δ¹⁵N) in order to assess the applicability of the method to the identification of these N sources. The mean δ¹⁵N values were: +1.48‰ for synthetic fertilisers, +15.98‰ for animal wastes and +11.52‰ for sludges and effluents. The synthetic fertiliser sources were significantly different from the organic sources and so, the method can be used for their identification. The highest variability was found within the animal waste category. The range of values found for the different kinds of animal wastes (+5.86 to +36.74) was very wide and overlappedthe range found for sludges and effluents from waste-water treatmentplants (+4.57 to +20.18). Accordingly, these two nitrogen sources areisotopically indistinguishable.  相似文献   

Use of Fast Repetition Rate Fluorometry on Detection and Assessment of PAH Toxicity on Microalgae     

Patricia Pérez  Emilio Fernández  Ricardo Beiras 《Water, air, and soil pollution》2010,209(1-4):345-356

Cultures of the flagellate Isochrysis galbana were used to carry out the ecotoxicological evaluation of four PAHs [(naphthalene, phenanthrene, pyrene (Pyr) and fluoranthene (Flu)] by monitoring growth rate and the fluorescence variables F ₀, F _m, F _v and F _v/F _m, determined with a fast repetition rate fluorometer. The results presented in this investigation showed that F _v was a suitable endpoint in acute ecotoxicological tests with marine phytoplankton. The derived effective concentrations followed the known narcotic mechanism of toxicity and showed sensitivity levels comparable to marine invertebrate embryo-larval bioassays. Pyr and Flu showed the lowest EC₁₀, which ranged between 168–279 and 189–697 nM, respectively.  相似文献