共查询到20条相似文献,搜索用时 31 毫秒
1.
Trudy J. Estes Joan U. Clarke Christian J. McGrath 《Journal of Soils and Sediments》2012,12(4):636-651
Purpose
Confined disposal facilities (CDFs) are widely used for disposal of navigation dredged material, but many are running out of capacity. Removal of dredged material for beneficial use offers potential for sustainable operations, but requires characterization with a high degree of confidence. Few data are available to inform characterization efforts in these artificial depositional environments; thus, a CDF case study was used to demonstrate a structured approach to sampling and data analysis. 相似文献2.
Background and Goal In the Netherlands about 40 million m3 of sediment has to be dredged annually for both maintenance and environmental reasons. Temporary upland disposal is the most
widely adopted alternative for dredged sediments worldwide. For good management of temporary disposal sites, knowledge is
needed on the processes controlling the behavior of the sediments during disposal. Therefore, a review of the literature was
made to get an integrated overview about processes that take place during temporary disposal.
Ripening After disposal of clayey sediments, the following spontaneous dewatering processes can be distinguished: sedimentation, consolidation,
and ripening. Sedimentation and consolidation are relatively fast processes, whereas ripening can take up to several years.
In a remediation perspective, the ripening of sediments is the most important dewatering process. Ripening, which may be subdivided
into physical, chemical, and biological ripening, transforms sediment into soil. Physical ripening is the irteversible toss
of water and results in the formation of soil prisms separated by shrinkage cracks. Continuing water loss causes a breaking
up of the prisms into aggregates. The aggregates produced by this ongoing desiccation process usually remain quite large (>50
mm) and can only be further broken down by weathering processes like wetting and drying or by tillage. As a result of the
aeration caused by physical ripening, also chemical and biological ripening take place. Chemical ripening can be defined as
the changes in chemical composition due to oxidation reactions and leaching of soluble substances. Biological ripening is
the result of the activity of all kinds of soil fauna and flora that develop as a result of aeration, including both the larger
and the microscopic forms of life. Decomposition and mineralization of soil organic matter caused by micro-organisms can be
seen as the most important aspect of biological ripening. Many interactions exist between the different ripening processes.
Conclusions and Outlook Oxygenation of the dredged sediment is improved as a result of the natural ripening processes: the air-filled porosity increases,
the aggregate size decreases, and the initially high respiration rates caused by chemical and biological ripening decreases.
Therefore, conditions in the disposal site become more favorable for aerobic biodegradation of organic pollutants like Polycyclic
Aromatic Hydrocarbons (PAH) and mineral oil. It is concluded that the naturally occurring process of ripening can be used
as a bioremediation technique. Ripening in an upland disposal site is an off-site technique, and therefore, the process could
be enhanced by means of technological interference. However, it is concluded that the knowledge currently available about
upland disposal is not sufficient to distinguish critical process steps during the ripening and bioremediation of PAH and
mineral oil polluted sediments because of the complex relationships between the different ripening processes and bioremediation. 相似文献
3.
Background, Aims and Scope Disposal of dredged material in subaqueous depots is increasingly considered an economic and ecologically sound option in
managing contaminated dredged material. The concept of subaqueous disposals capped with active barrier systems has been developed
to minimize this risk of contaminant release. As such a depot represents a permanent installation within a sensitive ecosystem,
it requires a thorough monitoring concept. It is the goal of this work to develop such a concept regarding general considerations
and results of laboratory and field investigations.
Methods In addition to the state-of-the-art techniques developed for other under-water constructions, this monitoring concept is developed
with particular respect to the chemical isolation of the dredged material from the overlying water body. It comprises the
use of seepage meters, dialysis samplers, and DGT gel probes for determining the migration of selected target solutes. The
capability of the dialysis samplers is demonstrated by comparing field results with model calculations. The appropriateness
of DGT probes to assess the impact of humic substances on trace metal speciation and on copper toxicity is demonstrated with
the aid of laboratory experiments.
Results and Discussion The experimental results show that, by using dialysis samplers, the temporal changes in concentration-depth-profiles of heavy
metals in the pore solution can be monitored. Additionally, the application of DGT probes facilitates the in situ detection
of labile species of a metal in the presence of dissolved humic substances, which serves to reflect its toxicity. Conclusions.
Three subsequent monitoring phases are distinguished on the basis of both general considerations and the findings from field
results: A hydraulic phase that is characterized by compaction and pore water expulsion, a geochemical phase in which the
demobilization of pollutants can occur due to substantial changes in the physico-chemical conditions (pH, EH), and a steady-state-phase
where pore water flow and geochemical conditions are approaching their minimum.
Recommendations and Outlook The monitoring concept suggested here provides a versatile tool to assess the chemical isolation of subaqueous sediment depots
and other contaminated sediment sites. This is of great importance as subaqueous disposal is increasingly considered a future
management strategy as space for upland disposal is limited and treatment, in general, proves to be too costly. 相似文献
4.
Harald Köthe 《Journal of Soils and Sediments》2006,6(2):75-83
Background Under anoxic conditions typically prevailing in disposal sites for dredged sediment, methanogenesis is the terminal step
during microbial degradation of sediment organic matter. Sediment gas production may pose several problems to site management
and post-closure utilisation. Depending on the magnitude of gas/methane formation and the intended utilisation of the site,
countermeasures will have to be effected during and after deposition of the dredged material. For this purpose it may be of
interest to pre-estimate the extent of gas formation from simple sediment variables. Therefore, the aim of the investigations
presented here was to analyse the interrelations between gas formation and sediment physical, chemical and biological qualities.
Methods Freshly sampled riverbed sediment from nine German federal waterways was analysed for standard solid physical and chemical
parameters, pore water composition, cell counts of methanogenic and sulfate-reducing bacteria, and gas formation over a period
of 500 days. Particle size and density fractionation were carried out in order to characterise organic matter quality. Correlations
between methane formation and sediment chemical, physical and microbiological characteristics were tested using linear and
multiple correlation analysis.
Results and Discussion The selected sediments, including two with marine influence, differed strongly regarding texture, chemical parameters, pore
water composition, and methanogen cell counts. The course of methane formation was found to follow distinct phases. The commencement
of methane formation was preceded by a lag phase of variable duration. The lag phase was followed by a strong increase of
the methane formation rate up to a sediment-characteristic maximum of 5–30 nmol CH4 h–1 g dw–1. Eventually, the rate of methane
formation decreased and reached a more stable, long-term level. The extent and amplitude of each phase varied strongly between
sediments and could be correlated well with only a few standard analytical parameters, despite the strong heterogeneity of
sediment with respect to chemical, physical, and biological characteristics. Lag phase duration depended strongly on the content
of inorganic electron acceptors and also on the number of methanogens present at the beginning of the experiment. Maximum
and steady state methanogenesis were mainly determined by sediment total nitrogen. As analysis of sediment density fractions
revealed that total nitrogen reflected the share of readily degradable macroorganic matter.
Conclusion and Outlook The results imply that the observed methane formation is a function of the temporally changing balance of the availability
of electron acceptors and H2, and the share of easily degradable organic matter. For fresh riverbed sediments, the latter
may be deduced from total nitrogen content. Overall, the results showed that methane formation by freshly dredged material
may well be pre-estimated from standard analytical data within the first few years of deposition. However, the differently
degradable organic matter pools will change over time with respect to size, chemical nature and association with the sediment
mineral phase. It can thus be expected that the correlations found in this study will not be readily transferable to older
materials. Further studies on the gas formation and organic matter quality by older sediments, e.g. from older dredged material
disposal sites of known age, should be conducted and results should be combined with existing organic matter degradation models
in order to improve the prediction of sediment gas formation over time. 相似文献
5.
Heinz Stichnothe Wolfgang Calmano Eduardo Arevalo Arne Keller Jorg Thöming 《Journal of Soils and Sediments》2005,5(1):21-29
- Dedicated to Prof. Dr. Ulrich Förstner on his 65th birthdayBackground, Aims and Scope Sediments in harbours and nearby shipyards demonstrate widespread contamination with tributyltin (TBT). Therefore, reuse and relocation of dredged material from these locations are prohibited. Even if the International Marine Organization (IMO) convention concerning TBT-based paints is ratified (Champ, 2003) the TBT problem in sediments will continue to remain for many years due to the persistence of TBT. Methods An electrochemical process has been developed to treat polluted sediments. Dredged materials with high and low TBT-contents were studied on a technical and a pilot scale. The treatment process was assessed by chemical analysis and a biotest battery. Additionally, an economic analysis was performed to check the economic feasibility of the process to treat dredged material from two different locations at different operating conditions. Furthermore an up-scaling estimation was performed to evaluate treatment costs at a larger scale, i.e. for a plant having a capacity of 720 000 t/a.Results and Discussion Butyltin species and polycyclic aromatic hydrocarbons (PAH) were decomposed due to electrochemically-induced oxidation, while the treatment did not alter heavy metal and PCB concentrations. The bacteria luminescence test indicated a reduced toxicity after the electrochemical treatment, while the algae growth inhibition test and bacteria contact test did not confirm these results. Based on a small consumer price of 0.12/kWh, treating the high-contaminated sediment in the pilot plant would cost 21/m3 and 31/m3 for the low contaminated sediment, respectively. Assuming an industrial consumer price of 0.06/kWh for electricity in an up-scaled process with a capacity of 720 000t/a, the total treatment costs for the low contaminated sediment would be 13/m3. Conclusion The results of treating dredged material from Bremerhaven and the fine-grained fraction from the METHA plant show that the effectiveness of the process performance is more related to the binding form and sediment composition than to the initial concentration of TBT. The electrochemically treated material complies with chemical criteria for relocation of dredged material, but post-treatment, e.g. washing and/or reduction of remaining oxidants with Fe-II-salts, is needed to fulfil ecotoxicological criteria for relocation.
Economic investigations have shown that the electrochemical treatment might be a technical option to treat TBT contaminated, dredged material. However, the technique is not fully developed and cannot remove all chemicals of concern, e.g. heavy metals. The decision as to whether this technique can be applied is site-specific and should be taken based on the case-by-case approach.Recommendation and Outlook Since biotests integrate the effects of all contaminants present in a sample, process-accompanying evaluation procedures need additional assessment methods such as TIE (toxicity identification evaluation) as a second tier following ecotoxicological tests, in which the reasons for the effects are identified.
For reasons of sustainability, a much more effect-oriented and long-term cost effective approach should be applied in future to avoid the release of harmful substances into the environment. Life cycle assessment should be carried out to identify and quantify impacts of sediment treatment processes in order to take into account both the distant effects of local actions and local effects of distant actions. 相似文献
6.
Sigua Gilbert C. Holtkamp Mike L. Linton John M. Coleman Samuel W. 《Journal of Soils and Sediments》2003,3(2):93-99
Background The continued need to dredge lakes, rivers, and canals in Florida, both for maintenance and environmental improvement, will
produce millions of cubic meters of dredged materials. Productive disposal options of lake-dredged materials (LDM) may provide
substantial and intangible benefits that will enhance the environment, community, and society.
Objective The objective of this study was to assess lake-dredged materials from Lake Panasoffkee as soil amendment for early establishment
of bahiagrass (BG,Paspalum notatum Flügge) in subtropical beef cattle pasture at Sumter County, Florida. Results and Discussion. This study encompassed two
phases: Phase 1 comprised of five small observation plots (0.3 x 0.3 m); Phase 2 consisted of five larger test plots (30.5
x 30.5 m). Each of the plots in Phase 1 and Phase 2 had a different ratio LDM to natural soil (NS): Plot 1 (0% LDM + 100%
NS); Plot 2 (25% LDM + 75% NS); Plot 3 (50% LDM + 50% NS); Plot 4 (75% LDM + 25% NS); and Plot 5 (100% LDM + 0% NS). Each
plot was seeded with BG and early growth and yield establishment were monitored for 16 weeks.
Conclusion Results disclosed significantly taller (p ≤ 0.001) plants and higher biomass production (p ≤ 0.001) of BG from plots amended
with 75% LDM than those of BG planted on plots with 0% LDM. Results suggest that LDM can serve as source of lime and fertilizer
to establish BG beef pasture fields. Sediments with high CaCO3 improved the physical and chemical conditions of subtropical beef pastures. Lake-dredged materials could be removed from
the spoil containment areas, trucked to other locations, and incorporated into existing fields for agricultural uses. There
is still much to be learned, but it is certain that Lake Panasoffkee sediments should be regarded as a resource, with no observed
harmful ecological effects.
Recommendation and Outlook The agricultural or livestock industry could utilize these LDM to produce forages. LDM should be regarded as a beneficial
resource, as a part of the ecological system. This study has been continued for several years to explore and assess the long
term efficacy of LDM on productivity and quality of BG beyond its early establishment stage.
Joint contribution of the USDA-ARS and the Florida Agricultural Experiment Station, Journal Series No, R-09253. 相似文献
7.
施用河道污泥对水稻和土壤重金属含量及
水稻氮素利用的影响 总被引:1,自引:0,他引:1
2013—2014年以苏州市相城区望亭镇某河道污泥为研究对象,以农田施用污泥20 kg?m~(-2)和不施用污泥为主处理,以施氮肥120 kg(N)?hm~(-2)(LN)和240 kg(N)?hm~(-2)(NN)为副处理,连续两季种植粳稻品种‘武运粳24’,研究河道污泥农田施用对水稻和土壤重金属含量及水稻氮素利用的影响。结果表明:1)河道污泥农田施用,显著提高了稻田土壤有机质含量、速效氮含量和重金属Cu、Zn、Pb含量,水稻产量平均增加7.05%,水稻籽粒中重金属Cu、Zn、Pb含量分别增加53.66%、18.71%和802.29%,水稻吸氮量显著增加,氮素利用效率显著降低。2)河道污泥施用后,较高施氮量(NN)增加了稻田土壤有机质含量和速效氮含量,对稻田土壤重金属含量和水稻籽粒中重金属含量影响不大,水稻产量、水稻吸氮量显著增加,但氮素利用效率显著降低。3)污泥处理条件下,与第1季相比较,第2季稻田土壤重金属Cu、Zn、Pb含量平均下降5.0%左右、籽粒中重金属Cu、Zn、Pb含量下降7.27%~12.65%,但均显著大于不施河道污泥的对照处理。4)污泥×氮肥、污泥×年度、氮肥×年度和污泥×氮肥×年度的互作效应对稻田土壤养分含量、重金属含量,水稻产量、籽粒重金属含量和水稻氮素吸收利用的影响均未达显著水平。 相似文献
8.
9.
Gianni Andreottola Luca Bonomo Giorgia De Gioannis Elisa Ferrarese Aldo Muntoni Alessandra Polettini Raffaella Pomi Sabrina Saponaro 《Journal of Soils and Sediments》2010,10(1):142-150
Purpose
The fairly high amounts of sediments dredged in coastal or internal water bodies for navigational and/or environmental purposes claims for the identification of appropriate management strategies. Dredged sediments are frequently affected by organic and inorganic contamination, so that their reuse, as an alternative to final landfill disposal, could need remediation. In this framework, a two-year joint research project was carried out to assess the feasibility of different remediation technologies for the treatment of polluted sediments. 相似文献10.
Catriona A. Macdonald Xueyun Yang Ian M. Clark Penny R. Hirsch 《Soil biology & biochemistry》2010,42(9):1408-1417
In a study to assess the sustainable use of sewage sludge application to land, the long-term effect of Zn and Cu contaminated sludge additions on the structure of the bacterial communities (using T-RFLP analysis) and their tolerance to additional metal exposure through pollution-induced community tolerance (PICT) assays was assessed. This used two soils that received metal-rich sludge cake (SC), liquid sludge (LS) or metal salts (MS) additions more than 10 years previously. Soil type had the predominant influence on bacterial community structure and PICT. The source of the metal contamination also had a large influence on community structure and PICT, greater than the effects due to metal concentrations. Nevertheless, in both Zn and Cu contaminated soils, PICT was observed and decreased in the order MS > LS > SC. Within a metal source and site, there was evidence of increased PICT with increasing Zn or Cu contamination, however few differences were significant as a result of high variability between sample replicates. These results highlight the importance of considering soil physico-chemical properties and the source of metal contamination as well as total metal concentrations when considering the long-term effects of metals on soil microbial communities. Further, the matrix that a metal is associated with prior to addition may play an important factor in determining levels of toxicity. This could have consequences for the interpretation and use of data from metal spiking experiments when considering metal limits for sludge application to land. 相似文献
11.
Purpose
Cadmium (Cd) is a toxic heavy metal, accumulated in soil by anthropogenic activities and has serious effects on soil microbial activities in contaminated soils. Moreover, there is a lack of reliable data on the effects of Cd in the soil-plant system, since most of the information on Cd-microorganism interactions in soils are based on sewage sludge without plants. The main objective of this study was to assess the effects of Cd on soil microbial activities and community structure during growth of plant. 相似文献12.
疏浚底泥的养分特征及污染化学性质研究 总被引:19,自引:0,他引:19
本文以运河 (杭州段 )待疏浚底泥为材料 ,分析了疏浚底泥的养分特征及其污染化学性质。结果发现 ,疏浚底泥中含有较高的养分 ,其中有机质、P、K含量较高而N偏低 ;施入土壤后 ,有机质矿化很快 ,P的供应较为持久。疏浚底泥重金属含量较一般城市污泥低 ,基本低于污泥农用中污染物控制标准 ,可考虑直接使用以节约处置费用 ;重金属的有效态含量不高 ,相对活性顺序为Cd Cu Pb Zn,直接大量施用会对种子发芽产生一定的毒害。供试作物种子对疏浚底泥毒害作用的反应不同 ,抗性顺序为青菜 羊茅草 三叶草。直接利用疏浚底泥比城市污泥具有更大的安全性 ,只要物种选取合适、用量恰当 ,是一种很好的肥源和复垦用土。 相似文献
13.
The Ultuna long-term soil organic matter experiment in Sweden (59′82° N, 17′65° E) was started in 1956 to study the effects
of different N fertilisers and organic amendments on soil properties. In this study, samples were taken from 11 of the treatments,
including unfertilised bare fallow and cropped fallow, straw with and without N addition, green manure, peat, farmyard manure,
sawdust, sewage sludge, calcium nitrate and ammonium sulphate, with n = 4 for each treatment. Samples were taken from topsoil (0–20 cm) and subsoil (27–40 cm depth) and analysed for concentrations
of phospholipid fatty acids (PLFAs), organic C, total N and pH. The results showed that the subsoil samples reflected the
total PLFA content of the topsoil, but not the microbial community structure. Total PLFA content was well correlated with
total organic C and total N in both topsoil and subsoil. Total PLFA content in topsoil samples was highest in the sewage sludge
treatment (89 ± 22 nmol PLFA g dw−1). This contradicts earlier findings on microbial biomass in this sewage sludge-treated soil, which indicated inhibition of
microorganisms, probably by heavy metals added with sludge. A switch towards microbial growth and faster decomposition of
organic matter occurred around 2000, coinciding with lowered heavy metal content in the sludge. According to the PLFA data,
the microbial community in the sewage sludge treatment is now dominated by Gram-positive bacteria. A lack of Gram-negative
bacteria was also observed for the ammonium sulphate treatment, obviously caused by a drop in pH to 4.2. 相似文献
14.
Anaerobic sediment potential acidification and metal release risk assessment by chemical characterization and batch resuspension experiments 总被引:1,自引:0,他引:1
Background, Aim and Scope Sediments act as a sink for toxic substances (heavy metals, organic pollutants) and, consequently, dredged materials often
contain pollutants which are above safe limits. In polluted anaerobic sediments, the presence of sulphides and redox potential
changes creates a favorable condition for sulphide oxidation to sulphate, resulting in potential toxic metal release. The
oxidation reaction is catalyzed by several microorganisms. Some clean up measures, such as dredging, can initiate the process.
The aim of the present work is to assess the acidification and metal release risk in the event of sediment dredging and also
to compare two different acid base account techniques with the resuspension results. The oxidation mechanism by means of inoculation
with an Acidithiobacillus ferrooxidans strain was also evaluated.
Methodology The sediments were chemically characterized (pH; organic oxidizable carbon; acid volatile sulphides; total sulphur; moisture;
Cr, Cu and Zn aqua regia contents). A metal sequential extraction procedure (Community Bureau of Reference, BCR technique)
was applied to calculate the Acid Producing Potential (APP) and Acid Consuming Capacity (ACC) of the sediment samples through
Fe, Ca2+ and SO4
2− measurements. The acid base account was also performed by the Sobek methodology (Acid producing potential — AP — calculated
with total sulphur and neutralization potential — NP — by titration of the remaining acid after a reaction period with the
sample). Fresh sediments were placed in agitated shake flasks and samples were taken at different times to evaluate pH, SO4
2− and Cr, Cu, Zn and Fe2+ concentration. Some of the systems were inoculated with an Acidithiobacillus ferrooxidans strain to assess the biological catalysis on sulphide oxidation.
Results Sediment chemical characterization showed high organic matter content (5.4–10.6%), total sulphur (0.36–0.86%) and equivalent
CaCO3 percentages (4.5–8%). pH was neutral-alkaline for all of the samples. AVS content was high except for sample 5. The acid
base account obtained with the two methods gave different results for the acid generating risk of the samples. A decrease
of 0.4 to 3.1 pH units was measured in the agitated shake flasks. In all of the systems, sulphate concentration increased
(2,100–2,200 mg L−1 to 2,500–3,000 mg L−1), and positively correlated with the initial total sulphur content of the samples in the inoculated flasks. Cu and Cr in
solution were not detected in most of the sampling occasions (<0.5 mg Cu L−1 and <0.5 mg Cr L−1). Zn reached high concentrations (up to 11.8 mg L−1). For every system — except sediment 1 — the lowest pH registered was similar in comparison to inoculated and control systems.
The inoculation effect was mostly evidenced in the systems by a higher sulphate release rate compared to the control systems.
Discussion The BCR method categorized all of the samples as potentially acid generating material. The Sobek method using NPR (NP/AP)
criteria classified sample 3 as a possible acid generator and samples 1, 2 and 5 with a low acid generation potential. Despite
this, all the samples acidified the media in the kinetic tests in at least one of the conditions employed in this work. It
would seem that NPR and NNP (NP-AP) risk classification criteria should not be directly used with anaerobic sediments. Appropriate
classification levels for sediments should be developed considering the different sulphide reactivity between rock and sediments.
Sediment oxidation can cause acidification, which is partially explained by sulphide oxidation. In the samples studied, we
found a positive correlation between sulphate increase in solution after oxidation and total sulphur content in the inoculated
systems. Significant amounts of Zn could be released to solution while Cr and Cu remained insoluble despite the pH decrease
observed. The low Cu and Cr mobility could be explained by the very low solubility of their hydroxides and high affinity for
organic matter and iron oxides/hydroxides that might form during sediment oxidation. Dredged sediment management and disposal
should be carefully planned.
Conclusions All of the sediment samples lowered the pH media in the laboratory batch resuspension experiments. However, both risk classification
criteria (NNP, NPR) from Sobek acid base account were not able to predict the samples’ behavior as accurately as the BCR derived
base account. The inoculation effect was mostly associated with a higher sulphate release and not to a lower pH due to acid
base equilibrium.
Recommendations and Perspectives Appropriate risk classification levels for sediments should be developed considering the different sulphide reactivity between
rock and sediments.
ESS-Submission Editor: Dr. Sabine Ulrike Gerbersdorf (sug@st-andrews.ac.uk) 相似文献
15.
Catriona A. Macdonald Ian M. Clark Penny R. Hirsch Steve P. McGrath 《Soil biology & biochemistry》2011,43(5):932-941
Long-term impacts of metal contamination derived from sewage sludge on soil microbial communities have been widely evaluated, but confounding effects have made it difficult to draw firm conclusions and thus to advise on safe metal limits. Here we used Multiplex-terminal restriction length fragment polymorphism (M-TRFLP) to assess the long-term impact of sludge-borne Zn and Cu contamination on the structure of bacterial, fungal and archaeal communities across seven different soils at metal levels relevant to current guideline limits. Despite strong effects of site on microbial community structure, analysis of similarity (ANOSIM) demonstrated a small but significant effect of Zn on bacteria (P < 0.001), archaea (P < 0.001), and fungi (P < 0.001). Significant effects of Cu on bacteria (P < 0.001), archaea (P < 0.001) and fungi (P < 0.001) were also observed. Several bacterial and fungal T-RFs were identified as responding to Zn or Cu. For example the bacterial T-RF 72 was negatively correlated with Zn and Cu, and T-RF 259 was positively correlated with Zn. Attempts to identify these bacterial markers of Zn and Cu contamination suggest a negative impact of Cu on Acidobacteria in arable soils. These results demonstrate for the first time, that despite a strong influence of site on microbial community structure, effects of Zn and Cu derived from sewage sludge can be detected as shifts in bacterial, fungal and archaeal communities indicating a common response more than 11 years after sludge addition. 相似文献
16.
Tiago Natal-da-Luz Serena Tidona Bruno Jesus Paula V. Morais José P. Sousa 《Journal of Soils and Sediments》2009,9(3):246-260
Background, aim, and scope Sewage sludge use in agriculture should be limited by the presence of metals and other persistent environmental pollutants.
The present study aims to contribute for the definition of a test battery of ecotoxicological assays that allows a proper
ecotoxicological characterization of sludges, providing information on their potential hazard and identified “safe” application
levels.
Materials and methods Three sludges from distinct sources (urban, olive-processing, and electroplating industries) were tested using avoidance and
reproduction tests with earthworms (Eisenia andrei) and springtails (Folsomia candida) and plant growth tests with turnips (Brassica rapa) and oats (Avena sativa). Different soil–sludge mixture concentrations mimicking recommended/realistic field dosages were tested.
Results Only the sludge from the electroplating industry induced an avoidance response from the earthworms (EC50 = 0.4 t/ha) and collembolans (no observed effect concentration (NOEC) = 15 t/ha). This sludge was the only sludge responsible
for any effect on the reproductive output of the earthworms (EC50 = 7.74 t/ha). Regarding collembolans, none of the sludges tested caused any significant decrease in reproduction. In higher
plant tests, the two industrial sludges were toxic, causing a decrease growth in both species. The EC20 values determined for B. rapa were 20.3 and 24.2 t/ha and for A. sativa 14.7 and 16.2 t/ha for sludges from olive-processing and electroplating industries, respectively.
Discussion The metal loadings of the different test sludges could partially explain the results obtained. The toxicity of the test sludge
from electroplating industry observed on the tested invertebrates and plants could be explained by the high amount of total
chromium from which 22.3% was in the most toxic oxidation state—Cr(VI). However, the toxicity caused by the sludge from the
olive-processing industry in the test plants could be attributed to the presence of other compounds (not measured in this
study) since the metal content was not high enough to induce such an effect. The absence of toxicity showed by the urban test
sludge was in agreement with its low levels of metals.
Conclusions The response of the different test organisms and end points varied according to the sludge type. The urban sludge was non-toxic
whereas the sludge from the electroplating industry caused a toxic effect on almost all parameters measured (avoidance behavior
of both test organisms, reproduction of earthworms, and growth of both plant species). Sludge from the olive-processing industry
only caused a toxic effect on growth of both plant species. By analyzing the sensitivity of the different parameters for the
most toxic sludge, it was found that avoidance and reproduction were more sensitive than plant growth, whereas plant seed
germination was not sensitive at all.
Recommendations and perspectives The ecotoxicological evaluation of wastes can be used as an environmental safety control of sludge use in agriculture. A tiered
approach could be adopted for this purpose, incorporating avoidance tests in the first tier (screening level) and reproduction
and plant growth tests in a second tier. But more evidence aiming to define the most suitable ecotoxicological test battery
for specific sludges with a different contamination profile is still needed. 相似文献
17.
城市污泥农用的环境效应及控制标准的发展现状 总被引:10,自引:0,他引:10
由于城市污泥中富含植物生长所需要营养元素和有机质, 城市污泥农用已成为污泥资源化进程中的重要方式之一。近十几年来, 国内外在污泥重金属的形态、生物有效性及其在污泥-土壤-植物系统中的迁移转化规律等方面进行了广泛的研究, 并取得显著进展。同时, 污泥中有机污染物质和病原体的环境效应也越来越受到关注。但是在我国, 污泥农用的环境风险评价的长期性、系统性和田间数据验证还需进一步加强, 为合理制定或修改污泥农用标准积累有效的科学数据和提供可靠的科学依据。本文简述了国内外城市污泥的理化性质、污泥农用环境效应以及我国污泥农用标准的研究现状和进展, 并对污泥农用研究进行了展望, 以期为我国污泥农用的研究和发展提供参考依据。 相似文献
18.
Culture-dependent and culture-independent microbial investigation of pine litters and soil in subtropical Australia 总被引:1,自引:1,他引:0
Background, aim, and scope Forest plantations, widely grown for wood production, involve the selective promotion of single-tree species or replacement
of natural species by exotic tree species. Slash pine (Pinus elliottii) has been chosen for reforestation of infertile sandy soils in southeast Queensland, Australia. These exotic pine plantations
minimize soil and water losses and are important scientific study sites. The soil environment of these plantations, though
devoid of sufficient nutrients, organic carbon and other factors, harbors innumerable bacteria that may play a crucial role
in maintaining soil quality and ecosystem functions. These soil microorganisms also have the potential for use as sensitive
biological indicators to reflect environmental changes. It is therefore essential to understand the interrelationships among
bacterial communities and their environment by assessing their structural and functional diversity and their responses to
disturbances. The main aim of our investigation was to determine the diversity of bacterial communities in forest litters
and soil during the forest leaf litter decomposition using culture-dependent and culture-independent techniques.
Materials and methods A 25-cm (diameter) × 40-cm core sample was collected and fractionated into three subsamples designated E1 (L leaf litter layer),
E2 (F leaf litter layer), and E5 (0–10 cm soil layer). Both culture-dependent and culture-independent methods were applied
in this study. In the culture-independent study, a strategy of whole-community DNA extraction, polymerase chain reaction (PCR)
amplification followed by cloning and 16S rDNA sequence analysis was used; for culture-dependent study, the strategy included
sample plating and bacteria isolating, DNA extraction, PCR amplification, and 16S rDNA sequence analysis. The diversity similarities
between two bacterial communities and two methods are quantified using Jensen–Shannon divergence.
Results From culture-dependent study, 336 colonies in total were isolated and grouped from the three subsamples, and the 16S rRNA
sequence analysis from a representative isolate from each morphogroup (21 isolates) indicated that they belonged to the phyla
Actinobacteria, Firmicutes, and Proteobacteria. Culture-independent assessment based on 16S rRNA gene library comprising 194 clones revealed that members of the phylum Actinobacteria were absent in the culture-independent studies. Clones in libraries from E1 consisted exclusively of members of the Firmicutes. The majority of clones from E2 were related to Firmicutes (79%) and Proteobacteria (21%). Clones derived from E5 were mostly affiliated with Acidobacterium (42%), followed by unclassified bacteria (27%), Verrucomicrobiales (12%), Proteobacteria (11%), and Planctomycetes (8%).
Discussion This study showed that bacterial culturabilities in different fractions of leaf litters were similar, and both of them were
higher than the bacterial culturability in the soil. Unculturable bacterial diversity in the soil, however, was much higher
than the leaf litter bacterial diversity. The bacterial diversity on the top layer of leaf litters was slightly less than
that on the bottom layer of leaf litters. This might indicate that forest soils are a more complex environment than leaf litters
are and also that they might inhabit more unculturable microorganisms in the forest soils, which would need to be further
investigated. The leaf litter layer samples also demonstrate the significant difference between the bacterial community diversity
discovered by these two methods in this study. The information provided by assessing the different fractions of leaf litters
and forest soil has improved our understanding of the bacterial community distributions within the forest soil and the above-leaf
litters in an exotic pine plantation of subtropical Australia.
Conclusions This study represents the first attempt to examine the bacterial community in the different fractions of forest leaf litters
and soil in subtropical Australia. The data from this study show that the 16S rDNA clone libraries provided more comprehensive
phylogenetic diversity in the soil and leaf litter samples than the culture collections provided, and both the culture-dependent
and culture-independent studies revealed that the bacterial diversity present in the leaf litters was very different to that
present in the soil. The comparative analysis of bacterial communities in different fractions of leaf litters and soil samples
has also provided important baseline information about the bacterial diversity and composition in the exotic pine forest plantations.
Recommendations and perspectives The experimental data provided important information on the bacterial diversity in forest leaf litter and soil samples, though
additional surveys and comparisons at different locations would be needed to further characterize. In addition, combined methods
that can provide different parts of information on bacterial diversity are encouraged to be used in bacterial community study.
The established libraries of diverse 16S rRNA gene fragments from slash pine leaf litters and forest soil can be used to construct
specific DNA primers and probes to target bacterial groups of interest. It may then be possible to study the ecology of these
bacterial communities and the role of specific bacterial groups that contribute to the many interesting properties of these
environments. 相似文献
19.
An overview is given of decision making frameworks for Ecological Risk Assessment (ERA) used for sediment in a number of European
countries. These frameworks fall into two categories:
The first approach is usually part of an evaluation of whether remediation is needed in order to control or reduce the ecological
risks of sediment pollution in a given location. The purpose of the second approach is to evaluate the risks of possible (unconfined)
disposal options for dredged sediment (including sediment that is dredged for navigational reasons). Important aspects are:
相似文献
• | Biological Effects-Based Assessment of in situ risks (referred to as in situ BEBA); |
• | Biological Effects-Based Assessment of the ex situ quality of dredged sediments (referred to as ex situ BEBA). |
• | Objectives for sediment management; |
• | The level of integration of BEBA in legal frameworks; |
• | The use of chemical (numeric) SQG’s in BEBA and their integration with biological information; |
• | The criteria used to infer effects and to classify sediment quality. |
20.
André S. Nakatani Marco A. Nogueira Admilton G. Oliveira José P. Sousa 《Soil biology & biochemistry》2011,43(1):106-114
The application of tannery sludge to soils is a form of recycling; however, few studies have examined the impacts of this practice on soil microbial properties. We studied effects of two applications (2006 and 2007) of tannery sludge (with a low chromium content) on the structure of the bacterial community and on the microbial activity of soils. We fertilized an agricultural area in Rolândia, Paraná state, Brazil with different doses of sludge based on total N content, which ranged from 0 to 1200 kg N ha−1. Sludge remained on the soil surface for three months before being plowed. Soils were sampled seven times during the experiment. Bacterial community structure, assessed by denaturing gradient gel electrophoresis (DGGE), was modified by the application of tannery sludge. Soon after the first application, there was clear separation between the bacterial communities in different treatments, such that each dose of sludge was associated with a specific community. These differences remained until 300 days after application and also after the second sludge application, but 666 days after the beginning of the experiment no differences were found in the bacterial communities of the lowest doses and the control. The principal response curve (PRC) analysis showed that the first sludge application strongly stimulated biological activity even 300 days after application. The second application also stimulated activity, but at a lower magnitude and for a shorter time, given that 260 days after the second application there was no difference in biological activity among treatments. PRC also showed that the properties most influenced by the application of tannery sludge were enzymatic activities related to N cycling (asparaginase and urease). The redundancy analysis (RDA) showed that tannery sludge’s influence on microbial activity is mainly related to increases in inorganic N and soil pH. Results showed that changes in the structure of the bacterial community in the studied soils were directly related to changes of their biological activity. 相似文献