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1.
Bioremediation of petroleum hydrocarbons in anoxic marine sediments: Consequences on the speciation of heavy metals 总被引：3，自引：0，他引：3
Antonio Dell’Anno Francesca Beolchini Massimo Gabellini Laura Rocchetti Antonio Pusceddu Roberto Danovaro 《Marine pollution bulletin》2009,58(12):1808-1814
We investigated the effects of biostimulation and bioagumentation strategies applied to harbor sediments displaying reducing conditions and high concentrations of petroleum hydrocarbons and heavy metals. We compared the microbial efficiency of hydrocarbon removal from sediments maintained for 60 days in anoxic conditions and inoculated with acetate, sulfate-reducing bacterial strains and acetate and sulfate-reducing bacteria. All treatments determined a significant increase in the microbial growth and significant decreases of hydrocarbon contents and of redox potential values. The addition of sulfate-reducing bacterial strains to the sediment was the most efficient treatment for the hydrocarbon removal. In all experiments, significant changes of the heavy metals’ phase repartition were observed. The results reported here suggest that the biodegradation of petroleum hydrocarbons in anoxic marine sediments may be enhanced by stimulating microbial anaerobic metabolism, but care should be applied to monitor the potential changes in the mobility and bioavailability of heavy metals induced by bio-treatments. 相似文献
2.
Ferric iron reduction was studied in a pilot-scale enclosure experiment for passive biological remediation of an acidic mine pit lake in Lusatia, Germany. The metabolic properties of prokaryotes involved in Fe(III) reduction may be important for the outcome of biological remediation, as chemolithotrophic Fe(III) reduction can counteract the desired pH increase, but heterotrophic Fe(III) reduction will provide the necessary Fe(II) for precipitation of sulfide minerals following sulfate reduction. Therefore, vertical profiles of sediment parameters related to iron and sulfur cycling were determined in conjunction with viable counts of different ferric iron-reducing micro-organisms using selective media. Findings were compared to an untreated reference site. The addition of organic matter stimulated ferric iron reduction and sulfate reduction in the enclosure and led to elevated pH and accumulations of ferrous iron and reduced sulfur compounds. Numbers of neutrophilic heterotrophic Fe(III) reducers increased during treatment, those of acidophilic heterotrophic Fe(III) reducers remained similar, and those of acidophilic chemolithotrophic Fe(III) reducers decreased. Zones of ferric iron-reducing activity corresponded well with microbial depth profiles; however, viable counts of neutrophilic or acid-tolerant Fe(III) reducers must have been underestimated based on the corresponding observed activity levels. Ferric iron reduction by chemolithotrophic acidophiles seemed to be of minor importance, so a lowering of pH values due to Fe(III) reducing activity is unlikely. 相似文献
3.
Influence of IHSS Standard and Reference Materials on Copper and Mercury Toxicity to Vibrio fischeri
The reduction in light emission of the marine bacterium Vibrio fischeri used in the standard Microtox® bioassay was measured for the metals copper and mercury. The concentration at which the light emission was reduced by 50% (EC50) was determined to be (3.43 ± 0.83) μmol/L for Cu2+ and (0.66 ± 0.01) μmol/L for Hg2+. The reduction of the toxicity of these metals by humic and fulvic acids were studied using IHSS Standard and Reference Materials. Copper toxicity was reduced 17...20% by the soil and peat fulvic acids and 9...20% by the aquatic fulvic acids. While there appeared to be little difference in the reduction of Cu toxicity by fulvic acids from soils, peats, or aquatic systems, Hg toxicity was reduced 3.6...7.3% by the soils and peats, while aquatic fulvic acids reduced Hg toxicity 14...16%. Soil fulvic acids appear to have significantly less capacity to reduce Hg toxicity than Cu toxicity. Humic acids had much higher reductions of Cu toxicity (44...124%) compared to the fulvic acids, with little difference between aquatic and soil or peat humic acids, 44...124% and 67...100%, respectively. However, humic and fulvic acids, regardless of origin, had approximately the same effect on Hg toxicity with 3.5...16% reduction by fulvic acids and 8...20% reduction by humic acids. Unlike the fulvic acids, no clear trend was observed relative to origin of the humic acids. There was no correlation between percent reduction of Cu or Hg toxicity by the organic compounds and copper binding capacity (CuBC), C/N ratio, or carboxyl content of the materials. Examination of natural organic matter (NOM) isolated by reverse osmosis techniques from three water sources had reductions of both Cu and Hg toxicity that were most similar to the Suwannee River and Nordic fulvic acids. 相似文献
4.
太湖流域滆湖底泥重金属赋存特征及其生物有效性 总被引：1，自引：0，他引：1
为了探讨太湖流域滆湖底泥重金属(Cd、Cr、Cu、Zn、Ni和Pb)的赋存特征及其生物有效性,对底泥重金属总量、形态以及生物富集量进行了分析.结果表明,6种重金属含量的空间分布表现为北部湖区最高,其次为南部湖区,中部湖区最低,重金属Ni、Cu、Zn和Pb含量显著高于沉积物背景值,分别是背景值的4.77、3.89、2.96和2.76倍,重金属总量与沉积物中的黏土成分含量具有显著相关性.采用三级四部提取法对重金属形态进行分析表明,6种重金属的生物有效态(弱酸结合态、可还原态和可氧化态之和)含量顺序为CdCuZnPbNiCr,其中Cd、Cu、Zn和Pb的生物有效态含量分别占总量的84.15%、78.47%、76.50%和64.29%.Cu和Zn在铜锈环棱螺中富集含量要显著高于其他金属元素.相关性分析表明,6种重金属中仅Cr和Pb的生物富集量与有效态含量具有显著相关性,这表明,重金属在生物体内的富集不仅与有效态含量有关,还与底泥重金属总量有关.因此,评价滆湖重金属的生态风险时需要综合考虑重金属的总量及生物有效态含量. 相似文献
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The bioavailability of field‐aged Cd and Cu was calculated, and compared to the total concentrations determined by acid digestion. Only 0.60–4.15% for Cd and 0.59–9.43% for Cu were found to be bioavailable when determined by stomach‐phase extraction. The incorporation of bioavailability reduced more than 90% of the calculated risk of the metals at the site of study. It should be noted that such a reduction may not be generalized and the site‐specific bioavailability needs to be determined case by case. 相似文献
8.
Evidence for Systemic Changes in the Benthic Fauna of Tropical Estuaries as a Result of Urbanization
The effects of urban development cause substantial physical changes in coastal waterways through hardening and reclamation of river banks, alteration of water flow, and diffuse and point-source discharges of pollutants. The cumulative effects of urbanization on the fauna of estuaries are not well understood. This study examined the benthic infauna of two urban and three rural estuaries near Townsville, North Queensland. A range of univariate and multivariate statistics was used to relate variation in the benthic assemblages to concentrations of contaminants (heavy metals and hydrocarbons) within the sediments of each estuary. Sediments in the most developed estuary contained concentrations of heavy metals and petroleum hydrocarbons that were several orders of magnitude greater than those from non-urban waterways. The fauna at these sites was dominated by cirratulid and sternaspid polychaetes and lacked filter-feeding bivalves and other molluscs that were common in less developed estuaries. These differences were generally consistent throughout each estuary, indicating estuary-wide patterns of change, that were most strongly associated with spatial patterns in the distribution of Pb, Cu and hydrocarbons. 相似文献
9.
Recent evaluations of acute and chronical toxicity of arsenic resulted in a reduction of the standard value for total arsenic from 40 μg/L to 10 μg/L in drinking water which will be valid in Germany after a transition period as from January 1996. Arsenic is well known as substance of deep groundwaters, mainly of geogenic origin and normally found as As(III) or As(V). As(V) is well removable by flocculation and filtration after adding iron salts. As(III), however, has to be oxidized first to As(V). Therefore, it is important for treatment techniques to be able to distinguish between As(III) and As(V). A modified determination of As(III) using flow injection analysis was installed and optimized in order to investigate whether As(III) may be oxidized to As(V) by bacteria in natural waters. The results showed that at 4°C, no As(III)-oxidation was observed within 14 days. At room temperature, however, in the bacteria-containing samples, an As(III)-oxidation was found starting after 3 to 7 days. After 14 days, no As(III) was left over. In contrast, in the sterile samples, no As(III)-oxidation could be observed within 14 days. These results demonstrated that microbial processes influence the oxidation of As(III) to As(V) in natural waters. 相似文献
10.
太湖五里湖区表层沉积物中酸挥发性硫化物和同步提取金属 总被引：7，自引：0，他引：7
湖泊底泥中的酸溶硫化物易与二价金属生成难溶金属硫化物,从而制约沉积物中二价有毒金属的化学活性以及生物有效性,进而影响沉积物的环境质量.对沉积物中的酸溶硫化物(AVS)和同步提取金属(SEM)进行测定,依据SEM/AVS的比值可以判定重金属生物有效性.通过对太湖五里湖、梅梁湾表层沉积物夏季和秋季AVS与SEM的采样分析,结果表明:研究区域内AVS的含量夏季高于秋季,SEM受季节影响很小,SEM/AVS大于1,且秋季高于夏季,初步判断该湖区沉积物中重金属具有潜在的生物毒性. 相似文献
11.
Effects of Wastewater-borne Heavy Metals on Mangrove Plants and Soil Microbial Activities 总被引：11，自引：0，他引：11
Effects of wastewater-borne heavy metals on growth of young plants (9-month-old Bruguiera gymnorrhiza) and soil microbial activities in mangrove microcosms were evaluated. During the 26-week loading period, each mangrove microcosm received 31.2 litres synthetic wastewater of three strengths: normal, medium (5 times of normal strength) and strong (10 times of normal strength). Normal strength wastewater had Cu, Zn, Cd, Cr and Ni concentrations of 3, 5, 0.2, 2 and 3 mg l−1, respectively. Plant growth and total plant biomass in wastewater-treated microcosms were lower than that in the control, and the maximum reduction was found in microcosms receiving strong wastewater. Alkaline phosphatase activity and ATP contents of the mangrove soils receiving wastewater were also reduced. More than 95% reduction in these two parameters was found in soils loaded with strong wastewater. Microtox test demonstrated that soil elutriates obtained from microcosms receiving strong wastewater were of the greatest toxicity (EC50 was 23%). These results show that high concentrations of heavy metals present in strong wastewater were toxic and posed negative effects to both mangrove plants and soil microbial activities. Microbial activities were generally more sensitive to the toxicity of heavy metals than plants. 相似文献
12.
M. I. Dinu 《Water Resources》2010,37(1):65-69
Complex formation reactions with the interaction of fulvic and humic acids with zinc and iron ions in a model aqueous system.
The complexing ability of humic acids was experimentally proved to be much higher than that of fulvic acids. The complexing
ability of fulvic acids is found to decrease over time. The dependence of the complexing ability of heavy metals on the types
of ion and humic substances and the proportions of components in the solution is examined. The obtained experimental results
on the occurrence forms of heavy metals were compared with their theoretical estimates calculated for natural water bodies. 相似文献
13.
Heavy metal contamination and ecological risk in Spartina alterniflora marsh in intertidal sediments of Bohai Bay,China 总被引：1，自引：0，他引：1
《Marine pollution bulletin》2014,85(1-2):115-124
To investigate the effects of Spartina alterniflora on heavy metals pollution of intertidal sediments, sediment cores of a S. alterniflora salt marsh and a mudflat in Bohai Bay, China were analyzed. The results showed that S. alterniflora caused higher total C and P, but lower bulk density and electrical conductivity. The levels of Cd, Cu and Pb were higher in S. alterniflora sediment. Both Cd and Zn were higher than the probable effect level at both sites, indicating their toxicological importance. The geo-accumulation and potential ecological risk indexes revealed higher metal contamination in S. alterniflora sediment. Multivariate analysis implied that anthropogenic activities altered mobility and bioavailability of heavy metals. The percentage of mobile heavy metals was higher in S. alterniflora sediment, indicating improvement of conversion from the immobilized fraction to the mobilized fraction. These findings indicate that S. alterniflora may facilitate accumulation of heavy metals and increase their bioavailability and mobility. 相似文献
14.
Investigations of the Adsorptive Separation of Volatile Chlorinated Hydrocarbons (VCHC) from Water with Humic Substance by Novel Polymeric Adsorbents and Activated Carbons. Part II: Dynamics of Adsorption In this publication, the dynamics of adsorption of different volatile chlorinated hydrocarbons (VCHC) (1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene) and a humic substance from water as well as of these VCHC from water with humic substance onto novel polymeric ad-[QJ][HR] sorbents (WOFATIT EP 63, DOWEX XUS 43493, MACRONET MN 100 and MN 200) was studied in comparison to activated carbons (NORIT ROW 0.8 SUPRA, PRECOLITH BKK 3, HYDRAFFIN CG). The obtained breakthrough curves and the following predicted characteristic values reveal that the polymeric adsorbents do not remove or remove the humic substance only with low adsorption capacity in contrast to the activated carbons. At the adsorption of the VCHC from water with humic substance it was determined that the influence of the humic substance on the adsorption capacity is substantially less on polymeric adsorbents than on activated carbons. 相似文献
15.
Katrin Wendt-Potthoff Matthias KoschorreckMarta Diez Ercilla Javier Sánchez España 《Limnologica》2012,42(3):175-188
Microbial activity, abundance and biomass, and biogeochemical cycling of iron, sulphur and carbon were studied in the extremely acidic (pH 2.5-4.3), meromictic, nutrient-rich pit lake Cueva de la Mora in Spain. The goal was to find out (1) if the relatively high nutrient content influenced plankton abundance in the water column and alkalinity-producing microbial processes in the sediments compared to other acid pit lakes, and (2) if sediments in the shallow, mixed and the deep, stagnant parts of the lake exhibited differences in microbial activities and geochemical sediment composition related to meromixis. We hypothesised that redox cycling was more intense in the mixed part and higher amounts of reduced components would accumulate in the stagnant part. Especially phytoplankton biomass, CO2 production, and sulphate reduction were indeed higher than reported from typical acid pit lakes and were rather within the range of neutral or weakly acidic lakes, which can be attributed to the relatively high nutrient contents of Cueva de la Mora. Even in the monimolimnion, anaerobic processes occurred mainly in the sediments. Sediments from the mixed and stagnant parts of the lake differed markedly in their biogeochemistry. Mixolimnetic sediments showed high iron and sulphate reduction rates, and they appeared to undergo substantial recycling, as supported by reactive Fe, relation between gross sulphate reduction rate and net accumulation of reduced sulphur, and viable counts of iron and sulphur bacteria. Monimolimnetic sediments exhibited lower anaerobic microbial activities, and surprisingly they accumulated more Fe(II) than mixolimnetic sediments, but less reduced sulphur and carbon. This might be explained by a strong separation of the two water bodies, resulting in comparably less input of energy (light) and allochthonous matter into the monimolimnion. Regarding the total extent of alkalinity-generating microbial processes, their net effect is not sufficient to neutralise the lake within decades. 相似文献
16.
The kinetics of conversion of iron(III) (hydr)oxides to ferrous iron mediated by fulvic acid have been investigated in order to improve the understanding of the redox cycling of iron at the oxic-anoxic boundary in natural waters. Under the conditions similar to natural waters, fulvic acid is able to reduce the iron(III) (hydr)oxide. The kinetics of the reaction depend on the reactivity of iron(III) (hydr)oxides and the reducing power of the fulvic acid. The rate of reaction is 60 nm/h obtained under following conditions: total concentration of Fe(III) 1.0 × 10–4 M, pH 7.5, fulvic acid 5 mg/L. The rate is considered as a net result of reduction and oxidation in the > FeIII-OH/Fe(II) wheel coupled with fulvic acid. In a real natural water system, reductants other than fulvic acid may be of importance. The results obtained in the laboratory, however, provide evidence that the Fe(OH)3(s)/Fe(II) redox couple is able to act as an electron-transfer mediator for the oxidation of natural organic substances, such as fulvic acid by molecular oxygen either in the absence of microorganisms or as a supplement to microbial activity. 相似文献
17.
A combination of retention pond and reed bed was tested for its effectiveness in reducing non-point source runoff pollution from an urban area. This paper presents data on the development of reed plants (Phragmites australis Cav. Trin.), on the effectiveness of runoff purification and on the accumulation of contaminants in the pond sediment and the reed bed for the years 1993–1995. P. australis was well established and grew according to normal development. The measured length and biomass values of P. australis were larger on sand than on gravel and coarse materials. Toxic levels of heavy metals in the plants were not reached. Harvested plants can be composted. The purification system is effective within the following ranges: The rate of retention of suspended solids and heavy metals varies between 16% and 91%. For chemical oxygen demand the average values is 25%. Poor retention rates usually occur along with very low input concentrations. Generally retention within the reed bed is higher than in the pond. Between 1993 and 1995 the concentration of contaminants within the organic layer of the reed bed increased by 50% for lead and by 90% for poly aromatic hydrocarbons. Until 1994 the concentrations of mineral oil hydrocarbons also increased by 60%. Between 1994 and 1995 however the concentration of mineral oil hydrocarbons in the reed bed decreased rapidly by more than 50%: Mineral oil hydrocarbons underlie biological degradation within the reed bed. In the pond sediment a significant accumulation of heavy metals, poly aromatic hydrocarbons and mineral oil hydrocarbons has also been found. The concentrations of these contaminants are still far from inhibiting the function of the system. 相似文献
18.
《Acta Geochimica》2017,(3)
The bioavailability of 22 heavy metals was investigated at 19 sampling sites in Tieguanyin tea garden in Anxi County,Fujian Province,southeastern China.Heavy metal concentrations were determined by inductively coupled plasma-mass spectrometry(ICP-MS)and evaluated by geo-accumulation index(I_(geo)).Dilute nitric acid extraction was used to evaluate biological activity.Cu,Pb,and Cd were highly bioavailable and most easily absorbed by tea trees.Heavy metal bioavailability in the surface soil was as the ratio of the effective state to the total amount.Cd had the highest I_(geo)values,and the respective samples and sites were classified as moderately/strongly contaminated.Cd element is considered the main factor of heavy metal pollution in the tea garden in Anxi.The other heavy metals studied were present in lower concentrations;thus,the samples were classified as uncontaminated or slightly contaminated. 相似文献
19.
Current study presents the application of chemometric techniques to comprehend the interrelations among sediment variables whilst identifying the possible pollution source at Langat River,Malaysia.Surface sediment samples（0-10 cm）were collected at 22 sampling stations and analyzed for total metals（~（48）Cd,~（29）Cu,~（30）Zn,~（82）Pb）,pH,redox potential（Eh）,salinity,electrical conductivity（EC）,loss on ignition（LOI）and cation exchange capacity（CEC）.The principal component analysis（PCA）scrutinized the origin of environmental pollution by various anthropogenic and natural activities：four principal components were obtained with 86.34%（5 cm）and88.34%（10 cm）.Standard,forward and backward stepwise discriminant analysis effectively discriminate 2variables（84.06%）indicating high variation of heavy metals accumulation at both depth.The cluster analysis accounted for high input of Zn and Pb at LA8,LA 10,LA 11 and LA 12 that mergers three（5 cm）and four（10cm）into clusters.This is consistent with the contamination factor（C_1）that shows high Cd（LA 1）and Pb（LA 7,LA 8,LA 10,LA 11 and LA 12）contaminations at 5cm.These indicate that Pb and Zn are the most bioavailable metals in the sediment with significant positive linear relationship at both sediment depths.Therefore,this approach is a good indication of environmental pollution status that transfers new findings on the assessment of heavy metals by interpreting large complex datasets and predicting the fate of heavy metals in the sediment. 相似文献
20.
A 95-day field trial on the bioremediation of oil in beach sediment using Osmocote and chitosan was conducted on an inter-tidal foreshore in Singapore. Osmocote was the key factor in enhancing nutrient levels in sediments, the metabolic activity of the indigenous microbial biomass, and the biodegradation of aliphatics and polycyclic aromatic hydrocarbons (PAHs) with ring number of 2 and 3. In contrast, chitosan did not enhance these parameters in the presence of Osmocote. However, the addition of chitosan to Osmocote amended sediments significantly enhanced biodegradation of recalcitrant 4–6-ring PAHs. This is most likely due to the high oil adsorbancy capacity of chitosan, which enhances the bioavailability of high ring number PAHs to the microbial biomass. 相似文献