In order to better monitor N and P pollutants, heavy metals, pesticides and other organic pollutants in water areas, we researched sensitivity and tolerance of aquatic algae on water environment and effects of the pol...In order to better monitor N and P pollutants, heavy metals, pesticides and other organic pollutants in water areas, we researched sensitivity and tolerance of aquatic algae on water environment and effects of the pollutants on algae population, analyzing toxin and enrichment of pollutants on algae. The results indicated that aquatic alga is a better indicator for some pollutants in water, for which water contamination can be surveyed and analyzed rapidly.展开更多
Heavy metal pollution in agricultural water resources is very serious in re- cent years, resulting in large losses of the agricultural economy and endangering human life and health. Due to the advantages of low cost, ...Heavy metal pollution in agricultural water resources is very serious in re- cent years, resulting in large losses of the agricultural economy and endangering human life and health. Due to the advantages of low cost, high efficiency and less secondary pollution, microbial ramediation technology is widely used in the treatment of heavy metal pollution in agricultural water resources. At present, with the progress of modern biotechnology, microbial remediation of heavy metals in agricul- tural water resources has grown rapidly. The sources and status quo of heavy met- al pollution in agricultural water resources at home and aboard, and the principles of microbial remediation of heavy metals pollution in agricultural water resources were reviewed in this paper, as well as the several common microbial remediation technology of heavy metals in agricultural water resources. Additionally, the further research work of heavy metal contaminated agricultural water resources by microbial ramediation were prospected.展开更多
Statistical work and analysis were made based on data of monitored wa- ter quality data in Hedi Reservoir during 2000-2010 and the results show that the content of nutritive salt was higher and water was moderate or l...Statistical work and analysis were made based on data of monitored wa- ter quality data in Hedi Reservoir during 2000-2010 and the results show that the content of nutritive salt was higher and water was moderate or light eutrophication. Based on status quo and practical survey research of the Reservoir, the causes for eutrophication deterioration were analyzed and countermeasures were proposed, providing scientific references for sustainable development of Hedi Reservoir.展开更多
Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed...Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed high concentrations of heavy metals in the order of Cr〉Fe〉Zn〉Ni〉Co〉Mn while ground water did not show any heavy metal contamination except Fe. Physico-chemical parameters of mine water samples showed deviation from those of normal water. Mine water harboured low microbial populations of bacteria, fungi and actinomycetes in comparison with mine adjacent water samples. The correlation of data between metals with physico-chemical parameters showed both positive and negative responses while that of metal and microbial population exhibited negative correlation. Bacterial strains isolated from chromite mine water exhibited high tolerance towards chromium and other heavy metals as well as antibiotics which could be used as an indicator of heavy metal pollution.展开更多
Seashore landfill aquifers are environments of special physicochemical conditions (high organic load and high sa- linity), and microbes in leachate-polluted aquifers play a significant role for intrinsic bioremediatio...Seashore landfill aquifers are environments of special physicochemical conditions (high organic load and high sa- linity), and microbes in leachate-polluted aquifers play a significant role for intrinsic bioremediation. In order to characterize microbial diversity and look for clues on the relationship between microbial community structure and hydrochemistry, a cul- ture-independent examination of a typical groundwater sample obtained from a seashore landfill was conducted by sequence analysis of 16S rDNA clone library. Two sets of universal 16S rDNA primers were used to amplify DNA extracted from the groundwater so that problems arising from primer efficiency and specificity could be reduced. Of 74 clones randomly selected from the libraries, 30 contained unique sequences whose analysis showed that the majority of them belonged to bacteria (95.9%), with Proteobacteria (63.5%) being the dominant division. One archaeal sequence and one eukaryotic sequence were found as well. Bacterial sequences belonging to the following phylogenic groups were identified: Bacteroidetes (20.3%), β, γ, δ and ε-subdivisions of Proteobacteria (47.3%, 9.5%, 5.4% and 1.3%, respectively), Firmicutes (1.4%), Actinobacteria (2.7%), Cyanobacteria (2.7%). The percentages of Proteobacteria and Bacteroides in seawater were greater than those in the groundwater from a non-seashore landfill, indicating a possible influence of seawater. Quite a few sequences had close relatives in marine or hypersaline environments. Many sequences showed affiliations with microbes involved in anaerobic fermentation. The remarkable abundance of sequences related to (per)chlorate-reducing bacteria (ClRB) in the groundwater was significant and worthy of further study.展开更多
The effectiveness of vitamin C in treating Cr(VI)-contaminated water is being evaluated. Cr(VI) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and anim...The effectiveness of vitamin C in treating Cr(VI)-contaminated water is being evaluated. Cr(VI) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(VI) to essentially nontoxic Cr(III). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(VI) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration. The reaction mechanism of Cr(VI) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(VI)-contaminated soils and groundwater.展开更多
In solving the deterioration of biological treatment system treating petrochemical wastewater under low temperatures, bioaugmentation technology was adopted by delivering engineering bacteria into a pilot-scale two-st...In solving the deterioration of biological treatment system treating petrochemical wastewater under low temperatures, bioaugmentation technology was adopted by delivering engineering bacteria into a pilot-scale two-stage anoxic-oxic (A/O) process based on previous lab-scale study. Experimental results showed that when the concentrations of COD and NH4+-N of the influent were 370~910 mg/L and 10~70 mg/L, the corresponding average concentrations of those of effluent were about 80 mg/L and 8 mg/L respectively, which was better than the Level I criteria of the Integrated Wastewater Discharge Standard (GB8978-1996). According to GC-MS analysis of the effluents from both the wastewater treatment plant (WWTP) and the pilot system, there were 68 kinds of persistent organic pollutants in the WWTP effluent, while there were only 32 in that of the pilot system. In addition, the amount of the organics in the effluent of the pilot system reduced by almost 50% compared to that of the WWTP. As a whole, after bioaugmentation, the organic removal efficiency of the wastewater treatment system obviously in- creased.展开更多
A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble ph...A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble phosphorus (WSP),diluted calcium chloride extractable phosphorus (PCaCl2), and Olsen-P in the sediments of Taihu Lake, China, where potential P release in response to pH was analyzed. MPA for rapid P analysis was shown to be promising when applied on samples of natural water and sediment extracts. Concentrations of WSP and PCaCl2 in the sediments were much lower than those of Olsen-P. Olsen-P levels in the littoral sediments along the north coast of Meiliang Bay in Taihu Lake (80to 140 mg kg-1) were much higher than those in the mouth of the bay (less than 50 mg kg-1). The risk of P release in the mouth area of Meiliang Bay was lower than that in the north littoral zone with a risk of sediment P release induced by pH increases.展开更多
Heavy metal pollution in aquatic system is becoming a serious problem worldwide. In this study, responses of Sargassum thunbergii to dif ferent concentrations(0, 0.1, 0.5, 1.0 and 5.0 mg/L) of zinc(Zn) and cadmium(Cd)...Heavy metal pollution in aquatic system is becoming a serious problem worldwide. In this study, responses of Sargassum thunbergii to dif ferent concentrations(0, 0.1, 0.5, 1.0 and 5.0 mg/L) of zinc(Zn) and cadmium(Cd) exposure separately were studied for 15 days in laboratory-controlled conditions. The results show that the specifi c growth rates increased slightly under the lower Zn concentration treatment(0.1 mg/L) at the first 5 d and then decreased gradually, which were significantly reduced with the exposure time in higher Zn concentrations and all Cd treatments compared to respective control, especially for 1.0 and 5.0 mg/L Cd. Chlorophyll a contents showed significant increase in 0.1 mg/L Zn treatment, whereas the gradually reduction were observed in the other three Zn treatments and all Cd treatments. The oxygen evolution rate and respiration rate presented distinct behavior in the Zn-treated samples, but both declined steadily with the exposure time in Cd treatments. The P/R value analyses showed similar variation patterns as chlorophyll a contents. Real-time PCR showed that lower Zn concentration(0.1 mg/L) increased mRNA expression of rbcL gene, whereas higher Zn concentrations and Cd reduced the rbcL expression. Taken together, these findings strongly indicate that Zn and Cd had different effects on S. thunbergii both at the physiological and gene transcription levels, the transcript level of photosynthesis-related gene rbcL can be used as an useful molecular marker of algal growth and environment impacts.展开更多
An understanding of the long-term changes in the nitrate and microbial contamination pattern of the groundwater of Sidi Bouzid (Centre West of Tunisia) is critical to conservation of drinking water in rural areas su...An understanding of the long-term changes in the nitrate and microbial contamination pattern of the groundwater of Sidi Bouzid (Centre West of Tunisia) is critical to conservation of drinking water in rural areas supporting mixed land-use activities such as cropping, livestock farming, and residence. The phreatic aquifer was revealed polluted by domestic disposals of the wastewaters in the urban zone. The average nitrate concentration in the groundwater of the east of the mioplioquaternary aquifer of Saddaguia (Sidi Bouzid) rose from 50 mg NO3- during 1996 to over 100 mg in 2003, which represents an increase of some 10 mg per year. Nitrate groundwater pollution during the period 1996-2003 was the result of the abusive use of fertilizers.In the cultivated zone, we must reduce the effects of the excessive use of the nitrogen fertilizers on the basis of monitoring soil once a year, managing water resources, rationalizing the use of the chemical substances. In urban zones, most of lost wells located in the perimeter reveal the gravity of the state of the aquifer. This last is organically polluted and requires an immediate action for the generalization of the purification network. We need to take into account the reality of under soil in all future planning's and arrangements. A scheme of sanitation seems necessary before all plans of arrangement. The extension of the sewer network must give the priority to the most vulnerable zones.展开更多
This paper presents an environm centally friendly method of inhibiting biofouling especially acorn barnacles on surfaces under water by using nicotine and selenium in the form of Se(0), or such a substance which can...This paper presents an environm centally friendly method of inhibiting biofouling especially acorn barnacles on surfaces under water by using nicotine and selenium in the form of Se(0), or such a substance which can be converted into them. Both of the substances are necessary to oxygen dependent organisms and will be used after conversion, but are toxic in high doses. By adding the substances to paint or other surface treatment agent which marine surfaces are treated with, organisms which are trying to establish themselves on the surfaces will be exposed to so high doses, the reactions which the settling is based on are disturbed. When the substances leak out into the seas, they will act as environment protectors, as they promote the development of organisms. Nicotine is transformed to nicotine amid which is the reactive part in NADH and one of the most important substances for the transference of hydrogen. Selenite is reduced to Se(0), also involved in the transport chain of hydrogen to reducible oxygen. However, large quantities Se(0) may disturb the reactions of sulphur b'./binding to it and impairing the formation of S-S-bridges.展开更多
Biological activated carbon (BAC) has been developed on the granular activated carbon by immobilization of selected and acclimated species of bacteria to treat the micro-polluted water. The BAC removal efficiencies fo...Biological activated carbon (BAC) has been developed on the granular activated carbon by immobilization of selected and acclimated species of bacteria to treat the micro-polluted water. The BAC removal efficiencies for nitrobenzene, permanganate index, turbidity and ammonia were investigated. Effects of shock loading and SEM (Scanning Electron Microscope) observation on BAC were studied. Backwashing and its intensity of BAC were also discussed. The results showed that BAC took short time to start up and recover to the normal condition after shock loading. The shock loading studies showed that the removal efficiency of BAC was not completely inhibited even at high concentration of nitrobenzene. Backwashing performed once every 10-20 d, or an average of 15 d. Backwashing intensity was 12-14 L/(s·m2) with air and 3-4 L/(s·m2) with water.展开更多
The variation of water quality in water distribution system was investigated with assimilable organic carbon (AOC)and trihalomethanes(THMs) used as assessment indexes. Bacterium was identified in water distribution. T...The variation of water quality in water distribution system was investigated with assimilable organic carbon (AOC)and trihalomethanes(THMs) used as assessment indexes. Bacterium was identified in water distribution. The result showed that there were pathogenic parasites in water distribution system. The variation of AOC is related to chlorine residual and bacterium activity, and AOC concentration decreased first and then increased with the extension of water distribution system. The formation of THMs was related to the consumption of chlorine inside the distribution system, and THMs concentration increased with the extension of water pipe line.展开更多
In order to estimate the biodegradation of three polycyclic aromatic hydrocarbons (PAHs) compounds, bacterial strains were isolated from marine sediments in three heavily contaminated sites (Yuandang Lake, Dongdu Port...In order to estimate the biodegradation of three polycyclic aromatic hydrocarbons (PAHs) compounds, bacterial strains were isolated from marine sediments in three heavily contaminated sites (Yuandang Lake, Dongdu Port and Aquacultural zones in Maluan Bay) in Xiamen Western Sea. The results show three bacterial strains, which used pyrene as the sole carbon source, were identified as strains of Aureobacterium sp., Arthrobacter sp., Rhodococcus sp. The PAH-degrading bacteria isolated had a strong ability to degrade phenan-hrene, fluoranthene and pyrene at different degradation rates. The highest degradation rate was observed when three PAH compounds were mixed with an individual strain in the medium. The three PAHs were degraded after one week with a degradation rate of 89.94 % for phenanthrene and 93.4 % for both of fluoranthene and pyrene. In addition, after 25 days of incubation, the degradation rate was 99.98 % for phenanthrene and 99.97 % for both of fluoranthene and pyrene. Optical density was measured to estimate bacterial growth during the degradation of PAHs. Highest levels of bacterial growth were observed with a three PAH mixture in the culture, suggesting that the concentration of PAHs influenced bacterial growth and the highest levels of degradation for most series were detected after one week of incubation.展开更多
The biosorption of copper(Ⅱ) ions onto biofilm was studied in a batch system with respect to the temperature, initial pH value and biofilm sorbent mass. The biomass exhibited the highest copper(Ⅱ) sorption capacity ...The biosorption of copper(Ⅱ) ions onto biofilm was studied in a batch system with respect to the temperature, initial pH value and biofilm sorbent mass. The biomass exhibited the highest copper(Ⅱ) sorption capacity under the conditions of room temperature, initial pH value of 6.0 and the sorbent mass 8 g. The experimental data were analyzed using four sorption kinetic models, the pseudo-first order, the Ritchie second order, the modified second order and the Elovich equations to determine the best-fit equation for the sorption of metal ions onto biofilm. Comparing with the sum of squared-errors, the results show that both the Ritchie second order and modified second order equations can fit the experimental data very well.展开更多
A series of orthogonal array experiments were conducted using carbon source, ammonia nitrogen and total phosphorus (TP) as major influencing factors to investigate the effects of nutrients on biofouling formation an...A series of orthogonal array experiments were conducted using carbon source, ammonia nitrogen and total phosphorus (TP) as major influencing factors to investigate the effects of nutrients on biofouling formation and preponderant bacteria diversity in the recirculatiug cooling water system. Carbon source was demonstrated to be the most significant determinant affecting the biofouling formation. A minimum biofouling outcome was obtained when BOD2, NHa+-N and TP were 25, 10, and 1 mg/L, respectively. Then the preponderant bacteria strains in biofouling mass under two typical culture conditions (negative and favorable) were identified applying both traditional biochemical methods and further molecular biology technology with phylogenetic affiliation analysis, which indicated that Enterobacteriaceae Enterobacter, Micrococcaceae Staphylococcus, Bacillaceae Bacillus, Enterobacteriaceae Proteus, Neisseriaceae Neisseria and Pseudomonadaceae Pseudomonas were dominant under negative condition, while Enterobacteriaceae Klebsiella, Enterobacteriaceae Enterobacter and Microbacterium - under favorable one.展开更多
In this study, two common pollutants (benzo[a]pyrene and methamidophos) in marine environment were tested by comet assay for their inducement of in vivo genotoxic effect to the blood cells of black porgy ( Acanthopagr...In this study, two common pollutants (benzo[a]pyrene and methamidophos) in marine environment were tested by comet assay for their inducement of in vivo genotoxic effect to the blood cells of black porgy ( Acanthopagrus schlegeli). The fish was exposed to 2 μg/L of benzo[a]pyrene (BaP) and methamidophos, and their mixture. The assay was performed on whole blood at 2 h, 5 h, 24 h and 96 h exposure intervals. A signifi- cant increase in DNA damage was observed in each treatment with the pollutants. Additive effect of BaP and methamidophos was also found in the experiment. However, the decrease ratios of DNA damage for 5 h and 96 h exposure interals compared with 2 h and 24 h exposure ones, respectively, were noticed. This phenomenon may be explained by the function of repairing process via enzyme cytochrome P450 in the animal. Evidence of the genotoxicity of organophosphorus pesticides (OPs) and polynuclear aromatic hydrocarbons (PAHs) on marine fish are discussed in this paper.展开更多
While conventional wastewater treatments for urban effluents are fairly routine and have proved highly effective,industrial wastewater requires more complex and specific treatments.This paper provides a technological ...While conventional wastewater treatments for urban effluents are fairly routine and have proved highly effective,industrial wastewater requires more complex and specific treatments.This paper provides a technological strategy for removal of recalcitrant contaminants based on a hybrid treatment system.The model effluent containing a binary mixture of synthetic dyes is treated by a combination of a preliminary physicochemical stage followed by a biological stage based on ligninolytic enzymes produced by Phanerochaete chrysosporium.This proposal includes biosorption onto peat as pretreatment,which decreases the volume and concentration to be treated in the biological reactor,thereby obtaining a completely decolorized effluent.The treated wastewater can therefore be reused in the dyeing baths with the consequent saving of water resources.展开更多
基金Supported by China Agriculture Research System (CARS-49)~~
文摘In order to better monitor N and P pollutants, heavy metals, pesticides and other organic pollutants in water areas, we researched sensitivity and tolerance of aquatic algae on water environment and effects of the pollutants on algae population, analyzing toxin and enrichment of pollutants on algae. The results indicated that aquatic alga is a better indicator for some pollutants in water, for which water contamination can be surveyed and analyzed rapidly.
文摘Heavy metal pollution in agricultural water resources is very serious in re- cent years, resulting in large losses of the agricultural economy and endangering human life and health. Due to the advantages of low cost, high efficiency and less secondary pollution, microbial ramediation technology is widely used in the treatment of heavy metal pollution in agricultural water resources. At present, with the progress of modern biotechnology, microbial remediation of heavy metals in agricul- tural water resources has grown rapidly. The sources and status quo of heavy met- al pollution in agricultural water resources at home and aboard, and the principles of microbial remediation of heavy metals pollution in agricultural water resources were reviewed in this paper, as well as the several common microbial remediation technology of heavy metals in agricultural water resources. Additionally, the further research work of heavy metal contaminated agricultural water resources by microbial ramediation were prospected.
基金Supported by Guangdong Natural Science Foundation(8152500002000005)Guangdong Science and Technology Project(2011B030800017)Zhanjiang Normal University Talents Introduction and Undergraduates Innovation Program~~
文摘Statistical work and analysis were made based on data of monitored wa- ter quality data in Hedi Reservoir during 2000-2010 and the results show that the content of nutritive salt was higher and water was moderate or light eutrophication. Based on status quo and practical survey research of the Reservoir, the causes for eutrophication deterioration were analyzed and countermeasures were proposed, providing scientific references for sustainable development of Hedi Reservoir.
基金Financial support of the UGC-DAE, Center for Scientific Research, Kolkata Centre
文摘Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed high concentrations of heavy metals in the order of Cr〉Fe〉Zn〉Ni〉Co〉Mn while ground water did not show any heavy metal contamination except Fe. Physico-chemical parameters of mine water samples showed deviation from those of normal water. Mine water harboured low microbial populations of bacteria, fungi and actinomycetes in comparison with mine adjacent water samples. The correlation of data between metals with physico-chemical parameters showed both positive and negative responses while that of metal and microbial population exhibited negative correlation. Bacterial strains isolated from chromite mine water exhibited high tolerance towards chromium and other heavy metals as well as antibiotics which could be used as an indicator of heavy metal pollution.
基金Project (No. 20377030) supported by the National Natural ScienceFoundation of China
文摘Seashore landfill aquifers are environments of special physicochemical conditions (high organic load and high sa- linity), and microbes in leachate-polluted aquifers play a significant role for intrinsic bioremediation. In order to characterize microbial diversity and look for clues on the relationship between microbial community structure and hydrochemistry, a cul- ture-independent examination of a typical groundwater sample obtained from a seashore landfill was conducted by sequence analysis of 16S rDNA clone library. Two sets of universal 16S rDNA primers were used to amplify DNA extracted from the groundwater so that problems arising from primer efficiency and specificity could be reduced. Of 74 clones randomly selected from the libraries, 30 contained unique sequences whose analysis showed that the majority of them belonged to bacteria (95.9%), with Proteobacteria (63.5%) being the dominant division. One archaeal sequence and one eukaryotic sequence were found as well. Bacterial sequences belonging to the following phylogenic groups were identified: Bacteroidetes (20.3%), β, γ, δ and ε-subdivisions of Proteobacteria (47.3%, 9.5%, 5.4% and 1.3%, respectively), Firmicutes (1.4%), Actinobacteria (2.7%), Cyanobacteria (2.7%). The percentages of Proteobacteria and Bacteroides in seawater were greater than those in the groundwater from a non-seashore landfill, indicating a possible influence of seawater. Quite a few sequences had close relatives in marine or hypersaline environments. Many sequences showed affiliations with microbes involved in anaerobic fermentation. The remarkable abundance of sequences related to (per)chlorate-reducing bacteria (ClRB) in the groundwater was significant and worthy of further study.
基金Project (No. 20407015) supported by the National Natural ScienceFoundation of China
文摘The effectiveness of vitamin C in treating Cr(VI)-contaminated water is being evaluated. Cr(VI) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(VI) to essentially nontoxic Cr(III). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(VI) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration. The reaction mechanism of Cr(VI) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(VI)-contaminated soils and groundwater.
基金Project supported by the National Basic Research Program (973) of China (No. 2004CB418505)the Science and Technology Development Program of Heilongjiang Province (No. CC05S301), China
文摘In solving the deterioration of biological treatment system treating petrochemical wastewater under low temperatures, bioaugmentation technology was adopted by delivering engineering bacteria into a pilot-scale two-stage anoxic-oxic (A/O) process based on previous lab-scale study. Experimental results showed that when the concentrations of COD and NH4+-N of the influent were 370~910 mg/L and 10~70 mg/L, the corresponding average concentrations of those of effluent were about 80 mg/L and 8 mg/L respectively, which was better than the Level I criteria of the Integrated Wastewater Discharge Standard (GB8978-1996). According to GC-MS analysis of the effluents from both the wastewater treatment plant (WWTP) and the pilot system, there were 68 kinds of persistent organic pollutants in the WWTP effluent, while there were only 32 in that of the pilot system. In addition, the amount of the organics in the effluent of the pilot system reduced by almost 50% compared to that of the WWTP. As a whole, after bioaugmentation, the organic removal efficiency of the wastewater treatment system obviously in- creased.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No. 2002CB412304) the Chinese Academy of Sciences (No. KZCX1-SW-Ⅱ-32).
文摘A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble phosphorus (WSP),diluted calcium chloride extractable phosphorus (PCaCl2), and Olsen-P in the sediments of Taihu Lake, China, where potential P release in response to pH was analyzed. MPA for rapid P analysis was shown to be promising when applied on samples of natural water and sediment extracts. Concentrations of WSP and PCaCl2 in the sediments were much lower than those of Olsen-P. Olsen-P levels in the littoral sediments along the north coast of Meiliang Bay in Taihu Lake (80to 140 mg kg-1) were much higher than those in the mouth of the bay (less than 50 mg kg-1). The risk of P release in the mouth area of Meiliang Bay was lower than that in the north littoral zone with a risk of sediment P release induced by pH increases.
基金Supported by the National Natural Science Foundation of China(No.41306122)the National Special Research Fund for Non-Profit Marine Sector(Nos.201405040,201505022)+1 种基金the Scientific Funds for Outstanding Young Scientists of Shandong Province Award(No.BS2012HZ013)the Shandong Agricultural Application Technology Innovation of Research Project
文摘Heavy metal pollution in aquatic system is becoming a serious problem worldwide. In this study, responses of Sargassum thunbergii to dif ferent concentrations(0, 0.1, 0.5, 1.0 and 5.0 mg/L) of zinc(Zn) and cadmium(Cd) exposure separately were studied for 15 days in laboratory-controlled conditions. The results show that the specifi c growth rates increased slightly under the lower Zn concentration treatment(0.1 mg/L) at the first 5 d and then decreased gradually, which were significantly reduced with the exposure time in higher Zn concentrations and all Cd treatments compared to respective control, especially for 1.0 and 5.0 mg/L Cd. Chlorophyll a contents showed significant increase in 0.1 mg/L Zn treatment, whereas the gradually reduction were observed in the other three Zn treatments and all Cd treatments. The oxygen evolution rate and respiration rate presented distinct behavior in the Zn-treated samples, but both declined steadily with the exposure time in Cd treatments. The P/R value analyses showed similar variation patterns as chlorophyll a contents. Real-time PCR showed that lower Zn concentration(0.1 mg/L) increased mRNA expression of rbcL gene, whereas higher Zn concentrations and Cd reduced the rbcL expression. Taken together, these findings strongly indicate that Zn and Cd had different effects on S. thunbergii both at the physiological and gene transcription levels, the transcript level of photosynthesis-related gene rbcL can be used as an useful molecular marker of algal growth and environment impacts.
文摘An understanding of the long-term changes in the nitrate and microbial contamination pattern of the groundwater of Sidi Bouzid (Centre West of Tunisia) is critical to conservation of drinking water in rural areas supporting mixed land-use activities such as cropping, livestock farming, and residence. The phreatic aquifer was revealed polluted by domestic disposals of the wastewaters in the urban zone. The average nitrate concentration in the groundwater of the east of the mioplioquaternary aquifer of Saddaguia (Sidi Bouzid) rose from 50 mg NO3- during 1996 to over 100 mg in 2003, which represents an increase of some 10 mg per year. Nitrate groundwater pollution during the period 1996-2003 was the result of the abusive use of fertilizers.In the cultivated zone, we must reduce the effects of the excessive use of the nitrogen fertilizers on the basis of monitoring soil once a year, managing water resources, rationalizing the use of the chemical substances. In urban zones, most of lost wells located in the perimeter reveal the gravity of the state of the aquifer. This last is organically polluted and requires an immediate action for the generalization of the purification network. We need to take into account the reality of under soil in all future planning's and arrangements. A scheme of sanitation seems necessary before all plans of arrangement. The extension of the sewer network must give the priority to the most vulnerable zones.
文摘This paper presents an environm centally friendly method of inhibiting biofouling especially acorn barnacles on surfaces under water by using nicotine and selenium in the form of Se(0), or such a substance which can be converted into them. Both of the substances are necessary to oxygen dependent organisms and will be used after conversion, but are toxic in high doses. By adding the substances to paint or other surface treatment agent which marine surfaces are treated with, organisms which are trying to establish themselves on the surfaces will be exposed to so high doses, the reactions which the settling is based on are disturbed. When the substances leak out into the seas, they will act as environment protectors, as they promote the development of organisms. Nicotine is transformed to nicotine amid which is the reactive part in NADH and one of the most important substances for the transference of hydrogen. Selenite is reduced to Se(0), also involved in the transport chain of hydrogen to reducible oxygen. However, large quantities Se(0) may disturb the reactions of sulphur b'./binding to it and impairing the formation of S-S-bridges.
文摘Biological activated carbon (BAC) has been developed on the granular activated carbon by immobilization of selected and acclimated species of bacteria to treat the micro-polluted water. The BAC removal efficiencies for nitrobenzene, permanganate index, turbidity and ammonia were investigated. Effects of shock loading and SEM (Scanning Electron Microscope) observation on BAC were studied. Backwashing and its intensity of BAC were also discussed. The results showed that BAC took short time to start up and recover to the normal condition after shock loading. The shock loading studies showed that the removal efficiency of BAC was not completely inhibited even at high concentration of nitrobenzene. Backwashing performed once every 10-20 d, or an average of 15 d. Backwashing intensity was 12-14 L/(s·m2) with air and 3-4 L/(s·m2) with water.
文摘The variation of water quality in water distribution system was investigated with assimilable organic carbon (AOC)and trihalomethanes(THMs) used as assessment indexes. Bacterium was identified in water distribution. The result showed that there were pathogenic parasites in water distribution system. The variation of AOC is related to chlorine residual and bacterium activity, and AOC concentration decreased first and then increased with the extension of water distribution system. The formation of THMs was related to the consumption of chlorine inside the distribution system, and THMs concentration increased with the extension of water pipe line.
基金Supported by the NSFC (No.30070157 40206015) and the Scientific Fund of Quanzhou City (No. Z200234).
文摘In order to estimate the biodegradation of three polycyclic aromatic hydrocarbons (PAHs) compounds, bacterial strains were isolated from marine sediments in three heavily contaminated sites (Yuandang Lake, Dongdu Port and Aquacultural zones in Maluan Bay) in Xiamen Western Sea. The results show three bacterial strains, which used pyrene as the sole carbon source, were identified as strains of Aureobacterium sp., Arthrobacter sp., Rhodococcus sp. The PAH-degrading bacteria isolated had a strong ability to degrade phenan-hrene, fluoranthene and pyrene at different degradation rates. The highest degradation rate was observed when three PAH compounds were mixed with an individual strain in the medium. The three PAHs were degraded after one week with a degradation rate of 89.94 % for phenanthrene and 93.4 % for both of fluoranthene and pyrene. In addition, after 25 days of incubation, the degradation rate was 99.98 % for phenanthrene and 99.97 % for both of fluoranthene and pyrene. Optical density was measured to estimate bacterial growth during the degradation of PAHs. Highest levels of bacterial growth were observed with a three PAH mixture in the culture, suggesting that the concentration of PAHs influenced bacterial growth and the highest levels of degradation for most series were detected after one week of incubation.
文摘The biosorption of copper(Ⅱ) ions onto biofilm was studied in a batch system with respect to the temperature, initial pH value and biofilm sorbent mass. The biomass exhibited the highest copper(Ⅱ) sorption capacity under the conditions of room temperature, initial pH value of 6.0 and the sorbent mass 8 g. The experimental data were analyzed using four sorption kinetic models, the pseudo-first order, the Ritchie second order, the modified second order and the Elovich equations to determine the best-fit equation for the sorption of metal ions onto biofilm. Comparing with the sum of squared-errors, the results show that both the Ritchie second order and modified second order equations can fit the experimental data very well.
基金supported by the National Natural Science Foundation of China (No.20707040)the State Key Laboratory of Pollution Control and Resource Reuse Foundation(No. PCRRF08002).
文摘A series of orthogonal array experiments were conducted using carbon source, ammonia nitrogen and total phosphorus (TP) as major influencing factors to investigate the effects of nutrients on biofouling formation and preponderant bacteria diversity in the recirculatiug cooling water system. Carbon source was demonstrated to be the most significant determinant affecting the biofouling formation. A minimum biofouling outcome was obtained when BOD2, NHa+-N and TP were 25, 10, and 1 mg/L, respectively. Then the preponderant bacteria strains in biofouling mass under two typical culture conditions (negative and favorable) were identified applying both traditional biochemical methods and further molecular biology technology with phylogenetic affiliation analysis, which indicated that Enterobacteriaceae Enterobacter, Micrococcaceae Staphylococcus, Bacillaceae Bacillus, Enterobacteriaceae Proteus, Neisseriaceae Neisseria and Pseudomonadaceae Pseudomonas were dominant under negative condition, while Enterobacteriaceae Klebsiella, Enterobacteriaceae Enterobacter and Microbacterium - under favorable one.
基金The work was supported by Natural Science Foundation of China(Grant No. A20077023 and C40106012
文摘In this study, two common pollutants (benzo[a]pyrene and methamidophos) in marine environment were tested by comet assay for their inducement of in vivo genotoxic effect to the blood cells of black porgy ( Acanthopagrus schlegeli). The fish was exposed to 2 μg/L of benzo[a]pyrene (BaP) and methamidophos, and their mixture. The assay was performed on whole blood at 2 h, 5 h, 24 h and 96 h exposure intervals. A signifi- cant increase in DNA damage was observed in each treatment with the pollutants. Additive effect of BaP and methamidophos was also found in the experiment. However, the decrease ratios of DNA damage for 5 h and 96 h exposure interals compared with 2 h and 24 h exposure ones, respectively, were noticed. This phenomenon may be explained by the function of repairing process via enzyme cytochrome P450 in the animal. Evidence of the genotoxicity of organophosphorus pesticides (OPs) and polynuclear aromatic hydrocarbons (PAHs) on marine fish are discussed in this paper.
基金Supported by the Proyecto Fondecyt (1040089,1090098)
文摘While conventional wastewater treatments for urban effluents are fairly routine and have proved highly effective,industrial wastewater requires more complex and specific treatments.This paper provides a technological strategy for removal of recalcitrant contaminants based on a hybrid treatment system.The model effluent containing a binary mixture of synthetic dyes is treated by a combination of a preliminary physicochemical stage followed by a biological stage based on ligninolytic enzymes produced by Phanerochaete chrysosporium.This proposal includes biosorption onto peat as pretreatment,which decreases the volume and concentration to be treated in the biological reactor,thereby obtaining a completely decolorized effluent.The treated wastewater can therefore be reused in the dyeing baths with the consequent saving of water resources.