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A research was done to study the Pb adsorption by the root cell wall of tea plant extracted from Longjing 43. It was indicated that the amount of Pb adsorbed by the root cell wall increased with augment of the initial pH of the solution under acidic condition, dramatically as the pH ranged from 2. 0 to 4. 5. The amount of Pb increased with the Pb concentration in the solution at pH 4. 5, which could be well fitted by the Freundlich adsorption model. The adsorbed Pb reached 9.7 mg ∙ g-1 under equilibrium condition, 90% of which was adsorbed in 320 minutes, while 50% was desorbed in 60 minutes based on the desorption dynamic curve. The kinetics of both adsorption and desorption could be well described by a second-order rate equation. The amount of absorbed Pb by the root cell wall varied after modified treatments, reducing by 51. 1% after esterifing, 41. 3% with pectinase, and 10. 8% via aminomethylation, suggesting that carboxyl, galacturonic acid, pectin and amino, to some extent, all took part in the Pb adsorption by the root cell wall. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyls (PCBs) are the typical persistent organic pollutants (POPs) in the environment. As a ubiquitous attenuation course of chlorinated organic compounds in anoxic environment, the microorganism-mediated reductive dechlorination process plays an important role in PCBs transformation, especially the transformation of higher chlorinated PCBs. The higher chlorinated PCBs can be dechlorinated in anaerobic condition, and thus, their persistence and toxicity can be decreased. The resultant lower chlorinated PCBs from the dechlorination can be further degraded and completely mineralized in aerobic condition. This paper summarized the research advances of PCBs microbial reductive dechlorination, introduced the mechanisms and characteristics of the dechlorination and the related specific microorganisms, and approached the affecting factors of PCBs bio-dechlorination, as well as the significances of anaerobic dechlorination coupling with aerobic degradation. The future research directions, including the complex metabolic networks of dechlorinating microbial populations, the screening of novel specific dechlorinators and their practical applications in the remediation of PCBs contaminated sites were also prospected. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants have increasingly become a critical environmental concern, while thermophiles have the high potential of degrading various kinds of environmental organic pollutants. At high temperatures, thermophiles have higher metabolic activity, and the competition by mesophiles is reduced, meanwhile, the solubility and bioavailability of some persistent organic pollutants are greatly increased, and thus, the degradation of the pollutants by thermophiles is more rapid and complete. Therefore, thermophils are of great significance for the bio?treatment of organic wastewater and the bioremediation of organic pollutants?contaminated sites. This paper introduced the research progress on the degradation of organic pollutants by thermophiles in terms of the characteristics of thermophiles in degrading organic pollutants, the effects of temperature on the degradation, the degradation pathways, the degradation enzymes, their coding genes, and practical engineering applications. The future research directions including the degradation mechanisms of thermophiles, their resources reserve, related technology strategies and their applications were also prospected. [ABSTRACT FROM AUTHOR]

Soil microbial indicator is one of the important biological indicators in evaluating the extent of soil contamination. In recent years, with the development of molecular biology, many studies have focused on the ecological functions of soil microorganisms by using metagenomics, metatranscriptome and metaproteomics. Relative to metagenomics and metatranscriptome, soil metaproteomics aims to investigate the spatial and temporal changes of the proteins extracted from soil as well as the functional components of soil microbial genomic expression products, which is more conclusive to explore the ecological functions of soil microbes and their roles in soil pollutants transportation and transformation. Therefore, soil metaproteomics has great potential in soil pollution assessment. Currently, soil metaproteomics is still at its infancy stage, while soil protein extraction method is one of the key factors restraining the potential application of soil metaproteomics. In this paper, the advantages and disadvantage of soil metaproteomics in soil pollution assessment were reviewed, with the focus on the comparison of different soil protein extraction methods. In combining with case studies, the feasibility and limits of soil proteins as an indicator for soil pollution assessment were analyzed. In addition, the future research perspectives on the development of soil metaproteomics were discussed. [ABSTRACT FROM AUTHOR]

Activated sludge process is widely used in treating a wide variety of wastewater, but the by-product is the large amount of excess sludge. To treat the excess sludge properly could spend 25%-60% of the total cost of wastewater treatment, while improperly treating the sludge could cause serious secondary pollution. Therefore, the reduction of excess sludge is becoming a rising challenge. Using thermophiles to degrade excess sludge is a way easy in operation and inexpensive in maintenance, being a promising method in application. This paper reviewed the recent progress in the researches of sludge-degrading thermophiles, their working mechanisms, and the enzymes from thermophiles, such as thermophilic proteolytic enzymes and thermophilic lipases which play an important role in the degradation of sludge. The factors affecting the degradation of sludge by thermophiles were summarized, and the perspectives for the further research on the application of thermophiles in digesting sludge were discussed. [ABSTRACT FROM AUTHOR]

Solid state phosphorous is an important phosphorus speciation controlling the phosphorous bioavailability and mobility in the environment. Synchrotron-based X-ray absorption near-edge structure ( XANES) spectroscopy, with its unique advantage of being a non-destructive method in identifying the local chemical information of target element at molecular level in situ, has become one of the frontier technologies for characterizing the speciation of chemical substances and clarifying the microscopic mechanisms of chemical reactions, attracting extensive attention in the field of environmental chemistry. This paper briefly introduced the basic theory of phosphorus XANES spectroscopy , summarized the applications of XANES spectroscopy in the researches of solid state phosphorus speciation in minerals, soils, and organic fertilizers, and analyzed the challenges and prospects of the applications of XANES spectroscopy in identifying the solid state phosphorus speciation in the environmental samples. It was pointed out that XANES spectroscopy should combine with other microscopic spectroscopic techniques and macroscopic analytical methods, complementing each other, to provide a comprehensive and effective technical support for the research of the speciation characterization and transformation mechanisms of phosphorus in the environment. [ABSTRACT FROM AUTHOR]

A hydroponics experiment combined with subcellular fractionation and sequential extraction was conducted to study the Pb concentration in different organs of two tea plant varieties (Longjing 43 and Yingshuang) and the Pb subcellular distribution and chemical forms in the roots of the varieties. Under Pb stress, the root system of the two varieties had different features in morphology. With the increasing concentration of Pb in culture solution, the Pb concentration in Longjing 43 young leaves increased, but that in Yingshuang爷s had no significant variation. A marked difference was observed in the Pb subcellular distribution and its chemical forms in roots between the two varieties under Pb stress. In Longjing 43 roots, all subcellular fractions except soluble ones had a lower Pb concentration at low Pb stress, and all the subcellular fractions except cell wall ones had a higher Pb concentration at higher Pb stress, compared with those in Yingshuang爷s. In Longjing 43 roots, the HAc鄄extractable Pb occupied the greatest proportion, followed by NaCl鄄extractable Pb, HCl鄄and H2O鄄extractable Pb, and ethanol鄄extractable Pb; while in Yingshuang爷s, NaCl鄄extractable Pb had the greatest proportion, followed by HAc鄄extractable Pb, HCl鄄and H2O鄄extractable Pb, and ethanol鄄extractable Pb. Based on these findings, tea plant variety Yingshuang was likely to possess a higher tolerance to Pb than Longjing 43 did. [ABSTRACT FROM AUTHOR]

Taking non-transgenic parental rice as the control, and by using 13C pulse-chase labeling method coupled with phospholipid fatty acid (PLFA) analysis, this paper studied the effects of transgenic Bt rice on the here soil. The results showed that in the rhizosphere soils of transgenic Bt rice and its non-transgenic parent, saturated PLFAs and branched PLFAs were the main, followed by monounsaturated PLFAs, and polyunsaturated PLFAs. A significantly lower amount of Gram-positive bacterial PLFAs and a higher amount of Gram-negative bacterial PLFAs were observed in the rhizosphere soil of transgenic Bt rice at its seedling, booting, and heading stages, as compared with the control. In the whole growth ?period of rice, transgenic Bt gene had no significant effects on the fungal and actinomycete PLFAs in rhizosphere soil, and no significant difference was observed in the rhizosphere soil 13C-PLFA content between transgenic Bt rice and its non-transgenic parent. These findings indicated that the insertion of exogenous cry1Ab gene into rice only had temporary effects on the microbial community composition in the rhizosphere soil of rice. [ABSTRACT FROM AUTHOR]

Persisters are a group of special subpopulation of bacteria, only occupying <0-1% of the whole population but having the characteristics different from the ordinary bacteria and resistant mutants. They have complex formation mechanism, and are difficult to isolate and culture. The persisters can adapt to the adverse environment via "dormancy-growth-proliferation-to maintain their survival and cell structure stability, and play a vital role in the multi-drug and multi-metal tolerance of microbial biofilm, being of great significance in maintaining the stability of microbial community structure. This paper reviewed the research progress on the characteristics of persisters, their gene regulation mechanisms, and their effects on the multi-drug and multi-metal tolerance of microbial biofilm. The related research directions in the future were also prospected. [ABSTRACT FROM AUTHOR]

Phosphorus (P) release from sediments is one of the most important causes of lake eutrophication, while the activity of P is determined by P chemical form. Due to its advantages in improving our knowledge about the P fractions in environmental samples, the 31P nuclear magnetic resonance (31P NMR) technology has received extensive attention. This paper summarized the current studies on the characterization, translocation, and transformation of P fractions in sediments by using this technology, and described the technical principles, classification, analytical procedures, and specific application fields of this technology. At present, the researches of sediment P by using 31P NMR technology were focused on the characterization of different P forms, the effects of microbes on the P translocation and transformation, and the quantitative analysis of different P fractions. The studies on the P-extracting agents and extraction methods were the hot topics as well. The potential issues and research trends about the application of 31P NMR technology in environmental samples were also discussed. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted to study the microbial activity and community structure in a lead-polluted paddy soil under effects of amendment with different concentration sodium thiosulfate. The amendment of the sulfur-containing substrate increased the soil oxidation-reduction potential and respiration rate, promoted the growth of soil sulfur-oxidizing bacteria, and induced some changes in soil microbial community structure. The clone sequencing indicated that the specific bands of soil microbes in sodium thiosulfate treatments had very high similarity to Bateroidetes, Thiobacillus, β-proteobacteria, and Acidobacteria. Significant changes were observed in the contents of soil carbonate- and Fe/Mn oxide- bound Pb after the amendment of sodium thiosulfate. [ABSTRACT FROM AUTHOR]

Laboratory simulation tests were conducted to examine the effects of different washing reagents (distilled water, HCl, H3PO4, oxalic acid, and CaCl2) in extracting the heavy metals from contaminated soils left by a chemical plant. The effects of reagent concentration, reaction time, and washing time on the washing efficiency were investigated, and the form variation of test heavy metals was determined before and after HCl washing. Distilled water, H3PO4, and CaCl2 could remove less than 1% of most heavy metals, and the highest removal rate was only 3.58%; while 2 mol HCl∙L-1could obtain the highest washing efficiency under the optimal conditions, i.e., soil:liquid ratio was 1:3, reaction time was 1 hour, and the soils were washed twice by HCl solution. The removal rates of Cr, Pb, Zn, Cu, and Cd from test soils were 80.75%, 88.69%, 98.00%, 79.33%, and 95.52%, respectively. Among the washing reagents, HCl could effectively remove all forms of heavy metals. [ABSTRACT FROM AUTHOR]

Landfill sites are the major sources of offensive odor in urban public facilities. With the progress of urbanization and the residents' demands for a higher living environment quality, the odor emission from landfill sites has become a severe pollution problem, and the odor control at landfill sites has been one of the research hotspots. This paper summarized the main components and their concentrations of the odor from landfill sites, and expatiated on the research progress in the in-situ control of the odor. The further research directions in in-situ control of the odor from landfill sites were prospected. [ABSTRACT FROM AUTHOR]

Tea waste is an important part of agricultural solid wastes,because of its various sources and huge amount. The heavy metals removal from waste water by tea waste has been paid much attention by the researchers around the world,owing to the adsorption characteristic of tea waste. In this paper,the research advances in the heavy metals removal from aqueous phase by tea waste were summarized from the aspects of affecting factors,adsorption mechanism,pretreatment,desorption,and regeneration,and the prospects were put forward. It was considered that for the industrialized utilization of tea waste absorbents, further researches should be focused on their adsorption mechanism,pretreatment,desorption and regeneration,technological parameters,and aftertreatment. [ABSTRACT FROM AUTHOR]

A 2-month fumigation experiment was conducted with opened top chambers to study the effects of different concentration (0.1, 0.5, and 4.0 microl · L-1) NO2 on the growth and photosynthesis of 1-year Cinnamomum camphora seedlings. Fumigation with 0.1 and 0.5 microl NO2 · L-1 promoted the growth of the seedlings, while with 4.0 microl NO2 · L-1 was in adverse. The diurnal variation of net photosynthetic rate (Pn) presented two-peaks, with an obvious depression in midday. 0.5 microl NO2 · L-1 increased the Pn, the maximum of Pn reached 8.542 micromol CO2 · m-2 s-1; 4.0 microl NO2 · L-1 decreased the Pn in most period of time; while the effect of 0.1 microl NO2 · L-1 varied with time period. Fumigation with 0.5 and 4.0 microl NO2 · L-1 increased the maximal and minimal values of stomatal conductance (Gs) and intercellular CO2 concentration (Ci), while 0.1 microl NO2 · L-1 increased the maximal and minimal values of Ci but decreased the maximal and minimal values of Gs. At the middle and late stages of fumigation, the mean Pn of the seedlings treated with 0.5 microl NO2 · L-1 was significantly higher than that treated with 0.1 and 4 microl NO2 · L-1. At the early stage of fumigation, 0.5 and 4.0 micro NO2 · L-1 significantly decreased the maximal PS II efficiency (Fv/Fm); and at the late stage, 4.0 μNO2 · L-1 still decreased the Fv/Fm significantly. [ABSTRACT FROM AUTHOR]

Biomass-derived black carbon, also named biochar, has the characteristics of high stability against decay and high capability of adsorption, and can affect the environment through its interactions with climate and geology, playing a significant role in global climate change, carbon biogeochemical cycle, and environmental system. In recent years, more and more researchers in the fields of atmospheric sciences, geology, and environmental science focused on the environmental behavior and effect of biochar. As one possible source of the components with high aromatic structure in soil humus, biochar is of great importance in increasing soil carbon storage and improving soil fertility, and in maintaining the balance of soil ecosystem. This paper offered the latest information regarding the characteristics and biotic and abiotic oxidation mechanisms of biochar, its effects on global climate change, and the environmental effect of biochar in soil. Research prospects were briefly discussed on the environmental behavior and effect of biochar in soil ecosystem. [ABSTRACT FROM AUTHOR]

The inhibitory effect of allelochemicals released by submerged macrophytes on ph ytoplankton is considered as one of the mechanisms that contribute to the stabilization of clear-water status in shallow lakes. This paper reviewed t he research progress in the allelopathy of submerged macrophytes on algae from t he aspects of the occurrence frequency and coverage of allelopathically active s ubmerged macrophytes in lakes, and the kinds and allelopathical effects of the a llelochemicals released from the macrophytes. The previous researches indicated that allelopathically active submerged macrophyte species such as Myriophyllum , Ceratophyllum, and Elodea were efficient to control phytoplankton, especially when their biomass was high enough, and the dominant algae were sensitive species. The allelochemicals such as hydroxybenzene released by the submerged ma crophytes could inhibit the growth of algae. Different phytoplankton species exhibited different sensitivity against allelochemicals, e.g., cyanobacteria and diatom were more sensitive than green algae, while epiphytic species were less sensitive than phytoplankton. Environmental factors such as light, temperature, and nutrients could significantly affect the allelopathical effect of submerged macrophytes. The research of the allelopathy of submerged macrophytes is still at its beginning, and further researches are needed on the effects of environmental factors on the allelopathy, extraction and identification of allelochemicals, selective algal control mechanisms, and metabolism of the allelochmicals. [ABSTRACT FROM AUTHOR]

In this paper, a treatment process consisted of UASB, step-fed sequencing batch reactor (SFSBR) and magnesium ammonium phosphate precipitation reactor (MAP) was built to treat the large scale swine wastewater, which aimed at overcoming drawbacks of conventional anaerobic-aerobic treatment process and SBR treatment process, such as the low denitrification efficiency, high operating costs and high nutrient losses and so on. Based on the treatment process, a pilot engineering was constructed. It was concluded from the experiment results that the removal efficiency of COD, NH4(+) -N and TP reached 95.1%, 92.7% and 88.8%, the recovery rate of NH4(+) -N and TP by MAP process reached 23.9% and 83.8%, the effluent quality was superior to the discharge standard of pollutants for livestock and poultry breeding (GB 18596-2001), mass concentration of COD, TN, NH4(+) -N, TP and SS were not higher than 135, 116, 43, 7.3 and 50 mg x L(-1) respectively. The process developed was reliable, kept self-balance of carbon source and alkalinity, reached high nutrient recovery efficiency. And the operating cost was equal to that of the traditional anaerobic-aerobic treatment process. So the treatment process could provide a high value of application and dissemination and be fit for the treatment pf the large scale swine wastewater in China.

Polychlorinated biphenyls (PCBs) are the typical persistent organic pollutants (POPs) in the environment. As a ubiquitous attenuation course of chlorinated organic compounds in anoxic environment, the microorganism-mediated reductive dechlorination process plays an important role in PCBs transformation, especially the transformation of higher chlorinated PCBs. The higher chlorinated PCBs can be dechlorinated in anaerobic condition, and thus, their persistence and toxicity can be decreased. The resultant lower chlorinated PCBs from the dechlorination can be further degraded and completely mineralized in aerobic condition. This paper summarized the research advances of PCBs microbial reductive dechlorination, introduced the mechanisms and characteristics of the dechlorination and the related specific microorganisms, and approached the affecting factors of PCBs bio-dechlorination, as well as the significances of anaerobic dechlorination coupling with aerobic degradation. The future research directions, including the complex metabolic networks of dechlorinating microbial populations, the screening of novel specific dechlorinators and their practical applications in the remediation of PCBs contaminated sites were also prospected.

Soil microbial indicator is one of the important biological indicators in evaluating the extent of soil contamination. In recent years, with the development of molecular biology, many studies have focused on the ecological functions of soil microorganisms by using metagenomics, metatranscriptome and metaproteomics. Relative to metagenomics and metatranscriptome, soil metaproteomics aims to investigate the spatial and temporal changes of the proteins extracted from soil as well as the functional components of soil microbial genomic expression products, which is more conclusive to explore the ecological functions of soil microbes and their roles in soil pollutants transportation and transformation. Therefore, soil metaproteomics has great potential in soil pollution assessment. Currently, soil metaproteomics is still at its infancy stage, while soil protein extraction method is one of the key factors restraining the potential application of soil metaproteomics. In this paper, the advantages and disadvantage of soil metaproteomics in soil pollution assessment were reviewed, with the focus on the comparison of different soil protein extraction methods. In combining with case studies, the feasibility and limits of soil proteins as an indicator for soil pollution assessment were analyzed. In addition, the future research perspectives on the development of soil metaproteomics were discussed.

Anammox (anaerobic ammonium oxidation) is an important process of nitrogen cycle, with great potential for the practical use in removing nitrogen from the wastewater containing high concentration ammonium. However, the presence of high concentration organic carbon source is considered unfavorable to anammox. Coupling anammox and denitrification under the presence of organic carbon source could be a useful technique for removing both nitrogen and carbon. This paper reviewed the mechanisms of anammox-denitrification coupling process, functional microbial groups, initiation of the coupling process and its control, and related environmental affecting factors. The future research prospects and potential applications of anammox-denitrification coupling process in wastewater treatment were discussed.

In conventional wastewater bio-treatment, little attention has been paid on the bio-degradation of grease, causing low efficiency in the process, and thereby, further study should be made on the development and application of related mature and effective bio-treatment techniques. This paper summarized the pathways and mechanisms of grease bio-degradation in wastewater treatment, with the focus on the research progress in the functional microbes involved in lipid hydrolysis and long-chain fatty acid degradation, and briefly introduced a series of new treatment technologies based on the habitat differences of the functional microbes. The key breakthrough directions in the technological study of grease bio-degradation were prospected, expecting to provide theoretical guidance to the development of the related technologies.

As the first step of nitrification, ammonia oxidation is the key process in global nitrogen biogeochemical cycling. So far, the autotrophic ammonia-oxidizing bacteria (AOB) in the beta- and gamma-subgroups of proteobacteria have been considered as the most important contributors to ammonia oxidation, but the recent researches indicated that ammonia-oxidizing archaea (AOA) are widely distributed in various kinds of ecosystems and quantitatively predominant, playing important roles in the global nitrogen biogeochemical cycling. This paper reviewed the morphological, physiological, and ecological characteristics and the molecular phylogenies of AOA, and compared and analyzed the differences and similarities of the ammonia monooxygenase (AMO) and its encoding genes between AOA and AOB. In addition, the potential significant roles of AOA in nitrogen biogeochemical cycling in aquatic and terrestrial ecosystems were summarized, and the future research directions of AOA in applied ecology and environmental protection were put forward.

Phosphorus (P) release from sediments is one of the most important causes of lake eutrophication, while the activity of P is determined by P chemical form. Due to its advantages in improving our knowledge about the P fractions in environmental samples, the 31P nuclear magnetic resonance (31P NMR) technology has received extensive attention. This paper summarized the current studies on the characterization, translocation, and transformation of P fractions in sediments by using this technology, and described the technical principles, classification, analytical procedures, and specific application fields of this technology. At present, the researches of sediment P by using 31P NMR technology were focused on the characterization of different P forms, the effects of microbes on the P translocation and transformation, and the quantitative analysis of different P fractions. The studies on the P-extracting agents and extraction methods were the hot topics as well. The potential issues and research trends about the application of 31P NMR technology in environmental samples were also discussed.

Seasonal variations of self-purification ability for small natural shallow lakes in South Lake Taihu were investigated. The results showed that seasonal difference of self-purification of permanganate index, total nitrogen (TN), ammonium (NH4(+)-N), nitrate (NO3(-)-N), total phosphorus (TP), chlorophyll (Chl-a) in small shallow lakes were remarkable. Effects of self-purification were better in spring and winter, and were worse in summer by NH4(+)-N and NO3(-)-N and in autumn by TP and Chl-a. Organic pollution was light, TN and TP pollution were seriously in four seasons. Concentrations of TN and TP brought a well condition to algae growth, and lakes were eutrification easily by the limiting factor of phosphorus. Concentrations of Chl-a were showed that lakes were eutrophic in summer or autumn and mesotrophic in winter or spring. Growth and blooms of phytoplankton impacted water quality and self-purification of lakes. Species and quantity of aquatic plants were the main factors to affect the change of pH and dissolved oxygen (DO), and loss of fertilizer and domestic wastewater were the main reasons for high nitrogen and phosphorus concentrations in lakes. Organic nitrogen was the main portion of TN by using excessive organic fertilizer in summer, NO3(-)-N was the main portion in other seasons. The principal component analysis result showed that the three principal components of self-purification ability were phytoplankton factor (water temperature, pH, permanganate index and Chl-a), farm drainage factor (pH, DO and TN), nutrient factor (TN and TP). The cluster analysis result showed that the water quality of four seasons in 11 sampling sites of three lakes could be divided into two categories: first, in spring, autumn and winter; second, in summer. This was caused by the temperature changes and agricultural drainage. Water temperature and pH were used to calculate the concentrations of permanganate index, TN, TP, Chl-a by linear equations, which improved the quick prediction ability in locale.

The effects of bio-charcoal acted as sludge-composting additive on soil characteristics and plant growth were studied. Compared with the treatment of composted sludge without bio-charcoal, soil cation exchange capacity in treatment of composted sludge with bio-charcoal increased over 5% and 10% respectively and soil nitrogen content increased 13% and 18% respectively for two kind soils. The composted sludge with bio-charcoal also resulted in 23% higher enhancement on ryegrass biomass and 8%-10% higher enhancement on ryegrass chlorophyll content. In addition, with the amendment of bio-charcoal, the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in composted sludge was decreased, which resulted in the lower absorption and accumulation of ryegrass to PAHs. Compared with the control, the PAHs concentration in ryegrass amended composted sludge with bio-charcoal decreased 27%-34%. The results indicated that composted sludge with bio-charcoal resulted in much more improvement on the plant growth as well as less negative effect on environment. Therefore, biocharcoal was in favor of the safe land application of sewage sludge.

A 2-month fumigation experiment was conducted with opened top chambers to study the effects of different concentration (0.1, 0.5, and 4.0 microl x L(-1)) NO2 on the growth and photosynthesis of 1-year Cinnamomum camphora seedlings. Fumigation with 0.1 and 0.5 microl NO2 x L(-1) promoted the growth of the seedlings, while with 4.0 microl NO2 x L(-1) was in adverse. The diurnal variation of net photosynthetic rate (P(n)) presented two-peaks, with an obvious depression in midday. 0.5 microl NO2 x L(-1) increased the P(n), the maximum of P(n) reached 8.542 micromol CO2 x m(-2) s(-1); 4.0 microl NO2 x L(-1) decreased the P(n) in most period of time; while the effect of 0.1 microl NO2 x L(-1) varied with time period. Fumigation with 0.5 and 4.0 microl NO2 x L(-1) increased the maximal and minimal values of stomatal conductance (G(s)) and intercellular CO2 concentration (C( i)), while 0.1 microl NO2 x L(-1) increased the maximal and minimal values of C(i) but decreased the maximal and minimal values of G(s). At the middle and late stages of fumigation, the mean P(n) of the seedlings treated with 0.5 microl NO2 x L(-1) was significantly higher than that treated with 0.1 and 4 microl NO2 x L(-1). At the early stage of fumigation, 0.5 and 4.0 micro NO2 x L(-1) significantly decreased the maximal PS II efficiency (F(v)/F(m)); and at the late stage, 4.0 microl NO2 x L(-1) still decreased the F(v)/F(m) significantly.

As a main life element, carbon plays important role in the matter cycling in soil-plant system. Stable carbon isotope 13C has been widely used in the study of carbon cycling in soil-plant system, due to its safe, no pollution, and easy to be handled. Through the analysis of both natural and labeled 13C organic matter in soil-plant system, a better understanding of the mechanisms of photosynthesis, the distribution of photosynthates in plant-soil system, the fate of plant litter, and the source of new carbon in soil could be achieved. In this paper, the applications of stable carbon isotope technique in the researches of photosynthesis, reconstruction of paleoclimate, turnover of soil organic matter, and interactions between plants and rhizosphere microorganisms were briefly summarized, and the perspectives of the application of stable carbon isotope technique were also discussed, based on the issues existed in current researches.

Waste gases biofiltration is an emerging technology, and has played important roles in air pollution control. In this paper, the structure of biofilter and biotrickling filter and their mechanisms in air pollution removal were introduced, with focus on the research advances in the isolation and identification of microbes in the filters, correlations between microbial abundance, activity and community diversity, influences of operation conditions on microbial community, spatiotemporal change patterns of microbial community structure during operation, development of biofilm, and biodegrading dynamic models. The research perspectives in microbial ecology during biofiltration of waste gases were discussed.

With the effective control of point source pollution, the non-point source pollution (NPSP) of water environment has been paid more and more attention, and NPSP models are thriving with the development of 3S technology. This paper made a brief introduction about the classification and evolution of NPSP models. Ten NPSP models commonly used abroad were selected and compared, with their software developers and providers, data input and output, pollutant- and sediment types, time scale, simulation progress and characteristics, and model types illustrated. Based on the model applications and related literature reports, a qualitative evaluation was made from the viewpoint of the suitability of NPSP models to different watershed situation. Finally, the existing research insufficiency was analyzed, and the future development trend of non-point research was discussed, which would be helpful to the development of NPSP models and their applications in water management in China.

Using a multi-layer soil column device, the effect of new nitrification inhibitor DMPP (3,4-dimethyl pyrazole phosphate) on nitrogen leaching was studied for understanding the nitrogen vertical transformation and lowering the nitrogen leaching losses. The results indicate that, within 60 days of experiment, the regular urea added with 1% of DMPP can effectively inhibit the ammonium oxidation in the soil, and improve the concentration of NH4(+) -N in soil solution over the 20 cm tilth profile, while decline the concentrations of NO3(-) -N and N2(-) -N. No obvious difference is found on NH4(+) -N concentrations collected from deep layer soil solution under 20 cm between regular urea and the urea added with 1% of DMPP. There is also no significant difference for the NH4(+) -N and NO3(-) -N in the soil solution of deep layer under 40 cm among the treatments of urea by adding with 1% of DMPP within 60 days. So DMPP could be used as an effective nitrification inhibitor to control ammonium oxidation, decline the nitrate leaching losses, minimize the underground water pollution risk and be beneficial for the ecological environment.

Methane is the second largest contributor after carbon dioxide to global warming, while landfill is considered as one of the major sources of methane emission, accounting for 1.5%-15% of the global methane sources. Methanotrophic microorganisms play an important role in regulating global methane content, and landfill cover soil is proved to have high capacity of methane oxidation. The study of methanotrophic microorganisms in landfill cover soil and their mechanisms in methane oxidation becomes one of the hot research fields in environmental science and applied microbiology. This review summarized the recent progress on the research of methanotrophic microorganisms, mechanisms and dynamics of microbial methane oxidation, co-metabolism of methane and trace landfill gases, and environmental factors affecting methane oxidation in landfill cover soil. Some perspectives for further research on methanotrophic microorganisms in landfill cover soil were discussed.

This research investigated the concentrations of microcystins and environmental factors in three freshwaters of Zhejiang such as Taihu Lake (Huzhou section), Tiesha River and a blooming lagoon. The relativities between microcystins and environmental factors were studied by the methods of correlation analysis, principal components analysis, cluster analysis and stepwise multiple linear regression. The results show that the concentrations of MCLR and MCRR range from 0.049 microg/L. to 12.30 microg/L and from 0.032 microg/L to 7.90 microg/L, respectively, and the concentrations of microcystins at the bottom of the waters are higher than the aquatic surface. Significant positive relationships (p < 0.01) were observed between MCLR and TN, NH4+ -N, NO21- -N and TP, and also between MCRR and NO3- -N, N:P ratio; Significant negative relationships (p < 0.01) were observed between MCLR and water temperature, DO and N: P ratio (p < 0.01), and between MCRR and pH, DOC, permanganate index and optical density. Our research indicated TP and NO2- -N possibly be the main factors for the biosynthesis of MCLR, while NO3- -N and N:P ratio would be important for MCRR. NO2- -N and NO3- -N are possible the mainnitrogen resources for the biosynthesis of MCLR and MCRR, respectively.

As a new DNA fingerprinting technique, denaturing gradient gel electrophoresis (DGGE) can be used to analyze the microbial diversity in different environmental samples. Three biofilters treating air loaded with ammonia will be studied with respect to microbial diversity by applying cultivation-independent molecular methods DGGE. The principal objectives of this paper include the development and application of a suitable set of molecular tools to deliver information about the possible microbial community changes within carriers during treatment of ammonia-contaminated gas. Carriers were sampled at different time during operation of biofilters. After extraction and purification of the genomic DNA, the 16S rRNA genes (V3 region) were amplified by using the specific primers. These amplified DNA fragments were then separated by paralleled DGGE. The profile of DGGE showed that the same carrier at different time had the different bands' patterns. The structural diversity of the microbial community was examined by the Shannon index of general diversity H. Shannon indexes of three kinds of carriers all showed a decrease with time, which had a similar trend to NH3 removal efficiency.

TP-PCR,a method developed for fusion gene construction without the use of endonuclease and ligase, was performed to construct a fused fpg gene. The TP-PCR reaction system contained three primers and two templates and resulting PCR product, fused fpg gene, consisted of three sections: pheB gene, which was responsible for catechol 2,3-dioxygenase, gfp gene for GFP protein and the intermediate ligation segment which was designed for the correct expression of the fusion gene. The result in this paper showed that the TP-PCR method is one of rapid and convenient methods for fused gene construction.