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Ma G.,China National Environmental Monitoring Center | Wang Y.,China National Environmental Monitoring Center | Bao X.,Chinese Research Academy of Environmental Sciences | Hu Y.,Beijing Normal University | And 4 more authors.
Environmental Earth Sciences | Year: 2015

This study examined nitrogen (N) pollution characteristics based on water quality monitoring of the Ashi River and analyzed N sources by stable isotope tracer (SIT) techniques during a hydrological year in 2011. Twenty-two evenly distributed sites were sampled in the mainstream and tributaries of Ashi River during the temperate, wet, and dry seasons. The results showed that the concentrations of ammoniacal nitrogen (NH4 +-N), nitrate nitrogen (NO3 −-N), and total nitrogen (TN) were lower in the upstream section of Ashi River, while the concentrations were higher in most other sections of Ashi River. Different forms of N had significant seasonal variations. The range of δ15N-NO3 − values indicated different N pollution sources. The upstream headwater area of Ashi River was mainly polluted by atmospheric N deposition and soil organic N. In the midstream and downstream areas of Ashi River, some sampling sites were affected by water released from cropland and rural domestic sewage, while other sites were polluted due to wastewater from livestock and poultry production. In addition, pollution in the downstream section of Ashi River was mainly caused by industrial wastewater. The city zone located in the basin had a greater impact on the variations of NH4 +-N concentrations, and less impact on NO3 −-N. N pollution characteristics of NH4 +-N, NO3 −-N, and TN, as well as NO3 −-N analysis to identify sources, reflected the profound impact of non-point source pollution during the temperate and wet seasons and point source pollution during the dry season in Ashi River. © 2014, Springer-Verlag Berlin Heidelberg. Source

Li J.,Harbin Institute of Technology | Li J.,Heilongjiang Research Institute of Environmental Protection Science | Qi P.,Harbin Institute of Technology | Ma Y.,Heilongjiang Research Institute of Environmental Protection Science | And 2 more authors.
Procedia Environmental Sciences | Year: 2011

The effects of metals on the structure of phytoplankton communities were determined in the Zhalong Wetland of China during one hydrology year. 133 taxa occurring in at least two samples or the percentages over 5% in at least one sample were identified and utilized in statistical analysis, which belonged to 58 genera, 28 families, 17 orders, 9 classes, 7 phyla. Principle component analysis (PCA) based on metal levels displayed two major groups, the light and heavy metals. Canonical correspondence analysis (CCA) with forward selection and a Monte Carlo permutation test revealed that kalium ion (K) was significant (P<0.05) and though Fe, Mn, Na and Ca were not significant variables, they were the important characters together with K, accounting for the biggest variation (more than 3%) in algae floras. Those taxa resistant to metal levels in the present study had a short distance with relevant metals in CCA biplot showed a strong correlation, which should be indicators of the metal contamination. © 2011 Published by Elsevier Ltd. Source

Ma Y.,Harbin Institute of Technology | Ma Y.,Heilongjiang Research Institute of Environmental Protection Science | Li G.,Harbin Institute of Technology | Li J.,Harbin Institute of Technology | And 3 more authors.
Ecotoxicology | Year: 2014

A data set of phytoplankton community and environmental parameters in a hydrological integrity period, i.e. a poor water term, a medium term and a rich water term of North Temperate Zone climate, was analyzed in order to describe seasonal variation of phytoplankton community and its relationship with environmental variables in the Zhalong Wetland of China. The algal population of the Zhalong Wetland was not abundant, with a mean density of 5.08 × 107 cell/L (ranged from 4.54 × 107 cell/L in a poor term to 5.56 × 107 cell/L a medium term). However, its diversity was essentially limited to Cryptophyta, Bacillariophyta, Chlorophyta, Euglenophyta being the group with highest densities. There were considerable seasonal variations in phytoplankton composition. In general, the dominance of Bacillariophyceae was found in a medium term, which was higher than the other period (p < 0.05). The rich water period also showed Bacillariophyceae and Chlorophyta dominance while the phytoplankton was dominated by Cryptophyta erosa in a poor water term. 10 environmental variables, which were significant (p < 0.05) during the studied periods in one-way analysis of covariance, were selected to explore the relationship between phytoplankton structure and environmental factors by canonical correspondence analysis (CCA). The results of the CCA applied to the environmental factors indicated that water temperature (WT) and ammonia (NH3-N) significantly influenced the phytoplankton community (p < 0.05; Monte Carlo test of first constrained axis). Besides WT and NH3-N, the most discriminate physic-chemical variables were nitrite (NO2-N), suspend solid, nitrate (NO3-N), silicon dioxide (SiO2) and all the 10 physical-chemical parameters had a higher marginal effect and λA in the series of constrained CCAs though they were not significant. © 2014 Springer Science+Business Media. Source

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