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281.
采用多种形式的塘和湿地组合生态工艺完善传统的生态塘和湿地系统,能实现系统处理环境的多样化,提升对氮、磷的去除效能。对山东某组合生态处理系统的研究表明,组合生态处理系统能够有效提升对氮、磷营养物的去除效果。各生态单元水环境的差异影响着氮和磷的主导去除机制,使氮、磷表现出不同的季节去除规律。其中氮的去除主要依靠生物的硝化反硝化作用。底泥中的磷按照Fe-P>OPalk>Al-P>Ca-P>OPres逐渐变为Ca-P>Fe-P>Al-P>OPalk>OPres,与磷共沉降逐渐成为的主导去除机制。 相似文献
282.
田东石化工业园区污水处理工程设计规模为5000m3/a,采用水解酸化+A/O工艺,该工艺对工业园区污水处理效果好,运行稳定。出水水质优于《污水综合排放标准》(GB8978—1996)一级标准,完全满足排入右江的要求。污水处理运行成本1.13元/m^3。 相似文献
283.
Trophic State in Voyageurs National Park Lakes before and after Implementation of a Revised Water‐Level Management Plan
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Victoria G. Christensen Ryan P. Maki 《Journal of the American Water Resources Association》2015,51(1):99-111
We compiled Secchi depth, total phosphorus, and chlorophyll a (Chla) data from Voyageurs National Park lakes and compared datasets before and after a new water‐level management plan was implemented in January 2000. Average Secchi depth transparency improved (from 1.9 to 2.1 m, p = 0.020) between 1977‐1999 and 2000‐2011 in Kabetogama Lake for August samples only and remained unchanged in Rainy, Namakan, and Sand Point Lakes, and Black Bay in Rainy Lake. Average open‐water season Chla concentration decreased in Black Bay (from an average of 13 to 6.0 μg/l, p = 0.001) and Kabetogama Lake (from 9.9 to 6.2 μg/l, p = 0.006) between 1977‐1999 and 2000‐2011. Trophic state index decreased significantly in Black Bay from 59 to 51 (p = 0.006) and in Kabetogama Lake from 57 to 50 (p = 0.006) between 1977‐1999 and 2000‐2011. Trophic state indices based on Chla indicated that after 2000, Sand Point, Namakan, and Rainy Lakes remained oligotrophic, whereas eutrophication has decreased in Kabetogama Lake and Black Bay. Although nutrient inputs from inflows and internal sources are still sufficient to produce annual cyanobacterial blooms and may inhibit designated water uses, trophic state has decreased for Kabetogama Lake and Black Bay and there has been no decline in lake ecosystem health since the implementation of the revised water‐level management plan. 相似文献
284.
To increase the knowledge on the particulate matter of a wetland in Beijing, an experimental study on the concentration and composition of PM10 and PM2.5 was implemented in Beijing Olympic Forest Park from 2013 to 2014. This study analyzed the meteorological factors and deposition fluxes at different heights and in different periods in the wetlands. The results showed that the mean mass concentrations of PM10 and PM2.5 were the highest at 06:00–09:00 and the lowest at 15:00–18:00. And the annual concentration of PM10 and PM2.5 in the wetland followed the order of dry period (winter) > normal water period (spring and autumn) > wet period (summer), with the concentration in the dry period significantly higher than that in the normal water and wet periods. The chemical composition of PM2.5 in the wetlands included NH4+, K+, Na+, Mg2 +, SO42 −, NO3−, and Cl−, which respectively accounted for 12.7%, 1.0%, 0.8%, 0.7%, 46.6%, 33.2%, and 5.1% of the average annual composition. The concentration of PM10 and PM2.5 in the wetlands had a significant positive correlation with relative humidity, a negative correlation with wind speed, and an insignificant negative correlation with temperature and radiation. The daily average dry deposition amount of PM10 in the different periods followed the order of dry period > normal water period > wet period, and the daily average dry deposition amount of PM2.5 in the different periods was dry period > wet period > normal water period. 相似文献
285.
286.
Zhihao Si Xinshan Song Xin Cao Yuhui Wang Yifei Wang Yufeng Zhao Xiaoyan Ge Awet Arefe Tesfahunegn 《Frontiers of Environmental Science & Engineering》2020,14(1):4
287.
Ridhi Saluja 《Chemistry and Ecology》2017,33(6):499-515
The composition and structure of macrophyte communities of the littoral region of Bhindawas wetland (India) was investigated. Two hypotheses were tested: (1) if limnological variables such as water chemistry and soil parameters are important determinants of species composition and abundance and (2) what is the variance in species richness and composition within the wetland. Twenty-eight macrophyte species belonging to 17 different families were identified with relatively low species diversity and richness (H′?=?2.09; Margalef index?=?1.12). Eichhornia crassipes, attained the highest relative frequency (22.69%), followed by Salvinia natans, Paspalum paspaloides, Phragmites karka, Cynodon dactylon and Cyperus alopecuroides. The first and second axis of CCA ordination explained 38.4% and 28.5% of the total variance of species–limnological variables relationship, respectively. Water-related variables (dissolved oxygen, pH and nitrate concentration) and soil nutrient factors (soil carbon and phosphorus levels) were significantly correlated to macrophyte distribution. Sampling sites formed two distinct groups based on cluster analysis, indicating varying ecological conditions. Generally, composition and abundance of macrophytes evince highly productive nature of the lake, while dominance of invasive species like E. crassipes and S. natans indicates high influence of increased nutrient levels and anthropogenic activities in the catchment on lake macrophyte composition. 相似文献
288.
289.
对南山国家森林公园主要植被物种资源进行调查和区系结构研究。结果表明,南山国家森林公园森林覆盖率达73%,自然生态系统中目前已知的高等植物(藻菌、苔藓、地衣除外)共计有74科、251属、340种。构成镇江市区各类植被的优势成分共有约27种,其中东亚分布的种占55.6%,热带分布为主的植物占7.4%,连同东亚分布以及我国特有热带、亚热带分布为主的成分,一起可达88.9%。南山国家森林公园植被在区系组成上具有明显的亚热带特点,同时也反映出一定的过渡性,与江苏省森林木本植物区系分布特点基本一致。 相似文献
290.
豫东黄河故道湿地鸟类自然保护区现状调查及生态保护规划 总被引:4,自引:0,他引:4
对豫东黄河故道湿地鸟类自然保护区现状进行了调查,并提出了生态保护规划。 相似文献