By using the meteorological data in the pollution boundary layer which was observed in two ground observation sites:coast and land in the river outlet area of Grand Liao River during January-February in 2007,the daily...By using the meteorological data in the pollution boundary layer which was observed in two ground observation sites:coast and land in the river outlet area of Grand Liao River during January-February in 2007,the daily change characteristics of pollute boundary layer in winter in the area were discussed. The results showed that the pollute boundary layer in the river outlet area of Grand Liao River was affected by the sea and land. In the certain weather condition,maybe the sea-land breeze appeared in the low altitude which was below 200 m in the coastal zone. The stability change in the different height in the coastal zone was more stable than in the land zone,and the wind field change in the area was mainly in 300 m low altitude. At night,the temperature inversion often appears in the area,and the thickness of temperature inversion layer is stably during 200-300 m. The thermal internal boundary layer penetrated deeply into the land about 10 km,and the height could reach 800 m. The atmospheric diffusion ability in the coastal area was weaker and stronger in the land area.展开更多
The Tumen River had failed to meet Grade Ⅲ and Ⅳ levels in the environmental quality standard for surface water, and had exceeded Grade Ⅴ level. Surface water pollution is serious. The major excessive standard poll...The Tumen River had failed to meet Grade Ⅲ and Ⅳ levels in the environmental quality standard for surface water, and had exceeded Grade Ⅴ level. Surface water pollution is serious. The major excessive standard pollutants were COD Mn and SS. After taking effective treatment steps, the worsening trend of water pollution will be basically under control. But the change of runoff in the Tumen River is large in a year, especially during as long as five month freezing period, smaller flow and lower temperature of river waters led to weak dilution and self purification capacity. The water quality of the Tumen River will not reach the appoint functional water quality standards, even if sewage meets discharge standard, which will influence water resources utilization in the lower reaches of the Tumen River and regional economic development. Therefore water pollution has become the major restrictive factor of the development of the Tumen River area.展开更多
Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using...Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using the sigma-coordinate in the vertical direction and spherical coordinate in the horizontal direction. In the study, changing-grid technology and the "dry-wet" method were designed to deal with the moving boundary. The minimum water depth limit condition was introduced for numerical simulation stability and to avoid producing negative depths in the shallow water areas. Using the Eulerian transport approaches included in COHERENS for the advection and dispersion of dissolved pollutants, numerical simulation of dissolved pollutant transport and diffusion in the Changjiang River estuary were carried out. The mass centre track of dissolved pollutants released from outlets in the south branch of the Changjiang River estuary water course has the characteristic of reverse current motion in the inner water course and clockwise motion offshore. In the transition area, water transport is a combination of the two types of motion. In a sewage-discharge numerical experiment, it is found that there are mainly two kinds of pollution distribution forms: one is a single nuclear structure and the other is a double nuclear (dinuclear) structure in the turbid zone of the Changjiang River estuary. The rate of expansion of the dissolved pollutant distribution decreased gradually. The results of the numerical experiment indicate that the maximum turbid zone of the Changjiang River estuary is also the zone enriched with pollutants. Backward pollutant flow occurs in the north branch of the estuary, which is similar to the backward salt water flow, and the backward flow of pollutants released upstream is more obvious.展开更多
The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space...The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space-time pollution of river water with ammonium, nitrates, phosphates, biological oxygen demand (ВОD), fluorine and some heavy metals at seven water sampling points along theZarafshanRiver inUzbekistan. The experimental data showed that the water quality of the Zarafshanriver in 2002-2009 has undergone a considerable transformation, even by the length of the river. The chemical composition of the Zarafshan river water underwent changes due to the agricultural collector-drainage discharges and the sewage of the cities of Samarkand and Navoi. The water pollutants of the Zarafshan river, as a con- sequence of the agricultural pollution, consisted of mineralization, ammonium, nitrate, phosphate, and pesticides. Therefore, it is necessary to monitor the chemical composition of the large agricultural collector-drainage discharges into the river. The main sources of the heavy metals (primarily arsenic and zinc) in the Zarafshan river water were probably ore processing manufactures located interritoryofTajikistan.展开更多
南盘江是珠江源头、云南曲靖人民的母亲河,其综合系统治理关系到曲靖的生态环境改善和经济社会的可持续发展。为精准掌握南盘江流域水污染问题,本研究详细分析了水质时空变化,降雨时城区管网溢流情况,沿岸排污口分布及污染物排放、合流...南盘江是珠江源头、云南曲靖人民的母亲河,其综合系统治理关系到曲靖的生态环境改善和经济社会的可持续发展。为精准掌握南盘江流域水污染问题,本研究详细分析了水质时空变化,降雨时城区管网溢流情况,沿岸排污口分布及污染物排放、合流制截污管网覆盖及漏损情况,南盘江干流闸坝运行调度情况。结果表明:南盘江流域水质劣Ⅴ类,重度污染,水质旱季劣于雨季,支流劣于干流,下游劣于上游,主要超标因子为NH 3-N和TP;当城区降雨量高于约10 mm时,部分支流白石江等雨水口大量生活污水溢流,雨污合流制难以应对降雨天气;干支流共有排口225个,抽检50个排口水质达标率约24%,超标排放情况普遍;曲靖城区城市建设落后,建成区约30 km 2采用雨污合流制,仍有约40%区域未覆盖截污管网;城区人均水资源量760 m 3,仅为云南人均的15.6%,全国的36%,沿岸闸坝蓄水满足农业灌溉用水需求,闸坝运行调度混乱,河道生态流量无法保障。建议以河长制为抓手,加强工业及城镇生活点源污染治理,优化区域水资源配置,推进河道综合治理、理顺管理机制体制,构建快处高效的治理执行体系,形成全社会参与的南盘江治理局面,方能促进南盘江水生态环境质量持续改善,惠及民生,还河于民。展开更多
Water samples were collected from three stations along the water course of Oinyi River, Kogi State, Nigeria, bi-monthly for 12 months (October 2010 to September 2011). A total of 16 physical and chemical parameters (t...Water samples were collected from three stations along the water course of Oinyi River, Kogi State, Nigeria, bi-monthly for 12 months (October 2010 to September 2011). A total of 16 physical and chemical parameters (temperature, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, electrical conductivity, flow velocity, depth, nitrate, nitrite, phosphate, ammonia, pH, turbidity, total suspended solids, total dissolved solids and colour) were analyzed and results showed that pH (6.8 to 7.26), conductivity (106.0 to 211.7 μS/cm), colour (3.87 ± 0.159 Pt.Co), turbidity (14 - 22.7 NTU), total suspended solids (45 - 54 mg/l), biochemical oxygen demand (2.05 - 2.89 mg/l), chemical oxygen demand (17.19 ± 0.15 mg/l), temperature (24°C to 27°C) and depth (0.23 to 0.35 m) were significantly different across the different stations and between the months. However, total dissolved solids (52.7 to 108.8 mg/l), dissolved oxygen (6.02 to 7.01 mg/l), ammonia (0.00 to 0.02 mg·l-1), nitrite (0.01 - 0.09 mg·l-1), nitrate (0.045 ± 0.006 mg·l-1), phosphate (0.2 to 2.05 mg·l-1) and flow velocity (0.1 to 0.35 m·s-1) showed variations within the sampling stations. Maximum conductivity (211.7 μS/cm), colour (5.83 Pt.Co), turbidity (22.7 NTU), total suspended solids (54 mg/l), total dissolved solids (108.8 mg/l), nitrite (0.09 mg/l) and nitrate (0.006 mg/l) values were recorded at station 2 which is the discharge point of industrial waste. River water did show significant pollutional increase at the effluent impacted site during the present study. Dissolved oxygen showed direct relation with temperature, biochemical oxygen demand and chemical oxygen demand. The non-stop and continuous discharges of cement waste water into the river lessened water quality with significant or corresponding effect on the biota of the studied area, thus paving way for clear assertion that the water quality deterioration was as a result of the impacts of the waste water from cement industry.展开更多
基金Supported by The Special Project of Public Welfare Industry(Meteorology)of Science and Technology Ministry(GYHY200806020)The National Natural Science Fund(40975084)The Science Research Fund of Liaoning Meteorological Bureau(2008008)
文摘By using the meteorological data in the pollution boundary layer which was observed in two ground observation sites:coast and land in the river outlet area of Grand Liao River during January-February in 2007,the daily change characteristics of pollute boundary layer in winter in the area were discussed. The results showed that the pollute boundary layer in the river outlet area of Grand Liao River was affected by the sea and land. In the certain weather condition,maybe the sea-land breeze appeared in the low altitude which was below 200 m in the coastal zone. The stability change in the different height in the coastal zone was more stable than in the land zone,and the wind field change in the area was mainly in 300 m low altitude. At night,the temperature inversion often appears in the area,and the thickness of temperature inversion layer is stably during 200-300 m. The thermal internal boundary layer penetrated deeply into the land about 10 km,and the height could reach 800 m. The atmospheric diffusion ability in the coastal area was weaker and stronger in the land area.
文摘The Tumen River had failed to meet Grade Ⅲ and Ⅳ levels in the environmental quality standard for surface water, and had exceeded Grade Ⅴ level. Surface water pollution is serious. The major excessive standard pollutants were COD Mn and SS. After taking effective treatment steps, the worsening trend of water pollution will be basically under control. But the change of runoff in the Tumen River is large in a year, especially during as long as five month freezing period, smaller flow and lower temperature of river waters led to weak dilution and self purification capacity. The water quality of the Tumen River will not reach the appoint functional water quality standards, even if sewage meets discharge standard, which will influence water resources utilization in the lower reaches of the Tumen River and regional economic development. Therefore water pollution has become the major restrictive factor of the development of the Tumen River area.
基金Supported by the Public Welfare Special Scientific Research Project funded by the Ministry of Water Resources of China (No. 200701026)National Natural Science Foundation of China (No. 50709007)the Startup Fund of Hohai University (No. 2084/40801107)
文摘Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using the sigma-coordinate in the vertical direction and spherical coordinate in the horizontal direction. In the study, changing-grid technology and the "dry-wet" method were designed to deal with the moving boundary. The minimum water depth limit condition was introduced for numerical simulation stability and to avoid producing negative depths in the shallow water areas. Using the Eulerian transport approaches included in COHERENS for the advection and dispersion of dissolved pollutants, numerical simulation of dissolved pollutant transport and diffusion in the Changjiang River estuary were carried out. The mass centre track of dissolved pollutants released from outlets in the south branch of the Changjiang River estuary water course has the characteristic of reverse current motion in the inner water course and clockwise motion offshore. In the transition area, water transport is a combination of the two types of motion. In a sewage-discharge numerical experiment, it is found that there are mainly two kinds of pollution distribution forms: one is a single nuclear structure and the other is a double nuclear (dinuclear) structure in the turbid zone of the Changjiang River estuary. The rate of expansion of the dissolved pollutant distribution decreased gradually. The results of the numerical experiment indicate that the maximum turbid zone of the Changjiang River estuary is also the zone enriched with pollutants. Backward pollutant flow occurs in the north branch of the estuary, which is similar to the backward salt water flow, and the backward flow of pollutants released upstream is more obvious.
文摘The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space-time pollution of river water with ammonium, nitrates, phosphates, biological oxygen demand (ВОD), fluorine and some heavy metals at seven water sampling points along theZarafshanRiver inUzbekistan. The experimental data showed that the water quality of the Zarafshanriver in 2002-2009 has undergone a considerable transformation, even by the length of the river. The chemical composition of the Zarafshan river water underwent changes due to the agricultural collector-drainage discharges and the sewage of the cities of Samarkand and Navoi. The water pollutants of the Zarafshan river, as a con- sequence of the agricultural pollution, consisted of mineralization, ammonium, nitrate, phosphate, and pesticides. Therefore, it is necessary to monitor the chemical composition of the large agricultural collector-drainage discharges into the river. The main sources of the heavy metals (primarily arsenic and zinc) in the Zarafshan river water were probably ore processing manufactures located interritoryofTajikistan.
文摘南盘江是珠江源头、云南曲靖人民的母亲河,其综合系统治理关系到曲靖的生态环境改善和经济社会的可持续发展。为精准掌握南盘江流域水污染问题,本研究详细分析了水质时空变化,降雨时城区管网溢流情况,沿岸排污口分布及污染物排放、合流制截污管网覆盖及漏损情况,南盘江干流闸坝运行调度情况。结果表明:南盘江流域水质劣Ⅴ类,重度污染,水质旱季劣于雨季,支流劣于干流,下游劣于上游,主要超标因子为NH 3-N和TP;当城区降雨量高于约10 mm时,部分支流白石江等雨水口大量生活污水溢流,雨污合流制难以应对降雨天气;干支流共有排口225个,抽检50个排口水质达标率约24%,超标排放情况普遍;曲靖城区城市建设落后,建成区约30 km 2采用雨污合流制,仍有约40%区域未覆盖截污管网;城区人均水资源量760 m 3,仅为云南人均的15.6%,全国的36%,沿岸闸坝蓄水满足农业灌溉用水需求,闸坝运行调度混乱,河道生态流量无法保障。建议以河长制为抓手,加强工业及城镇生活点源污染治理,优化区域水资源配置,推进河道综合治理、理顺管理机制体制,构建快处高效的治理执行体系,形成全社会参与的南盘江治理局面,方能促进南盘江水生态环境质量持续改善,惠及民生,还河于民。
文摘Water samples were collected from three stations along the water course of Oinyi River, Kogi State, Nigeria, bi-monthly for 12 months (October 2010 to September 2011). A total of 16 physical and chemical parameters (temperature, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, electrical conductivity, flow velocity, depth, nitrate, nitrite, phosphate, ammonia, pH, turbidity, total suspended solids, total dissolved solids and colour) were analyzed and results showed that pH (6.8 to 7.26), conductivity (106.0 to 211.7 μS/cm), colour (3.87 ± 0.159 Pt.Co), turbidity (14 - 22.7 NTU), total suspended solids (45 - 54 mg/l), biochemical oxygen demand (2.05 - 2.89 mg/l), chemical oxygen demand (17.19 ± 0.15 mg/l), temperature (24°C to 27°C) and depth (0.23 to 0.35 m) were significantly different across the different stations and between the months. However, total dissolved solids (52.7 to 108.8 mg/l), dissolved oxygen (6.02 to 7.01 mg/l), ammonia (0.00 to 0.02 mg·l-1), nitrite (0.01 - 0.09 mg·l-1), nitrate (0.045 ± 0.006 mg·l-1), phosphate (0.2 to 2.05 mg·l-1) and flow velocity (0.1 to 0.35 m·s-1) showed variations within the sampling stations. Maximum conductivity (211.7 μS/cm), colour (5.83 Pt.Co), turbidity (22.7 NTU), total suspended solids (54 mg/l), total dissolved solids (108.8 mg/l), nitrite (0.09 mg/l) and nitrate (0.006 mg/l) values were recorded at station 2 which is the discharge point of industrial waste. River water did show significant pollutional increase at the effluent impacted site during the present study. Dissolved oxygen showed direct relation with temperature, biochemical oxygen demand and chemical oxygen demand. The non-stop and continuous discharges of cement waste water into the river lessened water quality with significant or corresponding effect on the biota of the studied area, thus paving way for clear assertion that the water quality deterioration was as a result of the impacts of the waste water from cement industry.