Characteristics Of Pollutant Loads Research Articles

Spatial and temporal distribution characteristics of typical pollution loads based on SWAT model across Tuojiang River watershed located in Sichuan Province, Southwest of China.

Tuojiang River watershed is an economically developed and densely populated area in Sichuan Province (southwest of China), which is also an important tributary of the Yangtze River. Nitrogen (N) and phosphorus (P) are the main pollutants affecting water quality, but there is still lack of study on the spatial and temporal distribution characteristics of these two pollutants. In this study, the typical non-point source pollution loads in the Tuojiang River watershed are simulated by Soil and Water Assessment Tool (SWAT) model, and the spatial autocorrelation method is used to reveal the spatial and temporal distribution characteristics of the pollution loads from the annual average and water periods. Combined with redundancy analysis (RDA) and geographically weighted regression (GWR) analysis, the main driving factors affecting the typical non-point source pollution loads in the Tuojiang River watershed are discussed from the global and local perspectives. The results show that (1) from different water periods, the pollution loads of total nitrogen (TN) and total phosphorus (TP) in three water periods show obviously different, is the highest in the abundant water period, with 323.4kg/ha and 47.9kg/ha, followed by the normal water period, with 95.7kg/ha and 14.1kg/ha, and the lowest in the dry water period, with 28.4kg/ha and 4.2kg/ha. The annual average value of TN pollution load is higher than that of TP, with 447.5kg/ha and 66.1kg/ha, respectively; (2) the TN and TP pollution loads are stable on the whole, and the overall level in the middle reaches is higher. The pollution loads of Shifang City and Mianzhu City are higher in all three water periods. (3) Elevation and slope are two main driving factors affecting the TN and TP pollution loads in the Tuojiang River watershed. Therefore, the visualization and quantification of temporal and spatial distribution characteristics of typical non-point source pollution loads in the Tuojiang River watershed are helpful to provide the basis for scientific prevention and control of pollution in the Tuojiang River watershed and are of great significance to promote the sustainable, coordinated, and healthy development of water environment and economy in the watershed.

Spatial and temporal characteristics of pollution loads in Tuojiang River watershed located in Sichuan Province, Southwest of China

Spatial and temporal characteristics of pollution loads in Tuojiang River watershed located in Sichuan Province, Southwest of China

Understanding benzene series (BTEX) pollutant load characteristics in the urban environment

Benzene series (BTEX) pollutants are toxic and can pose high ecological and human health risk. BTEX pollutants can accumulate on urban road surfaces during dry periods and then be washed-off by stormwater runoff into receiving waters, degrading water quality. In this context, designing effective stormwater treatment systems to remove BTEX pollutants before entering urban water bodies is essential to safeguard urban water environment and this is closely dependent on an in-depth understanding of characteristics of pollutant loads accumulated on urban catchment surfaces. This study investigated BTEX pollutant load characteristics through collecting samples on 17 urban roads and three petrol station sites using dry and wet vacuuming method. The research outcomes showed that petrol station sites had the highest BTEX pollutant loads (mean value was 8.41μg/g) than common urban roads (6.61μg/g, 4.38μg/g and 4.60μg/g for industrial, commercial and residential roads). This highlighted a high potential of petrol station areas to export BTEX pollutants to stormwater runoff. It is also noted that industrial development plays the more important role in influencing BTEX pollutant loads than other factors including total daily traffic volume, daily heavy-duty vehicle volume, daily light-duty vehicle volume, residential development, commercial development and road texture depth. Higher industrial land use fraction led to higher BTEX pollutant loads while the spatial variability of BTEX pollutant loads generally decreased with increasing industrial land use fraction. These outcomes can assist on improving stormwater quality modelling approaches and adequately understanding the modelling results.

周辺部河川からの宍道湖への汚濁負荷流入特性

周辺部河川からの宍道湖への汚濁負荷流入特性

한강하류 오염부하의 유출특성

Runoff characteristics of pollutant loads of the lower Han River was studied before full implementation of Total Pollution Load Management System(TPLMS). Magnitude of macroscopic(annual) fluctuation was in the order of Namhan River > Han River > Bukhan River, gross weight TP > gross weight TN > gross weight BOD, gross weight deviation > concentration deviation. Flux variation was higher than that of concentration. Microscopic(weekly) fluctuation showed similar pattern to macroscopic scale. TP showed the highest deviation resulting in the lowest reliability. 60% of annual flux passed during summer 3months resulting in 43-46% pass of gross weight at the lower Han River. Strong correlation was found between flux and gross weight especially in gross weight TN. Gross weight pollution increased as high as 400% while passing Seoul area due to the concentration. The deviation from moving average increased during summer season in the gross weight TP and BOD. Seasonal tendency was confirmed especially in gross weight TN and TP using autocorrelation function.

SWMM모델을 이용한 도시지역 비점오염원의 유출특성 연구 -전주시를 대상으로

The runoff characteristics of non-point source pollutions in the municipal area of Jeonju were investigated and analyzed by using the SWMM (Storm Water Management Model). The flow rates and water qualities of runoff from two types of drainage conduits were measured respectively. One was a conventional combined sewer system and the other was a separated sewer system constructed recently From August to November in 2004, investigations on two rainfall events were performed and flow rate, pH, BOD, COD, SS, T-N and T-P were measured. These data were also used for model calibration. On the basis of the measured data and the simulation results by SWMM, it is reported that <TEX>$80-90\%$</TEX> of pollution load is discharged in the early-stage storm runoff. Therefore, initial 10-30 mm of rainfall should be controlled effectively for the optimal treatment of non-point source pollution in urban area. Also, it was shown that the SWMM model was suitable for the management of non-point source pollution in the urban area and for the analysis of runoff characteristics of pollutant loads.

生活排水の水質特性の解析と処理水における水質変化

Characteristics of pollutant loads and water quality, and the relation between water quality of the influent and the effluent were investigated for domestic wastewater treatment facilities, which were designed for 51 persons or more and have long inflow pipeline. It was found that average values of pollutant loads were 243l for water quantity, 37.9g for BOD, 8.1g for T-N, and 1.0g for T-P per capita per day, and non-excess probability 75% values of pollutant loads were 286l for water quantity, 44.2g for BOD, 9.1g for T-N, and 1.1g for T-P per capita per day. By the result of principal component analysis, the first component mainly characterized the total water quality, while the second component described the dissolved matters. It was also found that chlorine ion compensation was an effective method for analyzing water quality characteristics of domestic wastewater. On the other hand, the ratios of BOD to TOC and D-BOD to D-TOC in influent were both about 1.5, while the ratios of C-BOD to TOC and D-BOD to D-TOC in effluent were 0.61 and 0.34 respectively. These results indicated that there was a given quantity of organic matters, which dissolved in the effluent and were not detected in BOD analysis. When the effluent T-N was under 20mg · l-1, the effluent D-COD and D-TOC were under 10mg · l-1. It was suggested that D-COD and D-TOC may be utilized as organic carbon source in nitrogen removing.

STUDY OF RUNOFF WATER QUALITY OF THE FLUSHING FROM THE STREET INLETS IN URBAN AREA

Since most accumulated loads, which are produced by human activities, on road surfaces are gathered into street inlets, we never ignor the influences of pollution loads in street inlets on runoff water quality. So, we carried out the investigations on the change of pollution loads in street inlets for a period of approximately 4 months, and we made clear the characteristics of pollution loads in street inlets in urban area. Furthermore, we derived the model for runoff loads from street inlets in order to make clear the influence on runoff loads on rainy day and the runoff characteristics. And we simulated runoff loads by our model on the basis of the results of our experiments of the flushing of pollution loads in street inlet.