scholarly journals Necessity of Acknowledging Background Pollutants in Management and Assessment of Unique Basins

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1103 ◽  
Author(s):  
Maoqing Duan ◽  
Xia Du ◽  
Wenqi Peng ◽  
Shijie Zhang ◽  
Liuqing Yan

The limitations of water quality management and assessment methods in China can be ascertained by comparison with other countries. However, it is unreasonable to use a uniform standard to evaluate water quality throughout China because one standard cannot fully account for the regional differences in background water quality. This study aimed to provide a basis for environmental water management decision-making. Areas seriously affected by background pollutants were identified by comparing several factors across 31 provinces in China. By coupling an improved export coefficient model (ECM) with a mechanistic model, a suitable pollutant yield coefficient was determined and its rationality was analysed. The export coefficient model was applied to estimate the pollutant (chemical oxygen demand and ammonia nitrogen) output of the basin in 2015. The spatial distribution characteristics of the pollutants were determined by simulating the pollutant outputs of 22 sub-basins and nine water function zones. For the year 2020, the simulation results of pollutant outputs far exceed the sewage discharge limit in water function zones and the pollutant concentration was much higher than the standard. Considering background pollutant outputs, more reasonable sewage discharge limit and water quality evaluation method are proposed.

Author(s):  
Li Linjin ◽  
Men Baohui ◽  
Peng Rui

Wenyu River is the “mother river” in Beijing. In recent years, the research on the water quality of the Wenyu River has increased gradually. In this paper, the monitoring data at Shahe Reservoir, Lu Tuan Gate, Xin Bao Gate, and Ma Fang sections for each month in 2019 were adopted. The single-factor evaluation method and the comprehensive pollution index method were selected to analyze the current situation of the water quality of Wenyu River in the Chang Ping section and its temporal and spatial variation trend. The single factor evaluation method showed that the dissolved oxygen exceeded the standard seriously in all other months of the year except that the situation was better in May, June, and July. The ammonia nitrogen content reached the highest level in January, followed by a month-by-month decreasing trend. After June, each section basically met the requirements of Class v water quality. The comprehensive pollution index method shows that the water quality of Shahe reservoir varies greatly throughout the year, and it is in grade v for 6 months. The evaluation results of both methods show that the water quality of all sections of Wenyu River in 2019 was mostly in category v.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sachidananda Mishra ◽  
Richard P. Stumpf ◽  
Blake A. Schaeffer ◽  
P. Jeremy Werdell ◽  
Keith A. Loftin ◽  
...  

AbstractCyanobacterial harmful algal blooms (cyanoHABs) are a serious environmental, water quality and public health issue worldwide because of their ability to form dense biomass and produce toxins. Models and algorithms have been developed to detect and quantify cyanoHABs biomass using remotely sensed data but not for quantifying bloom magnitude, information that would guide water quality management decisions. We propose a method to quantify seasonal and annual cyanoHAB magnitude in lakes and reservoirs. The magnitude is the spatiotemporal mean of weekly or biweekly maximum cyanobacteria biomass for the season or year. CyanoHAB biomass is quantified using a standard reflectance spectral shape-based algorithm that uses data from Medium Resolution Imaging Spectrometer (MERIS). We demonstrate the method to quantify annual and seasonal cyanoHAB magnitude in Florida and Ohio (USA) respectively during 2003–2011 and rank the lakes based on median magnitude over the study period. The new method can be applied to Sentinel-3 Ocean Land Color Imager (OLCI) data for assessment of cyanoHABs and the change over time, even with issues such as variable data acquisition frequency or sensor calibration uncertainties between satellites. CyanoHAB magnitude can support monitoring and management decision-making for recreational and drinking water sources.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 587
Author(s):  
Qiuxia Ma ◽  
Yong Pang ◽  
Ronghua Mu

In recent years, due to unsustainable production methods and the demands of daily life, the water quality of the Yangtze River has deteriorated. In response to Yangtze River protection policy, and to protect and restore the ecological environment of the river, a two-dimensional model of the Jiangsu section was established to study the water environmental capacity (WEC) of 90 water environment functional zones. The WEC of the river in each city was calculated based on the results of the water environment functional zones. The results indicated that the total WECs of the study area for chemical oxygen demand (COD), ammonia nitrogen (NH3-N), and total phosphorus (TP) were 251,198 t/year, 24,751 t/year, and 3251 t/year, respectively. Among the eight cities studied, Nanjing accounted for the largest proportion (25%) of pollutants discharged into the Yangtze River; Suzhou (11%) and Zhenjiang (12%) followed, and Wuxi contributed the least (0.4%). The results may help the government to control the discharge of pollutants by enterprises and sewage treatment plants, which would improve the water environment and effectively maintain the water ecological function. This research on the WEC of the Yangtze River may serve as a basis for pollution control and water quality management, and exemplifies WEC calculations of the world’s largest rivers.


2017 ◽  
Vol 18 (2) ◽  
pp. 723-736 ◽  
Author(s):  
Jingneng Ni ◽  
Jiuping Xu ◽  
Mengxiang Zhang

Abstract Water quality evaluation is a key task in water resource management and pollution control. Current evaluation methods are rooted in water quality index, which assesses the water quality based on the exact concentration of various pollutants. However, the interaction between the pollutants and the water environment should also be considered. This paper suggests a new approach, which integrates pollutant interaction with water environment and parameter uncertainty to water quality evaluation. The new approach is compared with traditional methods. Then, an inexact evaluation model, the integrated water quality evaluation model under uncertainty, is established in accordance with the proposed approach, in which catastrophe theory is used to deal with the ambiguous internal mechanism of the interaction between the pollutants and the water environment. As there are significant uncertainties in water quality evaluations, fuzzy random variables are employed to describe the inexact monitoring data. To solve the proposed model, a new algorithm is designed. The model is then applied to an actual case: Lake Chaohu, China. The results are compared between the proposed method and China's current evaluation method (i.e. max-index method). Some brief analysis and discussion are given about the results, which could be helpful in guiding environmental management decision-making.


1987 ◽  
Vol 19 (9) ◽  
pp. 1-7
Author(s):  
K. C. Das

The James River has its head waters in the Allegheny Mountains and flows generally southeasterly to Hampton Roads, Chesapeake Bay and thence to the Atlantic Ocean. Below Richmond, Virginia, the river is tidal with the channel meandering through the coastal plains. Below Hopewell it widens to a broad estuary, with a deep navigable channel bordered by tide marshes. The upper estuary, between Richmond and Hopewell, is heavily used for water supply, recreation, and industrial development. The water entering the estuary a few miles upstream of Richmond is of good quality. However, as one reaches Richmond, the quality of the water deteriorates. There are eleven major discharging municipalities and industries within a stretch of twenty two river miles between Richmond and Hopewell. The major factors contributing to water quality problems below the City of Richmond stem from the intermittent discharge from combined sewer overflows (CSOs) coupled with the continuous discharge from the City's sewage treatment plant. The CSOs contribute a large quantity of soluble BOD, suspended solids, settleable solids, and fecal coliforms to the estuary. The City's sewage treatment plant continuously discharges large quantities of ammonia-nitrogen and phosphorus, in addition to BOD and suspended solids. Rational Management and use of the waters of the upper James estuary appear to be critical. The objectives of this paper, therefore, are the discussion of the present water quality and the wastewater discharge reductions required in order to meet certain water quality and water use objectives.


2011 ◽  
Vol 58-60 ◽  
pp. 2462-2467 ◽  
Author(s):  
Ping Kuei Tang ◽  
Yi Chu Huang ◽  
Jih Sheng Huang ◽  
Ya Ju Lin

This study utilizes the river and stream water quality (QUAL2K) model as a tool to simulate and forecast the water quality and then to develop the management strategies for various flow rates above the Kaoping weir of Kaoping River in Taiwan. Model results based on the river assimilative capacity of four various flow rates including Q95, Q75, Q60, and Q25 were conducted to determine the corresponding amounts of pollution reduction. The average pollution reduction ratios of biochemical oxygen demand (BOD5) and ammonia nitrogen (NH3-N) should at least reach to 42.0% and 28.3% respectively to meet the restoration goals of Class A water quality standards regulated by Taiwan. The modeling results demonstrate that an increase of water extraction rates in the upstream reaches will have significant adverse effects on the water quality of the Kaoping River. Higher water extraction rates will lower the assimilative capacity that reduces the buffering capacity of river. It also induces that the water quality is susceptible to the impacts of the influent pollutant loads from the tributaries or drainages.


2019 ◽  
Vol 11 (21) ◽  
pp. 6022 ◽  
Author(s):  
Zhuohang Xin ◽  
Lei Ye ◽  
Chi Zhang

Water quality deterioration caused by excessive nutrient discharge from various point and non-point sources are a global challenge. Understanding the pollution sources and their respective contribution is the prerequisite for environmental planning, management and restoration. In this study, the influence of complex pollution sources on the water quality of the Dengsha River watershed in Dalian, China, was investigated. The export coefficient method was coupled with the QUAL2K water quality model to estimate the loads of ammonia nitrogen (NH4-N) and total phosphorus (TP) from different sources, and to explore their respective contributions. Results indicated that animal feedlot and crop production were major sources for NH4-N load, and crop production, soil erosion and animal feedlot are the largest three sources of TP load with an annual total contribution of 98.4%. The pollutant load exhibited an intra-annual variation mainly due to the seasonality of rainfall and anthropogenic agricultural activities. The overall waste assimilation capacity (WAC) is overloaded and suggestions for water pollution control and treatment regarding each pollution source were proposed. This study addressed a new application of QUAL2K model coupled with the export coefficient model for watershed managers towards a sustainable water environmental management, and can therefore be a reference example for other small and medium-sized rural watersheds.


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