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Selenium: Environmental significance, pollution, and biological treatment technologies
Published in Lea Chua Tan, Anaerobic treatment of mine wastewater for the removal of selenate and its co-contaminants, 2018
L.C. Tan, Y.V. Nancharaiah, E.D. van Hullebusch, P.N.L. Lens
A large scale connected evaporation pond was investigated by Ryu et al. (2011) in San Joaquin Valley (California, USA). The evaporation ponds were separated into 10 segments called cells, with cell 1 denoted as inlet and cells 9/10 as final cells. A significant decrease in total soluble selenium concentration, from an average value of 24.2 μg Se/L to 11.1 μg Se/L, was observed in cell 1 with an increase in selenium concentration in the sediments compared to the final cell 9, where the selenium concentration decreased from 1.94–2.50 mg/kg to 0.38–0.65 mg/kg. This showed active immobilization of selenium in the sediment of the Se loaded cells, but cells 9 and 10 also showed high total dissolved selenium concentrations (average 22.7 μg Se/L) due to evapo-concentration. Results showed that elemental Se and organic matter-associated selenium were mainly found in the sediments of the pond systems. Evaporation ponds have the advantage of low energy costs due to relying on solar radiation and no solidliquid separation phase is required. However, it has the disadvantage of large space requirements and being dependent on climate conditions.
Feasibility of Advanced Water Purification Processes
Published in Frank R. Spellman, Land Subsidence Mitigation, 2017
For evaporation pond design, sizing of the ponds, the evaporation rate, and pond depth are important parameters. Evaporation ponds function by transferring liquid water in the pond to water vapor in the atmosphere above the pond. The rate at which an evaporation pond can transfer this water governs the size of the pond. Selection of pond size requires determination of both the surface area and the depth needed. The surface area required is dependent primarily on the evaporation rate. The pond must have adequate depth for surge capacity and water storage, storage capacity for precipitated salts, and freeboard for precipitation (rainfall) and wave action.
Leachate Treatment
Published in Syed R. Qasim, Walter Chiang, Sanitary Landfill Leachate, 2017
Natural evaporation or evaporation ponds are used to concentrate wastes and sludges. The process involves impoundments with no discharge. The amount of evaporation from the water surface depends on temperature, wind velocity, and humidity. There are substantial variations in the average daily evaporation rate from month to month and year to year. However, depending on the climatic conditions, large impoundment may be necessary if precipitation exceeds evaporation over several months. Therefore, considerations must be given to net evaporation, storage requirements, and possible percolation and groundwater pollution.
Low-grade heat from solar ponds: trends, perspectives, and prospects
Published in International Journal of Ambient Energy, 2022
Farbod Esmaeilion, Abolfazl Ahmadi, Mehdi Aliehyaei
Şencan et al. (2007) employed various procedures to determine the performance of an absorption heat transformer for enhancing the obtained low-temperature quantities in a small-scaled pond. Bezir et al. (2008) applied analytical functions for air and soil temperatures by the local climatological statistics in models and indicated the influential considerations of the solar ponds. Garmana and Muntasserb (2008) evaluated solar energy as an energy source in an SGSP for desalination purposes and set a mathematical simulation to examine the aspects influencing the size of the solar pond. Agha, Abughres, and Ramadan (2004) used the evaporation pond model to two forms of water flushing under various conditions and forecasted the amounts of brine used by the evaporation pond. Andrews and Akbarzadeh (2005) proposed an alternative technique of heat extraction from SGSPs to grow the total energy efficiency of accumulating solar radiation, storing thermal energy, and supplying to an application. Husain et al. (2003) calculated the best size of the NCZ for rapid warm-up to raise the productivity of the pond and examined the prospects of attaining quick warm-up and full heat collection volume.
Case study on wastewater treatment technology of coal chemical industry in China
Published in Critical Reviews in Environmental Science and Technology, 2021
Jingxin Shi, Chunyan Xu, Yuxing Han, Hongjun Han
The wastewater of the coal chemical industry contains a large number of volatile organic compounds, among which phenolic substances are the main ones. Phenolic substances are typical carcinogenic substances. Such volatile organic compounds disperse around the plant, the odor is strong and the operating environment is bad. Some processes are designed as an open tank, and there are no sealing measures or odor treatment measures. During operation, the odors generated by volatile substances and the fermentation of pollutants will cause the overflow of the regulating tank and affect the environment. It is suggested to seal the regulating tank and increase the treatment facilities of odor (Lee, Moon, & Cho, 2017). Negative pressure extraction measures should be adopted in the regulating tank to send the odor to the treatment system. Furthermore, some photocatalytic advanced oxidation processes show a potential in degradation of volatile organic compounds in industrial effluents (Fernandes, Gągol, Makoś, Ali Khan, & Boczkaj, 2019a; Fernandes, Makoś, Wang, & Boczkaj, 2019b), which can be further studied in the treatment of coal industry wastewater. 3. Evaporation pond and salt
The occurrence, transformation and control of selenium in coal-fired power plants: Status quo and development
Published in Journal of the Air & Waste Management Association, 2022
Shuangchen Ma, Fang Xu, Dao Qiu, Shuaijun Fan, Ruimin Wang, Yang Li, Xiangyang Chen
The use of evaporation ponds to remove selenium compounds in wastewater is mainly used in agricultural wastewater Ryu, Gao, and Tanji (2011). The low pollutant concentration of agricultural wastewater and the low cost of agricultural water determine that the evaporation pond is highly competitive in areas with high agricultural utilization.Although the evaporation pond technology cannot quickly remove selenium pollutants, its simple and low input characteristics can be used as a feasible solution under special conditions. As the selenium-containing wastewater treatment technology of the WFGD system, the applicability of the evaporation pond treatment is poor at present and worse in the future.