Fundamental challenges and engineering opportunities in flue gas desulfurization wastewater treatment at coal fired power plants

Abstract

This review identifies challenges and opportunities facing the electricity generation sector in treating flue gas desulfurization wastewater.

A study on the properties and working mechanism of a waterborne polyurethane-modified silicate-based coating

“…[1][2][3][4][5] The ue gas produced by industrial boilers contains a large amount of sulfur dioxide, which has strong corrosiveness to chimneys and will seriously affect the durability of buildings. [6][7][8][9][10] Therefore, effective desulfurization should be carried out before the discharge of ue gases. However, the ue gas treated by the ue gas desulfurization system was still corrosive to chimneys.…”

Layered Double Hydroxide Sorbents for Removal of Selenium from Power Plant Wastewaters

“…The primary conclusion is that LDH does display efficacy for removing selenium present in power plant wastewater, but the adsorption capacities obtained here are very low (< 1 μg/g exhaustion capacity, ~ 200 BVs treated) due to the following factors: (1) the presence of selenium in low (ppb) levels in the waters investigated here, (2) sulfate anions that are present at much higher concentrations, and (3) the lack of LDH selectivity between these two species. The trend in sorption capacities in the various waters showed more correlation to the [S]/[Se] ratios than to the initial Se concentration, as summarized in Table 5.…”

“…The purpose of these ELGs was to set new, more stringent federal limits on the levels of pollutants that can be discharged in wastewaters from power plants, notably toxic and bioaccumulative pollutants such as arsenic, mercury, selenium, chromium, and cadmium. For example, under these guidelines, the maximum average daily concentration limit for selenium in flue gas desulfurization (FGD) wastewaters from existing sources is 12 µg/L over 30 consecutive days; for new sources the limit is 5 µg/L [1,2]. In cases where wastewater is discharged to surface waters used by aquatic wildlife, the discharge limit can be lower due to ecological and health risks [3] (e.g., 2 µg/L in the state of Arizona [4]).…”

“…The fundamental challenges and treatment technologies for selenium have been highlighted in several reviews [2,[7][8][9][10] and include chemical, physical, and biological methods, with bioreactors containing selenium-reducing microorganisms being one of the most mature technologies that have been evaluated for pilot and full-scale wastewater treatment [11,12]. However, some of these bacteria are sensitive to other anions in the water (e.g., chloride, nitrate) [2], and waters containing high levels of sulfate may encourage growth of sulfate-reducing bacteria, which can compete with selenium-reducing bacteria for nutrients [12]. Moreover, biological treatment requires larger footprints with longer residence times (4-6 hours) compared to physicochemical processes to remove selenium [8].…”

“…Volume (L) and2 bed volumes of water treated at breakthrough;3 Capacity of loading Se or S at breakthrough; 4 Volume (L) and5 bed volumes of water treated at bed exhaustion;6 Exhaustion capacity;7 Adsorption exhaustion rate; 8 Volume (L) of water that can be treated with 1 g of sorbent.…”