Removal of sulfate from wet FGD wastewater by co-precipitation with calcium hydroxide and sodium aluminate.

Title Removal of sulfate from wet FGD wastewater by co-precipitation with calcium hydroxide and sodium aluminate.
Authors J. Yu; J. Lu; Y. Kang
Journal Water Sci Technol
DOI 10.2166/wst.2018.019
Abstract

Chemical precipitation method was adopted to remove sulfate from wet flue gas desulfurization (FGD) wastewater and mixtures of Ca(OH)(CH) and NaAlO(SA) were used as precipitants. The mechanisms of sulfate removal were explored according to the experimental and simulated results. These showed that three kinds of precipitations, which were gypsum, ettringite and co-precipitation onto aluminum hydroxides, were formed when sulfate in water reacted with CH and SA. The optimum operation condition for removing sulfate was that the molar ratio of CH/SA was 2, the initial pH value 5, the precipitant dosage 15 g/L, the reaction time 20 min, and the reaction temperature 55 °C. The sulfate was reduced from 4,881 mg/L to 784 mg/L under the optimized condition. In addition, the heavy metals and fluoride were also mostly removed. The post treatments of the supernatant illustrated that removal of sulfate from wet FGD wastewater by co-precipitation with CH and SA was a better choice.

Citation J. Yu; J. Lu; Y. Kang.Removal of sulfate from wet FGD wastewater by co-precipitation with calcium hydroxide and sodium aluminate.. Water Sci Technol. 2018;77(5):13361345. doi:10.2166/wst.2018.019

Related Elements

Aluminum

See more Aluminum products. Aluminum (or Aluminium) (atomic symbol: Al, atomic number: 13) is a Block P, Group 13, Period 3 element with an atomic weight of 26.9815386. It is the third most abundant element in the earth's crust and the most abundant metallic element. Aluminum Bohr Model Aluminum's name is derived from alumina, the mineral from which Sir Humphrey Davy attempted to refine it from in 1812. Aluminum was first predicted by Antoine Lavoisier 1787 and first isolated by Hans Christian Øersted in 1825. Aluminum is a silvery gray metal that possesses many desirable characteristics. It is light, nonmagnetic and non-sparking. It stands second among metals in the scale of malleability, and sixth in ductility. It is extensively used in many industrial applications where a strong, light, easily constructed material is needed. Elemental AluminumAlthough it has only 60% of the electrical conductivity of copper, it is used in electrical transmission lines because of its light weight. Pure aluminum is soft and lacks strength, but alloyed with small amounts of copper, magnesium, silicon, manganese, or other elements, it imparts a variety of useful properties.

Calcium

See more Calcium products. Calcium (atomic symbol: Ca, atomic number: 20) is a Block S, Group 2, Period 4 element with an atomic weight of 40.078. The number of electrons in each of Calcium's shells is [2, 8, 8, 2] and its electron configuration is [Ar]4s2. Calcium Bohr ModelThe calcium atom has a radius of 197 pm and a Van der Waals radius of 231 pm. Calcium was discovered and first isolated by Sir Humphrey Davy in 1808. It is the fifth most abundant element in the earth's crust and can be found in minerals such as dolomite, gypsum, plagioclases, amphiboles, pyroxenes and garnets. In its elemental form, calcium has a dull gray-silver appearance. Calcium is a reactive, soft metal that is a member of the alkaline earth elements. Elemental CalciumIt frequently serves as an alloying agent for other metals like aluminum and beryllium, and industrial materials like cement and mortar are composed of calcium compounds like calcium carbonate. It is also an biologically essential substance found in teeth, bones, and shells. The name "calcium" originates from the Latin word "calics," meaning lime.

Sodium

Sodium Bohr ModelSee more Sodium products. Sodium (atomic symbol: Na, atomic number: 11) is a Block D, Group 5, Period 4 element with an atomic weight of 22.989769. The number of electrons in each of Sodium's shells is [2, 8, 1] and its electron configuration is [Ne] 3s1. The sodium atom has a radius of 185.8 pm and a Van der Waals radius of 227 pm. Sodium was discovered and first isolated by Sir Humphrey Davy in 1807. In its elemental form, sodium has a silvery-white metallic appearance. It is the sixth most abundant element, making up 2.6 % of the earth's crust. Sodium does not occur in nature as a free element and must be extracted from its compounds (e.g., feldspars, sodalite, and rock salt). The name Sodium is thought to come from the Arabic word suda, meaning "headache" (due to sodium carbonate's headache-alleviating properties), and its elemental symbol Na comes from natrium, its Latin name.

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