An extraction and precipitation process for the removal of Ca and Mg from ammonium sulfate rare earth wastewaters

A Novel Alternative Methods for Decalcification of Water Resources Using Green Agro-Ashes

“…The second mechanism may enhance the reduction in Ca 2+ ions due to the adsorption role of insoluble inorganic minerals existing in the composition of agro-ash such as charcoal, silicates, and CaCO 3 [50]. Precipitation by alkali/carbonate sources is a familiar method used for reducing the hardness of water [11,14,[52][53][54]. Mg(OH) 2 was used as an alkali source derived from the brine pre-treated waste of soda ash plant mixed with the flux of CO 2 for water decalcification by precipitation of CaCO 3 [17].…”

“…Among these techniques, MVR is more desirable because of its economical, energy-saving, easy operation, and low-temperature evaporation process. MVR has been broadly employed in various manufacturing industries such as the chemical of purification food, petrochemicals, wastewater purification, and desalination [10,11]. The water or wastewater used by the MVR technique should contain low concentrations of calcium and magnesium ions, below 100 ppm and 500 ppm, respectively.…”

“…The water or wastewater used by the MVR technique should contain low concentrations of calcium and magnesium ions, below 100 ppm and 500 ppm, respectively. A decline in scale ions has become essential as an earlier step in such evaporation techniques as a result of low thermal conductivity and a reduction in heat transfer in the heater or boiler of scales [11]. Therefore, the membrane fouling efficiency used for the discharged wastewater of flue gas desulfurization (FGD) employed in thermal power plants (such as wet scrubber technologies) is negatively affected by high levels of hardness ions such as Ca and Mg.…”

“…This can be accomplished by increasing the pH with the addition of a base (e.g., NaOH or Ca(OH) 2 ) as a conventional remedy for hardness problems in the occurrence of sand granules [9]. Several approaches have been published for the removal of ions causing scales (i.e., Ca and Mg ions) using different methods such as CaO/Na 2 CO 3 , precipitation by oxalic acid and phenoxy acetic acid [11], selective nanocomposite electrosorption electrode [13], ion exchange resins (the alkyl phenoxy acetic acid derivatives) [11], injection of CO 2 gas [14], microbial carbonate precipitation process (MCP) [15], phosphosilicate glass [5], wheat straw ash (WSA) and rice husk ash (RHA) [16], brine pre-treatment waste of soda ash plant such as an alkali source and CO 2 [17], and synthetic zeolite [18]. In the scope of the present circumstances, it is important to achieve sustainable development for future generations, utilizing the principles and concepts of green chemistry [1].…”

Facile Fabrication of Novel SrMoO4/g‐C3N4 Hybrid Composite for High‐Performance Photocatalytic Degradation of Dye Pollutant under Sunlight

“…[4][5][6] Hitherto, several methods such as photocatalytic degradation, membrane filtration, adsorption, flocculent precipitation, biological treatment, and so on were adopted for removal of water pollutants were adopted. [7][8][9][10][11] In comparison to these methods, the photocatalytic degradation method is widely preferred in the recent years, This is because, it is cost effective method as it employs the utilization of inexhaustible solar radiation as energy source and is found to be efficient, simple and convenient method. [12] Even though, numerous photocatalysts have been developed so far, nevertheless, designing of new photocatalyst is still on going and focused area of research with an objective to achieve more affordable photocatalyst with improved performance.…”