Removal of Cr(III) From Water By Polyurethane Foam Incorporated With Green Liquor Dregs Waste

Abstract

Water bodies contaminated by heavy metals cause a series of severe environmental and health issues. Chromium compounds stand out as one of the main contaminants since they are widely used by several industries. The low efficiency of effluent treatment facilities and the expensive sanitation procedures needed to remove metals from the water lead to serious concerns about the water quality in Brazil. In this study, a rigid polyurethane foam incorporated with green liquor dregs waste was prepared by the free expansion method. The foam composite and its isolated phases were evaluated for removing Cr(III) from water. The isolated dregs removed 81.93% of the Cr(III), which yielded a removal capacity of 135.45 mg·g-1. Whereas, the foam composite displayed Cr(III) removal percentage and capacity of 36.15% and 58.50 mg·g-1, respectively. Results suggests that the hybrid material may be considered for selective removal and extraction of Cr(III) from contaminated water.

Bacterial cellulose‐modified castor oil‐based polyurethane sponge for hexavalent chromium removal

“…The study of sorption through isotherm models may indicate how the Cr (VI) is adsorbed and estimate the maximum amount of ion that PU + 20%BC can absorb. Therefore, to evaluate isotherms model adjustment, the samples were submitted in different Cr (VI) concentration solutions (10,20,30,40, and 50 mg L À1 ) for 2.5 min, shirred (150 rpm), and at 25 C. The isotherm models used were Langmuir and Freundlich.…”

“…Several techniques are used to reduce Cr (VI) concentration in water, for example, chemical precipitation, ion exchange, membrane separation, ultrafiltration, sedimentation, and adsorption 7,10 . Among these techniques, adsorption has been used most frequently because of its availability, eco‐friendly process, and easy recovery 9,11–15 Activated carbon and clay are regarded as one of the most widely used adsorbents because of their large specific surface area and easy complexing with metal ions, but they also have disadvantages, such as short service life and complex regeneration 16–18 …”

“…[7][8][9] Several techniques are used to reduce Cr (VI) concentration in water, for example, chemical precipitation, ion exchange, membrane separation, ultrafiltration, sedimentation, and adsorption. 7,10 Among these techniques, adsorption has been used most frequently because of its availability, eco-friendly process, and easy recovery 9,[11][12][13][14][15] Activated carbon and clay are regarded as one of the most widely used adsorbents because of their large specific surface area and easy complexing with metal ions, but they also have disadvantages, such as short service life and complex regeneration. [16][17][18] Currently, there has been an increase in interest in polyurethane foam (PUF) applications since it is a sorbent that represents an inexpensive and efficient means of separation and pre-concentration, with increasingly versatile applications in the analysis of inorganic species.…”