Cleansing Mechanisms of Cementitious Filters in Textile Wastewater Treatment

With the rise of ultra-fast fashion and the ever-growing textile industry, dye pollution has become a critical issue in textile wastewater treatment in many emerging markets. Future cleansing strategies of wastewater polluted with synthetic dyes needs to be cost-effective and easy-to-use. The hydration phase assemblage of cements containing ground granulated blast-furnace slag (GGBS) offer a high potential for wastewater treatment. This study aims to provide insights into the interaction of hydrated cementitious materials with dye effluents. For that, granulates are produced using CEM I 42.5 R and various percentages of GGBS (0%, 35%, 65%, 80% wt%) mixed with water (w/s = 0.5). Therefore, prisms are produced and then cured in a saturated calcium hydroxide solution for 28 days and afterwards ground to fractions from 0.125 mm to 4 mm. These granulates are then further cured in the saturated calcium hydroxide solution for 14 days. Alongside, a selection of hydration phases (C-S-H, C-A-S-H, hydrotalcite, and Friedel’s salt) will be synthesized in the laboratory. The potential to immobilize the dyes by the granulates, the synthesized pure hydration phases, brucite, and calcite will be investigated for three different dye solutions (Congo red, methyl red and reactive blue 19). The experiments will be performed in four different storage solutions (Na2SO4, NaCl, MgSO4, H2O) to cover a broad range of wastewater compositions, which might affect the interaction of dyes with the hydration phases. The decolourisation behaviour will be analysed using a UV/VIS spectrometer with eight flow through cells in batch and column experiments for 24 hours. XRD, and 29Si and 27Al NMR will be used to analyse the intercalation of dye molecules into the interlayer regions. The zeta potential of the granulates and hydration phases is supposed to give insight on the ion-exchange processes on the surfaces pf the hydration phases. By elucidating the mechanisms of dye removal from wastewater from the textile industry, we aim to generate the basis for a cost-effective solution for emerging textile markets. Investigations towards the application of such technologies will then be investigated in a next step.     «

With the rise of ultra-fast fashion and the ever-growing textile industry, dye pollution has become a critical issue in textile wastewater treatment in many emerging markets. Future cleansing strategies of wastewater polluted with synthetic dyes needs to be cost-effective and easy-to-use. The hydration phase assemblage of cements containing ground granulated blast-furnace slag (GGBS) offer a high potential for wastewater treatment. This study aims to provide insights into the interaction of hydr...     »