Removal of fluoride from coke wastewater by aluminum doped chelating ion-exchange resins: a tertiary treatment

Jesús Rodríguez-Iglesias,Laura Megido,Lara Alcalá,Leonor Castrillón

doi:10.1007/s11356-021-16299-8

Jesús Rodríguez-Iglesias, Laura Megido + Show 2 more

Open Access

https://doi.org/10.1007/s11356-021-16299-8

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Abstract

Coke wastewater is one of the most problematic industrial wastewaters, due to its large volume and complex pollutant load. In this study, ion exchange technology was investigated with the objective of reducing the fluoride content of the effluent from a coke wastewater treatment plant (26.7 mg F-/L). Two Al-doped exchange resins with chelating aminomethyl-phosphonic acid and iminodiacetic groups were assessed: Al-doped TP260 and TP207 resins, respectively. The effect of resin dosage, varying from 5 to 25 g/L, was evaluated. F- removal was within the range 57.8–89.3% and 72.0–92.1% for Al-doped TP260 and TP207, respectively. A kinetic study based on a generalized integrated Langmuir kinetic equation fitted the experimental data (R2 > 0.98). The parameters of the said kinetics met the optimal conditions for the ion exchange process, which seemed to be more favorable with Al-doped TP260 resin than with Al-doped TP207 resin, using the same resin dosage. Furthermore, the experimental data were well described (R2 > 0.98) by Langmuir and Freundlich isotherm models, in agreement with the findings of the kinetic study: the maximum sorption capacity was obtained for the Al-doped TP260 resin.

Highlights

Coke is a product of the distillation of coal and has applications in the iron metallurgy, mineral wool production, noniron metallurgy, molding, metal sintering, lime kilns, iron blends and carbide production
F- removal was within the range 57.8–89.3% and 72.0–92.1% for Al-doped TP260 and TP207, respectively
In ion exchange processes, free mobile ions on a solid waterinsoluble substance are stoichiometrically replaced by different ions of similar charge present in the aqueous medium with which it is in contact, whereas in adsorption processes, the chemical species are captured without any exchange (Kumar and Jain 2013)

Summary

Introduction

Coke is a product of the distillation of coal and has applications in the iron metallurgy, mineral wool production, noniron metallurgy, molding, metal sintering, lime kilns, iron blends and carbide production. In 2018, European coking plants used 49 million tonnes of coking coal to produce 37 million tonnes of cokeoven coke (Eurostat 2019). Coke manufacturing implies several hydro-intensive operations, such as quenching of hot coke, washing the ammonia still, cooling and washing of the coke oven gases, and Responsible Editor: Angeles Blanco. Due to its large volume and complex pollutant load, coke wastewater is one of the most problematic industrial wastewaters, containing organic (organic matter, phenols, polycyclic aromatic hydrocarbons) and inorganic (cyanides, thiocyanates, ammonia, fluorides, sulfides) toxic compounds (Marañón et al 2008; Pal and Kumar 2014). Biological treatment is the most widely used alternative on an industrial scale for the removal of organic matter, thiocyanates, phenols, etc. Biological treatments are an established and viable technology for coke wastewater treatment, a tertiary treatment (e.g. chemical treatment and adsorption) is usually required to meet regulations concerning residual pollutant levels and acute colour bodies (Das et al 2020)

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