Optimization and economic evaluation of modified coagulation\u2013flocculation process for enhanced treatment of ceramic-tile industry wastewater

Tahereh Zarei Mahmudabadi,Morteza Mohamadzadeh,Hadi Eslami,Mehdi Mokhtari,Mohammad Hossein Salmani,Mohammad Taghi Ghaneian,Mohsen Pakdaman,Ali Asghar Ebrahimi

doi:10.1186/s13568-018-0702-4

Abstract

Enhanced treatment of ceramic-tile industry wastewater was investigated by modified coagulation–flocculation process using combination of poly-aluminum chloride (PAC) with anionic (A300), cationic polymer (C270) and nonionic polymers. The effects of pH, PAC coagulant dose alone and with polymers dose in various combinations was studied by jar tests. To compare the removal efficiencies of turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and color at different levels, we run multivariate analysis of variance. Regarding the economic evaluation, we applied the incremental cost-effectiveness ratio. PAC had the best performance in pH 7 and in optimal dose of 400 mg/L; so that removal efficiency of wastewater turbidity, TSS, COD and color were 99.63%, 99.7%, 47.5% and 50.38%, respectively. The best removal efficiency for wastewater turbidity, TSS, COD and color were 99.87%, 99.89%, 87.5% and 93.02%, respectively which were obtained by combination of anionic polymer (1.5 mg/L) with PAC (300 mg/L). Furthermore, with combination of PAC + anionic + non-ionic polymers, the removal efficiency for wastewater turbidity, TSS, COD and color were 99.93%, 99.94%, 88% and 94.57%, respectively. The imposed cost for treating one cubic meter of ceramic-tile wastewater treatment by PAC + anionic and PAC + anionic and non-ionic polymers in comparison with PAC alone was reduced to 22.96% and therefore economically more affordable for the tile industry wastewater treatment.

Highlights

Water is an important raw material in the ceramic-tile industries (Enrique et al 2000; Gabaldón-Estevan et al 2014)
Effect of coagulant dosage without coagulant aid The effects of poly-aluminum chloride (PAC) dosage on the removal efficiency of turbidity, total suspended solids (TSS), chemical oxygen demand (COD) and color is shown in the Fig. 4
The maximum removal efficiency of turbidity, TSS, COD, and color was observed at pH 7

Summary

Introduction

Water is an important raw material in the ceramic-tile industries (Enrique et al 2000; Gabaldón-Estevan et al 2014). Water consumption varies in different parts and processes of manufacturing tiles (Huang et al 2013). In the ceramic-tile industries, a considerable amount of suspended solids and wastewater turbidity can be removed using a simple sedimentation process (Chong et al 2009). The produced wastewater after this stage is only applicable in the slurry sector. This recycled water does not have the necessary quality to be used in other sectors, especially in glaze preparation or other coating processes. It requires a more comprehensive treatment process (Chong et al 2009; Martínez-García et al 2012)

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Conclusion