Treatment of highly turbid water in disaster conditions using coagulation-flocculation process: modeling and optimization

Danial Nayeri,Seyyed Alireza Mousavi

doi:10.2166/wqrj.2020.120

Danial Nayeri, Seyyed Alireza Mousavi

Open Access

https://doi.org/10.2166/wqrj.2020.120

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Abstract

Abstract In the present research, the coagulation-flocculation (CF) process was used to eliminate highly turbid water in disaster conditions. To better understand the efficiency of the system, the impact of various numerical factors namely; initial turbidity (10–350 NTU), pH (5–9), coagulant dosage (50–250 mg/L), rapid mixing (120–280 rpm), slow mixing (30–50 rpm), and sedimentation time (10–50 min) were optimized through the central composite design (CCD) under response surface methodology (RSM). Based on analysis of variance (ANOVA), the quadratic model was more suitable for the dataset with R2 = 0.85 for removing turbidity. Moreover, the results of the present study revealed that the highest turbidity removal (99.14%) was observed at pH (9), alum dosage (50 mg/L), initial turbidity (350 NTU), rapid mixing (280 rpm), slow mixing (50 rpm), and sedimentation time (50 min). Furthermore, the residual turbidity at the maximum efficiency of the system was 3 NTU.

Highlights

Over the past decades, disasters, especially floods and earth-Excessive turbidity in drinking water can be associated quakes, have had adverse effects on water quality such as with the presence of organic materials, dye, and microorganincreasing suspended solids (SS) and colloids more than isms such as viruses, and certain bacteria, it the standard range (Ang et al )
The drinking water-based on ation (WHO) proposed that acceptable levels of turbidity in turbidity value can be divided into four categories as foldrinking water must be less than 5 NTU
Another study (CF) process is the most reliable technology to reduce any by Baghvand et al ( ) reported that the highest turbidity pollutants removal by using alum and ferric chloride as coagulant was from drinking water (Zhao et al )

Summary

INTRODUCTION

Excessive turbidity in drinking water can be associated quakes, have had adverse effects on water quality such as with the presence of organic materials, dye, and microorganincreasing suspended solids (SS) and colloids more than isms such as viruses, and certain bacteria, it the standard range (Ang et al ). Another study (CF) process is the most reliable technology to reduce any by Baghvand et al ( ) reported that the highest turbidity pollutants (turbidity, particulates, and organic matters) removal by using alum and ferric chloride as coagulant was from drinking water (Zhao et al ). ). Agbovi & Wilson ( ) examined and optimized the extensively applied in water treatment plants (WTPs) removal efficiency of turbidity using an amphoteric chitobecause of its superior properties such as simplicity, costsan-based flocculant–ferric chloride by RSM. They found effectiveness, high efficiency, non-toxic method, and low that the turbidity removal under optimum conditions was energy consumption (Lim et al ; Ozairi et al ). ), multi-layer perceptron (MLP) (Gagnon et al ), generalized regression neural network (GRNN) (Specht ), and response surface methodology (RSM)

MATERIALS AND METHODS

RESULTS AND DISCUSSION

Results of ANOVA

CONCLUSIONS