Application of Electrocoagulation in Street Food Wastewater

Wilawan Khanitchaidecha,Khakhanang Ratananikom,Kanokphol Sing-Aed,Bunyaphon Yangklang,Auppatham Nakaruk,Shotita Intanoo

doi:10.3390/w14040655

Wilawan Khanitchaidecha, Khakhanang Ratananikom + Show 4 more

Open Access

https://doi.org/10.3390/w14040655

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Journal: Water	Publication Date: Feb 20, 2022
Citations: 2	License type: CC BY 4.0

Affiliation: Naresuan University, Kalasin University

Abstract

Street food is commonly known as ready-to-eat and go foods and beverages, which is very famous in Thailand and other Asian countries. The street food daily generates high organic content and oily wastewater from washing and rinsing plates. The discharge of street food wastewater to public drains leads to a clogged drain line and unpleasant smell. In this work, an electrocoagulation (EC) system with monopolar aluminum (Al) electrodes was developed to treat two well-known street foods; Hainanese chicken rice (HC) and noodles and dumplings (ND). The results revealed that excellent chemical oxygen demand (COD) and fat, oil, and grease (FOG) removals were achieved under a specific operating condition (i.e., an electric current of 20 mA/cm2 and electrolytic time of 10 min). The initial COD of HC wastewater decreased from 40.6 g/L to 1.9 g/L, approximately 95%, whereas the FOG decreased from 310 mg/L to 50 mg/L, approximately 84%. The lower initial COD and FOG concentrations of ND wastewater obtained approximately 98% for COD removal and 86% for FOG removal; the effluent contained 0.5 g/L of COD and 25 mg/L of FOG. In addition, a relatively low Al concentration of 0.02–0.08 mg/L was observed in the effluents. The appropriate design factors together with ease of use and fast pollutants removal were significant advantages of this study; the EC system has potential to apply to on-site street food treatment.

Highlights

Street food is known as ready-to-eat foods and beverages sold on a street or other public space including a mobile vendor selling from a cart and a fixed vendor selling from a stall
The chemical oxygen demand (COD) and fat oil and grease (FOG) from the street food wastewater were in a similar range to industrial waste and wastewater such as waste coolant [11] and high-concentration oil and gas fields [12]
Street food wastewater containing high organic concentrations was efficiently treated by the EC system

Summary

Introduction

Street food is known as ready-to-eat foods and beverages sold on a street or other public space including a mobile vendor selling from a cart and a fixed vendor selling from a stall. The buying and selling of street food is a common economic activity in Thailand and Asian countries. The signature of street food is a variety of food, authentic taste, quick assess, and inexpensive service. Due to food preparation and cleaning processes, a large volume of wastewater is daily generated and discharged to public sanitary sewers. The characteristics of food-service wastewater were high organic (represented in chemical oxygen demand; COD), total suspended solid (TSS), and total fat oil and grease (FOG); these were 1523, 664, and 197 mg/L, respectively [1]. The relatively high organic and FOG levels as well as high flow cause an unpleasant smell and sewer line clogging. In Thailand, the local government spends a large amount of the annual budget for sewer line cleaning to avoid flooding and improve residents’ quality of life

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