Electrolytic Oxidation as a Sustainable Method to Transform Urine into Nutrients

Nasr Bensalah,Ahmed Bedoui,Sondos Dbira,Mohammad I Ahmad

doi:10.3390/pr8040460

Nasr Bensalah, Ahmed Bedoui + Show 2 more

Open Access

https://doi.org/10.3390/pr8040460

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Journal: Processes	Publication Date: Apr 14, 2020
Citations: 4	License type: CC BY 4.0

Affiliation: Qatar University, University of Gabès

Abstract

In this work, the transformation of urine into nutrients using electrolytic oxidation in a single-compartment electrochemical cell in galvanostatic mode was investigated. The electrolytic oxidation was performed using thin film anode materials: boron-doped diamond (BDD) and dimensionally stable anodes (DSA). The transformation of urine into nutrients was confirmed by the release of nitrate (NO3−) and ammonium (NH4+) ions during electrolytic treatment of synthetic urine aqueous solutions. The removal of chemical oxygen demand (COD) and total organic carbon (TOC) during electrolytic treatment confirmed the conversion of organic pollutants into biocompatible substances. Higher amounts of NO3− and NH4+ were released by electrolytic oxidation using BDD compared to DSA anodes. The removal of COD and TOC was faster using BDD anodes at different current densities. Active chlorine and chloramines were formed during electrolytic treatment, which is advantageous to deactivate any pathogenic microorganisms. Larger quantities of active chlorine and chloramines were measured with DSA anodes. The control of chlorine by-products to concentrations lower than the regulations require can be possible by lowering the current density to values smaller than 20 mA/cm2. Electrolytic oxidation using BDD or DSA thin film anodes seems to be a sustainable method capable of transforming urine into nutrients, removing organic pollution, and deactivating pathogens.

Highlights

Human urine is an extremely complex liquid with variable chemical composition
We aimed to evaluate the effects of the principal parameters such as current density, flow rate, and temperature on the kinetics and performance of electrolytic oxidation using boron-doped diamond (BDD) and dimensionally stable anodes (DSA) anodes during electrolytic treatment of urine
Anodes achieved the almost mineralization of the organic carbon initially contained in synthetic urine, regardless of complete the current density, flow of the organic carbon initially contained in synthetic urine, regardless of the current density, rate, and temperature

Summary

Introduction

Human urine is an extremely complex liquid with variable chemical composition. Urine is an aqueous medium containing both organic and inorganic components. The hormones and pharmaceuticals excreted with urine as micro-pollutants can bioaccumulate in plants and be transferred to the food chain, which causes high risks to human health [12,13,14]. Urine can contain pathogenic organisms as disease-carriers that can multiply in the soil and contaminate the food web [12,15]. The reuse of insufficiently treated human and animal urine in agriculture may result in transmission of pathogens [5,9,15,16].

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