Characterization and treatment of landfill leachates by electro‐Fenton process: A case study in Algeria

Abstract

The feasibility of the electro-Fenton (EF) process to improve the biodegradability of Algerian leachates was examined, in order to prepare this kind of flux for conventional biological treatment. This work also included, for the first time in Algeria, the control and monitorization of a landfill-the "Hamici" landfill. Several physicochemical parameters were determined allowing its classification into an intermediate degradation phase, namely considering their alkaline pH (8.7), high ammonium concentration (3,120 mg/L), low content in heavy metals, and biodegradability (BOD 5 / COD = 0.22). The effects of important parameters such as current intensity, treatment time, and temperature on COD removal have been studied and optimized by using response surface analysis of a central composite design, where 91.1% of COD was removed with a treatment time of 285 min, a current intensity of 3 A, and a temperature of 20°C. A biodegradability test, which was performed on a solution electrolyzed with 120 min, 2 A, and 20°C, allowed to improve the leachates biodegradability from 0.2 to 0.42, with a removal rate of COD and TOC of 53.35% and 34.5%, respectively. However, the current efficiency declined from 137% to 76.6% when the current intensity was rise from 0.5 to 2 A. These results showed the relevance of EF process applied on raw intermediate leachates and its possible benefit in the Algiers leachates treatment processes. Thus, it was concluded that biological treatment can be combined with EF process for optimal mineralization of leachates with clear advantages in this studied location. • Practitioner points• Characterization and treatment of leachates by electro-Fenton (EF) process were carried out. • The leachates are intermediate type and therefore biologically recalcitrant. • The operating parameter for EF process were modeled and optimized by the central composite design. • Current intensity of 2 A reduces COD and TOC of 53.35% and 34.5%, respectively. • The ratio BOD 5 /COD increased from 0.2 to 0.42 after 120 min of electrolysis time.

Biological degradation of leachate from household and similar waste pre‐treated by electro‐Fenton process

“…These optimal values ( i = 2.6 10 3 A/m 2 , t = 120 min and T = 20°C) were retained and fixed for the rest of the experimental work. The details of this first phase of treatment have been published in a previous study (Rouidi et al, 2020).…”

“…The first pre-treatment phase using the electro-Fenton process was carried out in a batch reactor with a volume of 500 mL; 250 mL of raw leachate was used, and the initial pH was adjusted to 3 using H 2 SO 4 at 1N. Except for pH adjustment, no other chemicals were F I G U R E 1 Satellite view of technical landfill centre (TLC) Hamici by Google Earth and photograph of the leachate storage pond (Rouidi et al, 2020). added upstream, and the Fenton reaction was triggered by taking advantage of the high iron content (12.4 mg/L) and in conductivity (30.8 mS/cm) of Hamici leachates.…”

“…The leachates considered in this study are those of the TLC of the city of Algiers, the TLC-Hamici, located in Zeralda town at about 30 km from the city of Algiers where the climate is of the Mediterranean type with a rate of humidity varying around 80% (Rouidi et al, 2020).…”

“…Satellite view of technical landfill centre (TLC) Hamici by Google Earth and photograph of the leachate storage pond (Rouidi et al, 2020). …”

Removal of Organics from Landfill Leachate by Heterogeneous Fenton-like Oxidation over Copper-Based Catalyst

“…If mineralization is achieved during the Fenton reaction, the TOC decreases but if only partial oxidation occurs it remains constant with a decrease of the COD [52]. In addition, AOS (average oxidation state) and COS (carbon oxidation state) parameters have been evaluated for a better understanding of the degree of oxidation of a process [53][54][55].…”