Advanced oxidation as tertiary treatment for recovery of effluent from an integrated algal pond system

Abstract

In contemporary water‐scarce regions and with increasing pressure on the built environment, access to quality water within the peri‐urban space is of concern. It has been argued that integrated algal pond systems (IAPS) are ideally suited as these systems offer value recovery and water for irrigation. Advanced oxidation (AO) was evaluated as tertiary treatment for inclusion into the IAPS process. Chemical oxygen demand (COD), total suspended solids (TSS) and ammonium‐N in effluent from an IAPS treating municipal sewage were monitored after exposure to AO. All measured parameters were reduced but reduction in COD occurred only after long‐term exposure or high dosage. COD, TSS and ammonium‐N concentrations were reduced by 2%, 30% and 28%, respectively, within 24 h. Addition of an AO unit to the IAPS process can upgrade water quality to a level satisfactory for recovery to irrigation or for discharge without any substantial increase in process footprint.

Algal settling ponds contribute to final effluent quality of integrated algal pond systems for municipal sewage treatment

“…Results in Table 2 provide a detailed account of overall component performance and efficiency of the IAPS for treatment of municipal wastewater for the 9 month duration of the study. As previously shown, this treatment process rendered a final effluent that with the exception of TSS and COD was, prior to tertiary treatment, chlorination and/or advanced oxidation (Jimoh et al, 2021; Mambo et al, 2014), within the general limit values set by South African authorities (DWA, 2013) for either irrigation or discharge to a water resource that is not a listed water resource for volumes up to 2000 m 3 on any given day.…”

“…For detailed process flow diagrams, the interested reader is referred to the following publications: Mambo et al (2014), Jimoh and Cowan (2017), Laubscher and Cowan (2020), Jimoh et al (2021), and Titilawo et al, (2021).…”

“…The IAPS used in this study is located at the Institute for Environmental Biotechnology (EBRU) research station adjacent to the municipal Belmont Valley Wastewater Treatment Works (WWTW), Makhanda, South Africa (33 19 0 07 00 South, 26 33 0 25 00 East) and was configured and operated as previously described (Jimoh et al, 2021;Jimoh & Cowan, 2017;Mambo et al, 2014). In brief, this demonstration IAPS is supplied continuously with municipal sewage and comprises an AFP containing a cylindrical IPD or fermentation pit with point of influent located 6 m below surface water level.…”