Abeysiriwardana-Arachchige ISA, Delanka-Pedige HMK, Munasinghe-Arachchige SP, Nirmalakhandan N. Techno-economic optimization of phosphorous recovery in an algal-based sewage treatment system.
BIORESOURCE TECHNOLOGY 2021;
332:125128. [PMID:
33853026 DOI:
10.1016/j.biortech.2021.125128]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Previous reports have documented the technical viability of an algal pathway for treating primary effluent and recovering its phosphorus-content (P) via hydrothermal liquefaction (HTL) of the resulting biomass. In this pathway, leaching P from HTL-derived biochar was found as the critical step impacting the economics of P-recovery. As such, a process model was developed in the current study to optimize P leaching from biochar as a function of five parameters. Model predictions under various conditions agreed well with measured data (r2 = 0.93; n = 184). The validated process model was then integrated with a cost model to establish the following conditions as optimal for leaching P from biochar: batch leaching time of 72 h; eluent NaOH concentration of 0.5 M; eluent-to-biochar ratio of 20; temperature of 60 °C; and provision of mixing. Under these conditions, 73.5% of P from biochar could be recovered at $5.98/kg P.
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