Original scientific paper
https://doi.org/10.13044/j.sdewes.d13.0640
Simultaneous Recovery of Ammonium and Phosphate from Wastewater Using Magnesium-Activated Temple Waste Biochar
I Made Wahyu Wijaya
orcid.org/0000-0002-1847-0081
; Universitas Mahasaraswati Denpasar, Denpasar, Indonesia
I Ketut Sumantra
; Universitas Mahasaraswati Denpasar, Denpasar, Indonesia
Ni Made Dharma Shantini Suena
; Universitas Mahasaraswati Denpasar, Denpasar, Indonesia
Kailas Deoram Ahire
; KTHM College, Maharashtra, India
Pravin Mukund Nalawade
; KTHM College, Maharashtra, India
Abstract
Nutrient pollution from ammonium and phosphate in wastewater presents serious environmental challenges, including water eutrophication and resource inefficiency. The study aimed to analyse how magnesium-activated biochar made from temple waste could be used as a sustainable material for adsorping nutrients at the same time. The biochar was synthesised through pyrolysis and magnesium chloride activation, then applied to real wastewater from stabilisation ponds in Bali. The adsorption dynamics for both ammonium and phosphate were consistent with pseudo-second-order models, suggesting that chemical absorption was the prevailing mechanism. The Freundlich isotherm model provided the best fit, suggesting heterogeneous multilayer adsorption. Results demonstrated that adsorption capacity and rate varied across different wastewater sources, with the highest adsorption rates corresponding to ponds exhibiting more favourable surface interactions. Importantly, the adsorption rate constant for phosphate surpassed that of ammonium in some cases, emphasising the influence of ionic properties and biochar surface heterogeneity. The results confirm that biochar made from waste can effectively recover nutrients and should be included in circular approaches for managing wastewater.
Keywords
Adsorption; Biochar; Nutrient Recovery; Magnesium-Activated Biochar; Wastewater; Ammonium; Phosphate; Circular Economy
Hrčak ID:
346102
URI
Publication date:
25.5.2026.
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