The aim of this study was to assess the potential environmental impacts associated with high rate algal ponds (HRAP) systems for wastewater treatment and resource recovery in small communities. To this aim, a Life Cycle Assessment (LCA) was carried out evaluating two alternatives: i) a HRAP system for wastewater treatment where microalgal biomass is valorized for energy recovery (biogas production); ii) a HRAP system for wastewater treatment where microalgal biomass is reused for nutrients recovery (biofertilizer production). Additionally, both alternatives were compared to a typical small-sized activated sludge system. An economic assessment was also performed. The results showed that HRAP system coupled with biogas production appeared to be more environmentally friendly than HRAP system coupled with biofertilizer production in the climate change, ozone layer depletion, photochemical oxidant formation, and fossil depletion impact categories. Different climatic conditions have strongly influenced the results obtained in the eutrophication and metal depletion impact categories. In fact, the HRAP system located where warm temperatures and high solar radiation are predominant (HRAP system coupled with biofertilizer production) showed lower impact in those categories. Additionally, the characteristics (e.g. nutrients and heavy metals concentration) of microalgal biomass recovered from wastewater appeared to be crucial when assessing the potential environmental impacts in the terrestrial acidification, particulate matter formation and toxicity impact categories. In terms of costs, HRAP systems seemed to be more economically feasible when combined with biofertilizer production instead of biogas. On the whole, implementing HRAPs instead of activated sludge systems might increase sustainability and cost-effectiveness of wastewater treatment in small communities, especially if implemented in warm climate regions and coupled with biofertilizer production.
The aim of this study was to assess the environmental benefits of implementing low-cost digesters in small-scale farms in Colombia by using the LCA methodology. Four scenarios were taken into account considering two small-scale farms located in different areas: two (previous) scenarios where manure was stored in a manure pit and liquefied pretroleum gas (LPG) was used for cooking; and two (current) scenarios where manure is treated in low-cost digesters, the digestate replaces the synthetic fertiliser and the biogas is used for cooking replacing the LPG. Results showed that digesters implementation considerably reduced (by up to 80%) potential environmental impacts associated with manure handling, fuel and fertiliser use in the small-scale Colombian farms. This was mainly due to the reduction of LPG and synthetic fertiliser use which were replaced by biogas and digestate. An economic assessment showed that low-cost digesters reduced expenses associated with cooking fuel and fertiliser purchase by 80%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.