Sewage sludge handling with phosphorus utilization – life cycle assessment of four alternatives

Holistic sludge management through ozonation: A critical review

“…By sulphuric acid addition, 0.18 tonne of ferric phosphate (FePO 4 ) as DS was recovered from ash. Ferric phosphate can be applied on land directly as replacement for common artificial fertilizers (Johansson et al, 2008).…”

Problem or Resource - Why It Is Important For the Environment to Keep Track of Nitrogen, Phosphorus and Carbon in Wastewater and Sludge Management

“…As for N, the C may take different forms in the wastewater treatment and it may be turned into gaseous species, some being less problematic, such as carbon dioxide (CO 2 ), an emission of a greenhouse gas that in this case is normally not considered to contribute to an atmospheric increase as most of the C originates from biogenic sources, and CH 4 , which is more problematic as it is a very potent greenhouse gas. CH 4 formation is often utilized in biogas generation in anaerobic digesters in which some C (about half) is instead turned into a valuable resource (biogas consists roughly to 70 percent of CH 4 and 30 percent of CO 2 ). Emissions of N and C to air can, besides the problems that the direct emissions may give rise to in themselves, also be seen as a loss of potential resources.…”

“…In LCA literature, the difficulties of correctly estimating different flows, in particular gaseous emissions, from wastewater and sludge has been noted, as has their potentially large influence on the environmental life cycle performance; see e.g. Johansson et al [4], Foley et al [5] and Kampschreur et al [6]. As an example, Johansson et al [4] found that assumptions regarding emissions of N 2 O from the sludge after application on agricultural soil can completely determine the outcome in terms of the climate impact for some sludge management systems.…”

“…Johansson et al [4], Foley et al [5] and Kampschreur et al [6]. As an example, Johansson et al [4] found that assumptions regarding emissions of N 2 O from the sludge after application on agricultural soil can completely determine the outcome in terms of the climate impact for some sludge management systems. In LCA, the environmental impact categories that are the most strongly affected by air-and waterborne emissions originating from wastewater and sludge management are eutrophication, acidification and climate change, matching the concerns of Steffen et al well, and these should therefore be included in LCAs of such systems.…”

Support Phosphorus Recycling Policy with Social Life Cycle Assessment: A Case of Japan

“…Technically, P can be removed and recovered from municipal wastewater treatment plants (WWTP) through struvite precipitation [2] and sludge ash leaching processes [3]; however, producing recycled P fertilizers costs more than conventional mineral P fertilizers due to the investment in infrastructure and maintenance, which discourages most municipal governments from adopting these practices. To consider the externality, previous studies have assessed the environmental impacts of mineral and recycled P fertilizers production from a life cycle perspective [4][5][6][7]. As the concentration of P in wastewater is much lower than mineral P deposits, the energy demand to produce recycled P fertilizers is often higher, or equivalent to that of mineral P fertilizers, depending on various technological choices and accounting methods [4].…”