Environmental impacts and the possibility for sustainable development of human excreta

Abstract

The aim of our study is to explore and compare the environmental impacts and the sustainability of two different human excreta collection and treatment methods. We systematized and compared the environmental impacts of flush toilet based water infrastructure and composting of human excreta. Among the factors examined the energy demand of wastewater treatment, the nitrogen and phosphorus loading caused by purified sewage emission, the loss of nutrients of human excreta, the quantity of fertilizer used for increase soil productivity are highlighted and presented by Hungarian data. According to our approximate calculations, the excreta which are produced by humans in Hungary contain about 35-70 thousand tons of nitrogen, 4-13 thousand tons of phosphorus, 6-16 thousand tons of potassium annually. In spite of this human excreta are considered as waste which must be clear away as fast as possible by water. Meanwhile increasing amount of chemical fertilizers are used -but soil nutrient supply based on chemical fertilization cannot be sustainable in the long term. The solution would be the utilization of composted excreta in the agriculture.

Fecal Sludge Recycling to Useful Products: Environmental Concerns, Viability and Potential

“…Hence, finding solutions to HE disposal challenge (Patiya, 2009) must be prioritize by all human beings being the main recipients of failure consequences. Every individual produce 0.13-1.5 kg of feces and 1.5 L of urine daily (Ali, 2019;Muralidharan, 2017;Oseo-Marfo et al, 2022;Regattieri et al, 2018;Ronteltap et al, 2010), divided into 25 wt% dry solids (32.5-375 g/ person/day) and 75 wt% water (Mara & Cairncross, 1989;Somorin, 2020;Zseni & Nagy, 2016). On a per capita basis, Somorin (2020) reported a range from 15 -1505 g/cap/day for an average healthy adult while for China and Kenya respectively (Maurya, 2012), as minimum as 69 g/capita/day and a maximum of 520 g/ capita/day are generated in their country.…”

“…Wet latrines are designed to collect both solid and liquid waste, which is then allowed to decompose over time. The invention of the flush toilet tank was recorded by Joseph Bramah in 1788 (Zseni & Nagy, 2016). Dry latrines, on the other hand, are designed to collect solid waste, which can then be periodically emptied and disposed off.…”

“…Component gases in biogas as well as the metallic nutrient content of biofertilizer obtained via anaerobic digestion of HE can be extracted. Immediately HE is discharged and it began flowing through the sewage pipe, it begins to deteriorate -thereby losing its original organic content (Zseni & Nagy, 2016). As such, nutrient composition (e.g., phosphates, nitrates, magnesium and calcium) differences can be observed between the fresh excreta, digestate, compost and vermicompost derived from HE (Moya et al, 2019;Nsiah-Gyambibi et al, 2021).…”

The Utilization of Struvite Produced from Human Urine in Agriculture as a Natural Fertilizer: A Review

“…With the wide-spread use of flush toilets, the human faeces and urine have become a waste to be removed from the sewer system, especially in the developed world. Despite the significant improvement offered by this system, the flush toilets have a lot of harmful environmental effects [1,2]. The utilization of faeces and urine in agriculture may reduce the amount of chemical fertilizers used, which may result in decreasing energy demand and therefore decreasing CO 2 emission [3].…”