A comparison of various bulking materials as a supporting matrix in composting blackwater solids from vacuum toilets

Recycling of Faecal Sludge: Nitrogen, Carbon and Organic Matter Transformation during Co-Composting of Faecal Sludge with Different Bulking Agents

“…Selecting the right bulking agent for co-composting with FS is essential for a successful composting process and reduction of nutrient losses such as nitrogen through ammonia volatilization [ 7 ]. In the same vein, bulking agents deserve special consideration during FS composting, because of their essential role in (i) adjusting the carbon to nitrogen (C/N) ratio, (ii) absorbing the excess moisture content and odour, and (iii) improving the physical characteristics and support structure of the composting material to provide favourable conditions for successful aerobic composting activities [ 8 , 9 , 10 ]. However, there are few scientific FS composting studies that have investigated the effect of different bulking agents on nutrient losses and compost quality.…”

“…Further, although studies have investigated the feasibility of FS co-composting with different bulking agents [ 5 , 6 , 7 , 8 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]; few attempts have been made to systematically assess FS composting process of three bulking agents in a single research to understand the effect of the different bulking agents on the evolution of organic matter, carbon, and nitrogen forms, key maturity indices, and quality of the final compost. Moreover, carbon, organic matter, and nitrogen transformation during co-composting of FS with different bulking agents using an open-air composting system is not yet well understood.…”

Fate of faecal pathogen indicators during faecal sludge composting with different bulking agents in tropical climate

“…However, the effectiveness of FS composting has not been thoroughly explored especially in urban Africa. Few robust research studies on FS composting have been conducted and published in peer reviewed articles to date (Al-Muyeed et al, 2017;Berendes et al, 2015;Cofie et al, 2009;Hashemi et al, 2019;Koné et al, 2007;Mengistu et al, 2017;Nakasaki et al, 2011;Nartey et al, 2017;Oarga-Mulec et al, 2019;Oarga Mulec et al, 2016;Scott, 1952;Thomas et al, 2018), although doubtlessly, composting of FS has been and is extensively being practiced globally, both informally and formally. Raw or dewatered FS is characterized by low Carbon/Nitrogen ratio (C/N) and high moisture content, making it unsuitable for composting alone.…”

“…Considerable literature has been published on co-composting of various feedstock materials such as sewage sludge (Aghili et al, 2019;Banegas et al, 2007;Khadra et al, 2019), farm manures (Nolan et al, 2011;Tiquia and Tam, 2002), and bio-waste materials (Adhikari et al, 2008;Dadi et al, 2019;Khadra et al, 2019) with bulking agents such as rice straw, sawdust, bark, coffee husks, and woodchips. Similarly, studies have been conducted on the composting of FS with different bulking agents such as sawdust (Al-Muyeed et al, 2017;Evans et al, 2015;Hashemi et al, 2019;Nakasaki et al, 2011;Oarga-Mulec et al, 2019;Scott, 1952) oat husks, wheat bran, peat and bark (Oarga-Mulec et al, 2019;Oarga Mulec et al, 2016); rice straw and rice husks (Evans et al, 2015;Hashemi et al, 2019); oil palm empty fruit bunches and cocoa pod husk (Nartey et al, 2017); sugarcane husks (Berendes et al, 2015); and mixed organic waste, (Al-Muyeed et al, 2017;Cofie et al, 2009;Evans et al, 2015;Koné et al, 2007;Mengistu et al, 2017;Thomas et al, 2018). However, the use of other bulking agents has received very little research attention in terms of composting with FS.…”

Nutrient recovery technologies for management of blackwater: A review

“…Several studies on the composting of fecal matter and solid fraction of BW have been carried out (Vinnerås, 2007;Oarga Mulec et al, 2016). The effect of different bulking materials as a supporting matrix on the solid fraction of BW composting in terms of pathogen inactivation, nutrient loss, and CH 4 emission have been studied (Oarga-Mulec et al, 2019). Zhu et al (2022) composted faecal sludge with sawdust and rice straw in earthworm-based system and obtained significant promote in composting efficiency and global warming potential reduction.…”