Absorbent hygiene products (AHP) have received much interest due to the notion that their end-of-life (EoL) stage has high environmental impacts. Since the use of AHP will continue to rise in the foreseeable future, information that helps with a reduction in the environmental impacts of AHP through their life cycle is needed. This research presents an estimation of AHP in municipal waste, and it also reviews and discusses waste management options, available treatments at bench, pilot or full scale, and life cycle assessments (LCAs) available in the literature. Municipal waste of countries belonging to the Organization for Economic Co-operation and Development contains on average 2.7% of baby nappies, 4.8% of adult nappies and 0.5% of sanitary pads (in weight), whereas that of Latin-American countries have 7.3%, 3.3%, and 0.9%, respectively. Management options for AHP waste in developed countries are landfilling and incineration, while in developing countries AHP are disposed of in dumpsites and landfills. Most LCAs identify significant environmental impacts in the production of raw materials, while EoL scenarios involving incineration and landfill were found to have a significant contribution to global warming potential. Substitution with alternative products has been suggested as a way of decreasing environmental impacts; however, their use frequently causes a trade-off on different impact categories. Municipalities could use a wide range of policy tools, such as extended producer responsibility systems, bans, levies, ecolabelling, or a combination of these, to reduce the environmental and economic burden of AHP waste.

Waste with high biomass content generated in cities in developing countries is sent to landfills or open dumps. This research aims to degrade biomass content in urban waste through cultivation, at pilot scale, of the edible mushroom Pleurotus ostreatus. First, the number of diapers used by one baby per week was measured with a survey in day care facilities. Then, cellulose content of diapers was assessed. Finally, cultivation of P. ostreatus was carried out using as substrate a mixture of diapers with gardening waste, a co-substrate readily available at urban settings. The factors assessed were strain of P. ostreatus (grey BPR-81, white BPR-5), conditioning of the substrate (diapers with and without plastic) and co-substrate (wheat straw, grass, and withered leaves). Results show that diapers are a valuable source of biomass, as generation of diapers with urine is 15.3 kg/child/month and they contain 50.2% by weight of cellulose. The highest reductions in dry weight and volume (>64%) of substrates was achieved with the substrate diaper without plastic and co-substrate wheat straw. Although diapers with plastic and grass and leaves showed lower degradation, they achieved efficiencies that make them suitable as a co-substrate (>40%), considering that their biomass is currently confined in landfills.

This research assessed the viability to use disposable diapers as a substrate for the production of biohydrogen, a valuable clean-energy source. The important content of cellulose of disposable diapers indicates that this waste could be an attractive substrate for biofuel production. Two incubation temperatures (35 °C and 55 °C) and three diaper conditioning methods (whole diapers with faeces, urine, and plastics, WD; diapers without plastic components, with urine and faeces, DWP; diapers with urine but without faeces and plastic, MSD) were tested in batch bioreactors. The bioreactors were operated in the solid substrate anaerobic hydrogenogenic fermentation with intermittent venting mode (SSAHF-IV). The batch reactors were loaded with the substrate at ca. 25% of total solids and 10% w/w inoculum. The average cumulative bioH₂ production followed the order WD > MSD > DWP. The bio-H₂ production using MSD was unexpectedly higher than DWP; the presence of plastics in the first was expected to be associated to lower degradability and H2 yield. BioH₂ production at 55 °C was superior to that of 35 °C, probably owing to a more rapid microbial metabolism in the thermophilic regime. The results of this work showed low yields in the production of H₂ at both temperatures compared with those reported in the literature for municipal and agricultural organic waste. The studied process could improve the ability to dispose of this residue with H₂ generation as the value-added product. Research is ongoing to increase the yield of biohydrogen production from waste disposable diapers.

Biorefineries (BRFs) that process the organic fraction of municipal solid waste and generate bioproducts and bioenergies have attracted attention because they can simultaneously address energy and environmental problems/needs. The objective of this article was to critically review the microbial production of hyaluronic acid (MPHA) and its production profile for its integration into a GBAER-type BRF (a type of BRF based on organic wastes) and to identify the environmental and economic sustainability aspects of the modified BRF that would confirm it as a sustainable option. It was found that the MPHA by selected strains of pathogenic Streptococci was moderate to high, although the trend to work with genetically transformed (GT) (innocuous) bacteria is gaining momentum. For instance, A GT strain of Corynebacterium glutamicum reached a maximum HA production of 71.4 g L⁻¹. MPHA reports that use organic wastes as sources of carbon (C) and nitrogen (N) are scarce. When alternative sources of C and N were used simultaneously, HA production by S. zooepidemicus was lower than that with conventional sources. We identified several knowledge gaps that must be addressed regarding aspects of process scale-up, HA industrial production, economic feasibility and sustainability, and environmental sustainability of the MPHA.

Coffee is one of the tropical crops of great relevance. Mexico occupies one of the first places to produce it. Chiapas is the state that contributes the most significant amount of grain to the national and international market, harvested by organized groups such as cooperatives of origin indigenous. In these regions, cultivation is divided into five stages: cultivation, harvest, wet processing, dry processing and roasting. Thus, the agroecological approach based on the agroforestry system of coffee in the community of Ocotepec allowed generating an intercultural dialogue with a Zoque indigenous cooperative, where its members expressed the need to develop information regarding their production process and thus take the relevant decisions. Concerning environmental impacts. The life cycle analysis was applied as a methodological tool to evaluate the process of producing a kilogram of ground coffee in its honey and specialty varieties offered to the national market, showing the most significant impacts for both types of coffee. Cultivation level (water consumption around 80% and land use with effects close to 98%), wet processing (impacting the ecotoxicity of water sources close to 99% followed by marine ecotoxicity with 73%) and in its distribution stage affecting at least 15 environmental categories, likewise, comparative tests were carried out to calculate the carbon footprint and the water footprint, with shade-grown honey coffee being the type of coffee that has the most negligible environmental impact and contributes the most profits to the cooperative.