Presence and fate of priority substances in domestic greywater treatment and reuse systems

Abstract

A wide range of household sources may potentially contribute to contaminant loads in domestic greywater. The ability of greywater treatment systems to act as emission control barriers for household micropollutants, thereby providing environmental benefits in addition to potable water savings, have not been fully explored. This paper investigates the sources, presence and potential fate of a selection of xenobiotic micropollutants in on-site greywater treatment systems. All of the investigated compounds are listed under the European Water Framework Directive as either "Priority Substances" (PS) or "Priority Hazardous Substances" (PHS). Significant knowledge gaps are identified. A wide range of potential treatment trains are available for greywater treatment and reuse but treatment efficiency data for priority substances and other micropollutants is very limited. Geochemical modelling indicates that PS/PHS removal during treatment is likely to be predominantly due to sludge/solid phase adsorption, with only minor contributions to the water phase. Many PS/PHS are resistant to biodegradation and as the majority of automated greywater treatment plants periodically discharge sludge to the municipal sewerage system, greywater treatment is unlikely to act as a comprehensive PS/PHS emission barrier. Hence, it is important to ensure that other source control options (e.g. eco-labeling, substance substitution, and regulatory controls) for household items continue to be pursued, in order that PS/PHS emissions from these sources are effectively reduced and/or phased out as required under the demands of the European Water Framework Directive.

A modified constructed wetland system for greywater treatment

“…Existing greywater treatment systems show a wide range of design principles and sophistication, from simple single-household soil filter systems to more elaborate community-scale multi-stage rotating biological contact (RBC) reactors, constructed wetlands and membrane bioreactors, amongst others -all based on chemical, physical and biological processes such as settling, filtration, adsorption, aeration, precipitation, aerobic/anaerobic digestion, and disinfection (Donner et al, 2010;Ghunmi et al, 2011). The choice of a grey water treatment system includes considering different treatment steps that may be applied, depending on the required quality of the effluent .…”

The implications of household greywater treatment and reuse for municipal wastewater flows and micropollutant loads

“…Nevertheless, Eriksson et al (2002;2003) and Palmquist and Hanaeus (2005) have collectively shown that a large number of xenobiotic substances can find their way into greywater via bathroom and laundry products. Donner et al (2010) have reported initial investigations into the fate of a range of pollutants within greywater treatment and reuse systems. However, given the increasing implementation of greywater recycling technology, it is evident that additional research to elucidate the behavior of xenobiotic micropollutants during greywater treatment would be beneficial.…”

Life cycle costs analysis of the systems allowing water and energy consumption reduction in a single-family dwelling house

“…Charakteryzuje je jednak znaczna zawartość związków organicznych, co wymusza na potencjalnych eksploatatorach instalacji wykorzystania ścieków szarych zastosowanie układów do ich podczyszczania. Dodatkowo stężenie poszczególnych substancji zanieczyszczających ścieki szare warunkowane jest tym, gdzie powstają [8]. Charakterystykę ścieków pochodzących z różnych źródeł przedstawiono w tabeli 2.…”

“…Charakterystykę ścieków pochodzących z różnych źródeł przedstawiono w tabeli 2. Stężenie zanieczyszczeń obecnych w ściekach szarych odprowadzanych z poszczególnych urządzeń sanitarnych może zmieniać się w szerokim zakresie [8], jednakże za najbardziej zanieczyszczone uznać można medium pochodzące z kuchni. Zawiera ono często oleje oraz inne niekorzystne substancje, których obecność w ściekach szarych dyskwalifikuje ich zastosowanie do spłukiwania misek ustępowych czy podlewania ogrodu, co powoduje, iż zazwyczaj nie są one wykorzystywane [7].…”