Greywater Characteristics, Treatment Systems, Reuse Strategies and User Perception—a Review

Abstract

This paper presents a literature review of the quality of greywater generated in different, especially developing, countries, constituents found in greywater, some treatment systems, natural materials for treatment, some reuse strategies and public perception regarding greywater reuse. The review shows that generation rates are mostly influenced by lifestyle, types of fixtures used and climatic conditions. Contaminants found in greywater are largely associated with the type of detergent used and influenced by other household practices. Many of the treatment systems reviewed were unable to provide total treatment as each system has its unique strength in removing a group of targeted pollutants. The review revealed that some naturally occurring materials such as Moringa oleifera, sawdust, can be used to remove targeted pollutants in greywater. The study further showed that user perceptions towards greywater treatment and reuse were only favourable towards non-potable purposes, mostly due to perceived contamination or lack of trust in the level of treatment offered by the treatment system.

Performance of a greywater cathode in a microbial fuel cell with three ion exchange membranes

“…This is confirmed by the reported diffusion coefficients of 30.85 10 −8 cm 2 s −1 , 27.89 10 −8 cm 2 s −1 , 22.29 10 −8 cm 2 s −1 , 20.40 10 −8 cm 2 s −1 and 19.22 10 −8 cm 2 s −1 for Na + , K + , Ca 2+ , Mg 2+ and H + , respectively, when a CEM is used as separator . Conversely, it has been reported that greywater contains surfactants that are anionic in their majority, avoiding competition with protons for the functional groups in CEMs and pH splitting. Another important aspect is that the acetate used as a carbon source in the MFCs of this study is a simple substrate that does not favour fermentative processes, unlike glucose or lactose that produce volatile fatty acids, diminishing the pH in the anolyte to 6.5–5.6, as has been reported in other works …”

“…This wastewater is divided into blackwater, which come from toilets, and greywater, which come from kitchens, washing machines, showers, baths and hand basins . The greywater is of variable composition depending on lifestyle, geographical region and the activities of the occupants, but generally contains easily biodegradable organic matter, nutrients such as nitrogen and phosphorus, and high levels of dissolved oxygen 5.0–6.1 mg L −1 , and is alkaline pH (8) due to laundry activities . It has been reported that greywater represents c .…”

“…It has been reported that greywater represents c . 70–75% of wastewater generated in a household, and for this reason its treatment or reuse is important . In recent decades microbial fuel cells (MFC) have emerged as a technology for wastewater treatment.…”

“…1-3 It has been reported that greywater represents c. 70-75% of wastewater generated in a household, and for this reason its treatment or reuse is important. 2 In recent decades microbial fuel cells (MFC) have emerged as a technology for wastewater treatment. These devices convert chemical energy to electrical energy through the catalytic action of microorganisms in the anode being able to treat wastewater and produce electrical energy as a by-product.…”

Clustering the Adsorbents of Horizontal Series Filtration in Greywater Treatment

“…The treatment kind was ascertained to have a meaningful impact on the quality of the treated GW [20]. Oteng-Peprah et al (2018) resulted that among the traditional treatment technologies, filtration techniques look feasible and have the potential of integration with other methods to obtain target specific treatment [21]. Opher et al (2017) used an analytical hierarchy process (AHP) to assess the effects of four methods of water reuse on three related stakeholders including public, community, and consumer groups [22].…”