Households' willingness to adopt greywater treatment technologies in a developing country - Exploring a modified theory of planned behaviour (TPB) model including personal norm

This study explored willingness of households to adopt a greywater treatment and reuse system using the theory of planned behaviour in its original form and an extended model including personal norms. The study was conducted among 478 household heads in the central region of Ghana. The results indicate the original theory of planned behaviour (TPB) model explained about 54% of the variance in respondents' intentions to adopt this system and the extended model which includes personal norms explained 59% of the intentions. The extended model turned out to be the better model to predict willingness to adopt this household greywater and treatment system. The findings of this study shed more light on the role of personal norms in households' willingness to adopt a greywater treatment and reuse system and may inform interventions aimed at promoting such systems.

Greywater characterization and generation rates in a peri urban municipality of a developing country

The quantity and quality of combined greywater from houses with in-house water supply and houses that rely on external sources of a peri-urban area in a developing country were determined. Data for quantity of greywater was collected from 36 households while 180 samples of greywater were collected from 60 households between December 2016 and February 2017. The results indicate that, average water consumption from households with in-house access was 82.51 ± 12.21 Lc^-1d^-1 while households which rely on external sources was 36.64 ± 4.31 Lc^-1d^-1 with return factors of 74.16% and 88.57% respectively. Quality analysis also showed significant differences between greywater from the two sources with most of the quality parameters exceeding the regulatory limit. The ratio between biochemical oxygen demand (BOD₅) and chemical oxygen demand (COD) ranged between 0.22 and 0.59 for greywater from in-house sources and 0.23-0.62 for external sources indicating low biodegradability of the greywater. The nutrients recorded exceeded the trigger levels for eutrophication while significant levels of microorganisms such as E. Coli and Salmonella spp. were also detected in both streams. Direct reuse of greywater for irrigation was found to be unsuitable based on the salinity and sodium hazard analysis. Principal component analysis of the data indicated that the characteristics of the combined greywater in the study area is influenced by cooking and cleaning practices, personal hygiene, biodegradability, frequency of water use before disposal and sanitary practices in the bathroom. The greywater discharged is detrimental to the environment and poses a health risk to humans and livestock. There is therefore the need for authorities involved to prioritize greywater management and treatment in peri-urban areas of developing countries.

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

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.