Reusing greywater for cultivation of Capsicum frutescens and Calendula officinalis

This study investigated the impact of greywater application for home yard gardening. Greywater was collected and treated using screening, sedimentation and solar disinfection methods. Finally, a field experiment was conducted to investigate the impact of untreated and treated greywater on a selected vegetable, Capsicum frutescens and flowering plant, Calendula officinalis for 2 months. The findings depicted that untreated greywater contains higher macro-nutrients with excessive bacterial population compared with tap water (control), however, the treatment process reduced the concentration of most of the unwanted parameters from greywater samples to bring them into irrigation standards. Overall, treated greywater irrigation showed the species-specific impact on experimental plants with more stimulation in Capsicum frutescens species compared with tap water irrigation. Both treated and untreated greywater irrigation increased the growth parameters of Calendula officinalis in comparison with control. The impact was not significant for most of the parameters of Calendula officinalis while compared between greywater (treated and untreated) and control, and between treated and untreated greywater irrigation. Treated greywater irrigation significantly stimulated most of the parameters of Capsicum frutescens while untreated greywater increased only moisture content, and number of branches compared with control. Most interestingly, treated greywater irrigation had significant impact on Capsicum frutescens particularly for number of branches and leaves compared with untreated greywater irrigation. In fine, the greywater, after treatment was bacterially safe and had positive impact on plant growth. The findings of this study will help to conserve irrigation water and to protect and manage aquatic ecosystem from the adverse impact of wastewater. •Direct use of greywater can be harmful for irrigation.•Screening, sedimentation and solar disinfection method were followed as treatment.•Calendula officinalis was free from the impact of varied irrigation water.•Treated greywater irrigation exhibited positive impact for Capsicum frutescens.•We suggest the proposed treatment process especially for irrigating vegetable crops.