Reuse of Domestic Greywater for the Irrigation of Food Crops

Abstract

As global water resources decline, reuse of domestic greywater for the irrigation of home gardens is quickly becoming widespread in many parts of the world. However, the sanitary implications of reusing greywater to water edible crops remain uncertain.This study examined the benefits and risks associated with domestic greywater reuse for the purposes of vegetable garden irrigation. Untreated (settled only) and treated (settling and slow sand filtration) greywater collected from a family home was analyzed for basic water quality parameters, over a period of eight weeks. During that time, both greywaters were used to irrigate individually potted plots of lettuce, carrots and peppers in a greenhouse. Tap water was used as control. Upon maturity, plants were harvested and the edible portions tested for fecal coliforms and fecal streptococci, common indicators for the presence of pathogenic microorganisms. Heavy metals were not detected in the greywater, but both fecal coliforms and fecal streptococci were present in high levels, averaging 4 x 10 5 /100mL and 2 x 10 3 /100mL of greywater, respectively. Despite these high counts, no significant difference in contamination levels was observed between crops irrigated with tap water, untreated and treated greywaters. Fecal coliform levels were highest in carrots and fecal streptococcus levels highest on lettuce leaves. However, contamination levels for all crops were low and do not represent a significant health risk.Plant growth and productivity were unaffected by the water quality, owing to the low N, P and K levels of the greywater. These results reinforce the potential of domestic greywater as an alternative irrigation source.

Reuse potential of laundry greywater for irrigation based on growth, water and nutrient use of tomato

“…Reuse of untreated greywater for irrigation is considered hazardous due to the potential risk of infection from direct human exposure (Jeppesen, 1996). However, recent reports (Jackson et al, 2006;Finley et al, 2009) suggest that public health risks arising from pathogenic contamination of food crops irrigated with greywater are relatively small. Since our research focuses on the environmental impacts of reusing greywater to irrigate crops, we discuss the sensitivity of tomato to greywater and surfactants with implication to other soils and plants.…”

Prospects and Potential Risks of Gray Water Reuse

“…Zawartość azotu ogólnego mieszcząca się w granicach 40÷74 mg/dm 3 oraz fosforu ogólnego w zakresie 12÷74 mg/dm 3 świadczy o tym, że ścieki te podatne są na rozkład biologiczny [14]. Powszechnie uważa się, że mycie surowych artykułów spożywczych jest źródłem obecności mikroorganizmów, przez co wzrasta poziom ich skażenia bakteriologicznego [15].…”

“…Stosunkowo czysta szara woda, za pomocą węża, może być odprowadzana do ogrodu lub też na odpowiednio wcześniej przygotowane pole filtracyjne, czyli grunty wykorzystywane do oczyszczania ścieków, ale niewykorzystywane rolniczo. Tam woda ta zostaje poddana fitoremediacji, czyli działaniu roślin oczyszczają-cych wodę i ich korzeni [15]. Z uwagi na fakt, że szara woda zawiera pozostało-ści substancji odżywczych i patogenów oraz jest ona wylewana jako ciepła, nie powinno się jej przechowywać bez uprzedniej filtracji, tylko rozprowadzać bezpośrednio po ogrodzie.…”

Assessment of Grey Water Disposal and Different Treatment Options for Domiz Camp in Duhok City

“…The expected average grey water production in Domiz camp by different sources was 42 L/c.d (1380 m 3 /d) depending on 33,209 population; 80 L/c.d of clean water to be supplied and according to 80% to be converted to wastewater (Finley et al, 2009) and then 65% from the wastewater to be converted to grey water (Shamabadi et al, 2015, Siggins et al, 2016. This production rate was lower than the European communities production rate which are ranged between 66 and 274 L/c.d.…”