Generation and Quality Analysis of Greywater at Dhaka City

Abstract

<p>One of the natural resources available in nature is water; however, it is not readily available for domestic use for millions of people across the globe. An increasing global population coupled with growing urbanization worldwide has led to increased demands on water supply. The rapid growth of water-intensive agriculture in developing countries and inefficient water management practices in the developed world are contributing to a global reduction in future freshwater supplies. The world is currently in the midst of cross roads where the unsustainable and impractical uses of water are no longer acceptable. The recycling and reuse of water is therefore imperative in some areas, and increasingly such in the others to meet the demands for urban, industrial and agricultural water requirements. Greywater, which can be defined as all in-building wastewater streams with an exception of toilet wastewater, is a potential water source for urban reuse, as it contains a few or no pathogens and 90 percent less nitrogen than blackwater. This study reveals the generation and quality of greywater in Dhaka City. The groundwater level is depleting by 2/3 of a meter per year in Dhaka. Thus, the recycling and reuse of water have become imperative to meet the demand for it. To analyze the generation of greywater in Dhaka City, water use in five households has been studied and about 67% of water was found to be reusable, whereas about 17% of potable water was wasted in toilet flushing. From the quality analysis, kitchen water was found to be polluted to some degree, and judging by its quality, it should not be reused. Greywater must be treated before any kind of reuse as it exceeds the standards of the acceptable quality of potable water and irrigation water.</p><p>DOI: <a href="http://dx.doi.org/10.5755/j01.erem.64.2.3992">http://dx.doi.org/10.5755/j01.erem.64.2.3992</a></p

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

“…It is considered high volume, low strength wastewater with high potential for reuse and application. The composition of greywater is varied and depends on the lifestyle, fixtures and climatic conditions (Abedin and Rakib 2013; do Couto et al 2013; Katukiza et al 2014). Reuse of greywater has been an old practice, and it is still being done in areas that are water stressed.…”

Greywater Treatment Technologies

“…The investigation of the grey water qualities by various classes shows that kitchen grey water and clothing grey water are higher in both natural and physical toxins contrasted with the lavatory and the blended grey water [3]. The grey water has much lower oxygen request than black water [4]. Grey water is separated from black water by natural material and supplements introduce [6].…”

“…50-80% of the aggregate family unit wastewater is grey water [3]. It contains less or no pathogens and 90% less nitrogen than black water [4]. Grey water speaks to up to 70% of aggregate expended water yet contains just 30% of the natural division and 9 to 20% of the supplements [5].…”

Sustainable wastewater management

“…Many studies have all analyzed greywater without cognizance to the source of water and the lifestyle patterns. Research on greywater characterization and quantity generations has largely focused on sources such as kitchen, bathroom, hand wash basin (Abedin & Rakib, 2013;Katukiza et al, 2014), water use fixtures such as washing machines, dishwashers (Abedin & Rakib, 2013;O'Toole et al, 2012) and location or type of settlement such as periurban and slums, (Antonopoulou, Kirkou, & Stasinakis, 2013;do Couto et al, 2013;Katukiza et al, 2014;Ramona, Green, Semiat, & Dosoretz, 2004). However, the differences in quality and quantity between greywater from houses fitted with household taps and those that rely on other external sources of water in a peri-urban area in a developing country remains uninvestigated.…”

“…It is considered high volume, low strength wastewater with high potential for reuse and application. The composition of greywater is varied and depends on the lifestyle, fixtures and climatic conditions (Abedin & Rakib, 2013;do Couto, Calijuri, Assemany, Santiago, & Carvalho, 2013;Katukiza, Ronteltap, Niwagaba, Kansiime, & Lens, 2014). Reuse of greywater has been an old practice and it is still being done in areas that are water stressed.…”