Recycling reverse osmosis reject water for burnt clay brick production

Abstract

Chronic Kidney Disease of unknown etiology (CKDu) was identified in North Central Provincein 1990s. Then it started spreading over the next two decades in most of the farming areas not only in NCP but also,in other provinces. It has been widely accepted that the supply of potable water is one of the most important interventions to prevent the said disease. Therefore, strategies were implemented like installing Reverse Osmosis (RO) plants to supply potable water inCKDu affected areas. However, treated effluent of a plant varies from 30−50 %, so that a large amount of concentrate water releases to the environment without any beneficial use and it may create the environmental pollution in long-term practice. A project was carried out at Sangilikanadarawa RO plant, which is located in Medawachchiya DS division. The brick manufacturing process was implemented using two different water samples. One sample was from well water and other sample was from RO concentrate. Followed thefour steps; winning of clay, tempering, moulding, and drying, for brick manufacturing. 24 numbers of bricks were manufactured from each sample and carried out physical tests as soundness, hardness, and visual inspection. Laboratory tests were performed for dimension, compressive strength, water adsorption and efflorescence. All the Tests were carried out according to SLS 39:1978 standard. Results show that the compressive strength increases up to 9−52% using RO concentrate and water absorption and the efflorescence are within the standard limits. It can,therefore,be concluded that Reverse Osmosis concentrate can be used for industrial purposes such as brick manufacturing process in this area.