In recent times, the worldwide consumption of useable water had increased due to the surge in human population ((
Choy SP (2015) A review on common vegetables and legumes as promising plant-based natural coagulants in water clarification. Int J Environ Sci Technol 12(1):367–390)). As a result of this, developing and third world countries who have inadequate financial resources have their special attention on the pollution of water as an environmental issue which causes shortage of water supply ((
Ali EN, Muyibi SA, Salleh HM, Alam MZ, Salleh MRM (2010) Production of natural coagulant from Moringa oleifera seed for application in treatment of low turbidity water. J Water Res Prot 2(3):259)) Meanwhile, large volume of wastewater contains contaminant comprising of pathogens, heavy metals, nutrients and suspended solids which are harmful and dangerous for human and the environment. ((
Olalere OA, Olunusi OS, Olatunji AJ, Twibi Farag, Alftessi SA (2016) A bioleaching regeneration and recovery of spent refinery catalyst using adapted microorganisms. J Adv Chem Eng 6:1–19)). If they are kept untreated, safely disposed back to the sea or reused of the wastewater will be prevented ((
Paula HM, Ilha Oliveira, Andrade LS (2014) Concrete plant wastewater treatment process by coagulation combining aluminum sulfate and Moringa oleifera powder. J Clean Prod 76:125–130)) Drinking water supplies have been identified to have thousands of chemicals which are potentially hazardous to human health at relatively high concentrations as maintained by World Health Organization 2004 ((
Vikashni N, Matakite M, Kanayathu K, Subramanium S (2012) Water purification using Moringa oleifera and other locally available seeds in fiji for heavy metal removal. Int J Appl Sci Technol 2:125–129)).
Safe and pure water is extremely important for human health and welfare, and water must undergo for purification and treatment to reach the world standard of drinking water before consumption. Different water purification and treatment methods are used to make water safe and healthy to the consumer. The treatment method used depends on the character of the raw water. A major problem with treatment of surface water is due to large seasonal variation in turbidity . Water treatment method in many developed countries is based on arbitrary guidelines, they particularly relate to the dosage of chemicals which is not a good approach. In the treatment of these large volumes of water for drinking purposes, the following processes are always employed in sequential order and these include flocculation, sedimentation, filtration and disinfection . Moreover, previous study proposed different natural coagulants for the treatment of water for safe drinking viz ferric sulphate, aluminium sulphate and ferric chloride which called synthetic coagulant . On the other hand, there is a natural coagulant which is usually recommended in place of synthetic coagulants, because the synthetic coagulant have side effect to environment due to chemical involved in this coagulant. Recently, there is an increase in the research of plant to be used as natural coagulant for various traditional water purification systems. However, there are also several other plants which can act as natural coagulant in water treatment such as peanut seeds, watermelon seeds, Vigna unguiculata, Parkinsonia aculeata, Cicer arietinum and Dolichos lablab, Cassia alata and Opuntia ficus-indica. .
The M. oleifera is an important commodity plant which has been traditionally used for the treatment of water in tropical area of the world . Therefore, M. oleifera seeds provide a lot of advantages compared to conventional coagulants towards the water treatment. The advantages of M. oleifera are cost-effective, eco-friendly, no pH alteration required, no necessity for alkalinity addition and reduction in sludge volumes ((Vikashni N, Matakite M, Kanayathu K, Subramanium S (2012) Water purification using Moringa oleifera and other locally available seeds in fiji for heavy metal removal. Int J Appl Sci Technol 2:125–129)). Although many researchers studied the use of M. oleifera as bio-coagulants, none had employed the use of its residue for the treatment of water. This study therefore investigated the use of M. oleifera seed residue as bio-coagulant for water treatment. The effects of treatment factors such as dosage, high speed time, high speed, low speed and low speed time on the residual turbidity were carefully examined.