title: Removal of fouling species from brackish water reverse osmosis reject stream.
abstract: Brine disposal from reverse osmosis (RO) systems remains a major challenge for the desalination industry especially in inland areas where discharge options are very limited. Solutions will entail the introduction of economic treatment processes that will alleviate the brine's negative impact on the environment and reduce its discharge volume. Such processes could act as an intermediary treatment process for the recycling of the brine through an additional RO stage which, for brackish water (BW) desalination, could lead to saving valuable water while reducing the amount of brine discharge. In this context, the study at hand attempts to evaluate the effectiveness of a one-step chemical process for the treatment of BWRO brine. This study seeks to determine optimal operating conditions relative to type, ratio, and dosage of alkalizing chemicals, pH and temperature, for substantially reducing the concentrations of scaling parameters such as calcium, magnesium, silica, and strontium. The results indicate that precipitation softening at pH = 11.5 using combined chemical dosages of NaOH and Na2CO3in a ratio of 2:1 leads to substantial removal of calcium and magnesium (>95%) and moderately high removal of strontium and silica (>71%).
authors.affiliation: a Department of Civil and Environmental Engineering , American University of Beirut , Beirut , Lebanon.
authors.forename: G M
authors.initials: GM
authors.lastname: Ayoub
authors.affiliation: a Department of Civil and Environmental Engineering , American University of Beirut , Beirut , Lebanon.
authors.forename: L
authors.initials: L
authors.lastname: Korban
authors.affiliation: b Department of Chemical and Petroleum Engineering , American University of Beirut , Beirut , Lebanon.
authors.forename: M
authors.initials: M
authors.lastname: Al-Hindi
authors.affiliation: a Department of Civil and Environmental Engineering , American University of Beirut , Beirut , Lebanon.
authors.forename: R
authors.initials: R
authors.lastname: Zayyat
mesh_terms: D005374:Filtration; D008567:Membranes, Artificial; D009995:Osmosis; D045483:Rivers; D000068357:Saline Waters; D018508:Water Purification
chemical_list: D008567:Membranes, Artificial
keywords: Reverse osmosis; brackish water brine; precipitation; scaling; sodium carbonate; sodium hydroxide