丁香园AV

Abstract

Surface water is an important fresh water resource around the world. In developing countries, around 159 million people use surface water for drinking purposes, without any treatment. Many public water supplies in developed countries (66% in USA and 35-45% in Europe) are also based on surface water sources. Water resources, in developing countries, are polluted heavily by discharge of untreated industrial effluents. 鈥淐oagulation鈥� is an important unit process in surface water treatment plants (SWTPs) and industrial effluents treatment plants (IETPs). Metallic salts (alum and iron salts) and polymers are mostly used coagulants in SWTPs and IETPs around the world. Though efficient in removing pollutants, these have certain accompanying disadvantages. Plant-based natural coagulants can act as potential alternatives to most of the commonly used chemical coagulants. Not only have Plant-based coagulants been found to be eco-friendly they can generally be classified as non-toxic and produce less sludge in comparison to chemical coagulants. This presentation will focus on the findings of a study, conducted by the speaker, for evaluating coagulation potential of some plant-based natural coagulants for treatment of surface water and industrial effluents. Extracts from seeds of Pearl millet (Pennisetum glaucum), Black-eyed pea (Vigna unguiculata subsp. unguiculata) and Soybean (Glycine max L.) were evaluated for treatment of turbid water. Moreover, two species of Cactus (Opuntia stricta and Euphorbia acrurensis) were appraised for treatment of industrial effluents. The studied plant-based coagulants were compared with alum, a conventional coagulant, in respect to efficacy, cost and sustainability.