title: A novel method of sludge pretreatment using the combination of alkalis.
abstract: The present study aims to utilise the advantage of higher sludge solubilisation potential of sodium hydroxide (NaOH) and sludge management properties of lime to achieve sludge pretreatment and its subsequent management. The optimum dosage and time required for sludge pretreatment using NaOH was found to be 1.6 g l(-1) and 3 hr, respectively. At the optimized condition, lime was added at varying concentration (0.3 to 1.6 g l(-1)) to study its effect on capillary suction time, soluble chemical oxygen demand (SCOD) release and total phosphorous (TP) removal. A lime dosage of 0.7g l(-1) was found to be beneficial for soluble chemical oxygen demand (COD) release. When compared to control, the combination of alkalis (NaOH and lime) reduced the TP and capillary suction time (CST) in the supernatant of the sludge. The TP removal was from 100 to 40 mg l(-1) and CST reduction was from 1360 to 350 sec, respectively. The combined alkali pretreatment not only prevent the subsequent TP increase in the effluent, but also decreased the time to filter the sludge, thus makes the digested sludge easier to manage.
authors.affiliation: Department of Civil Engineering, Anna University of Technology, Tirunelveli-627007, India.
authors.forename: J Rajesh
authors.initials: JR
authors.lastname: Banu
authors.forename: Uan Do
authors.initials: UD
authors.lastname: Khac
authors.forename: S Adish
authors.initials: SA
authors.lastname: Kumar
authors.forename: Yeom
authors.initials: Y
authors.lastname: Ick-Tae
authors.forename: S
authors.initials: S
authors.lastname: Kaliappan
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D017610:Calcium Compounds / Q000737:chemistry* / Q000494:pharmacology; D010087:Oxides / Q000737:chemistry* / Q000494:pharmacology; D010101:Oxygen Consumption; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D012972:Sodium Hydroxide / Q000737:chemistry* / Q000494:pharmacology; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D017610:Calcium Compounds; D010087:Oxides; D012722:Sewage; D012972:Sodium Hydroxide; C016538:lime