title: Water recovery from saline streams produced by electrodialysis.
abstract: Advances in technologies to enable water reuse in industry have been the objective of many research efforts, mainly due to the need to reduce the use of natural resources and due to factors related to their availability. This paper evaluates the crystallization of salts from petrochemical saline waste to achieve zero water discharge by the recovery of water and dissolved salts as a solid mixture. In line with process symbiosis, the recovered water should be suitable for use as cooling water in heat exchangers. Vacuum evaporative crystallization, at the batch scale, was used to remove the salts present in the concentrated stream from reverse electrodialysis of pretreated wastewater by a biological process. The partition of organic compounds in the feed solution between the condensate and the mother liquor was obtained from measurements of the total organic carbon and total nitrogen in the solutions. The solid phases formed experimentally are compared with those predicted by chemical modelling by PHREEQC. The recovered water presented almost 50 times less total dissolved solids than the feed stream (from 2100 to 44 mg/L). Calcium sulphate hydrate, calcium sulphate and sodium chloride were the majority crystalline phases formed, in accordance with the modelling by PHREEQC.
authors.affiliation: a Departamento de Engenharia de Minas , Universidade Federal de Minas Gerais , Av. Antônio Carlos, 6627, Pampulha , Belo Horizonte 31270-901 , Brazil.
authors.forename: Emily Mayer
authors.initials: EM
authors.lastname: Andrade Becheleni
authors.forename: Ricardo Perobelli
authors.initials: RP
authors.lastname: Borba
authors.forename: Marcelo Martins
authors.initials: MM
authors.lastname: Seckler
authors.forename: Sônia Denise
authors.initials: SD
authors.lastname: Ferreira Rocha
mesh_terms: D003246:Conservation of Energy Resources / Q000379:methods*; D003956:Dialysis / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D012492:Salts / Q000737:chemistry / Q000302:isolation & purification*; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
chemical_list: D012492:Salts; D014867:Water
keywords: PHREEQC; calcium sulphate; chemical modelling; sodium chlorate; water reuse