Treatment of concrete wash wastewater from ready-mix concrete operations

Document Type

Article

Source of Publication

Desalination and Water Treatment

Publication Date

1-1-2015

Abstract

© 2013 Balaban Desalination Publications. All rights reserved. Wash wastewater generated from ready-mix concrete (RMC) drums poses major environmental problems due to its high alkalinity and elevated heavy metal contents that need to be removed prior to disposal. The present study aims at developing a technology that will be able to reduce chromium and strontium concentrations as well as effluent pH to acceptable disposal levels set by various environmental agencies. Representative samples of wash wastewaters from RMC trucks were prepared and different treatment technologies were evaluated for their efficiencies of removing chromium and strontium present in solution. Sample characterizations indicated that the alkaline wash wastewater contained elevated concentrations of chromium and strontium at levels of 2.59 and 12.26 mg/l, respectively. Treatment of wash wastewater with barium chloride lowered the chromium to non-detectable limits. Whilst treatment with disodium hydrogen phosphate lowered the strontium to less than 0.063 mg/l, it is then hypothesized that sequence treatment of barium chloride, disodium hydrogen phosphate, and carbon dioxide bubbling will result in an effluent solution with acceptable disposal characteristics that satisfy regulatory bodies.

ISSN

1944-3986

Publisher

Taylor and Francis Inc.

Volume

53

Issue

4

First Page

928

Last Page

939

Disciplines

Civil and Environmental Engineering

Keywords

Chemical precipitation, Chromium, Ion speciation, Mineral formation, Ready-mix concrete, Saturation index, Strontium, Wash wastewater

Scopus ID

84922446424

Indexed in Scopus

yes

Open Access

no

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