Abstract
Magnesium hydroxide continuous coagulation process was used for treating simulated reactive orange wastewater in this study. Effects of mixing conditions and retention time on the coagulation performance and floc properties of magnesium hydroxide were based on the floc size distribution (FSD), zeta potential, and floc morphology analysis. Floc formation and growth in different reactors were also discussed. The results showed that increasing rapid mixing speed led to a decrease in the final floc size. The floc formation process was mainly carried out in a rapid mixer; a rapid mixing speed of 300 rpm was chosen according to zeta potential and removal efficiency. Reducing retention time caused a relatively small floc size in all reactors. When influent flow was 30 L/h (retention time of 2 min in rapid mixer), the average floc size reached 8.06 μm in a rapid mixer; through breakage and re-growth, the floc size remained stable in the flocculation basin. After growth, the final floc size reached 11.21 μm in a sedimentation tank. The removal efficiency of reactive orange is 89% in the magnesium hydroxide coagulation process.
Highlights
Magnesium hydroxide was used as a potential coagulant for reactive dyes wastewater treatment for many years [1,2,3]
During the continuous coagulation samples of flocs were taken from a rapid mixer, with
During the continuous coagulation process, samples of flocs were taken from a rapid mixer, with the third flocculation basin and sedimentation tank using a tube with an inner diameter of 5 mm every 10 minutes
Summary
Magnesium hydroxide was used as a potential coagulant for reactive dyes wastewater treatment for many years [1,2,3]. Typical characteristics of this kind of coagulant include nontoxicity, an environmentally-friendly nature, recoverability, and rapid reaction [4]. Floc size settling properties are the main parameters influencing reactive dyes removal efficiency in real industrial scale unit operations [7,8,9]. During the magnesium hydroxide coagulation process, mixing conditions influenced the removal efficiency and floc properties. Several authors have found that operational conditions influenced the coagulation process and flocs properties especially for mixing conditions [11,15].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
