Some industrial processes result in the release of heavy metals in the natural water systems. In the present study, four dried brown algal biomasses; Colpomenia sinuosa, Cystoseira trinodis, Padina pavonica and Sargassum asperifolium were used to build up four types of fixed-bed columns for removal of toxic heavy metal ions Cd2+, Pb2+, Cu2+, Co2+, Zn2+, Mn2+, Ni2+, Fe2+, and Cr3+ from two chemical industrial effluents. The highest efficiency of metal ion bioremoval was recorded for algal column of C. sinuosa followed by S. asperifolium then C. trinodis and P. pavonica with mean metal removal values of 91%, 88%, 82% and 74%, respectively. Biological treatments of two industrial effluents with algal columns were capable to reduce effluent toxicities, using standard algal biotest of Pseudokirchneriella subcapitata, from 13% to 53% and 34% to 98%. Thus, brown algal column may be considered as an inexpensive and efficient alternative technology for sequestering heavy metal ions from industrial effluents in continuous flow processes.
Brown algae, fixed-bed columns, heavy metals, bioremoval, toxicity assessment