Potential Of Water Hyacinth ( Eichhornia crassipes ) In Treating Textile And Sugar Wastewater In Mauritius

Abstract

The potential use of water hyacinth (Eichhornia crassipes) as a means for water pollution abatement was investigated. Two types of industrial wastewaters, namely that from the textile/dyeing industry and raw sugar manufacturing were studied in batch systems. The percentage reduction in COD for textile effluents was on average 67% for a one-week retention time, while a maximum reduction of 83% was obtained with sugar wastewater. It was observed that the rate of COD reduction was higher with higher initial CODs. The system was also very effective in Total Suspended Solids (TSS) reduction from sugar factory wastewater, and prevented growth of algae as well. The pH during retention time tended to be near neutral. Plant decay and odour due to presence of hydrogen sulphide were the main problems encountered with some of textile set- ups. These could be attributed to the high salt content and sulphate content of the wastewater respectively. The results obtained indicate that water hyacinth can be considered as a treatment option for sugar factory effluents, while the complex and varying nature of textile effluent makes it unsuitable for such a treatment system. Keywords : Wastewater treatment, tropical climate, water hyacinth, biofilter, industrial wastewater.