Ethiopian Water Hyacinth Leaf Extract as a Potential Tannery Effluent Treatment Material

Abstract

Industrial effluents have a serious problem on our ecosystem. Tannery effluent contains a huge amount of pollutant compounds such as toxic substances which need to be treated using either synthetic or natural products. The present study focussed on the treatment of tannery effluents using water hyacinth plant leaf extract. Though some researchers have tried to use this extract for the same, the researchers have experimented only to treat that of Cr3+ and there are a bit of difference in the methodology they followed. In addition, the scope of this research was wider. In this study, fresh raw WH leaves were collected from around Lake Tana, Ethiopia, cleaned and made to powder and then extraction was performed using different solvents. The solvent effects were examined using the ANOVA test. The tannery wastewater was treated with the extracts and parts of the effluents were kept as a control for comparison. Treated and untreated tannery effluents were compared using standard methods such as SLC 22, SLC 8, APHA 2540C, APHA 2540D, and Hack LCK 139 to determine Cr6+, Cr3+, TDS, TSS, and TKN, respectively. The highest amount of Cr6+, Cr3+, and TKN were removed at 30% water hyacinth leaves extracted by distilled water solvent and that of the least was found at hyacinth leaves extract by ethanol solvent but by acetone in BOD and COD treatment. In addition, though it was out of the permissible limit, by using the same amount of the material extracted by distilled water solvent some amounts of BOD and TDS were removed from the wastes compared to that of untreated tannery effluents. Generally, water hyacinth leaf extract is found effective material for the treatment of tannery effluents and can be used in the sector industries. Future studies may be required for setting the most optimum extract concentration for better results.

Extracción y aplicación de taninos de la almendra de mango (Mangifera indica) como curtiente para la piel ovina Santa Inés (Ovis aries)

“…During this research, the leather tanned with tannins extracted from mango kernel obtained an average shrinkage temperature of 60°C, which is lower than the standard limit (75°C) for the manufacture of leather products according to the international standard UNE-EN ISO 3380 (UNE-EN ISO, 2016c). This indicates that the crosslinking reaction between the leather (collagen fibers) and tannins (seed) was weak, implying that the leather would not be as durable over time (42), a higher resistance to shrinkage temperature will mean a better degree of stabilization and resistance to degradation. However, the results suggest that the shrinkage temperature of the leather may vary according to the tanning method used and the orientation index of the collagen fibrils.…”

Characterization and Pollution Profile of the Tanning Industry by Distance in Gandong River, Indonesia

“…According to the results of the study, the highest pH level was located at point 1 at a distance of 0 m after mixing with tannery industry waste with a pH concentration of 8. Most natural waters have a pH in the range of 6-9 [27]. The pH value also greatly affects aquatic biochemical processes such as nitrification [28].…”