Changes in Physico-Chemical Composition of Wastewater by Growing Phragmites ausrtalis and Typha in an Arid Environment in Saudi Arabia

Abstract

Kingdom of Saudi Arabia is facing an acute shortage of good quality of water which is further aggravated due to inadequate and non-renewable groundwater resources. Hence, it is very important to explore other alternatives such as natural wastewater treatment (phytoremediation) for water supplies that can both lower the dependent on groundwater resources and overcome the challenges and limitations associated with conventional wastewater treatment technologies. Therefore, the main objective of this research was to study the performance and efficiency of green plants such as Typha and Phragmites australis for wastewater treatment in eastern Saudi Arabia. The experiment was carried out in fiberglass tanks (each with a capacity of 4.0 x 7.0 x 0.5 m3) in the field. There was a total of 4 fiberglass tanks with 2-replications. A percent decrease of 72.86 and 49.74%, 39.30 and 18.07%, 39.84 and 52.87%, 38.73 and 40.86%, 74.49 and 57.82%, and 66.82 and 63.14% was observed for turbidity, TSS, nitrate, ammonia, BOD, and COD by growing Phragmites australis and Typha, respectively. The heavy metals such as aluminum, zinc, and arsenic showed considerable reduction of pollutants in treated water compared to raw wastewater under both plants. Overall, it seems that the improvement in wastewater quality was better by growing phragmites australis than Typha, however, there were no statistically significant differences between the two plants means in their performance of raw wastewater treatment. The study results indicate that green plants could be used in a phytoremediation system to treat wastewater in rural and small communities.