Effects ofaeration associated with application of free-floating aquatic plants salviniacucullataroxb. Ex bory and azollapinnata r. Br.) on Pig-Farm Wastewater Treatment
Pig-farm anaerobic effluent, which consists of high ammonium (NH4+) and biological oxygen demand (BOD), but low dissolved oxygen (DO), could be improved to reach standard water quality before drained to natural water bodies. Because of high nutrients contamination, so that phytoremediation is one of the interesting and being considered as a high efficiency method. In this experiment, the pig-farm wastewater was aerated for two weeks. After that, it was divided into two groups: undiluted and 50% diluted wastewater. Then, Salviniacucullata and Azollapinnata were planted to each treatment, including controls, totally six treatments. The water parameters, including dissolved oxygen (DO), Biological Oxygen Demand (BOD5), pH, Electrical Conductivity (EC), Total Dissolved Solid (TDS), Total Suspended Solid (TSS), Nitrate (NO3-), Ammonium (NH4+), and Orthophosphate (PO43-), were determined before an aeration, at the beginning of the experiment (after an aeration for two weeks), and weekly until the sixth week. It was found that pig-farm wastewater could be improved by an aeration. DO had been increased and this high oxygen had reduced NH4+, PO43-, EC, TDS, and TSS. Furthermore, these two species have highly rate to take up NH4+ (70-90% in one week). They could also slightly reduce NO3-for 3-9% higher than control in undiluted wastewater during the second and fourth week. Furthermore, S. cucullatacould remove a high number of BOD5 (77-85%) during a week. In addition, TSS in all treatments had been removed for 50-95%. As a result, S. cucullata and A. pinnata were interesting species to reduce these three parameters in the water treatment systems.
Keywords - aeration, Salviniacucullata, Azollapinnata, pig-farm wastewater treatment