TITLE:
Biomass Accumulation and Water Purification of Water Spinach Planted on Water Surface by Floating Beds for Treating Biogas Slurry
AUTHORS:
Xiaomei Yu, Zhaohua Li, Sha Zhao, Kun Li
KEYWORDS:
Floating-Bed; Water Spinach; Piggery Wastewater; Purification
JOURNAL NAME:
Journal of Environmental Protection,
Vol.4 No.11,
November
19,
2013
ABSTRACT:
To find a new way treating the
wastewater from biogas reactors in a pig farm, vegetated floating
bed was built for observing the water-purifying capability of water spinach (Ipomoea aquatic) planted on the water surface. Experiments were carried out
to record the growth and biomass
accumulation of water spinach and its effect on purification of biogas
wastewater. The results show that the water which mixed with biogas
wastewater has been purified significantly by water spinach on the floating
bed. During its growth season within four months, the overall length of water
spinach reached 199 ± 35 cm, while
its root length reached 63 ± 28.6 cm. The average weight of individual
fresh plant is of 1285 ± 619.7 g. Meanwhile, the concentration of
total nitrogen (TN) in water under the floating bed decreased from 8.9 ± 0.062
mg·L-1 to 0.5 ± 0.011 mg·L-1;
the concentration of total phosphorus (TP) decreased from 4.4 ± 0.236 mg·L-1 to 0.92 ± 0.024 mg·L-1; the concentration of chemical
oxygen demand (COD) decreased from 87.3 ± 6.68 mg·L-1 to 0.74 ± 0.46
mg·L-1. It suggests that the water spinach removed more than 90% of
pollutants in terms of TN, TP, and COD from the water. Results show that the
vegetated floating bed technique is a
feasible way to dispose the biogas slurry.