Keywords: HRTS, high rate transpiration system, hydraulic loading, pulp and paper mills, wastewater treatment, zero liquid discharge, phytoremediation, bioremediation, salt, metal concentration, colour, coloured wastewater, groundwater quality
Phytoremediation technology for wastewater treatment: high rate transpiration system
High Rate Transpiration System (HRTS) is a well-designed land treatment system composed of ridges and furrows and well-controlled hydraulic loading of wastewater. The present case study describes long-term operating experience of zero discharge of pulp and paper mill wastewater, which is characterised by high BOD, COD, TDS and colour that poses disposal problems into water bodies and on land. The result of field trials showed that there was no appreciable build-up of salt concentration in the furrows, at wastewater application rate of 250 m³/ha/day. The quality of groundwater was monitored within and outside the HRTS through well water sampling and it was satisfactory with respect to salt, metal concentrations and colour. The findings showed that HRTS is environmentally acceptable solution to manage the problem of coloured wastewater and also minimise the impact on groundwater quality.