Water Reclamation Using Constructed Wetland in Indonesia Fish Canning Industry

Abstract

Wetland is an effective system in water conservation and water reclamation due to its natural water purification capability consisting of several mechanisms e.g. filtration, absorption, adsorption, bioconversion, biodegradation, pathogen neutralization, that can remove inorganic, organic and biological pollutants in water. In Indonesia, fish canning industry is one of the major maritime industries that support the economy and food security and will continue to grow along the years. It is also a water-intensive industry that requires a lot of clean water during the operations and processes. It is a necessity to have a water conservation scheme that can anticipate the growth of this industry. In this study, the implementation of constructed wetland in wastewater treatment plant (WWTP) at one of the fish canneries in Bali, Indonesia, was evaluated using a small-scale vertical-subsurface-flow constructed wetland planted with Typha angustifolia. 10 L of the effluent from WWTP was flowed into the wetland constructed with media composed of sands and gravels, and a hydraulic conductivity of around 0.5 m/h was maintained by sieving the sand and gravel particles into certain size ranges. The liquid was recycled several times to simulate retention times of 24, 48 and 72 h. At 24-h treatment the average removal rate of TSS and COD were 87 %, and 63 %. Further increase of treatment time to 72 h could improve the average removal rate of TSS and COD up to 90 % and 72 %. Around 0.4 ppm of sulfide was also detected in one of the WWTP effluent sample, indicating a possible system failure in the aerobic treatment tank. The wetland could reduce sulfide concentration significantly lower than detection limit of standard analysis method. In conclusion, constructed wetland is a potential method to treat and stabilize the WWTP effluent further for recycling use in the production process. A larger-scale study using subsurface-flow constructed wetland is worthy to be pursued for full scale implementation of water reclamation in Indonesia fish canning industry.