Striving to develop innovative water quality control and monitoring technologies, the EPA presented its latest achievements in water sampling by drone and household wastewater electrolysis phosphorus removal technology at Chengqing Lake Reservoir on 21 October. During the onsite demonstration, a drone carrying a monitoring instrument and sampling bag was used to conduct remote water quality monitoring and sampling of the reservoir water, demonstrating that drones can be used for water monitoring in a swift and safe fashion with low pollution and disturbances. An electrolytic phosphorus removal recycling tank that removes nutrients such as nitrogen and phosphorus from wastewater and converts them into fertilizer using electrolytic crystallization technology was also displayed in a public restroom nearby.

Reservoir water surveys are currently carried out by transporting personnel to sampling points in boats, which is time- and money–consuming, not to mention the risks to staff safety and the possibility of oil pollution. The traveling paths of the boats are often restricted by the terrain and water depth, and the representativeness of the water samples is therefore compromised. To solve the problem, the EPA commissioned National Cheng Kung University to examine the sampling spots and methods of current reservoir water sampling operations and develop feasible drone sampling technology with the aim of enhancing monitoring quality and maintaining data integrity. With the aid of drones, the management staff can quickly obtain the needed samples and accurately determine water quality and pollution hot zones.

Nutrients such as nitrogen and phosphorus can cause eutrophication and water quality deterioration in reservoirs. Sources of nutrients include excess fertilization, agricultural and livestock wastes, and household and recreational wastewater. Currently, wastewater from households, restaurants, and restrooms around the reservoir watershed is usually only treated through septic tanks, which have limited phosphorous-removal capability. To cut down the pollution from nutrients in the reservoirs, National Cheng Kung University and National Kaohsiung University of Science and Technology applied electrocoagulation or dosing methods to recycle nitrogen and phosphorus in the septic tanks of public restrooms. The processes not only crystallize the nutrients into struvite (magnesium ammonium phosphate) which can be used as fertilizer, but also reduce the nutrients in the wastewater, achieving environmental protection and resource recycling at the same time.

Excerpt from Environmental Policy Monthly, 23 (11)