Efficiency of Artemia Cysts Removal as a Model Invasive Spore Using a Continuous Microwave System with Heat Recovery

Abstract

A continuous microwave system to treat ballast water inoculated with Artemia salina cysts as a model invasive spore was tested for its efficacy in inactivating the cysts present. The system was tested at two different flow rates (1 and 2 L x min(-1)) and two different power levels (2.5 and 4.5 kW). Temperature profiles indicate that the system could deliver heating loads in excess of 100 degrees C in a uniform and near-instantaneous manner when using a heat recovery system. Except for a power and flow rate combination of 2.5 kW and 2 L x min(-1), complete inactivation of the cysts was observed at all combinations at holding times below 100 s. The microwave treatment was better or equal to the control treatment in inactivating the cysts. Use of heat exchangers increased the power conversion efficiency and the overall efficiency of the treatment system. Cost economics analysis indicates that in the present form of development microwave treatment costs are higher than the existing ballast water treatment methods. Overall, tests results indicated that microwave treatment of ballast water is a promising method that can be used in conjunction with other methods to form an efficient treatment system that can prevent introduction of potentially invasive spore forming species in non-native waters.

A Review and Perspective of Environmental Disinfection Technology Based on Microwave Irradiation

“…Moreover, microwave power was an important parameter in liquid medium disinfection [ 65 ]. In the study on the treatment of fluids containing different kinds of biological pollutants in the continuous microwave system, it was found that in addition to the microwave power, the flow rate also directly affected the efficiency [ 66 ]. Since the purification retention time of different organisms can be calculated, this technology might become an effective tool to control/prevent invasive species from entering the local environment [ 67 ].…”

Technologies for ballast water treatment: a review

“…The targeted organisms were microalgae ( Nannochloropsis oculata ), zooplankton ( Artemia ) in two different growth stages and oyster larvae ( Crassosstrea virginica ). Inactivation of the selected microorganisms was achieved at 55 °C and a holding time of 200 s. Balasubramanian et al 47 tested the same system on the inactivation of Artemia cysts. 100% inactivation was observed using the same parameters, but a lower holding time (100 s).…”

Thermal desalination of ballast water using onboard waste heat in marine industry

“…Heat treatment technique under different operational conditions was also studied to treat the organisms smaller than 50 μm (phytoplankton and bacteria) in the ballast water . Many studies have focused on developing thermal treatment systems for ballast water management . Some other studies have developed microwave heating systems for artemia cysts and other microbial contaminant removal .…”

“…4 Many studies have focused on developing thermal treatment systems for ballast water management. [16][17][18][19][20][21] Some other studies have developed microwave heating systems for artemia cysts and other microbial contaminant removal. 19,20 Waste heat from the main engine was extracted to treat the ballast water.…”