Parametric Investigation on 1064 and 355 nm Nd:YAG Based Laser Cleaning of Biofouling from Ship Hulls for Marine Applications
Nandini Patra, Konica Katare , Namit Nabria, Rohit Pandya, Kiran Bala and I. A. Palani
Biofouling, the accumulation of microorganisms, algae, and sessile marine organisms such as mussels on submerged surfaces, presents a significant challenge in marine environments. This phenomenon is particularly problematic on technical surfaces, including ship hulls. Hence, fuel consumption significantly increases and associated CO2 emissions, thereby imposing substantial economic and environmental costs on the maritime industry.
In this study, a laser-based cleaning method was developed for the in situ removal of biofouling from ship hull surfaces under underwater conditions. A nanosecond-pulsed Nd: YAG laser was employed, operating at two different wavelengths—532 nm and 1064 nm—and with two distinct energy levels—approximately 250 mJ and 350 mJ. The laser-treated surfaces were subsequently subjected to microstructural analysis to assess the efficacy of cleaning and the impact on the surface. It was observed that at 532 nm wavelength with an energy of 250 mJ uniform removal of algal biofouling without leaving any residual matter. Additionally, minimal thermal or mechanical alteration to the underlying substrate was observed, indicating that the laser energy was sufficient to ablate surface level biofouling without damaging the hull material. To evaluate the longterm effectiveness of the treatment, the laser-cleaned samples were re-exposed to the marine environment. No regrowth of macrofouling organisms was detected up to 7 days; however, surface colonization by rust and algal cells was observed. This suggests that laser cleaning is effective for immediate fouling removal and short-term prevention, further surface treatments or coatings may be required to inhibit microbial recolonization and corrosion.
Keywords: Laser cleaning, biofouling cleaning, 532 nm and 1064nm laser wavelengths, algal growth restricted