[Environmental Sciences]

Hi. I am trying to modify a piece of equipment I have to help protect it from biological fouling and would really appreciate some chemistry advice here.  I have a piece of equipment made from marine grade anodised aluminium, which I want to wrap with copper mesh.  The environment it will be used in is a high saline environment. I am aware that there could be some galvanic corrosion occur if I do so.  I have read about this galvanic corrosion and how in terms of copper mesh this could be beneficial to release more copper, however in my tests so far, copper mesh has caused the anodised aluminium to pit. I have installed a zinc sacraficial anode, one that is in direct contact with the copper and aluminium and one which is only attached to the aluminium.  It appears that the zinc anode attached to both metals has reduced the amount of pitting however my concerns are 1. is the zinc anode actually required and 2. is the zinc anode reducing the effectiveness of the copper to release copper into the near environment.  Any advice here on this would be greatly received.  My main aim here is to protect the piece of equipment made of marine grade aluminium whilst being able to reduce biological fouling using copper mesh.

As an extension of this question, I also have a piece of equipment made of Titanium.  From what I understand, an anode will not be required for this as the copper is more reactive and will break down first.  Am I right in thinking this? Again the aim is to protect the titanium equipment and reduce biofouling using copper mesh

[Hunter2]

I think it doesn't work because copper is more noble as zinc and this is more noble as aluminium. So aluminium will be dissolved first. But so far I understood your target is to dissolve copper. So no need to have aluminium or zinc. Use only copper or have a more noble element like silver for example to force copper to dissolve. You can also put an electrical potential to the copper, means use it as anode, cathode maybe a carbon stick.