Development of electric rust preventive machining method system-safe water using for machining fluid: Complete removal of bacteria (Legionella pneumophila) and assay

In manufacturing, machining fluid as cutting oil or grinding fluid is used for machining. This fluid contains several chemicals such as oil, surface active agent, extreme pressure agent (chlorine, phosphorus, sulphur, etc.), rust preventive agent, antiseptic agent, germicide and so on for improvement machining performance. However, it is not good for human body and environment. It is afraid that workers health hazard is occurred by fluid mist absorption in breath and splash contacting. In addition, waste fluid needs disposal treatment (incineration or coagulative precipitation and landfill, etc.) that is high cost and heavy environmental load. Therefore, environmental friendly and harmless machining is proposed for nanomanufacturing and green manufacturing. The electric rust preventive machining method system is developed in this investigation. This method system use only water (tap water, under ground water, industrial water) as machining fluid. Water only machining lead to greatly decreasing of waste fluid treatment and petroleum oil resources saving. In addition, complete removal of bacteria (Legionella pneumophila) for safe machining water by improvement water recycle system installed reverse osmosis membrane and ultraviolet radiation unit with nonusing chemicals is evaluated by biological cultivation assay. And artificially contaminated tank water bacteria amount tendency is estimated.