How kidneys get rid of acids from our body?

The oxygen we inhale is acidic, (electron attracting). Our blood is slightly basic. To keep blood basic, our bodies need to discharge acids continuously. Part of the job is done by kidneys. The urine we discharge is acidic. How kidneys get rid of acids?

The structure of kidneys is quite complex. I just want to mention one point here. The membrane where blood filters into kidney is negatively charged. This attracts positively charged ions such as H+ and deters negatively charged ions. This is very much like an exhibition hosted by attractive ladies. Both men and women will come. But more men will likely show up.

By filtering blood with negatively charged membranes, kidneys can filter out more positively charged ions such as H+. This is part of the story how kidneys get rid of acids.

P.S. For more details, please watch the following YouTube video. This guy is amazing
https://www.youtube.com/watch?v=SVqSqPOcahY