>>2169545>Are there chemicals solar distillation wont filter out?
Yes. It won't "filter out" any chemicals.
What it does, is vaporize them at different times depending on their boiling point (mostly, that is. It's not 100%).
If you have methanol mixed in, for example, that'll vaporize and condense first. Same with any other chemical that has a lower boiling point than water, which includes several chemicals used in agriculture and industry.
Then there's things like granola oil, for example, which will vaporize shortly after water, makingthem hard to separate with distillation.>inb4 oil and water don't mix
some organic farmers use granola oil / water/ emulgator mixtures to kill bugs.
In a real still, you'd bring things to a boil, then measure the temperature of the steam to tell the composition. If it's 100C, your steam is almost certainly safe water (unless you have a really freaky multicomponent azeotrope, which is unlikely).
In a standard sun still, which'll run at ~60-80C, you don't have that option.
Thus, a sun still can only remove chemicals that have such a high boiling point that they virtually don't vaporize at the temps you get. And even those will remain in neglible amounts.