I would ask for @CaCO3Girl and anyone else to chime in.
I am doing research on neutralization of base and acid chemicals.
Let’s say you are working with HCL. You can neutralize with NaOH to bring the PH level back to 7. Some information goes on to state at that point you can discharge down the drain.
Why I am even doing this is to explore the possibility - Can one neutralize chemicals to reduce toxicity for both run-off into landscaping and/or drains thus allowing the use of certain chemicals in situations that normally one would not use?
In the example of HCL, you can neutralize with NaOH to result in NaCL + H2O (salt water). Salt water is not the best for landscape but safer all around then HCL going into it.
@CaCO3Girl - could I use pH test strips to monitor neutralization? Is this line of thinking valid or worthwhile?
I have several gas stations that want me to clean their parking lot. I would be using strong bases to do so. My concern is run-off into drains. I cover the drain and reclaim the water. I really do not want to transport large volumes of water, so I am looking to neutralize the water followed by filtering and oil socks to capture oil solids and other contaminants and then discharging on-site. If the water is in a neutral state with solids removed, it is now safe to discharge into drains or at least not into storm drains but into municipal waste water drains?
Can you use test strips to monitor neutralization, YES! I often do.
Should you neutralize with NaOH, NO!
The process of overshooting is SOOOOO easy! Plus, there is a violent chemical reaction between a strong base and a strong acid as you have there. So violent it could result in heat hot enough to burn the surface you are working on! Plus if there is the smallest hint of SH we are talking about producing a deadly chlorine gas if HCl and SH get together.
ALWAYS, ALWAYS, ALWAYS neutralize with something benign. For neutralizing caustics and acids I recommend baking soda or soda ash. If you need the caustic to neutralize faster I’d use citric acid.
Every state, township, county, area…they all have different rules on what can go down the drain. A pH of 0-3 and a pH of 12-14 is going to be banned everywhere. However, you should always contact the water authority to see who is the local contact for what goes down the drain. I’ve been shocked in some cases. If you are near the chesapeake bay the answer to what soaps can go down the drain is NONE! No soap at all can go down the drain. Same in several parts of Colorado.
pH is usually not the issue for local waste water treatment plants. It’s high levels of BODs that stresses their process of inputting dissolved oxygen into the waste stream. Never assume or take anyone’s word for it that you’re doing the right thing unless it’s an official from the local municipality and you have it in writing.
I do plan to speak with the city on this, just wanted to get an idea of what or how it would work before going to them. Surprisingly it is not often that I even have to worry about this as the use of retention ponds is widespread around here or in the case of some places, they just don’t install drains on the property. I guess they opted to just let water pool and naturally evaporate to avoid any issues with waste water. Their is a huge shopping center not far from my house that is less than 10 years old that does not have a single drain. Weird.
“Plus if there is the smallest hint of SH we are talking about producing a deadly chlorine gas if HCl and SH get together.”
Spot on. I’ve worked in a chemical plant with these two and had them mix. It’s bad news. Granted, it wouldn’t be on an a large industrial scale, but I would imagine it would still be unpleasant. Also the heat generated might might be detrimental to whatever you are working on.
