Hi, I don’t think anyone will be able to give you an answer other than the eductor and dilution line will most likely will plug up. It depends a lot on if the dilution water has a lot of alkalinity in it because the more alkalinity in the water the more it will resist pH changes (i.e. buffering capacity of the water), how much you are dosing and how much dilution water you are using. The answer is not that easy because believe it or not it is not a well discussed topic and you have to have a chemical background to do proper calculations. If you don’t understand what buffering capacity means I will give you the following example:
In northern Ontario we have a lot of small lakes. The lakes have very little alkalinity (i.e. 5-7 mg/l as CaCO3) aka “no buffering capacity” and the worry was that “acid rain” was causing the pH in the lake water to drop. But why don’t we hear about acid rain causing the pH in Great Lakes water, Lake Ontario for example, to drop? It is because it Lake Ontario water has a lot of buffering capacity. Lake Ontario water has a hardness of pH ranging from 7.5-8 depending on the time of the year, Hardness= 125 mg /l as CaCO3 and alkalinity = 110 mg/l as CaCO3.
We heard of a water plant in eastern Ontario where they were using carrier water dosed with sodium hypochlorite and conveyed in had a 400 ft long 2” diameter line to the head of the water plant intake for zebra mussel control. It clogged SOLID with calcium carbonate in a three month period. The characteristics of the St Lawrence River water at that plant (it really is Lake Ontario water) is about 7-7.5 pH, Hardness= 125 mg /l as CaCO3 and alkalinity = 110 mg/l as CaCO3 (the numbers are close enough for our purposes). At my plant we were mandated to use sodium hypochlorite and not gaseous chlorine and in order to not encounter the same problem I dreamt up this solution and this was well before the age of the internet. But rather than try to solve the problem myself by boxing myself to my own way of thinking…which may be incorrect. I went to others (i.e. the chemical engineering professor) to work out the numbers for me. I am a civil engineer and not a chemical engineer but I have been around the block a few times. I however provided him an envelope of design conditions that will be encountered(i.e. range of alkalinities, pH, water temperatures, dosing range, water flows etc). He came up with the how much dilution water I needed, how much acid I needed to add to the dilution water etc. I at the end of the day still questioned the professor about how he went about to get the answer before I was comfortable with the answers.
Many years ago I scanned a book titled “Alkalinity-pH Changes with Temperature for Industrial Waters”. For chemistry novices like me I use it to figure out how much the pH will change if you dose a quantity of acid or alkaline solution etc. The scanned copy is in my laptop and it is pretty accurate….I did jar tests to prove the results…I have a copy that can be sent by email if you want
