impact of the regeneration effluent on the environnement 3

[abs24]

we have an ion ion exchanger (mixed bed)which is regenerated simultaneousely with naoh and h2so4. the effluent are directed to a trench of neutralization to adjust pH. this trench is not covered.i want to know the impact of these effluents on the environnement . thanks

 

[kenvlach]

I presume that you are outside of the USA or other nations with environmental programs. In the USA, you would need an EPA Generator's ID No. since you are generating 2 waste streams, a treatment permit for both the neutralization of NaOH and H2SO4 and removal of any metals (typically Cr, Cu, Ni, Zn), a containment area for your treatment unit, and a discharge permit to send the cleaned effluent out to a sewer or surface stream [lower limits apply for the latter case].

You have concentrated the impurities that had been in the water into your effluent. So, the output depends upon what was in your water. Do you have a) analysis of the incoming water and b) the number of gallons of water treated prior to regeneration? With these numbers, assuming 100 % removal from the initial water, you can calculate the mass of each constituent in your neutralized effluent. And, from the volume of the effluent created, you get concentrations.

Presuming that your combined effluent streams are neutral, the effect on the environment could be as little as adding salt water or as bad as contaminating the site with toxic metals. There is also the chance of contamination with illegal levels of anions such as cyanide or chromate if you have been treating industrial waste water (instead of creating DI water from tapwater).

 

[kenvlach]

To illustrate what I said above, that your ion exchange units have greatly concentrated the impurities in the water,maybe by 10000x, and can make the effluent from regeneration be considered hazardous for toxic metals, etc. Some thing non-detectable or at 1 ppb can end up at 10 ppm, something 1 ppm can end up 10000 ppm. {and this method can even be used to recover metals from rinsewater from metal plating}

In the USA, one of the largest water treatment companies was fined by the EPA for treating hazardous waste without proper permits or secondary containment. They were regenerating ion exchange units, used to produce high purity DI water from tapwater (legal drinking water). Had been doing so for many years. I don't remember which impurity or impurities caused the problem, but they argued the case and lost.