I have found out that conductivity meters and total dissolved solid meters (TDS meter) are used to measure the quality of RO water. Which method is more accurate and why is this the case?
Besides TDS and conductivity measurement, you can follow up with ion chromatography. It will give you detailed concentration profiles of different ionic species.
The choice of method of water analysis depends mainly on the purpose of water use. If the water is used for drinking purpose, I agree with Raka. In terms of the suite of ions you consider analysing, this depends on the quality standards applied on different water uses and the respective suite of contaminants controlled by the government or health authorities.
As the partners said before, first which is the use?, for several applications including human consumption, conductivity is a cheap and very precise methode, obviously if is for human consumption you must know the source profile and make a frequent check of the traces and the normative parameters, TDS many times is an indirect parameter calculated form the conductivity, so, many times it is not so accurate as the direct measure of conductivity.
Depending on use. ICPM-MS and AAS are the most appropriate. Conductivity? depending if the meter is sensitive enough to measure such low levels elements/compounds, I would say not. Regards.
Conductivity is the simplest, whether it is wastewater reuse or desalination of seawater. In the case of seawater, boron is known to be poorly removed by RO membranes and is at significant concentration in average seawater (~4.5 mg/L). For desalination, I refer you to the American Waterworks Association (AWWA) Manual of Practice 61: Desalination of Seawater; Chapter 2: Water Quality.
I have read answers to Vikki's question. Can I consider using RO for removing Sulphates and Chlorides from the waste effluent? The municipality tolerates a maximum of 1500 mg/l we produce a minimum of 190 000 Liters per month of liquid waste and we're hugely fined for having high concentration of sulphates and chlorides in our effluent that is discharged to the municipal sewer. Thank you
It is a good question that should probably be posed in a separately initiated question. But I would say that the first thing to do is compare the initial concentrations of sulphates and chlorides to their solubility limits of relevant compounds (depending on cationic composition). Whether you use RO or ion exchange or some other process, you will still need to deal with the rejected brine. With the energy of pumping, disposal of brine is a major cost consideration. With small volume, in some climates it may be possible to implement "zero liquid discharge" by evaporation. But beside treatment, there may also be the possibility of blending this flow with another of much lower ionic content, or of trucking this wastewater to another more accepting municipality.
I agree with Laith, Hopewell should post his question separately. Just to view from a regulator's angle, I am surprised by the limits imposed by the municipality on this occasion. It may well be that the municipality discharge is regulated and enforced by another agency and there may be stringent requirements for SO4 and Cl levels in the municipality discharge. High levels of SO4 or Cl should not be an issue in the receiving environment.
Generally, municipalities refer to Hopewell's type of discharges as 'trade wastes' and impose a fee and standards for its discharge into their system. If the cost of upgrade is enormous to discharge into the municipality system, you have the following choices: (a) negotiate with the municipality to accept a higher level of SO4 and Cl and (b) given your discharge is small by volume (190 m3 per month) you may collect and truck your discharge to another site that could accept your discharge or irrigate onto land provided you have the permit and the discharge does not have high levels of heavy metals.
Researchers I enjoyed the comments here. Please I had a recent question on my wall on water quality I will to get a clarification on it. Please If you can assist, do help
it reads
Water Quality Assessment, Calibration and Instrumentation in Water Quality Monitoring and Environmental Management?
In water quality assessment and water monitoring, is there any link/ ideas based on experience/literature on detailed methods in assessment like volumetric and Titrimetry / Electrometric, Gravimetry and Photometric use of certain equipments like the AAS. Identifying the principles, pros and cons for the methods outlined?
e.g in pH determination with the portable pH meter calibration is performed with local specified standard for example some organisations calibrate with the range of 5.0 - 5.5 is there any authorized standards by certain organisations and things like that.
Other calibrations for the instruments of DO meter, AAS, etc. I also needed a clarification on this
In bacteriological assessment talk of Most Probable Number technique, coli-form count, Standard Plate etc. is there any literature on the methods outlining the principles adopted.
Distinguished colleagues Please, kindly assist in any capacity
I think conductivity is more accurate than TDS, since TDS meter equipment is based on conductivity of dissolved component which is multiplied by certain factor.
I would agree with Mr Wenten, conductiviy is the standard way to measure total dissolved salts, regarding possible organic I would go to detect TOC. All these methods can be found easily. Best luck.