Chloride water quality indicator

WA water quality labs by atomic absorption and autoanalyzer techniques. Charge balance calculations Indicated that all dissolved species of significance were analyzed. Comparison of filtered and unflltered aliquots suggested that un-lonlzed species were not present In appreciable quantities. Sampling and analysis uncertainties were determined by the operation of two co-located samplers for 16 weeks. The calcium and sulfate data were corrected for the Influence of sea salt to aid In the separation of the factors. This correction was calculated from bulk sea water composition and the chloride concentration In rainwater (11). Non seasalt sulfate and calcium are termed "excess" and flagged by a ... 

International Standard Organization. 1989. Water quality. Determination of chloride. Silver nitrate titration with chromate indicator (Mohr s method). ISO 9297. International Organization for Standardization, Case Postale 56, CH-1211, Geneva 20 Switzerland. 

The solubility of elements in freshwater is limited and the solubility of calcium and magnesium carbonates are of particular importance in freshwaters. The solubility of carbonates is inversely proportional to the temperature of the water. In other words, as the water temperature increases, calcium and magnesium carbonates become less soluble. If the solubility decreases sufficiently, carbonates will precipitate and form a scale on the surfaces of the system. This scale can provide a protective barrier to prevent corrosion of the metallic elements in a system. Excessive scale deposits can interfere with water flow and heat transfer. The quality of the scale is dependent on the quantity of calcium that can precipitate as well as water flow and the chloride and sulfate content of the water. The tendency of water to precipitate a carbonate scale is estimated from corrosion indices such as the Langelier Saturation Index (LSI) and Caldwell-Lawrence calculations [6-8] which use calcium, alkalinity, total dissolved solids, temperature and pH properties of the water. Other indices, such as the Ryznar Index... 

Concentration measurements of aqueous solutions of salt, sugar, antifreeze etc. Quality control of a number of industrial processes requires checking the concentration stability of different solutions and water soluble fluids. The off-line use of Abbe refractometers is sometimes an obstacle to real-time process control. Several researchers have tested different types of LPGs for the measurement of concentrations of aqueous solutions of sugar, salts, and antifreeze. Falciai et al. [16] used a UV written LPG (X = 1,530 nm, A - 400 pm) to measure concentrations of aqueous solutions of sodium chloride (NaCl) and calcium chloride (CaCl2) having refractive indices in the 1.32-1.42 range. In a later paper, Falciai et al. [17] also measured... 

The salinity of seas, oceans, hypersadine lakes and the Dead Sea is represented mostly by chlorides inland waters contain mostly carbonates and hydrocarbonates. Salts present in industrial wastewaters can influence the quality of underground and surface water. A variety of microorganisms indicate the presence of salts in water. For example, the diatom Thalassiosire fluviatilis is an indicator of potassium salts in wastewaters. 

The electrical resistivity is an indication of the amount of moisture in the pores, and the size and tortuosity of the pore system. Resistivity is strongly affected by concrete quality, that is, cement content, water/cement ratio, curing and additives used. The chloride level does not strongly affect resistivity as there are plenty of ions dissolved in the pore water already and a few more chloride ions here or there does not make a big difference. However, chlorides in concrete can be hygroscopic, that is, they will encourage the concrete to retain water. This is why chlorides are often accused of reducing concrete resistivity. 

Damp-proofing admixtures or water repellents can also be added to concrete. However, several researchers indicate that they offer little benefit to corrosion protection in good quality concrete [52,53]. Succinate type admixtures have been tested at the Universities of Connecticut and Massachusetts [54,55]. Good dampproofing and corrosion resistance properties were shown however, due to the extreme drying conditions and artificial cracks, it is not known if these materials raise the chloride threshold level at the reinforcing steel for corrosion initiation. 

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