Chromium is an element used in stainless steel production, hardening of steel and obtaining of various alloys. It is also widely used in the automotive industry as an anti-corrosion coating agent in the production of various automobile components and in the manufacture of cutting tools. Due to its high melting temperature, it is also in demand in brick and mold making. Chromium is also preferred as a catalyst since it gives the glass an emerald green color. It is a chromium element that gives color to ruby ​​and emerald. In addition, one of the most used dyestuffs for dyeing wool fibers is chromium.

Chromium, which is so widely used in the industry, is mixed with wastewater as a result and harms nature. Therefore, the amount of chromium to be found in wastewater is now limited. In order to achieve the desired limit values ​​in wastewater, enterprises use reactive dyes without metal ions.

Wastewaters containing chromium wastes are generally acidic waters with low biological oxygen demand. This is a danger for living or using water. Chromium in these highly toxic wastewaters destroys micro-organisms that are effective in self-cleaning or purification. These wastewaters are inorganic in nature and lethal in nature.

Chromium is an element that can take various values. In the waters, + 3 and + 6 are generally valent. + 3-valued chromium forms chromium hydrostatic. This compound is a salt with little solubility. + 6-valued chromium is present in the form of negatively charged ions in water and forms highly soluble compounds together with positively charged ions in water.

+ 6-valent chromium reacts in the acid solution to form a red magenta color. Chromium (Cr + 6) measurements are determined colorimetrically in authorized laboratories.