Abstract:
There has been great demand for development of technologies that
remove toxic heavy metal ions from wastewater. Chemical precipitation
operation is known to remove heavy metal ions from water. In this Research
studying the reduction and separated of hexavalent chromium (which is very
toxic heavy metal) from waste water ,and the automation of the process was
undertaken. Reduction process is done by adding suitable quantity of sodium
bisulfite solution to waste water in pH range 2.0 - 2.5 after acidifying the
media with solution of sulfuric acid. The trivalent chromium ions were then
precipitated by adding sodium hydroxide which increases the alkalinity of
the solution up to the pH value 10.0.The size of chromium hydroxide crystal
enlarged by adding flocculent solution. Then the treated waste water solution
filtered to separate chromium hydroxide flocculated crystals. The pH of
remaining treated waste water is reduced to pH 7.0 and discharged directly
to the sewage.
Experimental works was carried out to determine the exact value of
solution potential in ml volts during treatment process steps. The standard
solutions after prepared were treated ideally to determine the end points of
the reactions in ml volts.
Sepotrrato 100R is one of intelligent systems which were developed
for treatment of waste water from electroplating processes. The
Electroplating Department,Sudan Currency Printing Press, waste water
usually contain many heavy metals ions such chromium, and nickel. This
Sepotrrat 100R was recalibrated and programmed according to research
finding, for reactions end points.
