Removal of iron and manganese from drinking water supply

Abstract

The water treatment plant at the Hingna industrial area receives raw water from Ambazari Lake and supplies drinking water to industrial area, after conventional treatment. The treated water was found to have a pungent odour and yellow colour, which in turn changed from a brown to black precipitate. The water becomes aesthetically unacceptable to consumers. It was observed that a blackish precipitate formation was due to the presence of iron and manganese in lake water, which was not completely removed during treatment. To remove iron and manganese from drinking water, treatment studies were carried out with chlorine and KMnO 4 as oxidants. Alum and lime were added for coagulation and pH correction. Jar test studies revealed that treatment with potassium permanganate at pH 7.7-8.0 was effective in the removal of iron, manganese and organics, which were responsible for causing colour and odour to water. The studies helped in improvements in water quality for safe drinking water supply.

Anaerobic manganese- or iron-mediated pharmaceutical degradation in water

“…Removal by Fe(III)bio-production is expected via adsorption since it has a large specific surface area [97] . Fe(III)DWTP is usually produced via chemical processes with O2 (aeration) while biological processes are also observed under conditions where substantial organic matter is present [135,144] . The production process leads to potentially different Fe(III) compounds and thus different pharmaceutical removal from Fe(III)bio-production.…”

“…The Mn(II) and Fe(II) generated during the anaerobic pharmaceutical degradation will enter the DWTPs. However, the Mn(II) and Fe(II) are also target compounds for drinking water production [135,307] . Therefore, anaerobic metal-mediated pharmaceutical degradation will increase the loading of Mn and Fe removal in DWTPs.…”

“…Compared to these compounds, Mn(IV) or Fe(III) produced during the drinking water treatment (labelled as Mn(IV)DWTP and Fe(III)DWTP) could be a more desirable source. Mn(IV)DWTP and Fe(III)DWTP are waste streams from the drinking water treatment plants [135] . Thus, these materials could be a cheap alternative for Mn(IV)chem-synthesis and Fe(III)chem-synthesis.…”

“…Both chemical and biological methods can be used to regenerate Mn(IV) and Fe(III) from the Mn(II) and Fe(II) released during pharmaceutical degradation. Chemical production is achieved through direct oxidation using oxygen (O2) or a strong oxidant such as chlorine, chlorine dioxide, ozone or KMnO4 [135] . For example, chemically produced Mn(IV) can be obtained via the oxidation of MnCl2 with KMnO4 [65] .…”

“…Another source of Mn(IV) and Fe(III) is waste from drinking water treatment plants. Mn(IV) or Fe(III) produced during drinking water treatment (Mn(IV)DWTP and Fe(III) DWTP) are usually produced via chemical or biological processes, or the combination of these two processes [135,144] . Thus, Mn(IV)DWTP and Fe(III) DWTP likely have different properties than Mn(IV) or Fe(III) produced solely via defined chemical or biological processes.…”