The use of natural indigenous material as a coagulant and coagulant aids in water and solid waste leachates

Dissertant

Zurab, Aku Rashid Hama

Thesis advisor

al-Samawi, Adnan A. Ali

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Ph.D.

Degree Date

2011

English Abstract

-Coagulation-Flocculation processes play an important role in the treatment of water and wastewater.

Aluminum sulfate (alum) and polyelectrolyte (polymer) are the common chemical coagulants which are used in this process.

Recently, there have been many scientific evidences of the possible link between high levels of these residual coagulants and several medical disorders.

This initiated a global interest in the search for suitable coagulants that will be safe from the stand point of health and economy.

A natural indigenous coagulant is suggested as an alternative or as an aid for alum and polymer.

Okra is suggested for this study.

The results of this study have shown that okra is a powerful coagulant whether it is used as a primary or as a coagulant aid to alum or polymer.

The optimum pH values for all the three coagulants (alum, polymer, and okra) when used in raw water treatment were 8.00, 8.50 and 7.75, respectively.

The amount of optimum okra dose was as small as 10%, 9.0%, 70% with respect to the optimum alum dose required to remove raw water turbidity of 100,200 and 500 NTU turbidity levels, respectively.

The amount of optimum okra dose was more than optimum polymer doses by 200%, 112.5%, 224% required to remove raw water turbidity of 100,200 and 500 NTU turbidity levels, respectively.

Other significant results were obtained when using okra as a coagulant aid to alum and polymer conventional coagulants.

The produced leachate in waste disposal places is considered to be one of the highly contaminated resources from the physical, chemical, and biological point of view.

In Sulaimaniah, Tanjaro was found to be one of those solid waste landfill areas.

The raw leachate samples were obtained directly from Sulaimaniah solid waste sanitary landfill area which is located in Tanjaro [10 km south west of the city center (35o29´14.25″N, 45o26´08.09″ E, and 691 m above mean sea level)].

Fresh solid waste samples of the leachates were taken and tested for their heavy metals concentrations contents.

It was found that the leachate contains a high amount of heavy metals of cadmium, chromium, copper, nickel, and zinc.

By using conventional coagulants of alum, polymer and natural indigenous okra (as a primary coagulant or in combination with the other two primary coagulants) and by the jar testing, the optimum concentrations and pH values of the coagulants were determined.

Analyzing the results, it was found that the optimal pH values were 6.65, 9.00 and 7.00 for alum, polymer and okra, respectively.

In addition, the optimum dose of alum was1400 mg/L in which a removal of heavy metals yielded 45-80 %.

While the optimum dose of polymer was 500 mg/L in which a removal of 70-95% was achieved.

For okra, the optimum dose was 500 mg/L in which a removal of heavy metals yielded 20-100%.The relative abundance of heavy metals after treating fresh investigated leachate of Tanjaro landfill area with alum followed the order: Cd>Ni>Zn >Cu>Cr, while after treating with polymer, it was Cu> Ni> Cd>Cr > Zn; and after the treating with okra, it was Zn > Cr > Cu > Ni > Cd.

It was found that okra has an efficient coagulation power with respect to alum and polymer in removing heavy metals elements in solid waste leachates.

Main Subjects

Earth Sciences, Water and Environment

Topics

• Sanitation
• Waste water
• Water

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305160