EVALUATION OF THE EFFECTIVENESS OF SOME AGRICULTURAL WASTE IN THE TREATMENT OF PRODUCED WATER

This study investigated the concentration of heavy metals in oil field produced water

from Niger Delta, before and after treatment with locally sourced agricultural

wastes. Two produced water samples were investigated for different metal ions such

as; Lead, Nickel, Cadmium, Copper, Iron, Magnesium, Chromium, Zinc,

Manganese, Calcium, Arsenic, Boron, Tin and Barium. The produced water samples

were treated with four different adsorbents which are; Orange peels, Banana peels,

Palm Kernel Fiber and Luffa Cylindrica. These adsorbents were used at different

particle sizes of 63 and 150 microns. Ten of these metals were analyzed using the

atomic absorption spectrophotometer (AAS) and the remaining four were analyzed

using the UV-Visible spectrophotometer. The analysis was carried out (in line with

the industrial standard) in order to determine the concentration of the metals in the

produced water samples.

The results obtained from the analysis showed that the concentration of the metal

ions investigated reduced drastically after treating. For example, the concentration

of lead, iron and zinc reduced from 0.095ppm, 0.045ppm, 0.108ppm to 0.018ppm,

0.001ppm and 0.002ppm respectively in sample X. The physical and chemical

properties as well as other contaminants of the produced water samples such as

chloride content, total dissolved solids and density were also determined before and

after treatment. There were reductions in the concentrations of these properties.

This showed that the produced water from the oil and gas activities should be treated

for metal ions present that may have concentrations higher than standard limits set

by regulatory bodies before disposal and/or re-use due to their negative effects to

man and its environment.

LIST OF FIGURES 

Figure 1.0: Petroleum hydrocarbon reservoir. ........................................................... 3 

Figure 1.1. Steps involved in the dynamics of adsorption. ........................................ 9 

Figure 3.0 Raw luffa cylindrica fiber and raw palm kernel fiber. ...........................24 

Figure 3.1 Raw banana peels and raw orange peels. ...............................................25 

Figure 3.2: Crushed and sieved banana peels. .........................................................26 

Figure 3.3 Crushed and sieved orange peels............................................................26 

Figure 3.4 Crushed and sieved palm kernel fiber. ...................................................27 

Figure 3.5 Crushed and sieved luffa cylindrica. ......................................................27 

Figure 3.6 Drying of the adsorbents in the oven after treatment with HNO3. ........28 

Figure 3.7 Produced water samples and Adsorption process with the adsorbents. .28 

Figure 3.8 Atomic absorption spectrophotometer (AAS). .......................................30 

Figure 3.9 UV-Visible spectrophotometer (spectrumlab 752s). ..............................35 

Figure 3.10 Standard stock solutions for determining the concentration of arsenic, 

boron, tin and barium in the samples. ......................................................................35 

Figure 3.11 Filling the burette with the silver nitrate solution ................................37 

Figure 3.12 Appearance of a reddish brown precipitate to determine the chloride 

concentration. ...........................................................................................................38 

Figure 3.13 Determination of the carbonates and biocarbonates concentration. ....40 

Figure 3.14 Drying the evaporating dish filled with sample in the oven. ...............42 

Figure 3.15 Sample of the filter paper with residue. ...............................................43 

Figure 3.16 Taking the pH values from the pH meter. ............................................44 

Figure 3.17 Pycnometer bottles used for density determination. ............................45 

Figure 3.18 Electronic weighing balance. ...............................................................45 

Figure 4.2.1 Calibration Curve of Absorbance vs Conc. Of Arsenic (mg/l). ..........55 

Figure 4.2.2 Calibration Curve of Absorbance vs Conc. of Boron .........................57 

Figure 4.2.3: Calibration Curve of Absorbance vs Conc. of Tin (mg/l)..................60 

Figure 4.2.4 Calibration Curve of Absorbance vs Conc. of Barium (mg/l) ............62 

Figure 4.4.1 Calibration Curve of Absorbance vs. Conc of Sulphate .....................66 