Muhammad Abbas bin Ahmad Zaini, PhD CEngCentre of Lipids Engineering & Applied Research (CLEAR)

Universiti Teknologi Malaysia

This presentation is aimed at sharing some insight on the utilization of oily sludge as g y g

adsorbent for wastewater treatment

“Use waste to treat waste” approach

Why sludge?

Why adsorbent?

P ti   f  l d   d b t  Preparation of sludge adsorbents 

Characteristics  of sludge adsorbents

Adsorption of Rhodamine B

Performance comparisonPerformance comparison

Conclusion

Sludge is a solid residue of wastewater treatment‐ SW204

Incineration and land filling – expensive treatment methods and may result in secondary pollution problems

To search suitable applications of sludge – fertilizer, solid fuel, adsorbent, concrete blend, animal  feed, etc.

Some sludge contains  pathogens, and phyto‐toxic  substances

Different origin, so different characteristics

Adsorption ‐ cheap and effective wastewater treatment strategyAdsorbent – surface chemistry and textural propertiesAbundant potential precursors – sludge, agricultural wastes, etc.Ch i ll   t bl  Chemically stable 

The dried sludge contains 61.8% carbon, 9.7% hydrogen, 0.3% nitrogen  0 1% sulfurnitrogen, 0.1% sulfurParticle size of about 3 mm, dried in furnace at 300°C for 2 h to remove excess oil. The sludge sample was immersed in 5 M HCl solution for 24 h at room temperature.The sludge sample was immersed in 5 M KOH solution and was g p 5dried in oven at 100°C overnight. Then, the impregnated sample was heated in furnace at 600°C for 2 h.

Adsorbent Yield (%) pH Specific surface area (m2/g)

Untreated 86.1 6.7 0.45

HCl-treated 71.2 4.6 1.05

KOH-treated 53.9 8.9 2.08

Similar surface groups of C—H saturated aliphatic (alkane) and C=C aromatic ring. 

T t t  i  HCl i t d  Treatment using HCl introduces carbonyl compound (quinone or conjugated ketone) at 1690 cm‐1

A peak in the region of 1200 1400 cm‐A peak in the region of 1200‐1400 cm1 that corresponds to the presence of alcohol group (O—H in‐plane bend). 

18KOH

40

9

12

15

rem

oval

(mg/

g)

KOH-treatedHCl-treatedUntreated sludge y = 16.954x

R² = 0.954320

30

rem

ova

l (m

g/g)

Langmuir

Experiment

0

3

6

9

Rhod

amin

e B

r

y = 7.3846xR² = 0.9226

0

10

Rhod

amin

e B

00 20 40 60 80

Equilibrium concentration (mg/L)

00.0 0.5 1.0 1.5 2.0 2.5

Specific surface are (m2/g)

Adsorbent Surface area (m2/g)

Maximum uptake (mg/g)

Treated parthenium biomass - 59.2Modified tannery waste - 250Bagasse pitch activated carbon - 104carbon

Carbonaceous industrial waste - 91.1

Sago waste carbon - 16.2gCarnauba leaves treated with CaCl2

431 40.0

Carnauba leaves treated ith H PO 402 36.0with H3PO4

402 36.0

Macauba leaves treated with H3PO4

371 33.7

Pine nut shell treated with Pine nut shell treated with H3PO4

296 33.1

KOH-treated oil-rich sludge 2.08 14.4

The chemically treated adsorbents demonstrate an yimproved removal performance compared to the untreated one. Th   d i   f  h d i B  h    li  The adsorption of rhodamine B shows a linear correlation to the specific surface area of adsorbent. Adsorption process is recommended for lower Adsorption process is recommended for lower concentration as a higher concentration would inevitably lead to the decrease in removal percentage.