Nadirah binti Ismail1st Assessment (2013/2014)

Supervisors:Assoc. Prof Dr Zaiton Abdul Majid

Assoc. Prof Dr Zaharah Ibrahim

Chemistry DepartmentFaculty of Science,

Universiti Teknologi Malaysia

Proposed Title

Isotherm, Kinetics and Thermodynamic Studies on Adsorption of Chlorpyrifos Using Modified

Ananas Comosus (Pineapple) Leaf Powder

Chlorpyrifos

1 or more aromatic ring

Lack of polar functional groups

Variable numbers of halogen

substitutions

Persistent Organic Pollutants

Pesticide Movementthe spraying of pesticides into our external space results in only 5% of the pesticide reaching the target pest. The rest runs off into water and dissipates in the air.

damaging soil microbes

weaken the ecosystem

Active ingredients + wetting agents, solvents, buffers, preservatives & emulsifiers

photochemical degradation

biodegradation

1

2

3

Methods for pesticides removal

PhotodegradationOzone treatment

Membrane filtrationCombined Ozone and UV

Disadvantages of conventional treatment

CostPesticides not

removed during physical treatment

Adsorption• The binding of molecules or particles to a surface.• Happens at the surface of the substance.

• Physical adsorption : forces of attraction between the molecules are of the weak type. Can be easily reversed by heating or decreasing the pressure

• Chemical adsorption :forces of attraction between the molecules are very strong. Chemical bonds present on the surface.

Lignocellulosic materials

Lignocellulose refers to plant biomass. It is the most abundantly available raw material on the earth, It is composed of carbohydrate polymers (cellulose and hemicellulose) and an aromatic polymer (lignin).

Lignin

High C

Good adsorption

capacity

Dyes, pesticides, phenols,

surfactant

Good adsorbent

Towards phenols and nitrogen containing

compounds

A good adsorbent for pesticides

Cellulose

Develops micropores

Develops macropores

Adsorption

• Physicochemical process. • Enable microorganism communities to adsorb some

toxic materials from solutions. • Allows it to passively concentrate and bind

contaminants onto its cellular structure.• EPS in microbial aggregates have many available

sites for the adsorption. The adsorption of organic pollutants by microbial aggregates may be attributed to the fact that there are some hydrophobic regions in EPS.

Problem Statement

• The application of PLP to adsorb pesticides have not entered the scientific literature extensively

• Adsorption is a difficult subject because adsorption may occur via several different mechanism.

• Understanding adsorptive interactions between Chlorpyrifos, lignocellulosic material (PLP) and biomass/biofilm

Hypothesis

• PLP that comprises of lignin, cellulose and hemicelluloses embedded with immobilized bacteria has the potential to remove Chlorpyrifos from aqueous solution via several adsorptive interactions.

Objectives of study To characterize the lignocellulosic materials in PLP for adsorption of

Chlorpyrifos

To evaluate the adsorptive interaction of interaction between chlorpyrifos with biofilm coated PLP

To determine the composition, thickness and efficiency of biofilm for the removal of Chlorpyrifos

Significance of study

• Chlorpyrifos has been detected in unfiltered river water sample taken from Sungai Sayong, Kulai, Johor.

• To solve the disposal problem of agricultural waste• The adsorption behaviour of chlorpyrifos onto

lignocellulosic material is essential in predicting their potential to be adsorbed or desorbed from the adsorbent.

• Development of biofilm onto lignocellulosic material in PLP will enhance the Chlorpyrifos removal and degradation.

Novelty of study

• The adsorptive interaction of Chlorpyrifos, lignocellulosic material, biofilm in PLP has not been investigated in any research.

Knowledge Gap

• Biofilm

• Biodegradation• Adsorbent

OrganoclayCalcium alginate +

Pseudomonas Bacillus cereusEnterobacter sp

Klebsiella spSerratia sp

Chlorpyrifos (None)-Heavy Metal-Hydrocarbon

-PAHDyes

Surface of lignocellulosic material

ChlorpyrifosGram negative, LPS

*Cell membranes, many classes of lipids and lipoproteins, pesticide accumulation

Sorption may occur through hydrogen bonding from the hydroxyl surfaces toward oxygen atoms in the organic molecules.

carbonyl oxygen of thecarbon surface acting as the electron donor and the aromaticring of the adsorbate acting as the acceptor.

-Hydrolysis may occur at several reactive centres in the pesticide molecule, in the presence of OH- or H2O acting as nucleophilic reagents

hydroxyl groups on the polymer surfaces, which probably have a positive effect on cell adherence.

FINDINGS

• Part 1: Preparation of adsorbent

Storage

Dessicator

Pre-treatment

Wash Dry and sieve

Collection of pineapple leaves

Pineapple leaf

(d)

Pineapple leaf powder

Wash

Dry

Grind & Sieve

Chemical treatment of adsorbent

• Methanol to remove inorganic and organic matter from the surface of sorbents.

Rewash withDeionized water

0.1M nitric acid 1hour

Methanol1hour

• Part 2 : Characterization of adsorbent

4) Surface images

Field Emission Scanning Electron Microscope (FESEM)

3) Elemental Analysis

C,H,N,S

2) Surface Area

Brunauer, Emmett and Teller1) Functional groups

Fourier Transform Infra Red Spectroscopy

SEM of raw & treated PLP

Unmodified PLP Modified PLP

Rough inhomogeneous surfaces have multiple site-types available for adsorption

Lignocellulosic biomass has a complex and rigid cell wallstructure which consists of three principal biopolymers, namelycellulose, hemicellulose, and lignin.

Fiber and elemental analysisParameter Composition (%)

Cellulose 26.15

Hemicellulose 53.45

Lignin 6.93

Carbon 40.49

Hydrogen 6.45

Nitrogen 1.60

Sulfur 0.56

•Soft wood• Carbonaceous material- suitable for adsorption

Surface area of PLP

• Surface area - 8.61m²/g *(Carbonaceous materials 10-15 m²/g)

Pore size - 5.948 Angstroms (micropores)

• * micropores are directly accessible from the external surface of the fiber. Thus, Chlorpyrifos can reach adsorption sites through micropores. May ease the adsorption process.

X-ray fluorescence(XRF) of PLP

No Parameter Results (%)1 Potassium Oxide 4.942 Calcium Oxide 2.603 Chlorine 1.664 Sulphur Trioxide 1.345 Magnesium Oxide 1.076 Silicon Dioxide 1.05

Inorganics and minerals

* it can block the porosity of the carbon matrix and can preferentially adsorb water dueto its hydrophilic character, in this case reducing the adsorption of the lipophilic Chlorpyrifos.

Ash content of PLP

• Ash is the inorganic residue remaining after the water and organic matter have been removed by heating

• 8.7%• Low ash content and have advantage in

preparing adsorbent with high specific surface area

FTIR of raw PLP

Carbonyl group in hemicellulose

Hydroxyl groups,Presence of –OH groups

Aromatics groups in lignin

FTIR of modified PLP

Presence of –OH groups. The acid pre-treatment increases the concentration of the hydroxyl groups on the support.

Carboxyl groups,

pH at zero point of charge of modified PLP(pH at which the net surface charge is = 0)

0 2 4 6 8 10 120

2

4

6

8

10

12

pH finalpH initial

At this value (7.2), the adsor-bent is neutral, while it turns positively charged at lower pH values or negatively charged at higher pH values

pH drift method

Part 3 : Isolation, Screening and Biofilm development

4) Surface images

Field Emission Scanning Electron Microscope (FESEM)

3) Biofilm developemnt & degradation

Biofilm thickness, biofilm composition, isotherm, kinetics, thermodynamic

2) Screening

Chlorpyrifos tolerance, degradation, removal1) Isolation

Microclear, soil, cultured drink

Gantt Chart

Thank You

Proposed title

• Isotherm, kinetics and thermodynamic studies on combined adsorption and biodegradation of Chlorpyrifos using lignocellulosic material in Ananas comosus (Pineapple) leaf powder.

• Pesticides ingredients:-

• not really “inert” at all; they are actually more toxic than the active ingredients.

• This inert information is usually not required to be displayed on the product label by the authorities.

Active ingredients intended to kill the

target pest

Inert ingredients used as bulk carriers for active ingredients

PESTICIDES

Pineapple Leaf Powder Optical & Phase Contrast Microscope images

Reactive Red dye adsorbed onto PLP

Reactive Black 5 dye adsorbed onto PLP

Unmodified PLP Modified PLP

SEM of raw & modified PLP

* Crystalline and amorphous structures- XRD

Adsorbent Modification(Biologically Inspired Design = Biomimetics)• What? : Biomimetics is the study of the structure

and function of biological systems as models for the design of materials. It is widely regarded as being synonymous with biomimicry

• Why? : Pesticides can bioconcentrate: The primary "sink" for some pesticides is fatty tissue ("lipids"). Some pesticides, such as DDT, are "lipophilic", (fat loving) meaning that they are soluble in, and accumulate in, fatty tissue such as edible fish tissue and human fatty tissue.

Triolein -embedded PLP composed of the supporting PLP and the surrounding triolein- cellulose acetate membrane.

PLP

Triolein layer

is a symmetrical triglyceride

derived from glycerol and

three units of the oleic acid

Triolein has a high accumulating capacity for trace lipophilic chemicals. Naturally found in fatty tissues, cheap.

Pesticides / non polar NEPs

CA = useful polymer, used to combine triolein and PLP.

Triolein-embeddedACTIVATED

CARBONCELLULOSE

ACETATE MEMBRANE

LIPOID ADSORBENT

MATERIAL

BIOMIMETIC FAT CELLS

Hydrophobic nucleolus (triolein)

Hydrophilic membrane structure

(polyamide)

AtrazineNitrobenzeneLindane Dieldrin

Chlorpyrifos degradation

The degradation pathway of chlorpyrifos in aquatic environments involves the breakdown of the thiophosphoric esters, forming 3,5,6-trichloropyridinol (TCP) and desethyl chlorpyrifos (DEC) as main metabolites.

FTIR

• The region to the right-hand side of the diagram (from about 1500 to 500 cm-1) usually contains a very complicated series of absorptions. These are mainly due to all manner of bending vibrations within the molecule. This is called the fingerprint region.

• It is much more difficult to pick out individual bonds in this region than it is in the "cleaner" region at higher wavenumbers. The importance of the fingerprint region is that each different compound produces a different pattern of troughs in this part of the spectrum.

Lignocellulosic

Lignin macroporous structure

Cellulose microporous materials

Cellulose

Lignin

Adsorption kinetics

• The rate of adsorption of a molecule onto a surface

Adsorption isotherm

• For a better understanding of binding mechanism of the sorption system, between liquid and solid

• Langmuir adsorption isotherm is based on the following assumptions.

• i) Adsorption is a monolayer coverage.• ii) All the sites available on the adsorbent

surface are equivalent and the surface is perfectly uniform.

• Freundlich isotherm equation is based on the assumption that cations and anions are adsorbed onto the same surface simultaneously.

• This situation results in the formation of attractive forces between adsorbed cations and anions on the surface.

• Multi-layer adsorption can occur

Thermodynamic studies

• To study the effect of temperature • Positive values of entalphy ∆H – endothermic• Positive value of entropy ∆S confirms

possibility of favorable adsorption• Negative value of free energy ∆G – removal to

be spontaneous