Water pollution is a major problem in the global context. Several
industrial wastewater streams may contain heavy metals such as Cr, Cu, Pb, Zn,
Ni, etc. including the waste liquids generated by metal finishing or the
mineral processing industries. The toxic metals, probably existing in high
concentrations, must be effectively treated/ removed from the wastewaters. If
the wastewaters were discharged directly into natural waters, it will
constitute a great risk for the aquatic ecosystem, whilst the direct discharge
into the sewerage system may affect negatively the subsequent biological
wastewater treatment. In recent years, the removal of toxic heavy metal ions
from sewage, industrial and mining waste effluents has been widely studied.
Among the many methods available to reduce heavy metal concentration from
wastewater, the most common ones are chemical precipitation, ion-exchange,
adsorption and reverse osmosis (Chao et al., 2005).

 

            Heavy metals are
the non-degradable metals .These metals are toxic and possess high density.
Heavy metals occur in the earth’s crust naturally. Some of the heavy metals are
lead, cadmium, mercury, arsenic, chromium and thallium. High concentration of
heavy metals causes poisoning. The improper disposal of these heavy metals
leads to pollution. 

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            Heavy metals are
major pollutants in marine, ground, industrial and even treated wastewaters.
Toxic metals are often discharged by a number of industrial processes and this
can lead in turn to the contamination of freshwater. Industrial waste
constitutes the major sources of various kind of metal pollution in natural
waters. Heavy metals are dangerous because they tend to bio accumulate.
Bioaccumulation means an increase in the concentration of a chemical in a
biological organism over time, compared to the chemical’s concentration in the
environment. Compounds accumulate in living things any time they are taken up
and stored faster than they are broken down or metabolized.

 

            Any oxidizable
material present in a natural waterway or in an industrial wastewater will be
oxidized both by biochemical (bacterial) or chemical processes. The result is
that the oxygen content of the water will be decreased. Basically, the reaction
for biochemical oxidation may be written as:

 

Oxidizable material + bacteria + nutrient + O2 ? CO2
+ H2O + oxidized inorganic such as NO3 or SO4.

 

            Those biochemical
reactions create what is measured in the laboratory as the Biochemical oxygen
demand (BOD). Such chemicals are also liable to be broken down using strong
oxidizing agents and these chemical reactions create what is measured in the
laboratory as the Chemical oxygen demand (COD). Both the BOD and COD tests are
a measure of the relative oxygen-depletion effect of a waste contaminant. Both
have been widely adopted as a measure of pollution effect. The BOD test
measures the oxygen demand of biodegradable pollutants whereas the COD test
measures the oxygen demand of oxidizable pollutants.

 

            Various treatment
processes are available, among which sorption is considered to be
cost-effective if low-cost sorbents such as zeolites are used (Bailey, 1999).
Zeolites are naturally occurring hydrated alumina silicate minerals. They
belong to the class of minerals known as “tectosilicates.” Most common natural
zeolites are formed by alteration of glass – rich volcanic rocks (tuff) with
fresh water in playa lakes or by seawater (Karapinar, 2004).  The structures of zeolites consist of
three-dimensional frameworks of SiO4 and AlO4
tetrahedral. The aluminium ion is small enough to occupy the position in the
centre of the tetrahedron of four oxygen atoms, and the isomorphous replacement
of Si4+ by Al3+ produces a negative charge in the
lattice. The net negative charge is balanced by the exchangeable cation
(sodium, potassium, or calcium). These cations are exchangeable with certain
cations in solutions such as lead, cadmium, zinc, and manganese (Barer, 1987).
The fact that zeolite exchangeable ions are relatively innocuous (sodium,
calcium, and potassium ions) makes them particularly suitable for removing
undesirable heavy metal ions from industrial effluent waters.

 

            Adsorption of heavy
metal ions onto activated carbon is an efficient and well established method
for their removal from contaminated waters, but high costs limit its widespread
use. Thus, in recent years much research has been undertaken to develop
comparably effective but less expensive adsorbents. Adsorption is one of the
methods commonly used to remove heavy metal ions from various aqueous solutions
with relatively low metal ion concentrations. The efficiency of adsorption
relies on the capability of the adsorbent to adsorb metal ions from the
solutions onto its surfaces.

 

Adsorbent such as natural zeolite are cost – effective for
the removal of copper, although their modified versions tend to perform better.
It should be noted that at times this modified cation is not deliberate, but
may be a result of natural processes in environments where the adsorbents are
deployed. For instance, ammonium is one of the dominant components in aqueous
systems and may influence the surface properties of such adsorbents. The catalyst characterization was done by performing Scanning
Electron Microscope (SEM) and Fourier Transform Infrared
Spectroscopy (FTIR) test.  

 

1.1  
Problem Statement

Activated carbon usually use by chemical industry for
wastewater treatment. Activated carbon is a form of carbon processed to have
small, low – volume pores that increases the surface area available for
adsorption or chemical reactions. But the industries have to spend high cost or
to buy activated carbon. Due to this problem, some researcher found the other
alternative adsorbent which have characteristics almost the same like activated
carbon especially to remove copper (ii) ions from wastewater solutions.
Ammonium – modified zeolite are known to be effective in wastewater treatment.

 

             The purpose of this research is to remove
copper (ii) ions from industrial wastewater. 
It’s important to ensure there are no harmful heavy metals in the water
stream because it can accumulate in the environment elements such as food
chain. In this research, reused ammonium zeolites was used as an adsorbent
because of its cost. Therefore, this study will be done to observe the effect
of various parameters on adsorption by using ammonium zeolites to remove copper
(ii) ions.

1.2  
Objectives of the study

            The research project aims are to
achieve the following objectives:

·        
To characterize reused
ammonium zeolite by scanning electron microwave (SEM) & Fourier Transform
Infrared Spectroscopy (FTIR)

·        
To study the effect of
various parameters such as temperature, pH, initial concentration of copper
(ii) ions, contact time and adsorbent dosage on the adsorption from wastewater

·        
To study the
adsorption kinetic and adsorption isotherm of copper removal process

 

1.3  
Significance of the study

            The
rational of significances of this study are:

·        
To improve current research by
increasing the percentage of copper ion degradation from wastewater using
adsorption assisted by ammonium zeolite as adsorbent.

·        
To open up opportunities to
increase the demand on wastewater treatment by using adsorption assisted by
modified absorbent as proven by researchers that it’s have a lot of benefits.

·        
To prevent the copper
concentration release to the water stream which can causes foul odour and
toxicity that can be potential hazard to human health and environment.

·        
To reduce the cost of
wastewater treatment by using ammonium zeolite to assist the adsorption process
on copper ion degradation.

1.4  
Scope of the study

            In order to
achieve the objectives, all the following parameters will be studied. The main
parameters are:

Effect of pH
Effect of temperature 

Effect of adsorbent dosage/concentration
Effect of contact time
Effect of initial copper ion concentration

 

1.5  
Limitations of the study

            Ammonium zeolites
are less sensitive to moisture than activated carbon, less susceptible to
reactions that could lead to spontaneous combustion in the bed and are slower
to pulverise. If a bed fire should occur, there will not be a problem if the
temperature remains below the zeolite’s transition temperature. If the
temperature should exceed this level, then the pore size of the ammonium
zeolite will decrease, whereby the adsorption properties will change. In this
case it may be necessary to replace part of the zeolite (Elisee, 2015)

 

1.6  
Chapter conclusion

Copper is the most prevalent metal, as it is used in
industrial production, metal mechanic factories, and even food production.
Although tiny amounts of copper are essential for human health, excess amounts
can cause adverse health effects, including nausea and gastrointestinal
problems. Despite the laws created to limit pollution, excess copper still
exists in many bodies of water, making it imperative that we find ways to
safely remove it. Adsorbent such as natural zeolite are cost – effective for
the removal of copper, although their modified versions tend to perform better.
It should be noted that at times this modified cation is not deliberate, but
may be a result of natural processes in environments where the adsorbents are
deployed. For instance, ammonium is one of the dominant components in aqueous
systems and may influence the surface properties of such adsorbents.

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