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ABSTRACT

Natural polymers with improved structure have been securing increasing value in the industry as they

are abundant, cheap, and biodegradable. Graft copolymerization is one of the effective ways to

enhance the properties of natural polymers. Starch based graft copolymers are becoming increasingly

important due to their remarkable adhesion, high water absorbency, and biodegradability. Methyl

methacrylate (MMA) grafted onto starch by using the ceric ammonium nitrate (CAN) as a redox

initiator in the presence of nitric acid in aqueous medium to form grafted copolymer (Starch-g-

PMMA) was investigated. The grafting reaction was carried out under stream of nitrogen gas. The

impact of different reaction parameters to achieve the highest percent grafting (%G) has been studied

by determining the initiator concentration, monomer concentration, time (hours), nitric acid

concentration, and polymerization temperature. The % G was found to be 97%. Evidence of grafting

was characterized and confirmed by Fourier transform infrared spectroscopy (FTIR). The peaks at

1736.70 cm-1 and 3449.78 cm-1 indicates that MMA has been successfully grafted to starch. %G was

found to be decreased at higher than 70°C, after 2 hours of reaction time, with an increase of MMA

monomer concentration, initiator concentration, and with HNO3 concentration. The highest percent

grafting was obtained at the parameters of 1 g starch, 70°C, 2 hours, 2 mmol CAN, 140 mmol MMA

and 0.4 mmol HNO3

Abstract:

This study investigated the potential use of olive pomace (OP) as an adsorbent to

reduce the concentration of methyl orange (MO) in aqueous solutions. The effect of

some important parameters on the process of adsorption was examined, including

pH, adsorbent weight, temperature, contact time, agitation speed, and the initial

concentration of MO. The results showed that the optimum concentration of MO was

10 ppm and the optimum pH = 2, indicating that the process of MO adsorption on the

surface of the OP was better in acidic medium. The equilibrium time was 80 min at a

speed of 100 rpm. The results of the study showed the significant role of OP weight,

agitation speed, temperature and the contact time in increasing the adsorption

efficiency. On comparing the pseudo first order and pseudo second order models, the

results showed that the pseudo second order model fitted the experimental data well.

The study also included testing of Langmuir and Freundlich models on the

adsorption isotherm data, and it was found that experimental data obey the

Freundlich isotherm. To sum up, the study showed that OP has high adsorption

efficiency to remove MO by applying a simple, inexpensive method.

Abstract- Many methods have been applied in order to reduce nitrate concentration in aqueous solutions, among them

is the adsorption onto the surface of agricultural wastes. In this study, batch experiments were carried out to investigate

the adsorption of nitrate onto olive pomace (OP), a solid by-product of olive oil industry. To achieve this, six parameters

were studied by varying only one parameter at a time. These parameters were the effect of: pH, contact time,

temperature, adsorbent weight, agitation speed and nitrate concentration. The optimum pH was found to be 5, while the

optimum time was 75 minutes. Nitrate removal percentage was found to increase with increasing adsorbent weight or

temperature, with 92.5% of nitrate removed by using 2 g of OP and 48% of nitrate was removed at 60ºC. Generally,

agitation speed increased the nitrate removal percentage, while high initial concentration of nitrate was found to decrease

its removal percentage. These findings, combined with the low cost of OP and its abundance, suggest that OP is a

potential adsorbent for nitrate removal provided that the optimum conditions are applied. Applying this method for

nitrate removal will make drinking water safer to drink and wastewater safer to discharge.