Thamer Ahmad Mohammad

Effect of Stabilizer Reagents on Zeta Potential of Kaolinite and Its Relevance to Electrokinetic Treatment

The influence of the dispersion of pH and concentration of chemicals on zeta potential of kaolinite were investigated. Adding the cationic species led to an increase of the zeta potential, contrary to measuring done in water. The results proved that even a very low concentration of the cationic species (0.001 mol/L) causes a remarkable change of the zeta potential. The zeta potential of the kaolinite soils varied from 204.6 to −41.9 mV, according to the chemical reagents and electrolyte concentration. Moreover, the negative charge in kaolinite soils is highly pH dependent and surface charge of pure kaolinite is dropped to zero, (pHpzc) at pH 3.2–3.5. The greater electrolyte concentration resulted in the thicker diffuse double layer and higher pH at the iso-electric point. While, for some reagents there was no isoelectric point that to be observed, increase the pH at isoelectric point and Na2CO3 as well as CH3COONa led to decrease in pH at iso electric point of suspension kaolinite. Results revealed that presence of low molecular weight CaCl2, , H3PO4, Na2Sio2, CH3COONa, and Na2CO3 led to a increase in diffuse double layer thickness in order of CaCl2, , Na2CO3 and H3PO4, and Na2SiO4, and electrolyte concentration has important effect on such incrasing. Based on results of ζ and pH observed from using different cationic species, those pHpzc which are more close to the soil pH (ζ is dropped to zero) are more succeptible to be chosen as best reagent to stabilizing soil.

Coagulation activity of spray dried salt extracted Moringa oleifera

Abstract A study on the effectiveness of salt extracted Moringa oleifera seeds as a coagulant for turbidity removal in water treatment process under different operational parameters (configurations) of spray drying, storage, and packaging conditions is presented. The operational parameters were inlet temperature, outlet temperature, and pumping rates. The coagulation activity was studied for the spray dried salt extracted M. oleifera which is stored under two different conditions, room temperature (29°C) and refrigerator (3°C), and two different packaging forms, closed container and vacuum packed. Eight configurations for operational parameters were used in this study. The results show that for inlet temperature below 115°C the spray drying process failed to produce dry powder. For the successful configurations, there was no significant difference in coagulation activity between different configurations stored at the same storage and packaging conditions. However, the comparison of the coagulation activit...

Effect of the packaging and storage conditions on the coagulation activity of spray-dried salt-extracted Moringa oleifera

Abstract Moringa oleifera is one of the natural coagulants considered as an alternative to synthetic coagulants. Several studies were carried out on the usage and extraction of this natural coagulant. In this study, the coagulation activity of spray-dried salt-extracted M. oleifera seeds powder was investigated under different storage conditions, packaging forms and storage duration. The spray-dried salt-extracted M. oleifera seeds powder was stored at room temperature (29°C) and refrigerator temperature (3°C); under different packaging forms; closed container and vacuum packed stored for 6 weeks. Optimization of spray-dried salt-extracted M. oleifera shows that the optimal dosage is half of the nonspray-dried salt-extracted M. oleifera. The results of residual turbidity of different packaging and storage conditions of salt-extracted M. oleifera show that there was no significant difference between them. The coagualtion activity decreased insiginficantly with the increase of storage duration during the study.

Effectiveness of salt-extracted freeze-dried Moringa oleifera as a coagulant

The effectiveness of freeze-dried Moringa oleifera (MO) seeds powder in the coagulation of synthetic wastewater was studied. Three modes of extraction were introduced, namely distilled water-extracted freeze-dried M. oleifera (FD-DW MO), salt-extracted freeze-dried M. oleifera (FD-KCl MO), and distilled water-extracted freeze-dried M. oleifera with salt addition (FD-DW MO + KCl). Jar test was used to evaluate the effectiveness of the extracted freeze-dried powder, in the coagulation of a synthetic municipal wastewater. The results show that FD-DW MO at an optimal dosage of 132 mg/l, increases the turbidity removal efficiency to nearly 93% as compared to distilled water-extracted MO which gave 76% removal at an optimal dosage of 300 mg/l. However, the comparison of FD-KCl MO with non-FD-KCl MO show that the freeze-drying neither improves the efficiency of salt-extracted M. oleifera nor the optimal dosage. On the other hand, adding KCl to the FD-DW MO in treating high turbidity synthetic wastewater at 200 ± 5 NTU improved the optimal dosage from 40 mg/l (without adding KCl) to 10 mg/l corresponding to 91% removal efficiency. As a conclusion, the freeze-drying process did not improve the coagulation efficiency with salt-extracted MO using KCL. But using the salt (KCL) solution for dilution of FD-DW MO causes the optimal dosage to decrease from 40 mg/l (using distilled water for dilution) to 10 mg/l. This is associated with a slight decrease in the efficiency from 92.73 to 91.32%.

Dual polyelectrolytes incorporating Moringa oleifera in the dewatering of sewage sludge

AbstractOne of the main costly problems at wastewater treatment plants is the treatment of sludge, which is responsible for about 50% of the total operating cost of the whole treatment system. Chemical conditioning of sludge before dewatering is often necessary to increase the process efficiency of dewatering devices. Moringa oleifera seeds were evaluated as an alternative natural conditioning material during dewatering; as a single conditioner and as a base conditioner in dual polyelectrolytes conditioning (using Zetag 8140) for sewage sludge dewatering. The sewage sludge used in the experiments was collected from a sludge holding tank of the treatment plant located in Taman Shamelin Perkasa, Kuala Lumpur, while the M. oleifera seeds were collected from Serdang, Selangor, and stored in a room temperature for not more than 3 d, and then the quality seeds were identified and used. The preparation of the stock solution will start with placing the seeds in the oven for 24 h at 50°C. After drying, the seeds w...

Assessment of using synthetic polymers in dewatering of sewage sludge

This study was carried out to identify the optimum dosage of different types of polymer for sewage sludge conditioning to achieve high dewaterability. The sludge conditioners used in this study were synthetic polymers; cationic polymer (Magnafloc LT 22S), anionic polymers (Magnafloc LT 25 and Magnafloc LT27), and nonionic polymer (Magnafloc LT 20). Sewage sludge samples were collected from the holding tank of the treatment plant located at Taman Tun Dr Ismail, state of Selangor, Malaysia. Different laboratory tests were carried out to determine the effectiveness of each polymer in conditioning the sewage sludge and to obtain the best conditioner. In this study, the optimum conditions for sludge dewatering were determined from the results of laboratory experiments conducted on polymers with different dosages, mixing speeds, and mixing durations. Laboratory experiments conducted for this purpose include capillary suction time (CST), specific resistance to filtration (SRF), and zeta potential. Measurement of CST and SRF on the cationic polymer showed that the optimum condition was obtained when mixing duration was 4.5Â min, polymer dosage at 5.3Â mg/L and mixing speed of 83Â rpm. The zeta potential values indicated cationic polymer managed to reduce the charge; however, the anionic polymers were not effective in causing any neutralization. At optimum condition, the zeta potential values are expected to be near to zero.

Assessment of using hollow fibre microfiltration in treating lake water

The main objective of this study was to determine the reliability of using microfiltration system which is composed of a coagulant such as ferric chloride (pretreatment substance) and hollow fibre membrane as filtering medium for improving water quality. In this study, raw water samples were collected from a lake located at the Faculty of Engineering, Universiti Putra Malaysia. The experiments were carried out in three stages: the first stage used distilled water, the second stage used lake water stored in a tank and the third stage used lake water stored in the tank and mixed with ferric chloride as coagulant. A storage tank and a separation tank were used; the storage tank is used to store water pumped from the lake (used in the second stage) while in the third stage, the stored water in tank was used for pretreatment or coagulation with optimum dosage of ferric chloride (determined from jar test). The experimental results show that the flux obtained from second and third stages was low. For lake water stage, the best flux was found to be 4.97 l/m2/h. The distilled water stage shows that shaft rotational speed of peristaltic pump was one of the factors affecting the flux. Therefore, a pump shaft rotational speed of 7 rpm was chosen based on flux and suction pressure. The experimental results show the ability of microfiltration using hollow fibre membrane together with ferric chloride as coagulant to produce treated water with 97% turbidity removal and 85% removal of total suspended solids (TSS). For treated raw water, it is found that the removals of TSS were ranged from 71.7 to 91.6% when alum was used as a coagulant while the TSS removals were ranged from 74.4 to 89.20% when ferric chloride was used as a coagulant. In this study, it is found that the optimum dosages of ferric chloride and alum were 4 and 20 mg/l, respectively. Although the percentage removal of TSS is slightly higher when alum is used as a coagulant compared with using ferric chloride, it is recommended to use ferric chloride as a coagulant due to its economical and health advantages. Furthermore, ferric chloride can be used in wide range of pH values while alum can only be effective when pH value around 7.