Osama Eljamal

Wastewater degradation by iron/copper nanoparticles and the microorganism growth rate

Nowadays, trends in wastewater treatment by zero-valent iron (ZVI) were turned to use bimetallic NZVI particles by planting another metal onto the ZVI surface to increase its reactivity. Nano size zero-valent iron/copper (NZVI/Cu0) bimetallic particles were synthesized in order to examine its toxicity effects on the wastewater microbial life, kinetics of phosphorus, ammonia stripping and the reduction of chemical oxygen demand (COD). Various concentrations of NZVI/Cu0 and operation conditions both aerobic and anaerobic were investigated and compared with pure NZVI experiment. The results showed that addition 10mg/L of NZVI/Cu0 significantly increased the numbers of bacteria colonies under anaerobic condition, conversely it inhibited bacteria activity with the presence of oxygen. Furthermore, the impact of nanoparticles on ammonia stripping and phosphorus removal was also linked to the emitted iron ions electrons. It was found that dosing high concentration of bimetallic NZVI/Cu0 has a negative effect on ammonia stripping regardless of the aeration condition. In comparison to control, dosing only 10mg/L NZVI/Cu0, the phosphorus removal increased sharply both under aerobic and anaerobic conditions, these outcomes were obtained as a result of complete dissolution of bimetallic nanoparticles which formed copper-iron oxides components that are attributed to increasing the phosphorus adsorption rate.

Evaluation of nano zero valent iron effects on fermentation of municipal anaerobic sludge and inducing biogas production

The application of nano size materials on wastewater is going extensive because its high reactivity compared with other materials. As a result, numerous research studies investigated the effectiveness of dosing nano zero valent iron (nZVI) or micro zero valent iron (mZVI) on anaerobic digestion (AD) of sludge and production of biogas as promising renewable energy but inconsistent outcomes have appeared. In this paper, different dosing concentrations of nZVI were applied on anaerobic activated municipal sludge to examine the impact of nZVI on sludge fermentation, biogas generation, and methane (CH4) content stimulation. The results showed that addition 250 mg/L nZVI nanoparticles could enhance 25.23% biogas production and the methane content reached 94.05% after one week of digestion compared with 62.67% without adding iron nanoparticles.

Product Rich in Phosphorus Produced From Phosphorus-Contaminated Water

The study investigates the capacity of different soils and byproduct materials on removal of phosphorus from water. The aim of this study has been drawn to gain a product rich in phosphorus, which can be recycled by the phosphorus industry or may directly be used as a fertilizer. For the development of this phosphorus removal and recovery method, batch and column experiments were carried out in the laboratory scale to evaluate the removal of phosphorus from water under dynamic conditions. Three columns were filled with mixed soils and marble dust and loaded with a phosphorus solution 100 mg/l concentration. The results showed that using the marble dust as adsorbent among other materials could be removing more than 93% of phosphorus from aqueous solution.

Repetitive Project Modelling With Penalty and Incentive

Repetitive construction activities have the same activities which are performed repeatedly. Repetitive projects include: pipelines, highways, and multi-story buildings. Repetitive projects have been modelled widely using the traditional network techniques although, they have some disadvantages. Furthermore, different approached have been developed for repetitive activities including the graphical and analytical techniques. The objective of this research is to add new enhancements on an approach called Repetitive Project Model (RPM) which is related to the repetitive construction projects. The enhancements incorporating the incentives and penalties within the RPM. This model incorporates a network technique, a graphical technique, and an analytical technique. A numerical example was demonstrated in this research paper to aid on using the suggested model in the real-life application.

Performance of nanoscale zero-valent iron in nitrate reduction from water using a laboratory-scale continuous-flow system

Nanoscale zero-valent iron (nZVI) is a versatile treatment reagent that should be utilized in an effective application for nitrate remediation in water. For this purpose, a laboratory-scale continuous-flow system (LSCFS) was developed to evaluate nZVI performance in removal of nitrate in different contaminated-water bodies. The equipment design (reactor, settler, and polisher) and operational parameters of the LSCFS were determined based on nZVI characterization and nitrate reduction kinetics. Ten experimental runs were conducted at different dosages (6, 10 and 20 g) of nZVI-based reagents (nZVI, bimetallic nZVI-Cu, CuCl2-added nZVI). Effluent concentrations of nitrogen and iron compounds were measured, and pH and ORP values were monitored. The major role exhibited by the recirculation process of unreacted nZVI from the settler to the reactor succeeded in achieving overall nitrate removal efficiency (RE) of >90%. The similar performance of both nZVI and copper-ions-modified nZVI in contaminated distilled water was an indication of LSCFS reliability in completely utilizing iron nanoparticles. In case of treating contaminated river water and simulated groundwater, the nitrate reduction process was sensitive towards the presence of interfering substances that dropped the overall RE drastically. However, the addition of copper ions during the treatment counteracted the retardation effect and greatly enhanced the nitrate RE.

Treatment and regeneration of nano-scale zero-valent iron spent in water remediation

Nano-scale zero-valent iron (nZVI) has shown its promising treatment technique to decontaminate nitrate from water. However, research reports lack the treatment and regeneration of the spent reagent from the treatment process. This research utilized different derivatives of nZVIs in the purpose of nitrate treatment in its aqueous solution to show their different reactivities in applied batch experiments. Selected nanoparticles were investigated via transmission electron microscopy, surface characterization analyzer, X-ray diffraction and laser-scattering particle size analyzer. The fresh synthesized nZVI had the highest performance with complete nitrate removal within 60 min. Treated nZVI succeeded to regain the lost reactivity of aged nZVI and boosted its removal efficiency 10 times. On the other hand, the regenerated nZVI, recovered from spent synthesized nanoparticles, regained full and complete removal efficiency of nitrate, the same as the synthesized nZVI. The obtained result gives a great competitiveness of nZVI reagent to treat nitrate against any other treatment technology.

Practice of Mass Transport Model Application for Biogeochemical Redox Process in Aquifer

Biogeochemical reduction processes are active in alluvial aquifers, because organic carbon which is indispensable for bacteria growth is abundant. As a result of reduction process, significant changes of groundwater quality take place; denitrification, reduction of manganese dioxide, iron-hydroxide, sulfate, arsenate, and methane are well known as reduction processes in an anaerobic groundwater condition. Therefore, the prediction of redox environment in an aquifer is a key subject in order to understand how the groundwater quality is affected. If the mechanism of groundwater quality formation in aquifer scale is systematically understood, impacts caused by accidents or illegal dumping can be predicted, and subsequently, an appropriate management of aquifer will be established. In the present paper, quantitative discussions are made by the numerical simulations applied for the one-dimensional column experiment and two-dimensional fresh-salt water mixing zone. Recommendation and the future subject are presented through the results of two numerical simulations.