Suitability of SBR for Wastewater Treatment and Reuse: Pilot-Scale Reactor Operated in Different Anoxic Conditions.

The present study investigates the performance of a pilot-scale Sequencing Batch Reactor (SBR) process for the treatment of wastewater quality parameters, including turbidity, total suspended solids (TSS), total solids (TS), nitrogen (ammonia (NH3-N), nitrite (NO2-), and nitrate (NO3-), phosphate (PO43-), the chemical oxygen demand (COD), and the 5-day biological oxygen demand (BOD5), from municipal wastewater. Two scenarios, namely, pre-anoxic denitrification and post-anoxic denitrification, were investigated to examine the performance of a pilot-scale SBR on the wastewater quality parameters, particularly the nitrogen removal. The correlation statistic was applied to explain the effects of operational parameters on the performance of the SBR system. The results revealed that the post-anoxic denitrification scenario was more efficient for higher qualify effluent than the first scenario. The effluent concentrations of the targeted wastewater quality parameters obtained for the proposed SBR system were below those of the local standards, while its performance was better than that of the North Sewage Treatment Plant, Dharan, Eastern province, Kingdom of Saudi Arabia (KSA), in terms of the BOD5, COD, TN, and PO43- treatment efficiencies. These results indicated the suitability of SBR technology for wastewater treatment in remote areas in the KSA, with a high potential of reusability for sustainable wastewater management.

Corrigendum to "Effect of Carboxylic Functional Group Functionalized on Carbon Nanotubes Surface on the Removal of Lead from Water".

[This corrects the article DOI: 10.1155/2010/603978.].

Effect of carboxylic functional group functionalized on carbon nanotubes surface on the removal of lead from water.

The adsorption mechanism of the removal of lead from water by using carboxylic functional group (COOH) functionalized on the surface of carbon nanotubes was investigated. Four independent variables including pH, CNTs dosage, contact time, and agitation speed were carried out to determine the influence of these parameters on the adsorption capacity of the lead from water. The morphology of the synthesized multiwall carbon nanotubes (MWCNTs) was characterized by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) in order to measure the diameter and the length of the CNTs. The diameters of the carbon nanotubes were varied from 20 to 40 nm with average diameter at 24 nm and 10 micrometer in length. Results of the study showed that 100% of lead was removed by using COOH-MCNTs at pH 7, 150 rpm, and 2 hours. These high removal efficiencies were likely attributed to the strong affinity of lead to the physical and chemical properties of the CNTs. The adsorption isotherms plots were well fitted with experimental data.

Investigation of the electro-coagulation treatment process for the removal of total suspended solids and turbidity from municipal wastewater.

In this work, raw municipal wastewater was electro-coagulated for the removal of total suspended solids (TSS), turbidity, and particulate BOD using stainless steel electrodes. The removal efficiency of TSS and turbidity is shown to depend on the amount of iron generated from the anode of the reactive electrode used in this study, when applying the lower currents of 0.05 A and 0.1A. For such lower currents, the results suggested that the removal is consistent with charge neutralization coagulation mechanism. When applying higher currents of 0.2 A, 0.4 A, and 0.8 A, the results suggested that the dominant removal mechanism is sweep-floc coagulation as the generated soluble ferrous ions are converted to insoluble ferric ions due to oxidation with chlorine generated during the electrochemical process at the higher currents. The highest TSS removal efficiency of 95.4% occurred at a current of 0.8A and contact time of 5 min. The effect of electro-coagulation on the removal of particulate BOD was shown to depend on the TSS removal efficiency.