Utilisation of factorial experiments for the UV/H2O2 process in a batch reactor

Factorial experiments provide a comprehensive understanding of the impact of operational variables on process performance. Utilisation of the Hadamard matrix taking into account all interaction effects, appeared to be efficient for giving a mathematical model that conformed to criteria validity. The predictions given by the factorial experiments model were confirmed by the experiments. Phenol oxidative degradation kinetics were not significantly influenced by pH or hardness of the solution to be treated, as is predicted by factorial experiments. On the other hand, initial H2O2 concentration, initial phenol concentration and temperature significantly influenced the efficiency of the process. Optimal values were determined: a temperature of about 20°C and a CH2O2/Cphenol ratio of 120 (mg/mg). WaterSA Vol.27(4) 2001: 551-55

Economic study of groundwater defluoridation of the North African Sahara

The economic evaluation of defluoridation of Sahara groundwater is presented for three processes: electrodialysis, reverse osmosis and the electrochemical bipolar reactor (EBR). The economic study was accomplished for a drinking water unit production of 100 m3/h. One of the findings was that the costs per cubic metre of treated water obtained with different processes were not too costly for the states of the North African region. The results also indicated that the most efficient process uses the EBR, followed by the electrodialysis and reverse osmosis process. However, the water produced by the first process does not have the required quality for drinking water; therefore, it has to be utilised for agricultural purposes. On the other hand, the electrodialysis unit do produce quality drinking water and appears to be an interesting solution to the fluorisis disease. Reverse osmosis method technique provides higher quality of drinking water with a salinity not exceeding 0.1 gsalts/l

Role of desalination technologies and water reuse in Water-Energy-Food nexus:an opportunity for Algeria

Water resources in Algeria are scarce, often low quality, fragile, and unequally dispersed over time and space. The pressure on water resources can be associated with industrial development, a steady population growth, and demanding land irrigation measures. These conditions create a tense competition for managing water resources and sharing them between agricultural development, drinking water supply, industrial activities etc. Water treatment and reuse for agriculture is common in some countries. For example, in Spain, 71% of wastewater is used for the agricultural industry. In addition, the effect of climate change has brought national policies focused on the water-energy-food nexus (WEF) to the forefront. Within this context, desalination membrane technologies could play an increasing role for supporting segments of the Algerian economy that are heavily water dependent. In addition, by using renewable energies, such as solar energy in desalination, we would be taking advantage of Algeria’s great potential, estimated at 13.9 TWh/y. By implementing water reuse and desalination strategies together in the agricultural sector, there is an opportunity to expand the access to healthy food and clean water, thereby keeping the WEF nexus effects under control. As well, effective use of energy potential for food use will be a step forward for economic growth in Algeria

Economic study of the treatment of surface water by small ultrafiltration units

The purpose of this work is to evaluate the possibility of utilising an ultrafiltration process for the treatment of water from the dam in the Kabylia region of Algeria and, in particular, for the provision of drinking water to people living in dispersed small villages. The water quality was determined by measuring turbidity, and natural organic matter concentration. The results obtained with an ultrafiltration process indicate that this technique can considerably reduce suspended and organic matter. It also improves the bacteriological quality of the treated water. An economic evaluation for ultrafiltration of surface water is presented. The economic study was performed for a drinking water unit of 20 m3/h . It was found that the cost per m3 of treated water ($ 0.235/m3) obtained would not be excessively high for the states of the North African region. WaterSA Vol.27(2) 2001: 199-20