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Based or) the results of a batch study, a bench‐scale pilot plant study was conducted to determine the improvements in effluent quality of secondary treated wastewater using ferrate (VI) and ozone with primary objective of achieving coliform level of 2.2 MPN/100 ml for reuse purposes. The batch study showed that a ferrate dose of 15 mg/L gave effective removal of turbidity, COD, and coliform. Therefore, in a continuous flow study a mixture of ferrate stock solution and secondary effluent at a flow rate of 250 ml/min, was subjected to ferrate (15 mg/L) coagulation and flocculation for 45 min followed by sedimentation, filtration, and ozonation. Ozone gas was allowed to react for 5 min in a contactor for an ozone utilization of 1–5.8 mg per liter of the effluent with resulting ozone residual (peroxide) of 0.4–1.9 mg/L. This treatment has shown a significant improvement with respect to removal of suspended solids (70.8&percent;), turbidity (78&percent;), besides achieving the desired level of disinfection (total coliform 99.99941&percent; and total plate count 99.99&percent;).

Three physico-chemical treatment schemes investigated in this study include: (i) lime precipitation, and ozonation-(ii) lime precipitation followed by ferrate treatment, filtration, and ozonation, and (iii) ferrate treatment followed by filtration, and ozonation. It was found that lime treatment followed by ozonation produced comparable effluent to the secondary treatment while other two schemes provided similar or better degree of treatment, however, the operation and maintenance of these two systems were more complex.

Three regional sources of freshwater around Saudi Arabia are identifed: the Indus River in Pakistan, the Nile River in Sudan and Egypt, and the Euphrates and Tigris Rivers in Iraq. Transportation costs are calculated using tanker shuttle service, in which case tankers are used exclusively for the transportation of freshwater between loading and unloading ports. The average water transportation costs from Karachi to Dammam, Port Sudan to Jeddah, and Suez to Jeddah are $0.79, $0.29, and $0.61 m3, respectively, in a 300,000‐dwt tanker. Reported transportation costs through backhaul service (return cargo) are $1 and $2/m3 at worldscales of 30 and 60, respectively. These costs compare favorably with desalination costs of $1.54−$4.5/m3 in Saudi Arabia. Using these unit costs, four scenarios are discussed for transportation of 910,000 m3 of water/day through different schemes. Water transportation from Pakistan appears to be the most cost‐effective of the alternatives and can be made operational at short notice with a small capital investment.

A study was conducted to determine the effects of ozonation on the removal of iron(II) and manganese(II) at different pH values in a pure water system. It has been found that the rates of oxidation of iron(II) and manganese(II) follow a 7.ero-order reaction. The respective values of detention time and applied ozone dosage for removal of 4 mg/L of iron(II) were 10-15 min and 3-5 mg/L, as compared to 20-30 min and 4-6 mg/L for the removal of 4 mg/L of manganese(II). No iron(II) and manganese(II) were detected in the pure water system above the pH values of 7 and 9, respectively.