Vol. 7 Issue 3
R.M. Natour, Fawzi M. Rayyan and S. El-Bitar
Al Samra Stabilization ponds is one of the largest waste water treatment plants in the world. This plant is formed of three parallel trains, each formed of two anaerobic, four facultative and four maturations ponds. It was designed to handle an average flow of 68000 M3/ day-1. The main disadvantage to the operational capabilities of the stabilization ponds is the heavy populations of algae which frequently occur in the effluents; however, algal populations that develop in the ponds play an essential role in their efficient operation. The production of algae within the ponds represents the reverse of the process which is normally considered to be that of waste stabilization.
Algal production was studied both on a mass and on a count basis. The maximum algal count recorded was 3.0 x 10^10 cells/l in pond M-3 at 250 mm below the surface. Throughout the study period, Chlamydomonas was the most abundant algal genus in the ponds, Euglena appeared during November and December, while Chlorella appeared in low numbers during April and May. Hydrogen ion concentrations in the ponds ranged from 7.0 to 8.6, which is suitable for algal growth.
Dissolved oxygen in the ponds was very low to zero due to high oxygen demand in the system.
Old algae for yellow color, low chlorophyll content and low activity, appeared in the ponds due to increase in light intensity. Efficiency of treatment achieved in terms of BOD removal was as high as 97% for filtered saamples and 87% for nonfiltered samples.
M.H. Mona and F.A.M. Shoukr
Five species of amphipods belonging to the genus Corophium are known from the Suez Canal (Egypt). Among these a new species (Corophium bidentatum n.sp.) is described and illustrated. Two species namely: C. sextonae Crawford and C. insidiosum Crawford are recorded for the first time in the Suez Canal. A key is provided for the identification of the known species of Corophium in the Suez Canal.
Sabri, A.W., Mahmoud, A.S. and Maulood, B.K.
The population of cladocera has been investigated in Tigris river from January 1983 to January 1984. A total of 33 species were identified. The dominant species were Bosmina coregoni, B. longirostris, Ceriodaphnia rigaudi, Macrothrix laticornis and Alona rectangula. A maximum of 163 x 10^3 m-3 was recorded. Late Summer and Autumn were found to be the best growth seasons. Upper stream stations were characterized with small number of species, mostly of benthic origin and lower population density. The effects of Samarra impoundment are shown in the results. Variations between stations along the river were evident and are discussed.
Ramsis G. Lutfy and Hammed Al-Hajj
The spermiogenesis of Siphonaria laciniosa (Gastropoda, Pulmonata) was studied by electron microscopy. Some of the most drastic changes comprising the process of spermiogenesis involve the nucleus which undergoes a series of changes affecting its shape, size, differentiation of various regions of its envelope, and progressive condensation of its chromatin. Active nucleo-cytoplasmic exchange seems to take place in the various phases of the process especially in its early stages. The various shapes acquired by the nucleus are described in detail, and are taken as salient points in the continuous process of spermiogenesis. These stages are: the "urn" stage; the" hammer head" stage; the "hazel-nut" stage; and the "spearhead" stage. Many of the morphological transformation exhibited by the nucleus, especially those of the later phases of spermiogenesis are effected by microtubules.
N. Alandis, I.Rico, F. Couderc, E. Perez and A. Lattes
Formamide microemulsions, largely studied in this laboratory, have been used as reaction media for the oxidation of olefins to carbonyl compounds with palladium (II) chloride, better known as the Wacker process. This reaction is generally slow and gives poor yields in ketones especially with internal olefins in biphasic medium. In formamide microemulsions, faster oxidation rates have been observed. Moreover better yields in ketones have been obtained with internal olefins, with better selectivity in methyl ketone as the main product.