Phytoplankton assemblage of a solar saltern in Port Fouad, Egypt

The present study is the first investigation of the phytoplankton community inone of Egypt's saltworks. The phytoplankton composition and distribution infive ponds of increasing salinity were investigated in the solar saltern of Port Fouad.The phytoplankton community consisted of 42 species belonging to cyanobacteria(16), diatoms (12), dinoflagellates (11), Euglenophyceae (2) and Chlorophyceae (1).The number of species decreased significantly and rapidly with increasing salinity,varying between 33 species in the first pond (P1) and one species in the crystallizerpond (P5). Conversely, the total phytoplankton density, except that recordedin P1, increased significantly with rising salinity, fluctuating between 8.7 and56 × 105 individuals l-1 in P2 and P5 respectively. In spiteof the local variations in climate and nutrient availability, the phytoplankton composition, density and spatialvariations along the salinity gradient were, in many respects, very similar towhat has been observed in other solar saltworks. The pond with the lowest salinity(P1 - -1) was characterized by a significant diversity andblooming of diatoms and dinoflagellates. Intermediate salinity ponds (P2 andP3) with salinity ∼ 112-180 g l-1 exhibited a decline in bothspecies richness and density, but the stenohaline blue green algae (Synechocystis salina) did flourish. The highly saline concentrating ponds andcrystallizers (P4 and P5) with salinity ∼ 223-340 g l-1 werecharacterized by few species, the disappearance of blue green algae and thethriving of the halotolerant green alga Dunaliella salina

HPLC-MS/MS Mechanistic Study of Direct Yellow 12 dye Degradation Using Ultraviolet Assisted Ozone Process

HPLC-MS/MS degradation mechanism of Direct Yellow 12 (DY-12) dye using O3 associated with UV was studied. The influent of different conditions such as pH, initial DY-12 dye concentration and reaction time were studied in a batch reactor method. The results revealed that the pH value and DY-12 initial concentration controlled the removal process. The maximum color removal was achieved in alkaline condition (pH 9) as compared to neutral or acidic conditions. The color removal of DY-12 dye followed the first-order kinetics. When UV was applied with ozone simultaneously, the first order rate constant (kd) increased, and the time of dye decolorization shortened to 10 min for 200 ppm dye concentration. These results indicated that the application of UV can reduce the reaction time and dose of ozone. Gas chromatography-mass spectrum and HPLC-MS/MS analyses of the treated synthetic dye solution at the end of the treatment time showed no toxic organic compounds were detected. The COD decreased by more than 85% of the initial COD of the untreated DY-12 dye concentration