Ibrahim Gar Al-Alm Rashed

Optimization of chemical precipitation to improve the primary treatment of wastewater

AbstractChemically enhanced primary treatment (CEPT) is a wastewater treatment method that serves as an attractive alternative to the conventional primary treatment, and it can also be used as an efficient preliminary step of the biological secondary treatment processes. CEPT adopts coagulation and flocculation and it accomplishes remarkable increases in the removal of common pollutants from the influent. The coagulants used in the present study were alum, sea-salt as a cheap coagulant, and homogenous mixtures of sea-salt (as a coagulant aid) and alum with different doses.These alternatives were tested in the direct precipitation of wastewater. The analytical hierarchy process was applied for the evaluation of different alternatives of coagulants according to four main criteria (i.e. removal efficiencies, sludge volume after 30 min, coagulant cost, and pH variation). In addition, the removal efficiencies were divided into five subcriteria, including COD, BOD5, TSS, T–P, and T–N removals. The obtained resu...

NOVEL SULPHOARYLAZO 4-PYRAZOLONE-BASED TARTRAZINE DYE ANALOGUES

In a multistep synthesis, a novel series of 4-pyrazolone–based tartrazine dye analogues were prepared benzimidazol-5-yl acetoacetamide derivative I. Chemical structure of the hitherto prepared dyestuffs were confirmed on the basis of correct elemental analysis as well as spectral data. The degree of exhaustion of the hitherto synthesized 3-[2-(oxoimidazo-5-yl) carboxamido] tartrazine dye analogues was determined and found to be in the range of 92.6–97.8%. The latter high ratios might be ascribed to the presence of the cyclic amide function in structure of these dyestuffs.

Anchored Synthesis for Some Novel Mono and Disarylazo 1,2,4-Benzothiadiazine-Based Dyestuffs as Alternatives for Benzidine-Based Dyes

A one mono and two disarylazo series of 1,2,4-benzothiadiazine-based dyestuffs has been synthesized with a view that these products, with their new all-round tinctorial properties, might find an application as new categories of direct dyes that satisfactorily replace prohibited benzidine-based dyes. The assigned structures for the hitherto prepared dyes were confirmed on the basis of elemental analysis as well as spectral data and, whenever possible, by alternative synthetic routes. Moreover, the predominant tautomeric structures for these highly colored products were tested and discussed on the basis of their spectral behavior.