Determination, occurrence, and treatment of saccharin in water: A review

Saccharin (SAC) is an emerging contaminant, widely detected in the environment, with potential ecotoxicity risks to aqueous organisms and human beings. Wastewater treatment plants (WWTPs) are key sources and sinks of SAC, and play a vital role in eliminating SAC entering the environment. An overview is provided of the potential ecotoxicity of SAC, its occurrence in the aqueous environment, and its degradation performance in WWTPs. SAC treatments, including physical, chemical (mainly advanced oxidation processes AOPs), biological, and hybrid processes, and possible degradation mechanisms are also considered. Of the various SAC removal processes, we find that adsorption-based physical methods exhibit relatively poor performance in terms of SAC removal, whereas chemical methods, especially hydroxy radical-mediated oxidation processes, possess excellent capacities for SAC elimination. Although biological degradation can be efficient at removing SAC, its efficiency depends on oxygen supply and the presence of other co-existing pollutants. Hybrid aerobic biodegradation processes combined with other treatments including AOPs could achieve complete SAC reduction. Furthermore, novel adsorbents, sustainable chemical methods, and bioaugmentation technologies, informed by in-depth studies of degradation mechanisms and the metabolic toxicity of intermediates, are expected further to enhance SAC removal efficiency and enable comprehensive control of SAC potential risks

The interaction and photostability of some xanthenes and selected azo sensitizing dyes with TiO2 nanoparticles

We have tested simple Graetzel-type solar cells using semiconductor thin films consisting of TiO2 nanoparticles and some electron injecting dyes. The possibility of using xanthenes (rhodamine 101, fluorescein and 5(6)-carboxyfluorescein) and selected azo dyes (alizarin yellow R, alizarin yellow 2G and carboxyaesenazo) as sensitizers has been explored. Fluorescence and electronic absorption measurements revealed complex formation between the chosen dyes and the surface of the colloidal TiO2. The apparent association constants (Kapp) of the surface complexes have been estimated and are correlated with the dyeinduced negative shifts of the reduction potential of colloidal TiO2 nanoparticles. Moreover, due to its utmost importance, photostability of the organic dyes in absence and presence of colloidal TiO2 nanoparticles and the influence of the used electrolyte have been examined. The results point to a remarkable enhancement of photostability in the presence of the electrolyte (I3−/I−), which is attributed to fast regeneration of the neutral dye via the redox couple of the electrolyte. Furthermore, photocurrent action spectrum of the fabricated and tested DSC shows the origin of photoelectric output to be optical absorption of the dye used

Utilization of black liquor as concrete admixture and set retarder aid

The utilization of black liquor, produced by the pulp and paper industry in Egypt, as a workability aid and set retarder admixture has been investigated. This approach may help eliminate the environmentally polluting black liquor waste. It also provides a low cost by-product, which can be widely used in the construction industry. The properties of black liquor and its performance on concrete at two different ratios of water to cement have been studied. The results revealed that black liquor from rice straw pulp increases concrete workability, improves compaction, and reduces honeycombing. Moreover, it retards the initial and final set time and enhances uniform compaction. The effect of incorporating small portions of silica fume has been investigated. The ageing effect of this material over a period of one year, to determine its safe storage period, has been studied. Finally, this admixture was found to comply with the relevant Egyptian standards

Solar photocatalytic treatment of industrial wastewater utilizing recycled polymeric disposals as TiO2 supports

Heavily contaminated industrial wastewater is treated using a homemade compound parabolic reactor utilizing recycled polymeric disposals as TiO2 supports. The recycled polymeric materials include cotton, cotton lycra, polyamide, paper, polyethylene terephthalate, polypropylene, and polyurethane. The loading of TiO2 onto different support materials was investigated to identify the optimal composite. The TiO2/polyethylene terephthalate collected from Factory i (PETi) composite was selected because of its durability, strong polymer-TiO2 binding, and significant photocatalytic activity. Infrared and scanning electron microscopy characterizations confirm the strong binding and homogenous distribution of TiO2 particles over the PETi surface before and after the photocatalytic process. The solar photocatalytic treatment of the sample wastewater resulted in significant photobleaching. A significant reduction in the chemical oxygen demand (COD) and mineralization percentages of up to 42% were reported. The increased biological oxygen demand to COD ratios indicate the formation of new biodegradable species, enabling further normal biological treatment. •Profoundly contaminated industrial wastewater is treated using CPC photoreactor.•Recycled polymeric disposals were utilized as TiO2 supports.•Photocatalytic treatment of wastewater resulted in significant photobleaching.•Mineralization percentages up to 42% inside the CPC reactor were reported.•Analyses suggest formation of biodegradable species, enabling biological treatment

Comparison of transvaginal cervical length and modified Bishop’s score as predictors for labor induction in nulliparous women

Objective: To compare the transvaginal cervical length (TVCL) to the modified Bishop’s score for prediction of successful labor induction in nulliparous women. Methods: A total of 210 nulliparous women who were diagnosed as premature rupture of membranes were recruited in this comparative prospective study, which was carried out in the Obstetrics and Gynecology Department of Ain Shams University, Egypt over two years for labor induction. The studied women were examined by trans-vaginal ultrasound for measurement of the cervical length (CL) and vaginally to calculate the modified Bishop’s score, followed by induction of labor. Collected data were analyzed to compare the TVCL to the modified Bishop’s score for prediction of successful labor induction in nulliparous women. The success of induction process was defined as vaginal birth after the induction of labor. Results: One hundred and forty-three women of studied women had CL 4; 128 of them delivered vaginally (P=0.006). The CL 4 than women with Bishop’s score of ≤4 (P=0.01; 95% confidence interval: 1.6-4.5). Conclusions: Both TVCL and the modified Bishop’s score are complementary tools in pre-induction cervical assessment before induction of labor, while the TVCL at <28 mm is significantly more specific with more positive predictive value as predictor of successful induction than the modified Bishop’s score