A Brief Comparative Study on Removal of Toxic Dyes by Different Types of Clay

Increasing amount of organic dyes in the ecosystem particularly in wastewater has propelled the search for more efficient low-cost bio adsorbents. Different techniques have been used for the treatment of wastewater containing toxic dyes such as: biological degradation, oxidation, adsorption, reverse osmosis, and membrane filtration. Among all these processes mentioned, adsorption with low cost adsorbents has been recognized as one of the cost effective and efficient techniques for treatment of industrial wastewater from organic and inorganic pollutants. Clays as material adsorbents for the removal of various toxic dyes from aqueous solutions as potential alternatives to activated carbons has recently received widespread attention because of the environmental-friendly nature of clay materials. This chapter presents a comprehensive account of the techniques used for the removal of industrial cationic and anionic dyes from water during the last 10 years with special reference to the adsorption by using low cost materials in decontamination processes. Effects of different adsorption parameters on the performance of clays as adsorbents have been also discussed. Various challenges encountered in using clay materials are highlighted and a number of future prospects for the adsorbents are proposed

Comparing different fentanyl concentrations added to local anesthetic mixture in peribulbar block for cataract surgery

Objective: Evaluation of the effect of different concentrations of fentanyl added to the local anesthetic mixture on the onset and duration of globe anesthesia, after peribulbar block, with the least side effects. Design: Double blinded randomized controlled clinical trial. Setting: Kasr Al Aini hospital, Cairo University. Methods: 60 patients with cataract grade 1–3 in the age group 40–70 years, with American Society of Anesthesiologists (ASA) grade I, II and III, scheduled for elective cataract surgery under regional anesthesia. They were randomly divided into four groups: in Group 1 (Control Group), patients received Lidocaine 2% and Hyaluronidase 15 IU/ml; in Groups 2, 3 and 4 (Fentanyl Groups), the patients received Lidocaine 2% and Hyaluronidase 15 IU/ml in addition to Fentanyl 1 μg/ml, 2 μg/ml and 3 μg/ml respectively. The onset and duration of lid and globe akinesia were assessed. Postoperative Visual Analogue Score was recorded each hour up to 6 h. Results: No statistical significant difference was observed between the four groups in the onset and duration of lid and globe akinesia. There was a significant difference between the control group and the fentanyl groups as regards the duration of analgesia that was significantly prolonged in the groups that received fentanyl at concentrations of 2 μg/ml and 3 μg/ml in these group patients required analgesia after 116 ± 19 min and 144 ± 11 min respectively compared to the control group and the group that received fentanyl at a concentration of 1 μg/ml group who required analgesia after 100–103 min. Conclusion: Adding Fentanyl at concentrations ⩾ 2–3 μg/ml to the local anesthetic mixture (Lidocaine and Hyaluronidase) for regional peribulbar block provides safe and effective method in improving postoperative analgesia in patients undergoing cataract surgery