This research deals with the effect of the electrolyte flow behavior on electrochemical continuous stirred tank reactor performance. The reactor was simulated to remove organic pollutants from the wastewater and to determine the conditions for removal that will examine the effect of the electrolyte flow through the reactor. The flow behavior has been investigated using the pulse tracer technique at selected operating conditions. A model comprises three hydrodynamic parameters (bypass, active volume, and recirculation fractions) that have been used to analyze the residence time distribution. The modeling results indicate that with the increasing of the space-time, the bypass and the active volume fractions were decreasing, while the active volume of the reactor was decreasing. The obtained non-ideal space-time of the reactor using the hydrodynamic parameters and the relationship of the tracer concentration with time was much less than the ideal space-time, because of the great effect of bypassing fraction. Finally, the experimental results for the organic removal were closeted to the results that simulated at non-ideal space-time. This comparison proving a significant impact of non-ideal flow on the reactor performance, and showing that the proposed model was well-describing the behavior of the electrolyte through the reactor.

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The dimensions of bubbles were measured in a stirrer tank electrochemical reactor, where the analysis of the bubble size distribution has a substantial impact on the flow dynamics. The high-speed camera and image processing methods were used to obtain a reliable photo. The influence of varied air flow rates (0.3; 0.5; 1 l/min) on BSD was thoroughly investigated. Two types of distributors (cubic and circular) were examined, and the impact of various airflow rates on BSD was investigated in detail. The results showed that the bubbles for the two distributors were between 0.5 and 4.5 mm. For both distributors at each airflow, the Sauter mean diameter for the bubbles was calculated. According to the results, as the flow rate raised, the bubble size for cubic distributors increased from 2.35 to 2.41 mm and for circular distributors from 2.76 to 2.88 mm.

The disposal of the waste material is the main goal of this investigation by transformation to high-fineness powder and producing self-consolidation concrete (SCC) with less cost and more eco-friendly by reducing the cement weight, taking into consideration the fresh and strength properties. The reference mix design was prepared by adopting the European guide. Five waste materials (clay brick, ceramic, granite tiles, marble tiles, and thermostone blocks) were converted to high-fine particle size distribution and then used as 5, 10, and 15% weight replacements of cement. The improvement in strength properties is more significant when using clay bricks compared to other activated waste ceramics and granite tiles. The percentage increases to 11.59% at 28 days for compressive strength when using 10% replacement of cement weight. The ability to produce eco-SCC with less cement content and lower cost consumption is encouraged, although the enhancement in strength is not high since the waste can be disposable. While the percentage reduction in the strength of SCC mixes containing marble tile or thermostone block powder increases with the replacement of cement weight with a greater need for superplasticizer justification, we recommend using 5% as a replacement by weight of cement with an insignificant retardation of strength. Finally, there is a good relationship between compressive strength and ultrasonic pulse velocity and between tensile and flexural strength with a high R 2.

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