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Research on the Aeration Systems’ Efficiency of a Lab-Scale Wastewater Treatment Plant

Year: 2015 Volume: 9 Issue: 9 1073 - 1077 Pages

• Authors:
• Oliver Marunțălu
• Elena Elisabeta Manea
• Lăcrămioara Diana Robescu
• Mihai Necșoiu
• Gheorghe Lăzăroiu
• Dana Andreya Bondrea

Abstract: In order to obtain efficient pollutants removal in small-scale wastewater treatment plants, uniform water flow has to be achieved. The experimental setup, designed for treating high-load wastewater (leachate), consists of two aerobic biological reactors and a lamellar settler. Both biological tanks were aerated by using three different types of aeration systems - perforated pipes, membrane air diffusers and tube ceramic diffusers. The possibility of homogenizing the water mass with each of the air diffusion systems was evaluated comparatively. The oxygen concentration was determined by optical sensors with data logging. The experimental data was analyzed comparatively for all three different air dispersion systems aiming to identify the oxygen concentration variation during different operational conditions. The Oxygenation Capacity was calculated for each of the three systems and used as performance and selection parameter. The global mass transfer coefficients were also evaluated as important tools in designing the aeration system. Even though using the tubular porous diffusers leads to higher oxygen concentration compared to the perforated pipe system (which provides medium-sized bubbles in the aqueous solution), it doesn’t achieve the threshold limit of 80% oxygen saturation in less than 30 minutes. The study has shown that the optimal solution for the studied configuration was the radial air diffusers which ensure an oxygen saturation of 80% in 20 minutes. An increment of the values was identified when the air flow was increased.

• Keywords:
• Flow
• aeration
• bioreactor
• oxygen concentration.

Design and Development of an Efficient and Cost-Effective Microcontroller-Based Irrigation Control System to Enhance Food Security

Year: 2014 Volume: 8 Issue: 8 1350 - 1357 Pages

• Authors:
• Robert A. Sowah
• Stephen K. Armoo
• Koudjo M. Koumadi
• Rockson Agyeman
• Seth Y. Fiawoo

Abstract: The development of the agricultural sector in Ghana has been reliant on the use of irrigation systems to ensure food security. However, the manual operation of these systems has not facilitated their maximum efficiency due to human limitations. This paper seeks to address this problem by designing and implementing an efficient, cost effective automated system which monitors and controls the water flow of irrigation through communication with an authorized operator via text messages. The automatic control component of the system is timer based with an Atmega32 microcontroller and a real time clock from the SM5100B cellular module. For monitoring purposes, the system sends periodic notification of the system on the performance of duty via SMS to the authorized person(s). Moreover, the GSM based Irrigation Monitoring and Control System saves time and labour and reduces cost of operating irrigation systems by saving electricity usage and conserving water. Field tests conducted have proven its operational efficiency and ease of assessment of farm irrigation equipment due to its costeffectiveness and data logging capabilities.

• Keywords:
• Agriculture
• control system
• data logging
• food security
• irrigation system
• microcontroller.