Mechanical Technology March 2016

⎪ Pump systems, pipes, valves and seals ⎪

wastewater treatment aeration basin reaches its limit in terms of load.

further opportunities for the introduction of oxygen technology. Air Products develops and designs its oxygen-based technologies in line with changing markets and industry demand for optimising efficiencies and minimising environmental impact. “While oxygen processes for the biological treatment of wastewater are not new technology, there is scope for increased application of these tech- nologies in the current environment. The watchwords in industry are ‘reuse’ and ‘recycle’ – especially in the context of water scarcity in South Africa. “Although oxy-Dep ® provides rec- ognised benefits when compared to conventional aeration methods, it is not the final word in wastewater treatment. Air Products is making ongoing advances in the field through its research and development efforts, to gain a deeper understanding of the role of oxygen in the biological and water treatment processes. This will enable us to further assist our customers in industries with specific needs and to also address ever-present environmental demands going forward,” Kulkarni concludes. q

injector to deliver oxygen in the form of very fine bubbles to an activated sludge process, with minimal power consumption. “This technology is ideal when space is too limited for the installation of a new or additional plant, as it effectively increases the treatment capacity of the existing plant. This has important im- plications in minimising the need for large capital expenditure,” Kulkarni emphasises. Other specialist solutions offered by Air Products to address specific wastewater-related problems include ozone technology, which the company provides not only for water treatment but also for cyanide destruction in the mining industry; and carbon dioxide, which the company supplies to water-treatment companies for pH balancing. Looking beyond wastewater treatment and purification, Kulkarni notes that aquaculture, as one of the fastest grow- ing food-producing sectors, represents

“All wastewater plants have a limited capacity – and if the plant exceeds its capacity for wastewater, due to seasonal demands, for instance, the introduction of HP oxygen technology can serve to augment the capacity of the basin in the short term. This is a highly cost-effective alternative to expanding an existing plant’s infrastructure,” notes Kulkarni. “Moreover,” he adds, “the use of oxygen-based technology eliminates wasted energy in terms of separating oxygen from nitrogen in normal aeration processes. Using high-pressure (HP) oxygen also achieves faster oxygen mass transfer rates into water, as compared to air aeration transfer rates. Greater oxygen solubility enhances and assists the development of microorganisms in effluent or sludge.” Oxy-Dep ® offers treatment plants a highly efficient oxygen dissolution sys- tem, which incorporates a side-stream

Mechanical Technology — March 2016

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