Sewage Treatment Process

Designing an Efficient Yet Affordable Sewage Treatment Process for All

When taking a look at the marvels of the modern technological age, it may be surprising for some to learn how many of these apparently complex human achievements have their roots in some relatively simple mechanism first developed by Mother Nature and exploited rather than devised by man. Among the more obvious examples of this is the echo-location technique by which bats can navigate accurately at high speed, even in the dark. The same principle was eventually adapted to develop the sonar technology that has become a vital aid to anti-submarine warfare. Also, without the knowledge gained from studying the way in which plant burrs attach themselves so effectively to our clothing, we would be living in a world without the benefits of Velcro.

Not surprisingly, perhaps, when looking for ways in which to improve the sewage treatment process, the logical step for many researchers has been to study the way in which nature has been tackling this task since life on earth began. Since that time, life has been sustained as the result of a balance between three groups in which plants are the primary producers, animals the main consumers and microorganisms act as a type of middleman responsible for balancing the actions of the other two. Bacteria of various kinds obtain their nutrition from the waste products of both plants and animals. In each case, their food supply includes the remains of dead specimens while, in the case of animals, this also includes their liquid and solid bodily waste products.

Over the years, man has gained sufficient insight into the water cycle to leverage some of its more basic principles for use in waste water purification plants. However, such plants have relied more upon physical actions such as sedimentation and filtration, assisted by various chemical processes, such as the use of coagulants to facilitate sedimentation where needed, and dosing with chlorine compounds to kill residual bacteria. More recently, however, interest has centred on the more extensive use of biological methods for use in the sewage treatment process.

In a conventional plant, processing takes place in four main stages and begins with screening, in which large items such as disposable nappies, cotton buds, tissues, and similar detritus that might later cause obstruction, are removed. Stage 2 involves a primary treatment, in which the solids are allowed to settle and form a dense sludge at the bottom of the tank, which is removed by mechanical scrapers and pumped away for further processing. The remaining water is transferred to a new tank for secondary processing in Stage 3. Here, aeration occurs to assist the bacteria to break down any remaining suspended and dissolved organic material. Finally, after a further period of sedimentation, the remaining water is essentially free of harmful contaminants and after filtration through sand, can be safely released back into the water table for nature to complete the task.

Conventional plants tend to rely quite heavily on the use of pumps and mechanical scrapers and stirrers. Their use results in considerable consumption of electrical power and, in turn, adds significantly to the overall cost of grey and black water processing. During what is predominately a biological sewage treatment process, not only is there far less need for the use of electrical power, but the clear and odourless effluent produced by these systems can, if required, be used for selected purposes without the need for any further processing.

The biological units described are ideal for use in a variety of locations and can offer a means to reuse water that has already been paid for, providing the owners of these installations with a way to reduce their monthly bills, as well as helping to ease the burden on the nation’s limited water reserves. In South Africa, and in Mozambique, Bio Sewage Systems is widely known for its innovative products that are to be found on mines, in shopping centres, sports facilities, and nature resorts, as well as on farms and residential sites.

In addition to a wide range of standard processing capacities of up to half a million litres per day, we undertake installation and maintenance as well as the design of tailored installation to the client’s requirements. Let us show you how our efficient yet affordable biological sewage treatment process could work for you.