Abstract:
This research considered development of design procedures, for multipurpose septic tank for buildings. Various studies have shown that the convectional septic tanks as designed can only serve the purpose of partially treating wastewater to a level of safe disposal. Apart from the basic purpose, this research considered other ways in which septic tanks could function. The methane which could be potentially generated from the septic tank was estimated and also treatment units were designed for further treatment of the effluent so that it can be reused. The dimensions of the multipurpose septic system were obtained using necessary formula and equations prescribed by Indian Standard Code of Practice (IS: 2470 Part 1). The design calculations were initially done manually for both the septic and the treatment units. The volume obtained for the septic tank was 74.7m3. The dimensions of the depth, length and width of the septic tank were 3m, 7m and 3.5m respectively which were used to size the treatment units. The volumes of the sedimentation tank and aeration tank obtained were 9.3m3 and 22.41m3 respectively. The probable values of biogas and power obtained were 2.84 m3 and 4.4kwh respectively. The engineering drawings which show the plan and sections of the septic tank unit and the treatment units were drafted using AutoCAD software program. The 3-Dimensional digital prototype for the whole system was also rendered using Autodesk Inventor 3D CAD software which gave a better perspective of the whole system. Microsoft Excel software, which is flexible and dynamic with a decision support system feature, was adopted to size the multipurpose septic tank incorporating renewable energy production. It provides a user-friendly and easy-to-use interface which aids in the sizing of septic tank, for any number of persons in any type of building. The summary cost for prospective installers was prepared using Microsoft Excel tool
