Development of aerobic granules in sequencing batch reactor system for treating high temperature domestic wastewater
Loading...
Date
2018
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Teknologi Malaysia
Abstract
Research on aerobic granular sludge (AGS) technology using sequencing batch reactor (SBR) system known as AGS-SBR has generally been conducted at ambient temperature or lower. Even though some studies on AGS have been performed at high temperature, detailed knowledge regarding the influence of high temperature on aerobic granulation is still confined. The main aim of this study is to investigate the possibility of developing AGS technology with special emphasis on high temperature condition for the application of domestic wastewater treatment in hot climate areas such as Saudi Arabia. In this study, two parts of experimental work were involved. The first part involved operation of a 3-litre lab-scale SBR to cultivate granules at different high temperatures (30, 40 and 50°C) with the use of synthetic wastewater and influent loading rate of 1.6 COD g (L.d)–1. The COD/N ratio of the influent wastewater was 8. Meanwhile, the second part involved operation of a 4-litre lab-scale SBR to cultivate granules fed with domestic wastewater and influent loading rate of 0.6 COD g (L.d)–1 at high temperature (50°C). The SBR system was operated in a complete cycle time of 3 hours. The first part of experiment reveals that granules with the highest average diameter of 3.36 mm was cultivated at 50°C with excellent chemical oxygen demand (COD) removal efficiency of 98.17 %. The SVI value of biomass in the SBR run at the temperature of 30, 40 and 50°C were 63.21, 47.40 and 24.50 mL g–1, respectively indicating good settleability of the granules. The aerobic granules cultivated at different high temperatures also positively correlated with the accumulation of elements including carbon, oxygen, phosphorus, silicon, iron, aluminium, calcium and magnesium that played important roles in the granulation process. In the meantime, the second part of experiment shows that stable mature granules were cultivated in the SBR with diameters between 2.0 – 5.0 mm. At the end of experiment, COD and ammoniacal nitrogen removals and phosphorus were achieved at a maximum of 84.4 %, 99.6 % and 81.7 %, respectively. Based on the results of this study, AGS was successfully developed in the SBR fed with both synthetic and real domestic wastewater at temperatures that varied from 30 to 50°C indicating that the granulation process is achievable at high temperatures. Therefore, this represents the practical of AGS technology as one of the alternatives in wastewater treatment system for hot climate areas such as Saudi Arabia.
Description
Thesis (Ph.D (Civil Engineering))
Keywords
Sewage—Purification—Aeration, Sewage—Purification—Technological innovations, Granulation