Design approach for sewage treatment plant: a case study of Srikakulam greater municipality, India.
Ponnada Puspalatha*1, Polipalli Kalpana2
1 Environmental Engineering, GMR Institute of Technology, Rajam, AP, India
2 Department of Chemical Engineering, GMR Institute of Technology, Rajam, AP, India
*corresponding author Email id: firstname.lastname@example.org
Srikakulam city has been a developing place due to the steady increase in city population, which in turn resulted in the increase of domestic sewage generated, but still there is no sewage treatment plant. So it is required to construct a sewage treatment plant with sufficient capacity to treat the generated sewage. Sewage water treatment has challenges to treat the excess sludge and disposal of sludge. Sewage/Wastewater treatment operations are done by various methods in order to reduce, its water and organic content, and the ultimate…show more content… The grit basin is intended to scour the lighter particles while the heavier grit particles remain settled down. 
5 Primary sedimentation Sedimentation is the process of removing solid particles heavier than water by gravity settling i.e., the particle size less than 0.2mm and specific gravity 2.65. In wastewater treatment, sedimentation is used to remove both inorganic and organic materials which are settleable in continuous-ﬂow conditions.  The sedimentation tank comprises of a tank with 2 settling pipes where solid waste settles down. Baﬄes are provided to improve the settling process. At this stage the removal percentage of suspended solids are 60-65% and BOD from sewage is 30-35%. Skimmers are used to remove the floating impurities like grease and oil on the water surface during sedimentation.