DETAILED EVALUATION AND POST TREATMENT OF ANAEROBIC FILTER, MBR, SBR TYPE SMALL WASTE WATER TREATMENT PLANTS

Abstract

With the population of India crossing 1.25 billion mark, and still further increasing, there is a corresponding increasing requirement of sewage disposal, which is also considered as a prime issue. Along with this, the health and sanitation conditions in India are not very encouraging. To save from this grave wastewater challenge, numerous sewage treatment plants (both package and decentralised plants) have been set up in the country. The thesis, therefore, aims to understand the overall performance of piloted proven existing small wastewater treatment technologies functioning in India. In this study, a membrane Bio reactor (MBR), Sequencing Batch Reactor (SBR) and an Anaerobic Septic Tank Filter (ASl'F) were thoroughly investigated to ascertain details about their performance. The research work emphasize upon development of complete technical literature, thereby, leading to rcfnement of'end wastewater quality and augmenting its reuse prospective. lo begin the herculean task of assessing the chemical characteristics, a generic monitoring protocol was established which defines the organic and inorganic parameters which are monitored and the frequencies of monitoring. Monthly grab samples were brought and assessed in the Environmental Engineering Laboratory on regular basis. In addition, 24 hour composite sampling was also conducted to aplomb the earlier results. It can be said with dogged determination that such a documentation on the above three plants has not been carried out earlier. Furthermore, certain parameters not satisfying the criteria are experiniented for their abatement using Jar Test and Electrocoagulation test. The jar test, used 0 alum and ferric chloride as the coagulants, was utilised to bring down the turbidity in the SI3R effluent. More specifically, in the case Of effluent from ASTF, there was a need felt to mitigate the T-P levels by conjoining Submerged Aerated Bio Filter so as to satisfy the effluent standards.. Such innovative post-treatment techniques to treat effluent wastewater aims not only at cleansing the outlet wastewater, but also providing other benefits such as augmenting water reuse and conserving our rivers by adding less pollutants into them, which is infact the need of the day. This thesis finally aims at considering the costs for operation and maintenance and the fixed costs encompassing manpower, repair, fuel and chemicals. It is suggested that operation and maintenance cost can be optimized by the end-users depending on the operation of the system. An effort has also been made to compute the specific energy requirements of the three plants. With the difference in designed inflow and the actual inflow to the three plants, it can be said that to achieve a situation that is advantageous to the cost of treatment would be, if the plants are run at near its designed capacity.