Study on the Effect of Variation of Flow in Sequencing Batch Reactor Using PCA and ANOVA

Wastewater treatment using Sequencing Batch Reactor (SBR) technology is one of the state-of-the art wastewater management systems. In this technology equalization, biological treatment and secondary clarification are performed in a single reactor in a time control sequence. SBR system is idler for the areas where the available land is limited, since it operates in less space and very cost effective even on small scales. The control of the operational parameters during the process of biological wastewater treatment is often complicated due to the dynamic change in the composition and characteristics of the raw wastewater, flow rates and other parameters influencing the complex nature of the treatment process and the process in SBR has a unique cyclic batch operation. The performance of the SBR was studied using pilot and real plant at Puducherry. The parameters considered in this study are flow, Mixed Liquor Suspended Solids (MLSS), pH, temperature, influent and effluent of Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). As a part of the study, the effect of constant flow and varying flow on the organic loading of the influent TSS, BOD and COD and their influence on the organic load of the effluent parameters were examined to identify the level of significance of the parameters in relation to the flow. The impact of flow on other parameters was also examined. The experimental data obtained from pilot and real plants were analyzed using multi variate statistical analyses like correlation analysis, Principal Component Analysis (PCA) and Analysis of variance (ANOVA). The statistical analysis revealed that constant flow had no significant role and the influent parameters alone had the critical role, whereas varying flow as well as the influent parameters had the significant role on the performance of SBR.

Application of ANN and MLR Models on Groundwater Quality Using CWQI at Lawspet, Puducherry in India

With respect to groundwater deterioration from human activities a unique situation of co-disposal of non-engineered Municipal Solid Waste (MSW) dumping and Secondary Wastewater (SWW) disposal on land prevails simultaneously within the same campus at Puducherry in India. Broadly the objective of the study is to apply and compare Artificial Neural Network (ANN) and Multi Linear Regression (MLR) models on groundwater quality applying Canadian Water Quality Index (CWQI). Totally, 1065 water samples from 68 bore wells were collected for two years on monthly basis and tested for 17 physio-chemical and bacteriological parameters. However the study was restricted to the pollution aspects of 10 physio-chemical parameters such as EC, TDS, TH, , Cl-, , Na+, Ca2+, Mg2+ and K+. As there is wide spatial variation (2 to 3 km radius) with ground elevation (more than 45 m) among the bore wells it is appropriate to study the groundwater quality using Multivariate Statistical Analysis and ANN. The selected ten parameters were subjected to Hierarchical Cluster Analysis (HCA) and the clustering procedure generated three well defined clusters. Cluster wise important physio-chemical attributes which were altered by MSW and SWW operations, are statistically assessed. The CWQI was evolved with the objective to deliver a mechanism for interpreting the water quality data for all three clusters. The ANOVA test results viz., F-statistic (F = 134.55) and p-value (p = 0.000 2, low RMSE and MAE values but in Cluster 3 only ANN model fared well. Thus this study will be very useful to decision makers in solving water quality problems.

Studies on Characteristics, Applications and Strength Improvement of Marine Clay: A Review

Strength assessment and improvement of strength parameters are essential to design the foundation in clay and marine clay. Several studies have been made in this aspect. Marine clay is also a potential material for use as liner material to contain landfill leach ate. The applications include use of marine clay for transforming waste into light weight aggregates and thus create better environment. The physical parameters such as Atterberg limits, California Bearing Ratio (CBR) value, dry density, specific gravity, free swell, chemical properties such as pH value, cation exchange capacity, organic matter content, calcium carbonate, and mineralogical composition using X-ray diffraction analysis are studied. The consolidation characteristics, determination of strength improvement strategies using admixtures at different proportions are frequently adopted. Commonly used admixtures are lime, limes mixed with cement, coir, shredded plastics. The consolidation studies are very vital and play an important role.

Study on Geometric Factors Influencing Saturation Flow Rate at Signalized Intersections under Heterogeneous Traffic Conditions

The main objective of intersection design is to facilitate the convenience, comfort, and safety of people traversing the intersection by enhancing the efficient movement of road users. The intersections on urban roads in India generally cater to heterogeneous motorized traffic, along with slow-moving traffic including pedestrians. It is therefore necessary to consider saturation flow for mixed traffic conditions to evaluate the overall operation of signalized intersections. A proper traffic model must consider varying characteristics of all the road users to effectively design and efficiently manage signalized intersections. This paper presents the results of the study on analyses of saturation flow rate conducted at signalized intersections with mixed traffic conditions in the city of Bangalore, India. Studies were carried out at 15 signalized intersections in the city of Bangalore with varying geometric factors such as width of road (w), gradient of the road (g), and turning radius (r) for right turning vehicles. Saturation flow rate computed as per Highway Capacity manual (HCM: 2000), Indonesian highway capacity manual (IHCM), and IRC SP: 41-1994 was compared with the field observations. The geometric factors, which affect the saturation flow, have been considered in this study and accordingly a new model has been proposed for determining saturation flow. It has been shown that by the introduction of the suggested adjustment factors in this paper, the saturation flow rate can give better picture of the field conditions, especially under heterogeneous traffic conditions of an urban area.

Carbon Footprint Analyses of Wastewater Treatment Systems in Puducherry

Carbon footprint analysis is a method to quantify the life cycle Greenhouse Gases (GHGs) emissions and identify the measure to reduce climate change impacts. The Intergovernmental Panel on Climate Change (IPCC) has identified that the global warming and climate change which is one of the most important issues in the domain of environment are caused by the excessive emission of Greenhouse Gases (GHG) mainly constituting Carbon dioxide (CO2), Methane (CH4) and Nitrous oxide (N2O). The municipal wastewater treatment plant receives wastewater for treatment and finally discharges the treated effluent. The emissions of GHG during the treatment of wastewater as well as during the treatment process of sludge and also for energy generation are known to be on-site GHG emissions. Off-site GHG emissions are generated due to transportation and disposal of sludge, off-site energy and chemical production. In Puducherry, the municipal wastewater is being treated using oxidation ponds, Upflow Anaerobic Sludge Blanket (UASB) and Sequencing Batch Reactor (SBR). Wastewater treatment using Sequencing Batch Reactor (SBR) technology is one of the state-of-the art wastewater management systems. In this technology equalization, biological treatment and secondary clarification are performed in a single reactor in a time control sequence. The emissions of GHG from the Oxidation ponds of 12.5 MLD, UASB reactor of 2.5 MLD and SBR of 17 MLD were assessed based on the IPCC guidelines and the total emissions of GHG in terms of equivalent of CO2 were compared. The performance of the SBR is more efficient and the emissions of GHG are less than the emissions in the UASB as well as in oxidation ponds. The emission of GHG in SBR is about 60% of the existing treatment systems of oxidation ponds and UASB thus a reduction of 40% GHG emission could be achieved.

Spatial Variability of Ground Water Quality Using HCA, PCA and MANOVA at Lawspet, Puducherry in India

In ground water quality studies multivariate statistical techniques like Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), Factor Analysis (FA) and Multivariate Analysis of Variance (MANOVA) were employed to evaluate the principal factors and mechanisms governing the spatial variations and to assess source apportionment at Lawspet area in Puducherry, India. PCA/FA has made the first known factor which showed the anthropogenic impact on ground water quality and this dominant factor explained 82.79% of the total variance. The other four factors identified geogenic and hardness components. The distribution of first factor scores portray high loading for EC, TDS, Na+ and Cl−(anthropogenic) in south east and south west parts of the study area, whereas other factor scores depict high loading for HCO3−, Mg2+, Ca2+ and TH (hardness and geogenic) in the north west and south west parts of the study area. K+ and SO42−(geogenic) are dominant in south eastern direction. Further MANOVA showed that there are significant differences between ground water quality parameters. The spatial distribution maps of water quality parameters have rendered a powerful and practical visual tool for defining, interpreting, and distinguishing the anthropogenic, hardness and geogenic factors in the study area. Further the study indicated that multivariate statistical methods have successfully assessed the ground water qualitatively and spatially with a more effective step towards ground water quality management.