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This study investigates the monitoring of corrosion in the distribution network pipeline in Patna (Bihar), India, using a weight loss method and an image processing technique. The seven coupons were injected into the pipeline of the distribution network and ejected after 45, 90, 135, 180, 225, 270, and 315 days. The corrosion rate was calculated by weighing the initial and final weight of coupons. It was found to be 0.035, 0.078, 0.048. 0.035, 0.028, 0.052, and 0.039 mm/year during 45, 90, 135, 180, 225, 270, and 315 days, respectively. Scaling rate found at 45, 90, 135, 180, 225, 270, and 315 days was 0.006, 0.037, 0.042, 0.049, 0.011, 0.018, and 0.033 mm/year, respectively. Surface analysis was performed using the scanner method and MATLAB software. Coupons were first scanned using a scanner adjusted to 4800 ppi. A scanned image was imported into MATLAB. An algorithm was used based on color analysis. The output of a text file was generated that gave the corrosion pit in terms of pixels. The MATLAB analysis shows that the surface corrosion area sum of both sides of the coupon was 6.24, 6.39, 6.49, and 6.48 cm2 in 45, 90, 135, and 180 days, respectively. This study concludes that scale formation on the pipe surface decreased the corrosion rate. Corrosion and scaling were found in the opposite trend. SEM analysis shows that pitting corrosion was increasing with increasing duration of time. Physicochemical analysis shows that the water was alkaline. The presence of a greater concentration of hardness, alkalinity, and less concentration of chloride, sulfate, and DO water was found to have a scaling tendency. XRD analysis of iron dust represents the presence of salts in water, which is responsible for the scaling behavior of water. [ABSTRACT FROM AUTHOR]

Road traffic noise is a major environmental issue that has been faced by many people around the world, including in Patna city. There is a need to investigate noise regularly because of the rapidly increasing traffic volume. This study focuses on the estimation of the urban traffic noise level in Patna, Bihar, India. Based on a preliminary survey of traffic volume, 12 stations were selected. A sound meter was used to measure the "A"-weighted noise level. Noise parameters like L10, L50, and L90 were evaluated from the collected noise data. And these noise parameters were used for the calculation of noise pollution indices like Noise Climate (NC), Equivalent Continuous Noise Level (Leq), Noise Pollution Level (NPL), and Traffic Noise Index (TNI). These noise indices compare with the standard limit of the Central Pollution Control Board (CPCB). The equivalent continuous noise level (Leq) measured at different locations in the commercial cum residential zones varies from 77.7 dBA to 92.5 dBA, which is higher than the prescribed noise level limit of the CPCB. Other noise indices, such as the NPL and TNI, are found to range from 88.2 dBA to 111.5 dBA and 77.9 dBA to 125.9 dBA, respectively, at various sampling locations and are also higher than the prescribed limit of the CPCB. The noise level of all stations was found to exceed the prescribed limit of the CPCB. There is a strong correlation exists between NPL with TNI and NC (r > 0.5). Also, there is a strong correlation exists between Leq with NPL (r > 0.5). Using NPL as a dependent variable and TNI, NC, and Leq as independent variables, the regression model was completely validated. [ABSTRACT FROM AUTHOR]

This study is focused on the modelling of the composite effect of corrosion factors using Design Expert 13 software on the corrosion rate in the water distribution network of Patna (Bihar), India. A total of nine variables, including pH, temperature, total dissolved solid (TDS), alkalinity, calcium hardness, chloride, sulphate, dissolved oxygen (DO) and time, were considered for modelling. The physicochemical parameters were determined through regular monitoring of water samples. The corrosion rate was determined by the direct monitoring of water distribution pipes using adjustments of seven GI coupons for 45, 90, 135, 180, 225, 270 and 315 days. Modelling was performed for various corrosion factors using the low-level and high-level experimental ranges. Nine of the corrosion factors, i.e. pH, temperature, TDS, alkalinity, calcium hardness, chloride, sulphate, DO and time, were considered in this study. The data used for low-level and high-level range were 7.28, 23, 430, 115, 24, 18, 10.94, 3.5 and 0 and 7.86, 28, 704, 284, 180, 98, 38.7, 6.8 and 315, respectively. Using the Box-Behnken design (BBD), 160 runs were conducted, including ten replicates at the central point of each block. The results of ANOVA indicate that the values of R2, adjusted R2 and predicted R2 are 0.9714, 0.9507 and 0.8941, respectively. The value of R2 (0.9714) was close to 1, which indicates a good fit. The adequate precision was found to be 30.8442, indicating a good signal. The coefficient of variance discusses reproducibility, and in this case, it was 9.90%. On the basis of the ANOVA result, the quadratic model is well-fitted and can be accepted as a suitable model. A total of seven parameters, such as chloride, sulphate, hardness, alkalinity, pH, calcium and hardness, were used for the design of the experimental corrosion rate (CR). Corrosion rate as observed by direct monitoring of the water distribution system was 1.37, 3.08, 1.90, 1.38, 1.09, 2.05 and 1.45 MPY for 45, 90, 135, 180, 225, 270 and 315 days, respectively. These individual CR versus synthetic aqueous solutions were used to validate the interaction of the response surface. It was observed that the trend of individual corrosion rates in synthetic aqueous solutions and the interaction of composite variables with corrosion rates in a quadratic model of response surfaces were clearly correlated. [ABSTRACT FROM AUTHOR]

Corrosion in the distribution network pipe can lead to pipe failure and water quality problems. This study assesses the corrosion or scaling potential based on the Water Quality Index (WQI) of drinking water in the distribution networks of Patna, Bihar, India. The water samples were collected from 18 points of the distribution network. In situ parameters like temperature, pH, electrical conductivity, and TDS were measured. Other parameters such as Alkalinity, Total hardness, Calcium, Magnesium, Chloride, Residual chlorine, Sulfate, Nitrate, and Dissolved oxygen were examined in the laboratory. Corrosiveness indicators, such as the Langelier saturation index (LSI), Ryznar stability index (RSI), Puckorius scaling index (PSI), Larson-Skold index (Ls), and Aggressive index (AI) are being used for water sample corrosion prediction. Experimental Corrosion rate (CR) is analyzed to show the actual prediction of corrosion. WQI was calculated to observe the effect of water quality on Corrosiveness indices and CR. A general conclusion was reached that LSI concludes 66.67% corrosive, 22.22% scaling, and 11.11% neutral, RSI concludes 88.88% corrosive, 5.56% scaling, and 5.56% neutral, PSI indicates 38.88% corrosive, 5.56% scaling, and 55.56% neutral, Ls indicates 94.44% scaling, and 5.56% corrosive, AI indicates 77.78% corrosive, and only 22.22% scaling. The average Experimental Corrosion rate is found at 1.91 mils per year. In this study, a weak correlation (r = 0.35) between Corrosion rate and WQI has been observed. A weak correlation is also observed between corrosion rate and corrosiveness indices (r < 0.5). It is concluded that the Corrosiveness Indices fail to represent the actual behavior of water. [ABSTRACT FROM AUTHOR]