Develop an integrating coagulation and RO systems to treat highly turbid water using synthesized coagulants

In the present study coagulation process was used as pretreatment for the RO membrane with turbid raw water collected from Bisalpur Dam, Rajasthan, India. To optimize coagulation performance, three kinds of coagulants, namely, Alum (commercially available), synthesized inorganic polymeric coagulant-medium basicity (IPC-M), and inorganic polymeric coagulant-ultra high basicity (IPC-UH) were examined for turbidity removal with varying operating parameters. It was observed that in the optimum pH range of 6–7, the IPC-UH resulted as the best performing coagulant with 0.99 mg/L equivalent Al2O3 dose revealing 2 NTU residual turbidity and residual aluminium of 0.001 mg/L. Moreover, Langelier saturation index and Ryznar stability index values were evaluated at optimum conditions of all the three coagulants proclaiming negligible scaling potential. Furthermore, the coagulant-treated water (100 L) was fed to the RO membrane, and the performance was noted in terms of flux, pressure, and TDS. It was observed that IPC-UH has the lowest reduction in permeate flux of 0.78 L/min/m2 compared to commercially available coagulant alum (0.90 L/min/m2). Also, the increased feed pressure was observed for all the coagulants treated water with the lowest value of 2.3 kg/cm2 for IPC-UH, which was 2.5 kg/cm2 for Alum (commercially available coagulant). Henceforth, integration of coagulation before the RO system resulted in effective pretreatment of turbid water with very minute scaling.

Tingkat Korosivitas Air Terhadap Infrastruktur Sumber Daya Air Berbahan Semen atau Mortar dengan fc’ ≤ 30 MPa pada 9 Waduk di Indonesia

Abstrak. Korosi atau kerusakan yang terjadi di infrastruktur sumber daya air terutama yang berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30 Mpa, dapat menimbulkan banyak kerugian. Kerugian yang ditimbulkan antara lain kerugian secara materiil karena korosi menggerogoti semua aset infrastruktur dan tentunya kerugian dalam hal keamanan karena dapat mengancam keselamatan manusia. Korosi merupakan permasalahan yang sangat penting dan tidak akan ada habisnya, karena peristiwa korosi terjadi secara terus-menerus dan berkelanjutan. Peristiwa korosi tidak dapat terjadi dengan sendirinya, tetapi karena adanya berbagai faktor-faktor tertentu yang dapat menyebabkan terjadinya korosi. Tujuan dari studi ini adalah untuk menentukan tingkat korosivitas air terhadap infrastruktur sumber daya air berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30 MPa pada 9 waduk di Indonesia, sehingga akan diketahui rekomendasi yang tepat untuk pencegahan dan pengendalian korosivitas air terhadap infrastruktur sumber daya air berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30 MPa, karena semen merupakan salah satu material yang paling banyak digunakan saat ini. Studi ini menggunakan data-data primer kualitas air. Metode pengambilan, penyimpanan, dan pengawetan sampel air dilakukan dengan mengikuti ketentuan dari Standar Nasional Indonesia Nomor 6989.57:2008. Pengujian kualitas air dilakukan oleh laboratorium yang terakreditasi. Metode perhitungan menggunakan rumus Langelier Saturation Index (LSI) A, B, C, D, dan rumus Saturation Index (SI) dari Standard Method APHA-AWWA-WEF. Hasil perhitungan LSI A, B, C, D, dan SI Standard Method APHA-AWWA-WEF menunjukkan bahwa tingkat korosivitas air di 9 waduk berpotensi menyebabkan korosi terhadap infrastruktur sumber daya air berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30MPa. Kata kunci: infrastruktur sumber daya air, Langelier Saturation Index, Saturation Index, tingkat korosivitas air. Abstract. Water Corrosivity Level Againts the Water Resources Infrastructure Made of Cement or Mortar with fc' ≤ 30 MPa in 9 Reservoirs in Indonesia. Corrosion or damage that occurs in the infrastructure of water resources, especially those made of cement or mortar with fc' or with a compressive strength value of ≤ 30 MPa will be able to engender losses. Losses incurred, in the form of losses materially because of corrosion gnaw off all infrastructure assets and of course in losses terms of security, because it can threaten the safety of a human. Corrosion is a very important problem and will not be endless, as corrosion events occur continuously and sustainably. Corrosion events cannot occur by themselves, but because of certain factors that may cause corrosion. The purpose of this study is to determine the level of water corrosivity to the infrastructure of water resources made from cement or mortar with fc' or with a compressive strength value of ≤ 30 MPa in 9 reservoirs in Indonesia, to develop appropriate recommendations for the prevention and control of the water corrosivity to the infrastructure of water resources made from cement or mortar with fc' or with a compressive strength value of ≤ 30 MPa because cement is one of the most used materials today. This study uses water quality primary data. The methods of capturing, storing, and preserving water samples are carried out following the provisions of Indonesian national standard number 6989.57:2008. Water quality testing is done by accredited laboratories. The method of calculation uses the Langelier Saturation Index (LSI) A, B, C, D, and the formula Saturation Index (SI) of the Standard Method APHA-AWWA-WEF. Calculation results of LSI A, B, C, D, and SI Standard Method APHA-AWWA-WEF show that the level of water corrosivity in 9 reservoirs has the potential to cause corrosion of water resources infrastructure made of cement or mortar with fc' or with a compressive strength value of ≤ 30 MPa. Keywords: Langelier Saturation Index, Saturation Index, water corrosivity level, water resource infrastructure.

Decreasing the Tendency of Water to Form Scale and Corrosion in Cooling Towers – South Refineries Company (SRC) – Iraq

Scale formation and corrosion phenomena are major technical problems at Basra Refinery/ South Refineries Company (SRC). These technical problems are concentrated in cooling towers which are used to supply cooling water to the processing units. The Scales and corrosion products precipitate inside cooling units, heat exchangers and pipeline networks affecting negatively efficiency of refinery’s equipment. In this work, a real plant data was collected from four cooling towers which is supplied the coolant to the crude distillation units of the refinery and also from the raw water supplier. The collected data was fitted by Langelier model to predict the tendency of cooling water for scale forming and activation of corrosion. The obtained result shows that the cooling water has a tendency to form scale (CaCO3 Precipitation) at cooling tower units. Also the feed water has the same tendency for scale forming.After analyzing the LSI (Langelier Saturation Index) results, the research team recommends the particular company to overcome this problem by installing a Reverse Osmosis (RO) plant for treating raw water to decrease the concentrations of total dissolved solids (TDS) which result scale and corrosion in the parts of cooling tower as an option to solve the problem.

Decreasing the Tendency of Water to Form Scale and Corrosion in Cooling Towers – South Refineries Company (SRC) – Iraq

Scale formation and corrosion phenomena are major technical problems at Basra Refinery/ South Refineries Company (SRC). These technical problems are concentrated in cooling towers which are used to supply cooling water to the processing units. The Scales and corrosion products precipitate inside cooling units, heat exchangers and pipeline networks affecting negatively efficiency of refinery’s equipment. In this work, a real plant data was collected from four cooling towers which is supplied the coolant to the crude distillation units of the refinery and also from the raw water supplier. The collected data was fitted by Langelier model to predict the tendency of cooling water for scale forming and activation of corrosion. The obtained result shows that the cooling water has a tendency to form scale (CaCO3 Precipitation) at cooling tower units. Also the feed water has the same tendency for scale forming.After analyzing the LSI (Langelier Saturation Index) results, the research team recommends the particular company to overcome this problem by installing a Reverse Osmosis (RO) plant for treating raw water to decrease the concentrations of total dissolved solids (TDS) which result scale and corrosion in the parts of cooling tower as an option to solve the problem.

Groundwater quality and its suitability for different uses in lower Djendjen Watershed, Northest Algeria

Groundwater is a vital resource in coastal areas to supply domestic, drinking, irrigation and industrial needs. To study the hydrogeochemical characteristics of groundwater and their suitability, Thirty-one (31) groundwater samples were collected from the shallow tubewells in the plain of the Djendjen river (North-East of Algeria). The water quality assessment has been carried out by evaluating the physicochemical parameters such as temperature, pH, EC, major ions i.e., Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3- and nutrients (NH4+, NO2-, NO3-, PO43-). The chemical parameters plotted in Piper’s diagram show the dominance of two chemical facies “calcium and sodium chloride” and “calcium bicarbonate”. Based on the analytical results, groundwater in the area is found to be generally suitable for drinking. The organic pollution index (OPI) show that the water is generally in the good quality category with no organic pollution. Chemical parameters when plotted in the U.S. Salinity diagram indicate that waters are C2S1 and C3S1 types, i.e., medium to high salinity and low sodium which is good for irrigation. Four corrosion indices were calculated (The indices include the Langelier saturation index, Ryznar stability index, Puckorius scaling index, Larson). The result indicates the corrosive nature of the majority of water samples.

Comparison of indices for scaling and corrosion tendency of groundwater: Case study of unconfined aquifer from Mahoba District, U.P. State

This paper is an attempt to utilize the various indices available to assess the degree of corrosivity and calcite formation of groundwater sampled from Indian Mk. II handpumps from the district of Mahoba in Uttar Pradesh. The indices used include Langelier Saturation Index, Ryznar Stability Index, Puckorius Scaling Index, Larson-Skold Index, and Potential to Promote Galvanic Corrosion. Corrosivity of groundwater would cause materials used in construction of pipes to leach into drinking water since the same is used for household activities and drinking purposes. Calcite formation would affect the amount of exertion used to manually pump out required quantity of groundwater from the aquifer as it reduces the convey potential of pipes. One hundred five groundwater samples were collected from Indian Mk. II handpumps tapping shallow aquifer (up to 35mbgl) from different locations that were used by locals for analysis of basic parameters like pH, TDS, EC, ions like calcium, magnesium, sodium, potassium, chloride, carbonate, bicarbonate, sulphate, etc. Overall, majority of the groundwater samples display tendency to deposit calcium carbonate within the pipes, chlorides and sulphates not interfering with natural film formation in pipes and possibility of galvanic corrosion, whereas minority of the samples indicate the alternate scenario.

A Preliminary Study of Internal Corrosion in Condensate Pipelines at Geothermal Power Plants

In this study, we presented observations and analyze related to internal corrosion in condensate pipes in geothermal power plants. A damaged pipe of condensate pipeline taken from a power plant was investigated to determine the root cause of failure. The observation and failure analysis was carried out by visual and dimensional examination, chemical composition testing, macroscopic, and microscopic examination, Scanning Electron Microscope (SEM) examination with Energy Dispersed Spectrometer (EDS). The deposit in the pipe was analyzed by X-Ray Diffraction (XRD). The quality of the condensate fluid and their tendencies were determined by Langelier Saturation Index (LSI). Also, the corrosion rate of the pipe was simulated by condensate fluid by using a corrosion measurement system (Tafel polarization). The internal corrosion was found in the condensate line is strongly suspected to occur due to erosion-corrosion. Erosion corrosion is caused by insoluble and hard particles in the condensate fluid. The results of XRD found the presence of calcium-silicate compounds in the sediment that is suspected to be the cause of erosion particles. The reduction of the thickness of the bottom pipe wall and occurs in longitudinal directions the alleged damage to the pipe due to sediment corrosion. The presence of hard compounds and differential oxygen can accelerate the process of corrosion so that the corrosion rate in condensate pipelines was a category in the severe category based on NACE SP0775 standards.

Assessment of Water Quality of Khari River in Agra District During Lockdown Period using Multivariant Techniques and Quality Indexes

Throughout the world, the lock-down period during COVID-19 (March 2020- July 2021) has reported an improvement in the ecological scenario with controlled anthropogenic activities. This study presents a comparative assessment of water quality of the highly polluted Khari river in Agra district (India) during the pre-pandemic and post-pandemic period of COVID-19. The result was analyzed in terms of water quality index (WQI), the most accessed tool used by various researchers to report the water quality. In addition, Aggressive index (AI) and Langelier saturation index (LSI) have also been determined. Further, multivariate analysis has been performed in terms of principal component analysis (PCA). ANOVA has been used to study the variance of the parameters. The study revealed a positive impact of pandemic on the water quality as the parameters improved during the post-pandemic period as compared to the pre-pandemic period. However, as the river was highly polluted during the pre-pandemic period, strict actions are required for further improvement in its water quality for agricultural, industrial and industrial use.