Operation Of Water Treatment Plants Research Articles

Charge Neutralization Mechanism Efficiency in Water with High Color Turbidity Ratio Using Aluminium Sulfate and Flocculation Index

Most of the water supplied in Brazil comes from water streams that may have higher values for apparent color than turbidity. Treatability trials were performed for color and turbidity removal to evaluate the advantages of coagulation during the charge neutralization mechanism when compared to sweep flocculation for water with those characteristics. There were three types of trials: conventional Jar Test with raw water, with and without filtration, and in a pilot Water Treatment Plant, direct downward filtration, with synthetic water. Auxiliary equipment such as Continuous Flocculation Monitoring Equipment (CFME) and image analysis were used to evaluate the growth of flocs. In the Jar Tests experiments, similar levels of color (61.49%) and turbidity (61.30%) removal were observed, with a lower dosage of coagulant (46 mg/L) in the charge neutralization mechanism compared to the ones with sweep flocculation (58.22% for color and 54.73% for turbidity removal with 52 mg/L of aluminium sulfate). Similar results were found on pilot plant. At filtration rates of 180 and 300 m3 m−2 day−1, sweep flocculation mechanism had shorter filtration cycle (<5 m3) compared to other mechanisms. Therefore, a change in the operation of Water Treatment plants that use a coagulant dosage associated with sweep flocculation can bring advantages such as the reduction of coagulant consumption and sludge productions, as well as the increase of chlorine disinfection and filtration cycles.

Preferences for water treatment provision in rural India: comparing communal, pay-per-use, and labour-for-water schemes

ABSTRACTUsing a contingent valuation survey, this research identifies villagers’ willingness to pay towards the operation and maintenance of water treatment plants in 11 villages in Maharashtra with existing facilities. Preferences were elicited using three different payment mechanisms: a monthly fee, labour (time) contributions, and a pay-per-container mechanism. There was little support for the pay-per-container scheme (51% stated positive willingness to pay for this option), but the communal mechanisms were more popular (86.7% and 87.3%). We conclude that the long-term viability of water treatment in Maharashtra is weak, as few scenarios provide adequate revenue to properly operate and maintain the infrastructure.

Scenario-based pollution discharge simulations and mapping using integrated QUAL2K-GIS

Malaysia is a tropical country that is highly dependent on surface water for its raw water supply. Unfortunately, surface water is vulnerable to pollution, especially in developed and dense urban catchments. Therefore, in this study, a methodology was developed for an extensive temporal water quality index (WQI) and classification analysis, simulations of various pollutant discharge scenarios using QUAL2K software, and maps with NH3–N as the core pollutant using an integrated QUAL2K-GIS. It was found that most of the water quality stations are categorized as Class III (slightly polluted to polluted). These stations are surrounded by residential areas, industries, workshops, restaurants and wet markets that contribute to the poor water quality levels. Additionally, low WQI values were reported in 2010 owing to development and agricultural activities. However, the WQI values improved during the wet season. High concentrations of NH3–N were found in the basin, especially during dry weather conditions. Three scenarios were simulated, i.e. 10%, 50% and 70% of pollution discharge into Skudai river using a calibrated and validated QUAL2K model. Model performance was evaluated using the relative percentage difference. An inclusive graph showing the current conditions and pollution reduction scenarios with respect to the distance of Skudai river and its tributaries is developed to determine the WQI classification. Comprehensive water quality maps based on NH3–N as the core pollutant are developed using integrated QUAL2K-GIS to illustrate the overall condition of the Skudai river. High NH3–N in the Skudai River affects water treatment plant operations. Pollution control of more than 90% is required to improve the water quality classification to Class II. The methodology and analysis developed in this study can assist various stakeholders and authorities in identifying problematic areas and determining the required percentage of pollution reduction to improve the Skudai River water quality.

Multi-objective optimization of water treatment operations for disinfection byproduct control

This paper introduces a novel decision-making framework for the optimization of water treatment plant operations.

MODELING OF WASTE WATER TREATMENT IN VERTICAL SETTLER

Purpose. Increasing the effectiveness of water treatment plants is an urgent technical problem. To obtain the efficiency analysis of certain facility of water treatment plant, at the design stage, it is necessary to have special mathematical models. In the paper, the development of mathematical models for assessing the performance of vertical settler having additional structural elements and used in wastewater treatment systems is considered. Methodology. The pollutant distribution in the settler has been computed using the hydrodynamics equation for the viscous incompressible fluid. Additional equation is the equation for the spread of contaminants in a vertical settler. The equations used to calculate the vertical settler take into account the most significant physical factors affecting efficiency of the settler. For numerical integration of the modeling impurity transfer equation in the water treatment plant, difference splitting schemes are used. The numerical solution of the equation describing the process of pollutant movement in a vertical settler is based on splitting this equation into the equation of a more simplified structure. For numerical integration of the modeling equations of the inviscid fluid flow, implicit difference splitting schemes are used. Numerical calculation is performed on a rectangular difference grid. Findings. On the basis of the developed numerical models, a package of application programs was created. This package allows quick determining the settler efficiency using a computational experiment. The results of a computational experiment to determine the efficiency of the settler with two plates are presented. Originality. The developed mathematical models make it possible to determine the velocity field and the impurity transfer process, taking into account the geometric shape of the settler and the use of plates, which affect the flow hydrodynamics in the water treatment plant, and therefore the efficiency of water treatment. Practical value. The calculation time for one version of the task based on the constructed mathematical models is several seconds. The models can be used to obtain an expert assessment of the operation of water treatment plants that are being designed.

Characteristics of Fe and Mn bearing precipitates generated by Fe(II) and Mn(II) co-oxidation with O2, MnO4 and HOCl in the presence of groundwater ions

In this work, we combined macroscopic measurements of precipitate aggregation and chemical composition (Mn/Fe solids ratio) with Fe and Mn K-edge X-ray absorption spectroscopy to investigate the solids formed by co-oxidation of Fe(II) and Mn(II) with O2, MnO4, and HOCl in the presence of groundwater ions. In the absence of the strongly sorbing oxyanions, phosphate (P) and silicate (Si), and calcium (Ca), O2 and HOCl produced suspensions that aggregated rapidly, whereas co-oxidation of Fe(II) and Mn(II) by MnO4 generated colloidally stable suspensions. The aggregation of all suspensions decreased in P and Si solutions, but Ca counteracted these oxyanion effects. The speciation of oxidized Fe and Mn in the absence of P and Si also depended on the oxidant, with O2 producing Mn(III)-incorporated lepidocrocite (Mn/Fe = 0.01–0.02 mol/mol), HOCl producing Mn(III)-incorporated hydrous ferric oxide (HFO) (Mn/Fe = 0.08 mol/mol), and MnO4 producing poorly-ordered MnO2 and HFO (Mn/Fe > 0.5 mol/mol). In general, the presence of P and Si decreased the crystallinity of the Fe(III) phase and increased the Mn/Fe solids ratio, which was found by Mn K-edge XAS analysis to be due to an increase in surface-bound Mn(II). By contrast, Ca decreased the Mn/Fe solids ratio and decreased the fraction of Mn(II) associated with the solids, suggesting that Ca and Mn(II) compete for sorption sites. Based on these results, we discuss strategies to optimize the design (i.e. filter bed operation and chemical dosing) of water treatment plants that aim to remove Fe(II) and Mn(II) by co-oxidation.

Modeling of Chlorine and Coagulant Dose in a Water Treatment Plant by Artificial Neural Networks

Coagulation and chlorination are complex processes of a water treatment plant (WTP). Determination of coagulant and chlorine dose is time-consuming. Many times WTP operators in India determine the coagulant and chlorine dose approximately using their experience, which may lead to the use of excess or insufficient dose. Hence, there is a need to develop prediction models to determine optimum chlorine and coagulant doses. In this paper, artificial neural networks (ANN) are used for prediction due to their ability to learn and model non-linear and complex relationships. Separate ANN models for chlorine and coagulant doses are explored with radial basis neural network (RBFNN), feed-forward neural network (FFNN), cascade feed forward neural network (CFNN) and generalized regression neural network (GRNN). For modeling, daily water quality data of the last four years are collected from the plant laboratory of WTP in Maharashtra (India). In order to improve performance, these models are established by varying input variables, hidden nodes, training functions, spread factor, and epochs. The best models are selected based on the comparison of performance measures. It is observed that the best performing chlorine dose model using defined statistics is found to be RBFNN with R=0.999. Similarly, the CFNN coagulant dose model with Bayesian regularization (BR) training function provided excellent estimates with network architecture (2-40-1) and R=0.947. Based on the above models, two graphical user interfaces (GUIs) were developed for real-time prediction of chlorine and coagulant dose, which will be useful for plant operators and decision makers.

PFASs: Why They Matter and How to Treat Them

Per‐ and polyfluoroalkyl substances have surfaced as a threat to human health. As more of these chemicals find their way into water supplies, water treatment plant operators around the world will be tasked with removing them.

The properties of sludge formed as a result of coagulation of backwash water from filters removing iron and manganese from groundwater

The standard groundwater treatment technology is a simple, non-chemical reagent technology based on aeration and filtration processes. This treatment technology is resulted in the formation of groundwater treatment sludge (GWTS). Because one of the elements of sustainable development is the possibility of their reuse, that water treatment plant operators are looking for new ways of managing these sludges. At present, not all factors determining the adsorptive capacity of water treatment sludge are known. The explanation why the adsorption capacity of sludge with a similar structure and chemical composition may differ significantly will allow for their wider use as adsorbents. The information which must be known to ensure proper sludge management are the quality, chemical composition and texture characteristics of the GWTS. The sludges were characterized by X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy and N2 adsorption/desorption isotherms. The results showed that the composition and properties of the GWTS depend primarily on the quality parameters of the raw water and the processes and reagents used in its treatment technology. GWTS contains mainly amorphous iron oxides. Sludges are characterized by a large specific surface area (145 m2/g). Due to composition and textural parameters, GWTS demonstrates good adsorption properties toward different compounds such as heavy metals and metalloids. In this article, the authors describe the relationship between properties of resulting sludge and the properties of groundwater, the treatment technology and backwash water treatment from rapid filters.

RANCANG BANGUN PROTOTIPE SISTEM KENDALI IRON REMOVAL FILTER (IRF) PADA UNIT PENGOLAHAN AIR BERSIH BERBASIS PLC

Kukuh Karyadi, Jatmiko Endro Suseno in this paper explain that Water is a necessity of life that is very important for mankind. The availability of clean water has been sought to be fulfilled in various ways. One of them is by making a clean water treatment plant that can process water that is not yet suitable for consumption to be more feasible and ready to be consumed for everyday life. The operation of water treatment plant is still manually operated such as in the Iron Removal Filter (IRF) control system so that the processing is not easy to operate. To facilitate the operation of a clean water treatment unit, a control system based on a Programmable Logic Controller (PLC) is created on the Iron Removal Filter (IRF) processing unit. Control system consisting of PLC, relay circuit, power supply and Human Machine Interface (HMI), works to control the clean water processing unit including controlling the process on the IRF automatically. Also made a prototype of a water treatment plant consisting of an aerator unit, an IRF unit, a storage tank, several pumps and several control valves to be controlled by the control system in operation. The control system uses PLC as a control center because PLC is a controller that is simple, easy to program and very reliable as already widely used in the industrial world. The PLC brand used is Omron because it is cheap, reliable and has software named CX-Programmer which is easy in programming. The control system uses laptop computer as an HMI in the operation. HMI uses VTScada software and is connected to a PLC using OPC CX-Server software. The control system that is made can control the clean water processing unit in the form of a prototype. Operation on HMI is so easy and has a very attractive appearance. So it is highly recommended to be used in the actual clean water treatment unit

СИСТЕМНЫЙ АНАЛИЗ И ГИПОТЕЗА ФИЗИЧЕСКОЙ КАРТИНЫ ПРОЦЕССА ОЧИСТКИ ПОГРУЖНОГО ОБОРУДОВАНИЯ СКВАЖИН С ПРИМЕНЕНИЕМ МОДЕРНИЗИРОВАННОГО ОБРАТНОГО КЛАПАНА

Актуальность. Анализ технических средств и методов борьбы с пескопроявлениями дает основание предполагать наличие значительных резервов повышения их эффективности. В частности, установлено, что большинство методов снижения влияния механических примесей на работу насосного оборудования в настоящее время либо не решают проблему кардинально, либо не носят долговременного характера. Гидродинамическая очистка погружного оборудования, несмотря на свою эффективность, невозможна без проведения спускоподъемных операций. Альтернативой этого способа являются устройства клапанного типа. Однако их применение сдерживается из-за того, что не решен вопрос подбора оптимальных конструктивных параметров данных устройств. В связи с вышеизложенным есть необходимость проведения соответствующих теоретических исследований. Цель: провести системный анализ и предложить гипотезу физической картины процесса очистки погружного оборудования скважин с применением модернизированного обратного клапана. Методы: системный анализ процесса очистки погружного оборудования скважин. Результаты. Системный анализ работы очистных установок клапанного типа показывает, что из всех элементов внутренней структуры наибольшее число связей имеют параметры специального очистного оборудования. Следовательно, дальнейшее изучение рассматриваемой системы связано с выделением соответствующей подсистемы, определяющей только процесс очистки, а также с выяснением физической картины этого процесса. Предложена гипотеза физической картины процесса очистки, учитывая которую, можно заметить, что в подсистеме «Условия эксплуатации – конструктивные и технологические параметры клапана – производительность» в большей степени реализуется основное назначение всей системы. Выделение этой подсистемы отдельно позволило в общем виде найти взаимосвязь производительности процесса очистки и основных элементов внутренней структуры этого процесса. Практическая польза найденной взаимосвязи заключается в возможности обоснованного поиска оптимальных конструктивных параметров установки клапанного типа и скорости очистного потока через нее, в зависимости от основных факторов.

Industrial experiment on electrodialized separation of highly concentrated multicomponent technological solutions at thermal power plants

The main sources of highly concentrated multicomponent technological solutions at thermal power plants (TPPs) are water treatment plants. Analysis of operation of the ion-exchange water treatment plant at the Nizhnekamsk Thermal Power Plant-1 showed that half of alkali supplied to regeneration of the anion-exchange alkali filters is not used, but is discharged for neutralization and then to wastewater. Due to the fact that the cost of alkali used in technological processes is quite high, it is economically feasible to process the alkaline waste with the alkali extraction and its reuse in the production cycle. The article presents the experimental results on the electro-membrane separation of alkaline waste regeneration solutions and wash water after anion-exchange filter regeneration. The revealed differences in the selectivity of various ion transfer through the electrodialysis apparatus membranes, depending on time and amount of transmitted electricity, allowed us to establish the possibility of obtaining an alkaline solution purified from impurities.

Nitrosamines: A review of formation pathways, precursors, control, and occurrence in drinking water

Nitrogenous disinfection by-products (N-DBPs) are emerging by-products that may be present in drinking water as by-products of water treatment plant (WTP) operations. Nitrosamines are N-DBPs that form by reaction of chloramine with certain organic nitrogen-containing compounds; however, the exact processes and environments in which nitrosamines form are still not well understood. Organic nitrogen precursors react within the WTP and distribution system, forming the toxic by-products during chloramination, or while in distribution. To best control the formation potential of nitrosamines, precursors must be removed from source water prior to chloramine disinfection. These nitrosamine forming precursors are abundant in source waters worldwide, presenting a need for further study of the mechanisms that reduce the formation potential of nitrosamines in chloramination WTPs.

Combining Chemical Flocculation and Disc Filtration with Managed Aquifer Recharge

Natural organic matter (NOM) is a growing concern for artificial recharge plants. In the future, it is predicted that warmer climates and more precipitation will cause higher NOM production in lakes and more NOM transport to lakes. This, coupled with increasing drinking water demand due to the population increase, is pushing operators of water treatment plants (WTPs) to find new ways to treat water. In this study, the possibility of reducing the organic load in infiltration basins through a compact pre-treatment technique utilizing microsieves, or disc filters, instead of bulky sedimentation basins and rapid sand filters after chemical flocculation to separate flocs, was investigated. The experiments were conducted using a laboratory-scale flocculator, bench-scale disc filters (10 µm and 40 µm), FeCl3, an anionic synthetic polymer, and water from Lake Vomb, a lake in southern Sweden. Raw water was flocculated using FeCl3 and the polymer, and the filtrated samples were analyzed by measuring UV–VIS absorbance, total organic carbon (TOC), and permeate volume. The results when using 10-µm and 40-µm disc filters demonstrate that it is possible to reduce NOM (by approximately 50%) and separate flocs from raw water. The experiments also highlight the importance of sufficient flocculation times and the use of appropriate polymer dosage to achieve higher permeate volumes and avoid residual polymers in the effluent. In this paper, the possibility of using this technique as a standalone treatment step or as a pre-treatment step in order to manage the aquifer recharge is demonstrated.

Expert system for applying coagulant in water treatment: case study in Nobres (Brazil)

Abstract In most Brazilian municipalities, the water supply comes from surface water sources, requiring infrastructure and human resources, especially water treatment. Where infrastructure and human resources are lacking, auxiliary methods and/or substitutes are valuable. The aim of this work was to develop an expert system (ES) to determine and apply coagulant dosing, in real time, in a water treatment plant (WTP). The ES was developed and evaluated at the WTP in Nobres, Mato Grosso (MT) state, Brazil. It is called AIASD (artificial intelligence for aluminium sulphate dosage) and was validated using the Turing test. It can determine and apply coagulant dosing in water treatment. AIASD contributed successfully to WTP operations in Nobres and other WTPs; making decisions and applying the coagulant dosing necessary for water treatment.

Multi-Parameter Compensation Method for Accurate In Situ Fluorescent Dissolved Organic Matter Monitoring and Properties Characterization

The recent deployment of fluorescent dissolved organic matter (fDOM) probes in dam catchments and drinking water treatment plants (DWTP) for water quality monitoring purposes has resulted in the production of a large amount of data that requires scientific evaluation. This study introduces a comprehensive, transferable methodological framework for scientists and water professionals to model fluorescence site-specific quenching on fDOM probe readings caused by temperature, suspended particles, and the inner filter effect (IFE) and applies it to an Australian subtropical reservoir. The findings revealed that quenching due to turbidity and IFE effects were best predicted by threshold autoregressive models. Raw fDOM probe measurements were validated as being more reliable if they were systematically compensated using the proposed procedure. The developed fDOM compensation procedure must consider the instrument features (i.e., wavelength broadband and responsiveness) and site-specific conditions (i.e., DOM characteristics and suspended particles). A finding of particular interest was that the compensated normalized fDOM readings had a high correlation with the low (<500 Da) molecular weight fraction of the DOM, which is more recalcitrant to removal by coagulation. As a consequence, there is potential to use compensated fDOM probe readings to provide real-time, in situ information on DOM properties in freshwater systems, which will enable water treatment plant operators to optimize the coagulation process.

Pengolahan Air Bersih di Pondok Pesantren As – Shiddiqiyyah dan Panti Asuhan Al-Haq Kecamatan Sungai Kakap Kabupaten Kubu Raya

As – Shiddiqiyyah Boarding School and Al-Haq orphanage have shortage of clean water. Both of partners used well water for bathing, washing and latrines (MCK). Well water quality is bad because it contains high iron content. Therefore, a water treatment plant is needed that is capable of processing well water so it is safe to use. Water treatment design consists of aeration, adsorption, and filtration. The processing capacity is 1100-1550 liters. The method is a parcipatory and collaborative method whereby santri and orphanage children participate in activities such as socialization and training, operation and maintenance of clean water treatment plants. In addition, the water treatment guidebook is designed to facilitate the operation and maintenance of clean water installations. PKM runs smoothly and partners have high amino activity. The evident from the positive partner response and good communication between the participants and the team of devotion.

Enhanced Coagulation for the Different Mixture Ratio Raw Water of Yellow River Water and South-to-North Water Diversion Water

This study analysed the water quality of the mixed raw water of Yellow River Water(YW) and South-to-North Water Diversion Water (SNW) in the proportion of 2:1, 1:1, 1:2. According to the actual operation condition of most water treatment plant in Zheng Zhou, PAC was used as coagulant and activated silica acid as coagulant aid for enhanced coagulation. Finally, the removal efficiency of turbidity, UV254, NH3-N for different raw water was gave. The optimum coagulant and coagulant aid (activated silica acid) dose of enhanced coagulation were determined. The results of this study would provide guidelines to the optimization operation of the local water treatment plants which used the mixed raw water of YW and SNW.

Mobile Technology Expands Emergency Water Treatment Options

When emergencies strike or unplanned plant shutdowns occur, the need for an immediate solution is critical. As technology and innovation in the water industry have advanced in the past 25 years, fleets of membrane-based mobile water units have become increasingly prevalent. Such mobile water treatment solutions provide rapid, flexible solutions for the evolving needs of water treatment plant operators.

Cost-Optimal Flexibilization of Drinking Water Pumping and Treatment Plants

This paper examines potential cost savings attained through the flexible operation of water treatment plants and drinking water pumping and the benefits gained by investing in extended water storage capacities that enhance flexibility. An existing plant in South Germany serves as an example. Mixed-integer linear programming is used to model the plant and the electricity procurement on the German spot market while ensuring the security of supply. Cost optimization considering the different cost components reveals potential cost savings through flexible operation. The paper evaluates the benefits of building additional water reservoirs and rates the financial effects of the measures used to enhance the flexibility of water pumping and treatment plants.