Existing Water Treatment Plant Research Articles

Optimizing the processing conditions of ballasted flocculation of actual turbid river water

ABSTRACT Ballasted flocculation is effective for fast turbidity removal in water treatment processes. However, there is a lack of specific information for setting the conditions for ballasted flocculation. To enhance the settling velocity and removal efficiency of ballasted flocculation of actual river water, the process parameters were examined at three turbidity levels. The optimum pH and dosages for ballasted flocculation were investigated based on the relationship between the water turbidity and the floc settling velocity at the three turbidity levels. A nonionic polymer flocculant was the most suitable for floc formation and achieved the lowest turbidity and highest settling velocity. Under the optimum processing conditions at the three turbidity levels, the treated water turbidity was ˂2 turbidity units (TU) and the floc settling velocity was ˃0.7 cm/s, which was 30 times that of conventional coagulation–sedimentation, reducing the floc settling time by 97% of those used in existing water treatment plants.

Ultrafiltration and reverse osmosis integrated to conventional drinking water treatment to ensure human right to water in dam break scenarios: From bench- to pilot-scale

Previous events of tailing dam failures were associated with impacts in the water sources of drinking water treatment plants, which involves elevated concentrations of suspended solids and metal(oid)s. This study assesses the effectiveness of conventional treatment processes at a lab-scale, highlighting their limited robustness in treating water with different physicochemical qualities. Subsequently, it validates the integration of ultrafiltration (UF) and reverse osmosis (RO) into an existing water treatment plant to enhance its performance. The processes were conducted at a pilot scale, operating for 660 h under varied turbidity (<2 – 200 NTU) and contaminant (iron, manganese, and arsenic) concentrations. The membranes operated steadily with an average permeate flux of 38.6 ± 0.9 L/m2h and 19.6 ± 0.8 L/m2h for UF and RO, respectively. UF fouling was primarily related to internal pore blocking and attributed to organic matter and inorganic compounds, identified using excitation-emission matrix and energy-dispersive X-ray mapping across the cross-section of its fibers. Due to the limitations of UF in removing dissolved species, RO became necessary and ensured that all parameters analyzed met drinking water standards. The UF-RO contributes to higher robustness to conventional treatment processes and addresses operational challenges associated with a dam rupture event such as the unforeseen alteration in the quality of surface water that hinders the optimization of pre-oxidants and coagulants in conventional treatment process. To reduce costs, energy requirements, and the size of membrane-based systems, a blending strategy was proposed with a focus on achieving drinking water standards. The suggested blends include effluent from sand filters and RO permeate in a 1:1 ratio. That was only possible due to the high quality achieved for RO permeate. Apart from creating more compact systems, the blending strategy promotes the remineralization of RO permeate, mitigating undesirable characteristics such as corrosiveness, taste, and odor. For the concentrate, UF concentrate could be recycled back into the treatment process, improving water recovery in the drinking water facility, while the concentrate from RO adheres to discharge limits. Overall, the study advances investigations on integrating ultrafiltration and reverse osmosis with conventional drinking water treatment to address water quality issues from tailing dam ruptures.

Fiber-based super-bridging agents improve flotation and settling during water treatment

Increasing demand for water poses a major challenge to the water treatment industry. Consequently, water treatment plants are expected to require larger separation units and use more chemicals. Physicochemical treatments produce flocs that are limited in size, which limits floc removal efficiency during gravitational separation. Introducing fiber-based super-bridging agents has improved the floc size, which is 10–100 times larger than conventional flocs. Such improvements could lead to important gains in floc separation and ultimately increase the capacity of water treatment plants. This study analyzed the behavior and interaction of fibers under various coagulation/flocculation conditions to improve flotation and settling. The results also showed that fibers can allow a ~ 50 % reduction in coagulant. The benefits of fibers on floc size were particularly pronounced during suboptimal coagulation, as the injection of fibers compensated for poor coagulation conditions. Air bubbles during air flotation were also better incorporated into the larger and more porous floc structure obtained with fibers, which drastically improved floc removal during flotation. The best turbidity removal after flotation was obtained when combining 2 mg of cationic polyacrylamide and 200 mg of softwood fibers/L. Fiber-based super-bridging agents can be introduced in existing water treatment plants to increase plant capacity, reduce the demand for coagulants/flocculants, and improve contaminant removal.

ASPEN PLUS CONCEPTUAL DESIGN OF BASIC RAW HARD WATER TREATMENT AND SOFTENING OPERATION

Hard water can cause scaling concerns in pipes, turbines, boilers, and heat exchangers used in mining, oil and gas, and industrial applications. It also interferes with nearly every housekeeping chore, from laundry and dishwashing to bathing and personal hygiene. ENRTL-SR and PITZER property models in Aspen Plus V8.8 were chosen during the modelling and simulation of soft water production from a hypothesized hard water stream containing sand. Findings show that, under normal conditions, about 3 m3 of soft pure water can be generated from approximately 40 m3 of raw water using right unit configuration and treatment solvent proportion. Drawbacks which would have address several limitations faced during the simulation, as concluded, can be solved using suggested alternative software tools. Water treatment scientist should try to simulate the same process using Aspen Plus utilizing real data from an existing water treatment facility to correctly test for effectiveness of the software tool. Modification of several existing water treatment plants across the globe to soften water produced is recommended, given its suitability for both domestic and industrial use.

Fiber-based super-bridging agents enable efficient contaminant removal via settling and screening: Impact on microplastics, textile fibers, and turbidity

The water treatment industry relies heavily on coagulation and flocculation processes. This technology requires large amounts of chemicals and large settling tanks for floc separation. The flocs formed during conventional treatment are small (<100 µm), which limit their removal by gravitational separation. To improve floc separation, fiber-based super-bridging agents have been added to the coagulation/flocculation process. When fibers were used in combination with a coagulant and flocculant, the flocs formed were 10 – 100 times larger, and settling was remarkably improved. The tested super-bridging agents also led to a 50 % reduction in demand for both the coagulant and flocculant. The use of super-bridging agents is an effective technique for reducing turbidity and improving the removal of emerging contaminants in both synthetic and natural surface water. Formation of very large flocs with fibers also allowed the replacement of settling by screening without any effect on removal of monitored contaminants. Fibrous treatment removed up to 78 % of turbidity when using a 5000 µm screen mesh size, compared to only 45 % with conventional treatment (coagulant and flocculant, no fibers). Super-bridging agents also drastically improved microplastic removal. The fibrous treatment removed 80 % of 15 µm polyethylene beads, compared to only 20 % with the conventional treatment. Such low removal indicates potential concerns regarding the effective removal of smaller microplastics in existing water treatment plants.

Spatial Analysis of Groundwater Abstraction and Land Subsidence for Planning the Piped Water Supply in Jakarta, Indonesia

Although the special region of Jakarta Province (DKI Jakarta), Indonesia, has a large population of 10.9 million, piped water coverage remains at only 64%. Therefore, excessive groundwater abstraction has caused serious land subsidence over the last few decades. This study proposed the priority areas for piped water supply extension to alleviate the adverse effects of groundwater over-abstraction in DKI Jakarta. Water consumption and multilayer analyses (e.g., geology, groundwater abstraction, groundwater level, piped water coverage, and groundwater quality) were carried out to determine the priority areas for piped water development. Based on three parameters, namely the water demand–supply gap, land subsidence, and groundwater quality, the northern and western regions of Jakarta were selected as the priority areas for piped water development, followed by the southern and eastern regions. The demand for piped water by the population in the abovementioned priority areas is estimated to be 462,211 m3/d, while the total water demand of Jakarta is 1,878,899 m3/d, which is greater than the supply capacity of 1,747,440 m3/d from the existing water treatment plants. Therefore, the areas for controlled groundwater abstraction were also selected to augment the shortfall of the piped water supply capacity.

An environmentally sustainable way for effective water purification by adsorptive red mud cementitious composite cubes modified with bentonite and activated carbon

More practical, easy-to-design, inexpensive, environmentally-sustainable, and environmentally-friendly approaches are needed for access to clean water. The utility of red mud, which is considered hazardous waste, combined with bentonite and activated carbon in cement pastes has been investigated for effective water treatment method. Improvement rates of 51.7% and 90.27% was achieved in removing heavy metals such as, cobalt and barium, which is very toxic for human health from the raw dam water using adsorptive red mud cement paste cubes modified with bentonite and activated carbon, and these can be an important alternative for treating industrial wastewater originating from production in industrial facilities and factories. Designed adsorptive cubes used as a water softening tool, have brought dam water to drinking water standards in terms of its physical, chemical, and biological properties. These red mud cement pastes can be used in sand filters in existing water treatment plants or be used in pervious concrete roads with its porosity structure 2.12 times higher than that of control paste to prevent rainwater pollution, minimize floods in sewer systems, and reduce the pollution load of the wastewater treatment plant.

Facile synthesis and implications of novel hydrophobic materials: Newer insights of pharmaceuticals removal

The residual escape of pharmaceuticals from wastewater treatment plants (WWTP) is a serious environmental concern due to the adverse effects towards living organisms. Therefore, it is important to devise the newer technologies for safe and efficient elimination of emerging micro-pollutants from effluents of existing water treatment plants. Bentonite is grafted with 3-mercaptopropyletrimethoxy silane by facile one-pot method to obtain dense composite material (MPTS/BENT).The materials are characterized by the FT-IR, XRD, BET and SEM/EDX analytical tools. Various parametric experiments conducted for the removal of tetracycline hydrochloride (TCH) and triclosan (TCS) using MPTS/BENT under batch experimentations. Further, column adsorption experiments have been performed.The incorporation of organosilane with bentonite is confirmed by FT-IR and EDX analyses. BET surface area analysis showed that the surface area of MPTS/BENT is significantly small compared with pristine clay. pH dependent sorption of TCH and TCS is almost unaffected within the pH 3.0 to 7.0. Rapid uptake of TCH and TCS by MPTS/BENT followed PSO kinetics. High percentage removal was achieved at wide concentration range of pollutants. The uptake of TCH and TCS is unaffected increasing the background electrolyte concentrations for 1000 times. Column experiment confirmed the high efficiency of MPTS/BENT towards these pollutants. Moreover, the removal of TCH/or TCS from real water sample at varied pH values showed that the synthesized composite is selective and efficient towards these micro-pollutants. This study showed that the synthesize material, i.e., MPTS/BENT could be efficiently employed for the additional purification of WWTP effluents.

Ceramic membrane based hybrid process for the upgrade of rural water treatment plants: A pilot study.

An integrated process with ozonation, ceramic membrane ultrafiltration, and activated carbon filtration is investigated for the treatment of drinking water in the rural area of China. A pilot-scale experiment with a capacity of 20m3 /d is conducted, and a number of water quality parameters are evaluated, such as turbidity, color, organic matter (CODMn ), manganese (Mn), geosmin (GSM), 2-methylisoborneol (2-MIB), and 37 kinds of pharmaceutical and personal care products (PPCPs). The result shows that the removal efficiency of all the evaluated parameters of this integrated process is much higher than that of the conventional treatment processes. In particular, the removal rate of PPCPs achieves 52.5%, which is twice higher than that of the conventional process. Moreover, ozone can oxidize manganese ions, degrade organic matters, and reduce membrane fouling. It is believed that the integrated treatment process developed in this study is efficient in upgrading the existing water treatment plants and ensuring the safety of drinking water in the rural areas around the world.

A bench‐scale study of potable reuse impacts on surface water treatment

AbstractWater utilities are considering raw water augmentation schemes to blend potable reuse water directly into the raw water for existing water treatment plants (WTPs). In this study, bench‐scale testing evaluated the impacts of introducing advanced‐treated reuse water (treated by ozonation, biological active carbon, ultrafiltration, reverse osmosis, and advanced oxidation) into the raw water supply of an existing WTP. To determine whether treatment would remain effective, blends of raw water and reuse water were coagulated, flocculated, and settled in a jar test apparatus matching the flocculator energy dissipation rate of the full‐scale WTP and were tested for filterability, defined as positive removal of turbidity through 5‐μm filter paper. The testing demonstrated that blends were treatable across a range of conditions, and alkalinity was the main observed limitation for treatability. Conditioning the advanced‐treated reuse water to add both hardness and alkalinity buffered against extreme pH drops during coagulation. This also achieved pH and calcium carbonate indexes after treatment that matched the current finished water, but some stability indexes shifted in a more corrosive direction, suggesting a topic for future research. Overall, this study demonstrated that the coagulation, flocculation, settling, and filtration processes of an existing WTP can treat potable reuse blends provided alkalinity is sufficient, and this is an important finding for the viability of raw water augmentation.

Features of Application of Aluminum–Iron Composite Coagulants in Purification of Water with High Content of Natural Organic Substances

Disposal of red mud from aluminum production is a worldwide problem and is of great importance in protecting the environment. In previous studies, the authors determined the possibility of obtaining a composite coagulant for the treatment of natural water and wastewaters. The effectiveness of purification of colored Dnieper water by such a reagent due to the presence of iron and aluminum compounds in its composition was shown. On the other hand, there were difficulties associated with an increase in the content of residual iron in purified water. Obviously, for this reason, iron coagulants (in “pure” form and mixed with aluminum sulfate) have not been used in the purification of Dnieper water. In continuation of these works, we have studied the use of composite coagulants and mixtures obtained from red mud using hydrochloric and sulfuric acids, sulfates of iron and aluminum in different proportions. The article presents the results of seasonal studies on the treatment of Dnieper water using jar tests, simulating the real parameters of the existing water treatment plant. It has been found that the best effect of purifying Dnieper water is achieved by using composite mixtures with a ratio of Fe2O3/Al2O3 not exceeding 1/1. A significant effect of pH on the residual concentrations of iron and aluminum in water has been noted. The results of the work are in good agreement with modern ideas about the coagulation of such waters, explain the failures in the use of iron-containing coagulants, and determine the possible ways of this application in the purification of Dnieper colored water containing a significant amount of natural organic compounds.

Vertical Upgrading of Existing Water Treatment Plants by using Air Flotation Technique

Due to the rate increase for potable water need, the general market trend is the vertical expansions for water treatment plants instead of the horizontal ones. By upgrading the existing plants using new technology to reach the maximum capacity and conserve the water quality parameters as the Egyptian Code states. The most benefits of plant upgrading are no new land is needed also, low cost solution, as we could upgrade the WTP as mentioned before without adding major civil works comparing with the construction of new water treatment. This study aims to upgrade the existing water treatment plants using dissolved air floatation system, in order to reach the maximum possible capacity using several possible scenarios without adding major civil works. The study shows that, the scenario which involves DAF technology then sedimentation and filtration has the best removal efficiency because it has three treatment phases. The use of one treatment phase from floatation or sedimentation followed by filtration achieved lower efficiency. At last direct filtration, considering low removal efficiencies due to the high rate of filtration which allowed the suspended solids to escape.For the application upon Al Ameriyah water treatment plant, the first proposal which involves five combined tanks, two tube settler and one filter tank is the most convenient proposal to be achieved. Since it has quiet high value 72 points in the technical evaluation with the least estimated cost 85,769,200 LE. The use of DAF technology combined with sedimentation gives the chance to increase the existing plant capacity from 520000 m3/day to 864815 m3/day with rate of increase equals 66.31% which is a cheap and happy solution.

Diagnosis, recommendations and optimization for potable water treatment plant in Cauca (Colombia)

Currently the water supply system in the municipality of Corinto (Cauca) in Colombia provides drinking water to the entire urban and rural population of the municipality. In order to provide drinking water to the entire population, it became necessary to optimize and/or expand the existing water treatment plant. The article presents an assessment of the consideration of two optimization options: the need for reconstruction of existing water treatment facilities or the construction of additional water treatment units. A reasonable proposal was made to expand the station by building additional water treatment units, including advanced modern water treatment technologies, such as coagulation, flocculation, sedimentation, filtration, sorption, settling using thin-layer modules and disinfection, based on the survey (diagnostics), technical and economic analysis, analysis of the efficiency of the existing water treatment plant, taking into account the quality of drinking water preparation, confirmed by the analysis of samples, the results of physical, chemical and microbiological tests, indicating the optimal quality of drinking water for human consumption. The use of modern water treatment technologies will allow to achieve the required quality of purified sufficient water for drinking purpose.

Analysis of Hybrid Configuration Solar Power Plant Design at Water Treatment Plant

Human life needs are essentially supported by the need for electrical energy currently faced with environmental issues. Power plants in Indonesia 57.2% still use coal fuel as their primary fuel. The electrical load needed is undoubtedly a critical concern on energy. The existing water treatment plant is still completely dependent on the existing power generation system. We can utilize the available space at the water treatment plant to design a solar-powered electricity generation system. Later, the system with 800 PV modules and 290 batteries that produce 1106.175 MW of power will be able to support the daily electricity needs of water treatment plant.

Investigation of the influence of chlorine-containing disinfectant type on the quality of drinking water and the effectiveness of water treatment technology

Introduction. Effectiveness and applicability of chlorine-containing disinfectants used in the practice of water treatment were studied for the purpose of solving urgent environmental problems associated with the formation of secondary pollutants generated during the chlorination of natural water. Such contaminations are mostly represented by organohalogen compounds producing strong negative effect on the physiological state of living organisms, including human beings. To solve this problem, it is proposed to use technical grade sodium hypochlorite instead of traditional liquid chlorine when selecting disinfectants for natural water. Technical grade sodium hypochlorite is obtained by saturating solutions of diaphragmatic sodium hydroxide with chlorine gas at the stage of liquefaction of chlorine and caustic soda production. Sodium hypochlorite solution is significantly less toxic, non-flammable and not explosive. Materials and methods. A comparative study was conducted as to changes in the content of organohalogen compounds and heavy metals in water treated with sodium hypochlorite and liquid chlorine of one year duration. Analyses of water samples of water treated with liquid chlorine and sodium hypochlorite were made to measure concentrations of heavy metals, organohalogen compounds and other drinking water quality indicators, as specified by current regulations. Results. The obtained data demonstrate that the use of sodium hypochlorite for disinfection provides a higher quality of drinking water, therefore, it is advisable to replace liquid chlorine with technical grade sodium hypochlorite in the process of water treatment as potable water. Conclusions. The results of the study formed the basis for numerous industrial tests and subsequent implementation in existing water treatment plants in many large cities of Russia.

Study of Parameters in Redesign of Existing Water Treatment Plant

Study of Parameters in Redesign of Existing Water Treatment Plant

Review: Natural organic matter in aquatic systems – a South African perspective

Natural organic matter (NOM) is a complex heterogeneous mixture of humic (HS) and non-humic substances which are widespread in the aquatic environment. Other constituents are amino acids, aliphatic and aromatic hydrocarbons containing oxygen, nitrogen and hydroxyl groups. It is the combination and proportions of these motifs which give NOM its overall polarity and reactivity. Its main origins include soils, residues of fauna and flora, microbial excrements and anthropogenic faecal loads, agriculture activities and urban landscapes. Due to the different origins of the precursor material and the extent of transformation it undergoes, the composition of NOM in different water bodies varies. Characterization methods for NOM can be divided into three broad categories namely: (i) direct measuring methods, which measure the amount of organic matter in the sample; (ii) spectrometric methods, which measure the amount of radiation absorbed and or released by chromophores; and (iii) fractionation methods, which separate NOM according to size and polarity. South Africa has 6 distinct water quality regions, and each region has a unique NOM character and quantity. Existing water treatment plants do not remove NOM to levels low enough to inhibit the formation of disinfection by-products (DBPs). Currently, research is focusing more on the use of alternative techniques for NOM removal; these include advanced oxidation processes (AOPs), nanomaterials, and ceramic membranes. While NOM is well studied in other parts of the world, to the best of our knowledge, there is no state-of-the-art investigation of the occurrence and removal of NOM in South African source waters. This review aims at (i) synthesizing literature on the nature, occurrence and ecological impact of NOM, (ii) evaluating the removal of NOM in the six different water quality regions of South Africa, and (iii) suggesting novel approaches that can be used to remove NOM in South Africa.

Analytical studies to tracing the effects of ozone chemicals on an existing water treatment plant

The quest to living and dining in a healthy environment do not only prolong the life of human being alone but the lives of all other important creative rsquo s around them Human and industrial activities around the urban cities across the globe have continually posing treats to achieving the objective of a healthy living This study is on tracing the effects of ozone chemicals on the Kaduna North Water Treatment Plant KNWTP and some selected points on the public consumption outlets The qualitative analysis was done by comparing the laboratory results obtained with the acceptable value range of traced elements pH and turbidity as in accordance with World Health Organization WHO standard It was observed that many of the trace elements fall within the WHO standard with the exception of carbon IV dioxide CO concentration of the raw water and treated water of about ml and ml respectively and that of Nitrite NO with concentration range of mol liter and mol liter respectively in which both values fall above the required standard for drinking water of ml and mol liter respectively In summary the study shows that the activities and performance of KNWTP are relatively in good order

Configuration of a pilot station in a technological investigation of groundwater treatment

The purpose of pre-design technological investigations is to define the water treatment technology for a new or existing water treatment plant. The investigation is performed on model-scale equipment, making sure that the results can be extrapolated to the technological scale. The investigation should allow for the determination of unit process parameters and ensure the desired outcome i.e. treated water meeting the applicable quality standards. Indirectly, the investigation results can also be used as a basis for defining the estimated scope of the investment, the costs of its execution and the future equipment operating costs. Technological investigations are carried out on the grounds of existing or future treatment plants in order to take into account the variable composition and quality indicators of the raw water to be treated. The pilot station, being the main element of the technological investigation, should be designed, built and operated with a view to the possibility of formulating further design guidelines after the study is completed. In this article, the authors share their experience related to the configuration of a pilot station used in an investigation of a groundwater treatment technology.

PERFORMANCE EFFICIENCY ANALYSIS OF WATER TREATMENT PLANTS BY USING MCDM AND NEURAL NETWORK MODEL

The organization of safe and sustainable sources of water remains a priority for decision makers around the world. The centrality of water in public health as well as in industry creates a high demand for water supply of suitable quality that many nations around the world are harassed to meet. In India, in particular, water shortages and poor water quality continue to be major challenges in both domestic and industrial sectors. That is why, the evaluation of the performance efficiency of the existing water treatment plant is essential. This paper utilizes the Non-structural Fuzzy Decision Support System (NSFDSS) as well as Artificial Neural Network (ANN) to identify the parameter that is most significant in helping the decision makers to build an efficient water treatment plant operating system.