Efficiency Of Water Treatment System Research Articles

The estimation of DBPs formation potential depending on the molecular structure of natural organic matter

Objectives:Since natural organic matter(NOM) is generated from an ecosystem, it has various characteristics depending on its origin. Especially, aquatic NOM reduces an efficiency of water treatment system and forms disinfection-by-products(DBPs) as a precursor. In this study, DBP formation potential was estimated according to the molecular structure of NOMs resulted by pyrolysis-gas chromatography-mass spectrometer(py-GC-MS). Methods:Five NOM samples were characterized: Suwannee River NOM(SRNOM), Mississippi River NOM(MRNOM), Nakdong River NOM(NR), NOM in effluent of Jinhae wastewater treatment plant(WP), and NOM in a small stream(SG) in Changwon city. The various analytical instruments were used including TOC analyzer, UV spectrometer, fluorescence spectrometer, and size-exclusion chromatography. After freeze drying of NOMs, molecular structure of samples was identified by py-GC-MS. Results and Discussion:Molecular weights of SRNOM and MRNOM were similar each other (~1400Da). The others(NR,WP,SG) were larger than the SRNOM and MRNOM. Hydrophobicity of the samples followed the order: SRNOM≒MRNOM > NR > WP > SG. Py-GC-MS results showed that SRNOM and MRNOM contain high portion of humic components. Otherwise, NR, WP, SG have protein which is originated from microbials. The DBP formation potential of SRNOM and MRNOM were the highest.Conclusion:This research shows the different characteristics of NOMs originated from different source. The results confirmed that NOM contained high portion of humic components results in the formation of high concentration of DBPs.

Experimental research of electrical characteristics combined solar-electric air heater

Poor water quality in district heating systems leads to failure of boilers and pipelines in heating networks. The main reason for this is corrosion and scale deposits. The presence of these factors shows the low efficiency of water treatment systems. The article presents the results of the introduction of non-traditional water treatment technologies for district heating systems based on the experience of the Zhytomyrteplokommunenergo utility company of the Zhytomyr City Council in 2007-2021. In the boiler houses of the enterprise, water treatment systems were modernized, and the production chemical service was reorganized. In particular, chemical deaeration was launched in combination with traditional sodium cationization, as well as chemical deaeration in combination with complexonate water treatment against the classical water treatment technology - ion exchange. Installed magnetic sludge separators with magnetic inserts. The technology of water softening with anti-corrosion protection using Redox filters has been introduced. Gravimetric corrosion sensors of our own design have been developed and installed. The database of processing and statistical analysis Access "Corrosion damage of pipelines of heat networks" was created and put into operation. The experience of modernizing the water treatment system has shown that work in this direction increases the reliability of operation of district heating systems by reducing the consumption of energy carriers and material resources. In addition, the problem of improving the operational reliability of the heat exchange equipment of thermal stations needs to be solved. The projected start of the use of heat recovery devices on water heating boilers in operation, in condensation or partially condensation modes, will also bring with it a number of problems with the neutralization of condensate and its return to the heat supply system. The end result is an increase in production reliability, environmental friendliness and a reduction in the cost of heat for district heating systems.

Porous Pellicle Formation of a Filamentous Bacterium, Leptothrix.

The bacterium Leptothrix cholodnii generates filaments encased in a sheath comprised of woven nanofibrils. In static liquid culture, L. cholodnii moves toward the air-liquid interface, where it forms porous pellicles. Observations of aggregation at the interface reveal that clusters consisting of only a few bacteria primarily grow by netting free cells. These growing clusters hierarchically enlarge through the random docking of other small clusters. We find that the bacteria swim using their polar flagellum toward the interface, where their sheath assists them in intertwining with others and thereby promotes the formation of small clusters. In contrast, sheathless hydrophobic mutant cells get stuck to the interface. We find that the nanofibril sheath is vital for robust pellicle formation as it lowers cell surface hydrophobicity by 60%, thereby reducing their adsorption and enabling cells to move toward and stick together at the air-liquid interface. IMPORTANCE Efficient and sustainable management of water resources is becoming a fundamental issue for supporting growing populations and for developing economic activity. Fundamental to this management is the treatment of wastewater. Microorganisms are the active component of activated sludge that is employed in the biodegradation process of many wastewater treatment facilities. However, uncontrolled growth of filamentous bacteria such as Sphaerotilus often results in filamentous bulking, lowering the efficiency of water treatment systems. To prevent this undesirable condition, strategies based on a fundamental understanding of the ecology of filamentous bacteria are required. Although the filamentous bacterium Leptothrix cholodnii, which is closely related to Sphaerotilus, is a minor inhabitant of activated sludge, its complete genome sequence is known, making gene manipulation relatively easy. Moreover, L. cholodnii generates porous pellicles under static conditions, which may be a characteristic of filamentous bulking. We show that both swimming motility and nanofibril-mediated air-liquid interface attachment are required for porous pellicle formation. These insights are critical for a better understanding of the characteristics of filamentous bulking and might improve strategies to control activated sludge.

Assessing the efficiency of a recirculating fluidized bed biofilter in white leg shrimp (Litopenaeus vannamei) broodstock aquaculture

This paper shows the results of the efficiency of a circulating fluidized bed biofiltration system using polyethelene as a filtering material. Changes in water quality parameters and the growth rates of shrimp (broodstock and commercial production) were used to assess the efficiency of water treatment system. The concentration of NH4+ in waste water from the broodstock tanks decreased 61% after three months of treatment. The final concentration of NH4+ after treatment was 0.07 mg/ml which meet the Vietnamese regulations for discard of aquaculture waste into coastal waters. Biological oxygen demand decreased 48%. The corresponding figures for treating waste water from commercial shrimp tanks were decreases of NH4+ by up to 61% with outlet concentration 0.07 mg/ml accepted to discard according to Vietnamese Standard and biological oxygen demand by 55%. Outlet water providing from broodstock and commercial shrimp tanks were treated with COD concentration decreased from 3.12 down to 2.62 mg/ml and 4.62 down to 2.68 mg/ml, or 16% and 41.9% of COD removal, respectively.

Removal efficiency calculated beforehand: QSAR enabled predictions for nanofiltration and advanced oxidation

The efficiency of water treatment systems in removing emerging (chemical) substances is often unknown. Consequently, the prediction of the removal of contaminants in the treatment and supply chain of drinking water is of great interest. By collecting and processing existing chemical properties of contaminants, QSARs (quantitative structure-activity relationships) for typical removal parameters can be constructed. Depending on the definition of the predicted endpoint, QSARs are (1) embedded in a process model suite, where they serve to predict a model parameter and the total, hybrid model predicts a removal rate or (2) used to directly predict, e.g., the removal rate, or a rejection coefficient for membrane systems. The different types of resulting prediction models, ranging from mechanistic (causal) to empirical (data-based), allow for hypothesis testing of current physico-chemical mechanisms and interactions between the contaminant, the type of water and the materials or energy (e.g. UV light) of the removal barrier. Two case studies illustrate this viewpoint and also pinpoint that, firstly, QSAR development, validation and residual analysis stress the linkage between the QSAR endpoints and process model predictions, and secondly, they lay bare the need to share data, algorithms and models.

Entropy analysis of water and wastewater treatment processes

In the environment, due to its physicochemical properties such as action as a solvent in becoming a carrier to waste materials and waste heat, water especially as compared to other environmental media is very susceptible to pollution. Entropy is the measure of disorder of a system. In a closed system, entropy tends to increase. For example, if a compound is dumped in pure water, it is likely that the compound will be dissolved and diffused into whole water body. The meaning of a compound dissolved and diffusing in the water is twofold: (1) increase in entropy of the solution; (2) increase in the extent of pollution. It can be seen that an increase in entropy results in water pollution. Once water is polluted, input energy is required in order to remove the pollutants and purify the water and to decrease the entropy of polluted water. On the other hand, the entropy is created by the irreversibility. The author will show that if the efficiency of water treatment system (N) can be given by entropy production...

Evaluation of thermodynamical efficiency of reverse osmosis process using entropy

Entropy is the measure of disorder of a system. In a closed system, entropy tends to increase. For example, if a compound is dumped in pure water, it is likely that the compound will be dissolved and diffused into whole water body. The meaning of compound dissolving and diffusing in the water is twofold; (1) increase in entropy of the solution; and (2) increase in the extent of pollution. It can be realized that increase in entropy results in water pollution. Once water is polluted, input energy is required in order to remove the pollutants and purify the water, to decrease the entropy of the aqueous solution. The purpose of water treatment is to decrease the entropy of polluted water. On the other hand, the entropy is created by the irreversibility of the system. We may explain later, that if the efficiency of water treatment system (η) can be given by the rate of decrease in entropy of feed water ( ΔS/ Δt) and the rate of internal entropy production (d t S/d t), then we can evaluate the thermodynamical efficiency of water treatment systems.