Increasing the energy efficiency of water inlets by re-using washed water and reducing filter cycle time

PURPOSE. The purpose of this article is to study the search for ways to reduce energy consumption and develop methods for increasing the energy efficiency of water utilities. The studies reflected in the article are based on the results of an energy survey of a water utility in the city of Gomel (Republic of Belarus), one of the tasks of which is the search for reserves for saving fuel and energy resources by reducing technological water consumption. The article presents the results of research on the example of two water intakes «Iput» and «Sozh». METHODS. When solving the problem, the methods of mathematical statistics were used, including the method of analysis of variance to assess the significance of the effect of water flushing on reducing the iron content. RESULTS. The article discusses possible ways to reduce energy costs by reducing technological water consumption, which are used to flush filtering structures. The main activities are the following: changing the filter flushing schedule with increasing the filter cycle; the use of water-air flushing; reuse of wash water. The article formulates a hypothesis: filter flushing leads to a decrease in the iron content in the water, i.e. improving the quality of cleaning. CONCLUSION. An increase in the energy efficiency of water intakes, along with measures to modernize and optimize the operation of pumping equipment, is achieved by saving water resources and, accordingly, the cost of electricity for their extraction, which is necessary when flushing the filter materials of the deferrization station. The assumption about a possible increase in the filtration cycle was the lack of significance of the influence of washing on the decrease in the iron content, which indicated the presence of a significant reserve of the washing cycle. The use of combined water and air flushing contributes to a significant reduction in both technological water consumption (40.1%) and electricity consumption (38.8%). The energy saving potential due to the reduction of technological energy consumption for lifting water for the purpose of flushing reached 89857 kWh / year for the studied water intake.

Increasing the energy efficiency of water inlets by re-using washed water and reducing filter cycle time

PURPOSE. The purpose of this article is to study the search for ways to reduce energy consumption and develop methods for increasing the energy efficiency of water utilities. The studies reflected in the article are based on the results of an energy survey of a water utility in the city of Gomel (Republic of Belarus), one of the tasks of which is the search for reserves for saving fuel and energy resources by reducing technological water consumption. The article presents the results of research on the example of two water intakes «Iput» and «Sozh». METHODS. When solving the problem, the methods of mathematical statistics were used, including the method of analysis of variance to assess the significance of the effect of water flushing on reducing the iron content. RESULTS. The article discusses possible ways to reduce energy costs by reducing technological water consumption, which are used to flush filtering structures. The main activities are the following: changing the filter flushing schedule with increasing the filter cycle; the use of water-air flushing; reuse of wash water. The article formulates a hypothesis: filter flushing leads to a decrease in the iron content in the water, i.e. improving the quality of cleaning. CONCLUSION. An increase in the energy efficiency of water intakes, along with measures to modernize and optimize the operation of pumping equipment, is achieved by saving water resources and, accordingly, the cost of electricity for their extraction, which is necessary when flushing the filter materials of the deferrization station. The assumption about a possible increase in the filtration cycle was the lack of significance of the influence of washing on the decrease in the iron content, which indicated the presence of a significant reserve of the washing cycle. The use of combined water and air flushing contributes to a significant reduction in both technological water consumption (40.1%) and electricity consumption (38.8%). The energy saving potential due to the reduction of technological energy consumption for lifting water for the purpose of flushing reached 89857 kWh / year for the studied water intake.

Study on optimal start-up time and water usage volume of blowdown residue discharge of mesh filter

The water volume used for blowdown of a mesh filter is one of the important indicators to evaluate the economic benefit of a mesh filter. The amount of water used for drainage of the mesh filter can be controlled by setting the start-up time of the blowdown residue discharge of the mesh filter. Through the indoor prototype test, the sediment of the Manas riverbed in Xinjiang, China, was used as the filter medium to test the mesh filter and analyze the water usage volume at each stage. The test focused on the analysis of the trend of the pressure difference between the inlet and outlet of the mesh filter over the filtration time. The results showed that as the filtration time was prolonged, the inlet and outlet pressure difference of the mesh filter showed an S-shaped curve with time. The pressure difference between the inlet and outlet can be divided into four stages, i.e., the start of filtering to the first inflection point of the abrupt change in the pressure difference, the first inflection point of the abrupt pressure difference change to the median point of filtering, the median point of filtering to the second inflection point of the abrupt change in the pressure difference, and the second inflection point of the abrupt pressure difference change to the end of filtering. At the same time, the water usage volume for blowdown was calculated under various working conditions. This paper analyzed the start-up time of blowdown at three different time points, i.e., after the completion of the entire filtration cycle of the traditional mesh filter, at the first inflection point of pressure difference, and at the second inflection point of pressure difference. The tests were performed under the condition that the filtration cycle of the mesh filter was ten days. The results have shown that compared with the traditional screen filter that starts the blowdown at the end of the entire filtration cycle, starting the blowdown at the first inflection point of pressure difference can save 200–300 m3 of water resources for a single mesh filter, and starting the blowdown at the second inflection point of pressure difference can save 30–90 m3 of water resources for a single mesh filter. Meanwhile, the working conditions in the analyses in this paper were consistent with the actual engineering operating conditions. It is recommended that the mesh filter in the micro-irrigation system use the first inflection point of pressure difference to control the start-up time of the blowdown residue discharge, which can not only save water resources, but also ensure that the mesh filter runs at the optimal filtering conditions.

Enhancement of the Fouling Resistance of Zwitterion Coated Ceramic Membranes

Ceramic membranes suffer from rapid permeability loss during filtration of organic matter due to their fouling propensity. To address this problem, iron oxide ultrafiltration membranes were coated with poly(sulfobetaine methacrylate) (polySBMA), a superhydrophilic zwitterionic polymer. The ceramic-organic hybrid membrane was characterized by scanning electron microscopy (SEM) and optical profilometry (OP). Membranes with and without polySBMA coating were subjected to fouling with bovine serum albumin solution. Hydraulic cleaning was significantly more effective for the coated membrane than for the non-coated one, as 56%, 66%, and 100% of the fouling was removed for the first, second, and third filtration cycle, respectively. Therefore, we can highlight the improved cleaning due to an increased fouling reversibility. Although some loss of polymer during operation was detected, it did not affect the improved behavior of the tested membranes.

The Efficiency of Pt-Doped Titania Pillared Clay Membranes for the Treatment of Real Textile Wastewater: A Case Study

Titania pillared clay membranes exhibit unique charge characteristics which are dependent on the solution pH. Doping of such membranes with precious metal like Pt induces a positive charge on the surface of the membranes, thus increasing its resistance against fouling. X-ray Diffraction (XRD) and Fourier Transform Infra-Red Spectroscopy (FT-IR) confirm the complete intercalation of anatase titania in the interlayer spaces of Montmorillonite in the present work. These membranes efficiently removed 83% of the dye from the real textile effluent in a one filtration cycle.

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.

ADVANCED WASTEWATER TREATMENT BY HYDRAULIC AUTOMATIC FLOATING MEDIA FILTER

A pilot scale experiment was carried out in tertiary wastewater treatment using hydraulic automatic floating filter. The hydraulic automatic floating media filter has been working with 120 cm depth of polystyrene bed. Wastewater from secondary biological treatment of WWTP was treated in the pilot filter with filtration velocity of 4 m/h. Oxygen concentration was remained constantly at level 2.0 mg/l by using an ejector. Headloss development and evaluation of SS, COD, NH4+ removals during filtration were objectives of the study. The experiment results showed that concentrations of SS, COD and NH4+ in effluent wastewater were kept lower than 5 mg/l, 30 and 0.5 mg/l respectively for almost filtration cycle. Effects of treatment in SS, COD and NH4+ were 88.27 %, 68.54 % and 5.59 %, respectively.

Biofiltration optimization: phosphorus supplementation effects on disinfection byproduct formation potential

This study investigates the effects of phosphorus supplementation on the formation potential of total trihalomethanes (TTHMfp) and five species of haloacetic acids (HAA5fp) during exposure to clearwell disinfection contact times. In addition, the study investigates the effects of phosphorus supplementation on the dissolved oxygen, organic carbon and nitrogen removal along with biofilm coverage of the filter media and biomass viability of the attached biofilm. The uptake of total phosphorus in the P enhanced filter did not correspond to the consumption of readily assimilated nitrogen or the consumption of soluble carbon. As such, the dissolved organic carbon reduction in the biologically active filters was shown to not be phosphorus nutrient limited. The clearwell TTHMfp was shown to be reduced in all filters across all measured biological filtration times in the control and P enhanced filters. The HAA5fp increased with phosphorus-supplemented operation at specific filtration cycle times as compared to non-phosphorus-supplemented operation, indicating the potential for production of HAA5 with phosphorus supplementation. Enhanced biofilm coverage of the anthracite and sand media was observed during phosphorus supplementation. In addition, increased viability of the cells embedded in the biofilm was observed in the sand media at depth during phosphorus-supplemented operation.

Evaluation of Self Cleaning System in Aerosol Filtration Using Synthetic Filter

In industries that work with particulate material is observed from among other concerns, not to discard solid material in the air. Aiming to develop gas-solid filtration equipment more efficient, the study of a self-cleaning system utilizing filter fabric made ​​from synthetic material, was conducted using the phosphate rock as particulate material. The objective of this study is to evaluate the performance of a vibratory system filtration of gases. The system is made up a box filter coupled to an eccentric motor which causes a continuous vibration during the filtration cycle, not being necessary to interrupt the process to the procedure of fabric filter cleaning. We used polyester synthetic filter for the tests. With known relative humidity and temperature at which the tests were performed, it was possible to estimate the performance of the equipment in continuous vibration filtration of pulverulent material dispersed in gas currents, under the influence of different vibration frequencies.