A review on acoustic methods of algal growth control by ultrasonication through existing and novel emerging technologies

2017 ◽  
Vol 33 (5) ◽  
Author(s):  
Aditi Mullick ◽  
Sudarsan Neogi
Keyword(s):  
Energy Consumption ◽  
Algal Blooms ◽  
Nutrient Loading ◽  
Algal Growth ◽  
High Energy ◽  
Operating Conditions ◽  
Process Efficiency ◽  
Industrial Water ◽  
Algal Toxins ◽  
Algae Growth

AbstractThe uncontrolled proliferation of algae and algal blooms due to excessive nutrient loading in natural and industrial water bodies is a major issue for water quality maintenance. It reduces usability of the water, imposes hazardous effects of algal toxins released from algal blooms, and creates nuisance in the operation of several industrial water units. Among several existing water treatment methods to diminish the post-algae growth effects, ultrasonication has emerged as an environmentally safe technology that does not involve any use of algaecide. The interaction of several parameters, including climatic and environmental conditions with algae growth rate, have been reviewed in this article. The effects of different acoustic operating conditions for inhibition of algae growth have also been discussed. Concern about high energy consumption led other technologies to be integrated with ultrasonication. It has enhanced the process efficiency and reduced the energy consumption as reported in some long-term field investigations and patent proposals. Several issues that require further research for making this technology widely applicable or to install an effective system design have been highlighted in this article.

scholarly journals Mathematical Model of Pressure Formation Process along the Helix Channel Length of Screw Grinder

2020 ◽  
Author(s):  
Valery Pelenko ◽  
Ilkhom Usmanov ◽  
Vyacheslav Pokholchenko ◽  
Irina Smirnova
Keyword(s):  
Energy Consumption ◽  
Mathematical Description ◽  
Analytical Description ◽  
High Energy ◽  
Channel Length ◽  
Operating Conditions ◽  
Technical Equipment ◽  
Mining Equipment ◽  
Technological Parameters ◽  
Total Energy Consumption

The improvement of the technical equipment effectiveness is currently becoming particularly important. This applies not only to large and high-energy-intensive machines, but also to household appliances, the total energy consumption of which often exceeds the energy consumption of the overall equipment. These types of devices include, in particular, grinding and cutting equipment. The mathematical description of the processes carried out on this equipment is generalized and can be extended to a wider class of machines, including waste processing and mining equipment. The technological parameters, the design of screw grinders, and the processes of movement, deformation, extrusion and cutting carried out in them are characterized by a significant number of factors affecting the energy intensity. The main ones are the geometric parameters of the screw, machine’s body, cross knife, grinding plate’s thickness, the number and diameter of holes in it, as well as the product’s physical-mechanical characteristics and operating conditions. The most important for the mathematical description are the zones and processes where the main share of the consumed power is spent. The complexity of their analytical description is due to a simplified consideration of either individual technological zones of grinders’ existing designs, or the use of unreasonable simplifications.

Energy Consumption Discussions of Porcelain Produce with Operating Conditions in a Simplified Model

2014 ◽  
Vol 936 ◽  
pp. 1775-1779
Author(s):  
Jun Liang Yu
Keyword(s):  
Energy Consumption ◽  
High Energy ◽  
Operating Conditions ◽  
Simplified Model ◽  
Net Energy ◽  
Mass Ratio ◽  
Solid Mass ◽  
Fuel Distribution ◽  
Total Energy Balance ◽  
Excess Number

Porcelain produce is a very high energy consumption process. According to total energy balance analysis, a variety of operating conditions are analyzed for effect of net energy consumption. One real porcelain plate produce process is introduced as the reference case. Operating conditions are defined in three parameters, which are air excess number, fuel distribution and solid mass ratio. A simplified model based on finite difference method (FDM) is solved to calculate axial gas and solid temperature profiles and net energy consumption. The net energy consumption in porcelain produce is calculated and discussed in quantity with three operating conditions above separately. Finally, it is concluded that net energy consumption is higher with bigger air excess number and solid mass ratio, while fuel distribution will have no influence on net energy consumption.

scholarly journals Effects of activated carbon on the growth of Chlorella vulgaris in an aqueous solution

SURG Journal ◽  
2019 ◽  
Vol 11 ◽  
Author(s):  
Alannah Penno ◽  
Emily Agar ◽  
Jordyn Divok
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Chlorella Vulgaris ◽  
Algal Blooms ◽  
Algal Growth ◽  
Analysis Of Covariance ◽  
Lake Ecosystems ◽  
Significant Difference ◽  
Aqueous Environments ◽  
Algae Growth

Algal blooms, if left unmanaged, can negatively impact lake ecosystems. An unexplored method of removing excess nutrients from lakes, and therefore reducing algal blooms, is through the use of biochar. We hypothesize that due to the adsorptive characteristics of pyrolyzed material such as biochar and activated carbon, its presence would reduce the nutrient availability within aqueous solutions, therefore reducing algal growth. This experiment was conducted in an aqueous solution containing COMBO growth medium with and without the presence of activated carbon, studied under four conditions: 5 mg/L, 10 mg/L, 20 mg/L, and 50 mg/L phosphorous. We applied these treatments to an aqueous solution containing algae and measured fluorometer readings of the algae growth over a period of 12 days. An analysis of covariance followed by a Tukey’s HSD test demonstrated a significant difference between the means of samples containing activated carbon compared to samples without (p < 0.0001). Further, nutrient readings taken of each sample demonstrate a lower concentration of both phosphorus and nitrogen in samples containing activated carbon compared to those without. Our study demonstrates that activated carbon has the capacity to be used for the adsorption of phosphorous. This suggests that both activated carbon, as well as its more adsorptive counterpart, biochar, have the potential to be used in mitigating algal blooms and, more importantly, reducing the effects of anthropogenic eutrophication in aqueous environments.

scholarly journals ENERGY EFFICIENCY OF GEARBOXES APPLICATION IN POWER UNITS OF ELECTRIC VEHICLES

2021 ◽  
Vol 3 (56) ◽  
pp. 5-12
Author(s):  
Sergey N. PODDUBKO ◽  
◽  
Nikolay N. ISHIN ◽  
Arkadiy M. GOMAN ◽  
Andrey S. SKOROKHODOV ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Power Unit ◽  
Electric Vehicles ◽  
Electric Motor ◽  
Hydrocarbon Fuel ◽  
High Energy ◽  
Operating Conditions ◽  
Total Energy Consumption ◽  
Calculation Results

With all advantages, electric vehicles have a significant disadvantage — a relatively small driving range on a single charge of the traction battery compared to cars using hydrocarbon fuel. The solution to the issue is to choose a rational structural scheme of an electromechanical power unit to obtain its high energy efficiency regardless of the operating conditions. A significant number of electric vehicles produced today either do not contain gearboxes or contain single-speed reducers. The use of a multi-speed gearbox solves the problem of adapting the working processes of a traction electric motor to the loading conditions, bringing its efficiency as close as possible to the range of highly efficient values. Calculated estimation of energy consumption of the MAZ-4381EE electric delivery truck is carried out in the paper for various versions of the mechanical part of power unit: without a reducer, with the use of a reducer and two types of two-speed gearboxes (shaft and shaft-planetary). The evaluation is made based on consideration of the European test driving cycle NEDC, taking into account the use of efficiency maps of the traction induction electric motor. The calculation results showed that the use of two-speed gearboxes can reduce the total energy consumption by more than 1.8 times compared to a power unit with a high-torque motor and without a gearbox.

scholarly journals Measuring and Calculating Current Atmospheric Phosphorous and Nitrogen Loadings to Utah Lake Using Field Samples and Geostatistical Analysis

Hydrology ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 45 ◽  
Author(s):  
Jacob Olsen ◽  
Gustavious Williams ◽  
A. Miller ◽  
LaVere Merritt
Keyword(s):  
Atmospheric Deposition ◽  
Great Basin ◽  
Algal Blooms ◽  
Nutrient Loading ◽  
Inorganic Nitrogen ◽  
Algal Growth ◽  
Aquatic Life ◽  
Field Samples ◽  
Lakes And Reservoirs ◽  
Utah Lake

Atmospheric nutrient loading through wet and dry deposition is one of the least understood, yet can be one of the most important, pathways of nutrient transport into lakes and reservoirs. Nutrients, specifically phosphorus and nitrogen, are essential for aquatic life but in excess can cause accelerated algae growth and eutrophication and can be a major factor that causes harmful algal blooms (HABs) that occur in lakes and reservoirs. Utah Lake is subject to eutrophication and HABs. It is susceptible to atmospheric deposition due to its large surface area to volume ratio, high phosphorous levels in local soils, and proximity to Great Basin dust sources. In this study we collected and analyzed eight months of atmospheric deposition data from five locations near Utah Lake. Our data showed that atmospheric deposition to Utah Lake over the 8-month period was between 8 to 350 Mg (metric tonne) of total phosphorus and 46 to 460 Mg of dissolved inorganic nitrogen. This large range is based on which samples were used in the estimate with the larger numbers including results from “contaminated samples”. These nutrient loading values are significant for Utah Lake in that it has been estimated that only about 17 Mg year−1 of phosphorus and about 200 Mg year−1 of nitrogen are needed to support a eutrophic level of algal growth. We found that atmospheric deposition is a major contributor to the eutrophic nutrient load of Utah Lake.

scholarly journals Enhanced Performance of Membrane Distillation Using Surface Heating Process

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 866
Author(s):  
Fei Han ◽  
Shuxun Liu ◽  
Kang Wang ◽  
Xiaoyuan Zhang
Keyword(s):  
Energy Consumption ◽  
Energy Performance ◽  
High Energy ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Surface Heating ◽  
Commercial Application ◽  
Heating Process ◽  
Temperature Polarization ◽  
Vacuum Membrane Distillation

Membrane distillation (MD) is a thermally driven desalination process that has excellent application prospects in seawater desalination or hypersaline wastewater treatment, while severe temperature polarization (TP) and the resulting relatively high energy consumption have become principal challenges limiting the commercial application of MD. Therefore, the design of novel systems to overcome the shortage of conventional MD requires urgent attention. Here, we developed three surface heating vacuum membrane distillation systems, namely, SHVMD-1, SHVMD-2, and SHVMD-3, according to the different positions of the thermal conducting layer in the cell. The distillate flux, TP, and energy performance of these systems under different operating conditions were investigated. All three systems showed stable performance, with a salt rejection >99.98% for 35 g/L NaCl, and the highest flux was close to 9 L/m2·h. The temperature polarization coefficients were higher than unity in SHVMD-2 and SHVMD-3 systems, and the SHVMD-2 system produced the lowest specific energy consumption and the highest thermal efficiency. In addition, we tested the intermittent surface heating process, which can further improve energy performance through reducing specific electrical energy consumption in vacuum membrane distillation. This paper provides a simple and efficient membrane system for the desalination of brines.

Separation of Biologically Active Compounds by Membrane Operations

2017 ◽  
Vol 23 (2) ◽  
pp. 218-230 ◽  
Author(s):  
Xiaoying Zhu ◽  
Renbi Bai
Keyword(s):  
Energy Consumption ◽  
Bioactive Compounds ◽  
Membrane Fouling ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
High Energy ◽  
Separation Processes ◽  
Membrane Processes ◽  
Separation Technology ◽  
Pressure Driven

Background: Bioactive compounds from various natural sources have been attracting more and more attention, owing to their broad diversity of functionalities and availabilities. However, many of the bioactive compounds often exist at an extremely low concentration in a mixture so that massive harvesting is needed to obtain sufficient amounts for their practical usage. Thus, effective fractionation or separation technologies are essential for the screening and production of the bioactive compound products. The applicatons of conventional processes such as extraction, distillation and lyophilisation, etc. may be tedious, have high energy consumption or cause denature or degradation of the bioactive compounds. Membrane separation processes operate at ambient temperature, without the need for heating and therefore with less energy consumption. The “cold” separation technology also prevents the possible degradation of the bioactive compounds. The separation process is mainly physical and both fractions (permeate and retentate) of the membrane processes may be recovered. Thus, using membrane separation technology is a promising approach to concentrate and separate bioactive compounds. Methods: A comprehensive survey of membrane operations used for the separation of bioactive compounds is conducted. The available and established membrane separation processes are introduced and reviewed. Results: The most frequently used membrane processes are the pressure driven ones, including microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). They are applied either individually as a single sieve or in combination as an integrated membrane array to meet the different requirements in the separation of bioactive compounds. Other new membrane processes with multiple functions have also been developed and employed for the separation or fractionation of bioactive compounds. The hybrid electrodialysis (ED)-UF membrane process, for example has been used to provide a solution for the separation of biomolecules with similar molecular weights but different surface electrical properties. In contrast, the affinity membrane technology is shown to have the advantages of increasing the separation efficiency at low operational pressures through selectively adsorbing bioactive compounds during the filtration process. Conclusion: Individual membranes or membrane arrays are effectively used to separate bioactive compounds or achieve multiple fractionation of them with different molecule weights or sizes. Pressure driven membrane processes are highly efficient and widely used. Membrane fouling, especially irreversible organic and biological fouling, is the inevitable problem. Multifunctional membranes and affinity membranes provide the possibility of effectively separating bioactive compounds that are similar in sizes but different in other physical and chemical properties. Surface modification methods are of great potential to increase membrane separation efficiency as well as reduce the problem of membrane fouling. Developing membranes and optimizing the operational parameters specifically for the applications of separation of various bioactive compounds should be taken as an important part of ongoing or future membrane research in this field.

scholarly journals Tanning Wastewater Treatment by Ultrafiltration: Process Efficiency and Fouling Behavior

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 461
Author(s):  
Fu Yang ◽  
Zhengkun Huang ◽  
Jun Huang ◽  
Chongde Wu ◽  
Rongqing Zhou ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Shear Rate ◽  
Membrane Surface ◽  
Filtration Efficiency ◽  
Operating Conditions ◽  
Process Efficiency ◽  
Transmembrane Pressure ◽  
Leather Industry ◽  
Pore Blocking ◽  
The Impact

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.

scholarly journals Current Knowledge and Future Directions for Improving Subsoiling Quality and Reducing Energy Consumption in Conservation Fields

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 575
Author(s):  
Shangyi Lou ◽  
Jin He ◽  
Hongwen Li ◽  
Qingjie Wang ◽  
Caiyun Lu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Cover Crops ◽  
Current Knowledge ◽  
High Energy ◽  
Field Application ◽  
Research Progress ◽  
Monitoring And Control ◽  
Future Directions ◽  
Tillage Depth ◽  
And Control

Subsoiling has been acknowledged worldwide to break compacted hardpan, improve soil permeability and water storage capacity, and promote topsoil deepening and root growth. However, there exist certain factors which limit the wide in-field application of subsoiling machines. Of these factors, the main two are poor subsoiling quality and high energy consumption, especially the undesired tillage depth obtained in the field with cover crops. Based on the analysis of global adoption and benefits of subsoiling technology, and application status of subsoiling machines, this article reviewed the research methods, technical characteristics, and developing trends in five key aspects, including subsoiling shovel design, anti-drag technologies, technologies of tillage depth detection and control, and research on soil mechanical interaction. Combined with the research progress and application requirements of subsoiling machines across the globe, current problems and technical difficulties were analyzed and summarized. Aiming to solve these problems, improve subsoiling quality, and reduce energy consumption, this article proposed future directions for the development of subsoiling machines, including optimizing the soil model in computer simulation, strengthening research on the subsoiling mechanism and comprehensive effect, developing new tillage depth monitoring and control systems, and improving wear-resisting properties of subsoiling shovels.

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