scholarly journals Evaluate of head loss, sediment value and copper removal in sand media (rapid sand filter)

2014 ◽  
Vol 3 (2) ◽  
pp. 276-286 ◽  
Author(s):  
Daneshi Navab ◽  
Banejad Hossein ◽  
Pirtag Hamedany Reza ◽  
Daneshi Vahab ◽  
Farokhi Maedeh

Along with the technology development and increasing consumption of water resources, we are experiencing low qualities in the mentioned resources. Copper brings about serious environment al pollution, threatening human health and ecosystem. This metal found variously in water resources and industrial activities. Therefore, it needs to treat the water resources from these excessive amounts. Different methods have used for this reason but the most used method during recent years has been the absorption by economic absorbers such as sand. Rapid sand filters usually used in water and wastewater treatment plants for water clarification. In this research, a single layer gravity rapid sand filter has used to reduce different concentrations of copper. sediment value and head loss arising in filter media is simulated by using combination of Carman-Kozeny, Rose and Gregory models in different discharges of rapid sand filter. Results have shown that with increasing in discharge and decreasing in input copper concentration, arriving time to given head loss, is increasing. In addition, results demonstrated that with increasing in copper concentration in influent, removal efficiency is decreasing somewhat. Results of this research can applied in an appropriate design of rapid sand filter to copper removal, a prediction of rapid sand filter ability to copper removal and an estimation of arising head loss during filter work thus evaluating of time interval backwash. DOI: http://dx.doi.org/10.3126/ije.v3i2.10641 International Journal of the Environment Vol.3(2) 2014: 276-286

2003 ◽  
Vol 3 (5-6) ◽  
pp. 321-327 ◽  
Author(s):  
M. Gallenkemper ◽  
T. Wintgens ◽  
T. Melin

Endocrine disrupting compounds can affect the hormone system in organisms. A wide range of endocrine disrupters were found in sewage and effluents of municipal wastewater treatment plants. Toxicological evaluations indicate that conventional wastewater treatment plants are not able to remove these substances sufficiently before disposing effluent into the environment. Membrane technology, which is proving to be an effective barrier to these substances, is the subject of this research. Nanofiltration provides high quality permeates in water and wastewater treatment. Eleven different nanofiltration membranes were tested in the laboratory set-up. The observed retention for nonylphenol (NP) and bisphenol A (BPA) ranged between 70% and 100%. The contact angle is an indicator for the hydrophobicity of a membrane, whose influence on the permeability and retention of NP was evident. The retention of BPA was found to be inversely proportional to the membrane permeability.


2021 ◽  
Vol 13 (10) ◽  
pp. 5717
Author(s):  
Mian Muhammad-Ahson Aslam ◽  
Hsion-Wen Kuo ◽  
Walter Den ◽  
Muhammad Usman ◽  
Muhammad Sultan ◽  
...  

As the world human population and industrialization keep growing, the water availability issue has forced scientists, engineers, and legislators of water supply industries to better manage water resources. Pollutant removals from wastewaters are crucial to ensure qualities of available water resources (including natural water bodies or reclaimed waters). Diverse techniques have been developed to deal with water quality concerns. Carbon based nanomaterials, especially carbon nanotubes (CNTs) with their high specific surface area and associated adsorption sites, have drawn a special focus in environmental applications, especially water and wastewater treatment. This critical review summarizes recent developments and adsorption behaviors of CNTs used to remove organics or heavy metal ions from contaminated waters via adsorption and inactivation of biological species associated with CNTs. Foci include CNTs synthesis, purification, and surface modifications or functionalization, followed by their characterization methods and the effect of water chemistry on adsorption capacities and removal mechanisms. Functionalized CNTs have been proven to be promising nanomaterials for the decontamination of waters due to their high adsorption capacity. However, most of the functional CNT applications are limited to lab-scale experiments only. Feasibility of their large-scale/industrial applications with cost-effective ways of synthesis and assessments of their toxicity with better simulating adsorption mechanisms still need to be studied.


1999 ◽  
Vol 40 (4-5) ◽  
pp. 81-89 ◽  
Author(s):  
C. J. Brouckaert ◽  
C. A. Buckley

Computational Fluid Dynamics (CFD) studies of a secondary clarifier at Durban's Northern Wastewater Treatment Works, and of a clarifier at the potable water treatment plant at Umzinto, a small town near Durban, have been undertaken with a view to improving their load capacities. In both cases the units are located in relatively old treatment plants, which face continually increasing loads due to population growth. Increasing the capacity of existing equipment, rather than installing new equipment, constitutes an efficient use of development capital. Although the two clarifiers have considerable design differences, the CFD studies indicated remarkably similar circulating flows, which concentrate up-flow near the outer wall of the clarifier in the region of the clarified water overflow weirs. Baffles were designed to disrupt the circulation so as to distribute up-flow over a wider area, thereby reducing the maximum vertical velocities. In the case of the wastewater secondary clarifier, the modification has been implemented, and evaluated in comparative tests involving an otherwise identical unmodified clarifier. In the case of the potable water clarifier, the modification has still to be implemented.


2015 ◽  
Vol 15 (4) ◽  
pp. 817-824 ◽  
Author(s):  
Jing Peng ◽  
Ximin Yuan ◽  
Lan Qi ◽  
Qiliang Li

Water resources supply and demand has become a serious problem. Water resources allocation is usually a multi-objective problem, and has been of concern for many researchers. In the north of China, the lack of water resources in the Huai River Basin has handicapped the development of the economy, especially badly in the low-flow period. So it is necessary to study water resources allocation in this area. In this paper, a multi-objective dynamic water resources allocation model has been developed. The developed model took the overall satisfaction of water users in a time interval as the objective function, applied an improved simplex method to solve the calculation, considered the overall users' satisfaction variation with time, and followed the principle that the variation of the system satisfaction within adjacent periods of time must be minimal. The established model was then applied to the Huai River, for the present situation (2010), short-term (2020) and long-term (2030) planning timeframes. From the calculation results, the overall satisfaction in late May and mid September in 2030 was 0.65 and 0.70. After using the model allocation optimization, the overall satisfaction was improved, increasing to 0.78 and 0.79, respectively, thus achieving the dynamic balance optimization of water resources allocation in time and space. This model can provide useful decision support in water resources allocation, when it is used to alleviate water shortages occurring in the low-flow period.


2012 ◽  
Vol 39 ◽  
pp. 190-191
Author(s):  
Styliani D. Sklari ◽  
Petros Samaras ◽  
Anastasios I. Zouboulis ◽  
Athanassios Kungolos

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