Technological aspects of wastewater management in coastal tourist areas

1999 ◽  
Vol 39 (8) ◽  
pp. 177-184 ◽  
Author(s):  
Derin Orhon ◽  
Seval Sözen ◽  
Erdem Görgün ◽  
Emine Ubay Çokgör ◽  
Nazik Artan

Coastal tourist areas should be classified as environmentally sensitive areas. Effective nutrient control should be implemented to safeguard the quality of receiving waters in these areas. In this context, the applicable discharge limitations are reviewed with specific reference to European directives and criteria developed for small coastal residential areas in Turkey are reported; wastewater characterization and its impact on treatment technology selection is reviewed; appropriate treatment technologies are evaluated in terms of selecting new applications and upgrading and retrofitting existing systems.

2017 ◽  
Vol 44 (11) ◽  
pp. 971-983 ◽  
Author(s):  
Gurvinder S. Mundi ◽  
Richard G. Zytner ◽  
Keith Warriner

On average, it is estimated that up to 5 L of wastewater is generated per kilogram of produce in post-harvest processing of fruit, leafy greens, and root vegetables. The typical wastewater parameters vary in concentration (solids content, COD, BOD, nitrogen, phosphorus) based on the produce being processed. The challenge for producers and regulators is that the selection of the appropriate treatment technology is challenging, so decision matrices were developed to narrow down the treatment selections. Wash-waters for different types of fruit and vegetables from two different operation types, washing only versus washing and processing were investigated. Bench-scale treatments selected for testing included settling, coagulation and flocculation with settling, centrifuge, dissolved air flotation, electrocoagulation, screening, and hydrocyclone. The developed decision matrices summarize the removal effectiveness of the different treatments for typical wastewater parameters and serve as a reference tool in understanding wash-water treatment technologies and their effectiveness in treating various wash-waters.


2020 ◽  
Vol 10 (20) ◽  
pp. 7204
Author(s):  
Zhenyue Shi ◽  
Qingbiao Wang ◽  
Chuming Pang ◽  
Yueming Yuan ◽  
Fuqiang Wang ◽  
...  

Karst tunnels commonly pass through large karst caves during their construction and operation. Although treatment technologies are relatively mature, a systematic treatment method to guide the selection of treatment technologies is lacking. To solve this problem, a spatial decomposition method (SDM) of large karst caves is proposed that is based on analyzing the spatial relationship between tunnels and karst caves and summarizing the relevant treatment techniques. In this method, the space between the tunnel and the cavern is divided into eight parts using a space dividing line (SDL), which makes the spatial position relationship between the tunnel and cavern more intuitive. A geometric model of the SDM is established, and the numerical values of each geometric parameter are determined by field surveys and drawings. Constructing a three-dimensional spatial diagram by applying relevant parameters to the geometric model provides a reference for selecting a treatment technology. The SDM of the arch top, arch bottom, and two wings matching the treatment technology is proposed. Seven principles of technical selection—namely, safety, convenience, scientificity, sustainability, economy, feasibility, and openness—are mentioned in order to overcome the difficulty of technology selection due to such factors as technological diversity, materials, equipment, and environment. Finally, the SDM is used to solve the problem of the Shangyuan tunnel passing through a large karst cave. The implementation of the SDM in tunnel construction would represent a significant breakthrough and has important engineering value in solving the problem of tunnel passes through large karst caves.


2017 ◽  
Author(s):  
Gurvinder Mundi ◽  
Richard G Zytner ◽  
Keith Warriner

On average, it is estimated that up to 5 liters of wastewater is generated per kg of produce in post-harvest processing of fruit, leafy greens and root vegetables. The typical wastewater parameters vary in concentration (solids content, COD, BOD, nitrogen, phosphorus) based on the produce being processed. The challenge for producers and regulators is that the selection of the appropriate treatment technology is challenging, so decision matrices were developed to narrow down the treatment selections. Wash-waters for different types of fruit and vegetables from two different operation types, washing only vs. washing and processing. Bench-scale treatments selected for testing included settling, coagulation and flocculation with settling, centrifuge, dissolved air flotation, electrocoagulation, screening, and hydrocyclone. The developed decision matrices summarize the removal effectiveness of the different treatments for typical wastewater parameters and serve as a reference tool in understanding wash-water treatment technologies and their effectiveness in treating various wash-waters.


2012 ◽  
Vol 535-537 ◽  
pp. 2201-2208
Author(s):  
Yong Wang ◽  
Jie Nian Jie ◽  
Zhi Yong Li ◽  
Li Guo Wang ◽  
Jiang Wu ◽  
...  

Oily sewage is one of the wastes produced in the oil industry production process and its quantity has been increasing year by year, which influences the environment and human health severely. Electric flocculation method is one of the wide application electrochemical treatment technologies for the oily wastewater treatment at home and abroad, which has higher efficiency than other technologies at the aspect of the organic pollutants degradation. A simulative experiment device dealing with heavy oil sewage by the electric flocculation method has been designed in this paper. The mechanism of the electric flocculation method in removing organic matter of the heavy oil sewage by analyzing the change of the composition and content of the organic matter in water samples before and after the process of the electric flocculation has been studied. Research results show: the carbon/tin dioxide electrode is better than the carbon/ ruthenium dioxide electrode in removing organic matter; most alkanes matters in the oily wastewater have been removed in the dispersing oil form by the electric flocculation; as the current density increases, the types and quantity of the response organic matter can be improved while types of the new synthetic organics increase. At the same time, this paper provides a theory support in specific optimization of the electricity flocculation flotation in oily wastewater treatment technology and process.


2011 ◽  
Vol 63 (8) ◽  
pp. 1765-1771 ◽  
Author(s):  
S. Heubeck ◽  
R. M. de Vos ◽  
R. Craggs

The biological treatment of wastewater could yield high energy fuels such as methane and alcohols, however most conventional treatment systems do not recover this energy potential. With a simple model of the energy yields of various wastewater treatment technologies it is possible to demonstrate how minor shifts in technology selection can lead the industry from being identified as predominantly energy intensive, to being recognised as a source of energy resources. The future potential energy yield is estimated by applying energy yield factors to alternative use scenarios of the same wastewater loads. The method for identifying the energy potential of wastewater was demonstrated for the New Zealand wastewater sector, but can equally be applied to other countries or regions. The model suggests that by using technologies that maximise the recovery of energy from wastewater, the potential energy yield from this sector would be substantially increased (six fold for New Zealand).


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wang Zhizhong ◽  
Han Chao ◽  
Guosheng Huang ◽  
Han Bin ◽  
Han Bin

Purpose The deposition of particles onto a substrate during the cold spraying (CS) process relies on severe plastic deformation, so there are various micro-defects induced by insufficient deformation and severe crushing. To solve the problems, many post-treat techniques have been used to improving the quality by eliminating the micro-defects. This paper aims to help scholars and engineers in this field a better and systematic understand of CS technology by summarizing the post-treatment technologies that have been investigated recently years. Design/methodology/approach This review summarizes the types of micro-defects and introduces the effect of micro-defects on the properties of CS coating/additive manufactured, illustrates the post-treatment technologies and its effect on the microstructure and performances, and finally outlooks the future development trends of post-treatments for CS. Findings There are significant discoveries in post-treatment technology to change the performance of cold spray deposits. There are also many limitations for post-treatment methods, including improved performance and limitations of use. Thus, there is still a strong requirement for further improvement. Hybrid post-treatment may be a more ideal method, as it can eliminate more defects than a single method. The proposed ultrasonic impact treatment could be an alternative method, as it can densify and flatten the CS deposits. Originality/value It is the first time to reveal the influence factors on the performances of CS deposits from the perspective of microdefects, and proposed corresponding well targeted post-treatment methods, which is more instructive for improving the performances of CS deposits.


1995 ◽  
Vol 32 (11) ◽  
pp. 85-95 ◽  
Author(s):  
Hassaan A. Abd El Gawad ◽  
J. H. C. Butter

In 1993 the Governorate of Fayoum completed its master plan for wastewater management. The master plan presents a staged implementation schedule for the development of wastewater facilities for the Governorate, covering needs up to the year 2020. The targets are ambitious: in order to meet sanitary health standards, nearly two million people (or 60% of the total population) living in 70 towns and villages would need to be served with sewerage systems. Providing all these areas with separate wastewater treatment plants would be impractical. The centralization of treatment at a limited number of treatment plants for clusters of towns and villages has advantages in terms of manageability, cost and environmental protection. In the master plan the configuration of these clusters is presented. For that purpose a stepped approach has been developed: an approach in which aspects such as construction and operation costs of the facilities, existing infrastructure, the geography of the governorate, environmental impact, alternative treatment technologies and phasing of implementation have been considered. An important element of the stepped approach is an analytical model with which - from financial point of view - the optimum size of a cluster can be estimated. Variables of the model are sizes of towns and villages, distances and treatment technologies. The output of the model is a set of general design criteria which has been applied to the specific situation in the governorate. The model has contributed to the establishment of the Master Plan for Wastewater: a plan now used by the Fayoum Sanitation Department as a framework to initiate new projects and to direct the activities of other agencies working in the sanitation sector in the governorate.


Author(s):  
Joanne Adaway ◽  
Brian Keevil ◽  
Annmarie Miller ◽  
Phillip J Monaghan ◽  
Nicola Merrett ◽  
...  

Objective Sex hormone-binding globulin (SHBG) is a glycoprotein which binds hormones such as testosterone. Around 97% of circulating testosterone is bound to SHBG or albumin and is therefore biologically unavailable; 2–3% of testosterone is free. Free testosterone is very technically challenging to quantify; in order to circumvent this problem, equations using testosterone and SHBG are used to estimate free testosterone. We decided to determine the effect of using different SHBG immunoassays on calculated free testosterone results. Design Anonymized surplus serum samples were analysed for SHBG on four different immunoassay platforms (Abbott Architect, Roche, Beckman and Siemens). The SHBG results were used to generate a Vermeulen calculated free testosterone. Results Beckman Access and Siemens Centaur both gave results close to the overall mean. Roche gave the highest SHBG concentrations with Abbott Architect producing the lowest results. Abbott Architect gave the highest calculated free testosterone results, followed by Beckman. Roche gave the lowest results. Sixty-five per cent of male samples had low calculated free testosterone and 27.5% of the females had high calculated free testosterone using the SHBG from the Abbott assay compared with 69% low male calculated free testosterone and 20% high female calculated free testosterone with the Roche assay. Conclusion Our results have shown significant differences in SHBG results produced by different analysers and subsequently the calculated free testosterone, which may affect result interpretation if method-specific reference ranges for calculated free testosterone are not used. Care should be taken to ensure reference ranges are appropriate for the analyser used to avoid misdiagnosis of hypo or hyperandrogenism, and ensure patients get the most appropriate treatment.


Author(s):  
О. Кочетков ◽  
O. Kochetkov ◽  
Е. Иванов ◽  
E. Ivanov ◽  
Д. Шаров ◽  
...  

Purpose: The prospects and scale of the further development of nuclear energy depend to a large extent on the solution of the radioactive waste management (RW) problem. Special attention is given to management of the liquid radioactive waste (LRW), which poses the main potential hazard to the public and the environment, since LRW storage can lead to leaks into the environment. The purpose of the paper is to examine the radiological aspects of LRW management from nuclear power plants (NPPs) operation and to study the influence of the list of radionuclides controlled in RW on the evaluation of the efficiency of LRW treatment technology and on the validity of radioactive waste characterization and classification. Material and methods: The work is based on analysis of public materials (scientific publications, legal documents, international standards, recommendations of international organizations) in the area of LRW treatment and conditioning technologies, and methods of radioactive waste characterization, including information about accepted lists of controlled radionuclides. Results: It is shown that an unreasonable reduction of the list of controlled radionuclides can lead to a significant underestimation of the radiological hazard of RW packages transferred for disposal. In order to optimize the volume of RW radiation control, the radionuclide vector technology was proposed. It is stated that the technology is not universal and its application in each specific case requires additional justification. It is shown that the correctness of accounting for the radiological characteristics of radioactive waste can significantly influence the evaluation of the efficiency of the radioactive waste treatment technology. A possible approach to determining the acceptability of LRW treatment technology based on the characteristics of the final products formed is suggested. Conclusions: There is no universal approach to solve the problems of LRW treatment at the moment. A survey of the characteristics of LRW (chemical, physical, radiation) accumulated and formed during the operation of NPP with various types of reactors (VVER, RBMK, BN) should be performed to determine the initial requirements for LRW treatment technologies. A comprehensive analysis of the efficiency of LRW treatment technologies at all Russian NPPs is of interest with taking into account radionuclides that determine the radiological hazard of radioactive waste after the final disposal.


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