Comparison of Centralized versus Decentralized Wastewater Systems for Coastal Tourist Areas

1989 ◽  
Vol 21 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Pentti Väänänen ◽  
Eleftherios Gavrielides

A reliable, unobtrusive wastewater collection, treatment and disposal system in tourist areas is a must. In most countries where tourism has rapidly grown, public utilities have not managed to provide sewerage and sewage treatment facilities. As a result of this there are a great number of small sewage treatment plants each serving one hotel or a group of hotels in one area. The next step seems to be to join more and more hotels to one bigger treatment plant - mostly operated by a public utility. This paper discusses the pros and cons of a centralized vs. decentralized treatment system taking into account technical and economic aspects.

2020 ◽  
Vol 143 ◽  
pp. 02052
Author(s):  
Li Jia

with the continuous acceleration of urban and town construction, the output of urban and town sewage is also increasing. To a great extent, this promotes the technological development and capacity expansion of urban and town sewage treatment plants. In the process of sewage treatment, a lot of sludge is inevitable. However, many urban and town sewage treatment plants pay more attention to the treatment of sewage and ignore the treatment of sludge. In this way, the sludge without proper treatment can be disposed at will. In the long run, this will not only affect the surrounding environment, but also hinder the development of social economy. Therefore, the urban and town sewage treatment plant should pay enough attention to the application of surplus sludge treatment and disposal technology. In this paper, the main problems existing in the treatment and disposal technology of surplus sludge in urban and town sewage treatment plants, and the treatment and disposal technology of surplus sludge in urban and town sewage treatment plants are both explored and analyzed, hoping to contribute to the long-term development of urban and town sewage treatment plants.


2021 ◽  
Vol 2021 ◽  
Author(s):  
Karolina Wójcicka

This article presents a detailed analysis of the functioning of municipal sewage treatment plants. The presented findings are based on questionnaires from over seventy wastewater treatment facilities, covering from several hundred to several hundred thousand inhabitants. The required quality of treated sewage and the necessary efficiency level of the treatment plant were determined in the context of the content of the applicable regulations, and were then compared with the actual data obtained from sewage treatment plants. The findings provided the basis for formulating an evaluation of the efficiency of municipal sewage treatment plants and for further analyses of the possibility of the recovery of water from sewage and its reuse.


2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Maciej Walczak

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operationThis paper reports the results of studies of microbiological changes in the water quality of the Vistula and Brda rivers after the opening of sewage treatment plants in Bydgoszcz. The study involved determining the microbiological parameters of water quality. Based on the results obtained, it was found that the quality of the water in both rivers had improved decidedly after the opening of the plants, although an increased number of individual groups of microorganisms was found at the treated sewage outlet from one of the plants.


1995 ◽  
Vol 30 (4) ◽  
pp. 565-592 ◽  
Author(s):  
A.F. Gemza

Abstract Severn Sound continues to exhibit signs of eutrophication despite initial identification of the problem in 1969 and the construction of several sewage treatment plants since then. In general, improvements in trophic state indicators have been marginal, suggesting that the sewage treatment plants have had limited success in controlling phosphorus concentrations. These discharges likely contributed to the increased total phosphorus levels and consequently the higher phytoplankton densities of the nearshore waters. Phytoplankton biovolumes were on average one order of magnitude higher than in the open waters of Lake Huron with mean summer biovolumes as high as 8.0 mm/L. Algal biovolumes were most dense in Penetang Bay, which experienced limited exchange with the main waters of the sound. No significant long-term trends were observed. Water clarity was declining significantly, however, at a rate of -0.60 to -0.78 m/year throughout the sound except in Sturgeon Bay. Total phosphorus levels were highly variable from year to year; however, concentrations from a 20-year perspective were declining in the open waters at a rate of 0.70 µg/L/year, but response was limited in nearshore areas. In Sturgeon Bay, mean annual euphotic zone total phosphorus as well as soluble reactive phosphorus levels declined by as much as 50% following the construction of a sewage treatment plant with tertiary treatment. Phytoplankton genera typical of eutrophic waters continued to dominate the algal assemblage but members indicative of mesotrophic conditions have become apparent in some areas of the sound.


1993 ◽  
Vol 27 (9) ◽  
pp. 159-171 ◽  
Author(s):  
Eberhard Steinle

First an overview of the systems currently in use and being discussed for sludge treatment is presented will) particular emphasis on distinguishing between the object of the system (conditioning objective of the various phases in the system) and a system concept (concept of various phases of the system in sequence to attain the disposal objective). More detailed information is given as to the salient systems as used with smaller sewage treatment plants in rural areas, such as digestion, dewatering, hygienization, composting and thermal drying. A further item of discussion is how sludge treatment influences the sewage treatment process. For the critical emissions (nitrogen, phosphorus) demanded in Germany, and thus for the degree of sewage treatment required, the load of the sewage treatment system resulting from sludge treatment needs to be taken into account. Accordingly, operation of sludge treatment and sewage purification must always be harmonized. The extent of these return loads also limits the spatial centralization of the system phases; this applies in particular to smaller sewage treatment plants in rural areas. In conclusion, an attempt is made to present a perspective for the agricultural utilization of such sludge in Germany. Since the critical values for emissions have been further tightened by new regulations, thus considerably elevating the associated sophistication of monitoring techniques, it is to be expected that the use of sewage sludge in agriculture will also be further reduced in rural areas, especially since public awareness of emission control has considerably reduced the acceptance of sewage sludge as fertilizer.


2011 ◽  
Vol 183-185 ◽  
pp. 1417-1422 ◽  
Author(s):  
Xiang Sheng Cao ◽  
Xue Jing Meng ◽  
Xue Zheng Meng

With the booming construction of sewage treatment plants aiming at environmental protection, China has to face an emerging urgent task to address the sludge treatment and disposal problem. However there is a big controversy in China about the sludge treatment and disposal strategies. Some scientists suggest incinerating, while others insist on landfilling. In this paper, from the perspective of sustainable development and cyclic economy, a detailed analysis of nutrients cycle mainly related to nitrogen and phosphate before and after industrialization was made and a view that sludge should go back to soils to re-establish a sound nutrients cycle was put forward. Then the feasibility for sludge recycle to soils was discussed and some land application methods for sludge were introduced. At last, a successful case of producing compounded fertilizer from dewatered sludge in Northeast China was described in detail.


2021 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Natalia Taraszkiewicz

The development of sewage systems leads to an increase in people’s living standards and an improvement in the comfort of their daily lives. In 2021, the use of septic tanks is still a big issue; many of them are not properly sealed and can be harmful to the environment because of leakage. A good alternative for them is an individual sewage treatment plant. There are many types of such investment. This paper focuses on the selection between three types of sewage treatment plants (a biological wastewater treatment plant with activated sludge and a constructed wasteland) using MCDA–AHP and TOPSIS methods.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2746 ◽  
Author(s):  
Mojeed A. Agoro ◽  
Abiodun O. Adeniji ◽  
Martins A. Adefisoye ◽  
Omobola O. Okoh

This study assessed the distribution of five heavy metals (Cd, Pb, Cu, Zn, and Fe) across the various stages of treatment in three selected sewage treatment facilities and their receiving waterbodies in the Eastern Cape Province, South Africa. Aqueous and solid (sludge) samples were collected monthly from September 2015 to February 2016. Quantitation was achieved by atomic absorption spectrometry after necessary sample preparations. Concentrations of heavy metal cations in the sludge generally varied from <DL (below detection limit) to 1.17 mg kg−1, <DL to 0.14 mg kg−1, 27.588 to 69.789 mg kg−1, and <DL to 0.099 mg kg−1 for Cu, Cd, Fe and Pb; while Zn was below detection all through. Similarly, the levels of Cu, Cd, and Fe in the influents, effluents, upstream and downstream across the three plants ranged from <DL–6.588 mg L−1, <DL–0.636 mg L−1, <DL–0.878 mg L−1 and <DL–0.711 mg L−1, respectively; Zn and Pb were less than DL in all the matrices and study locations. All the contaminants were below hazardous levels in all the sludge and aqueous samples except Cd which was higher in effluents and surface waters across the board. Wastewater Treatment Plant (WWTP)-A exhibited better removal capacity for Fe (86.6%), compared to WWTP-B (34.7%) and WWTP-C (56.9%). However, the removal of Cu and Zn was very poor in all the treatment facilities studied. Carcinogenic and non-carcinogenic risks evaluated were sufficiently low. This suggests that the levels of contamination, even with respect to Cd, was minimal. Nevertheless, efforts should be made to keep the concentrations of these contaminants at levels safe for humans and aquatic organisms. Furthermore, the use of the effluents from these facilities for irrigation should be discouraged to prevent unnecessary build-up of metals in the soil and plants grown with such, as well as subsequent bioaccumulation and biomagnification in the food chain.


1983 ◽  
Vol 15 (9) ◽  
pp. 1205-1217 ◽  
Author(s):  
Y Kitabatake ◽  
T Miyazaki

A theoretical model of the sewage treatment plant location problem is presented, based on the assumptions of a homogeneous space and a homogeneous channel geometry of a river running parallel to a one-dimensional region. The analytical structure of the model is discussed. The model is then applied to the specific case of a suburban region of the Tokyo Metropolitan Region, where both the homogeneity assumptions are dropped. The numerical simulations show clearly how the heterogeneity in population distribution and river characteristics, as well as the trade-off ratio between water quality and least cost expenditure, affects the optimal plant locations.


2017 ◽  
Author(s):  
Xili Duan ◽  
Isa R. Haque ◽  
Aloysius Ducey

This paper presents feasibility study and concept design of a thermal energy recovery system with an adsorption heat pump integrated with a small sewage treatment plant in northern Newfoundland communities. Treated fluids from the sewage treatment systems are quite warm even in winter. For example measured fluids temperature is averaged at 17 °C when air temperature is at −10 °C in the town of Whitbourne. This provides an attractive heat source particularly for winter seasons. Four heat pump concepts, i.e., vapour compression, absorption, adsorption and chemical heat pumps, were reviewed and compared. The results show that the adsorption system best fits the sewage treatment plants with minimum power requirements. Thermal fluidic parameters of the key components were designed with fluid flow and heat transfer analysis. A brief economic and environmental analysis showed that the integrated energy recovery unit would lead to a net reduction of CO2 emission and feasible payback time.


Sign in / Sign up

Export Citation Format

Share Document