Cold climate facultative lagoons

1984 ◽  
Vol 11 (3) ◽  
pp. 542-555 ◽  
Author(s):  
Timothy Tilsworth ◽  
Daniel W. Smith

Facultative lagoons are of great importance to small communities of Alaska and northern Canada. Severe climatological conditions along with seriously impeded economic development have dramatically reduced the viable alternatives available for wastewater treatment. Design engineers face almost formidable constraints when attempting to produce “secondary” effluents for these communities. Because of permafrost, the absence of electrical power, average annual temperatures as low as −12 °C (10°F), the lack of skilled manpower, and other operating restrictions, lagoons can be of strategic importance to water quality protection in these locations.The use of “southern” technology may not be applicable under arctic–subarctic conditions and even if it is applicable it must be used with considerable reservation. This paper reviews the use of facultative lagoons in cold climate areas and addresses issues of design parameters, economics, and the system's ability to meet wastewater treatment regulations and water quality standards. Consideration of factors influenced by temperature including psychrophilic organisms and ice cover are reviewed in this discussion along with a “common sense” approach to design. Key words: lagoons, cold, permafrost, wastewater, design, BOD, ponds, facultative, algae, northern, ice, anaerobic, kinetics, arctic.

2019 ◽  
Author(s):  
Chem Int

Recently, process control in wastewater treatment plants (WWTPs) is, mostly accomplished through examining the quality of the water effluent and adjusting the processes through the operator’s experience. This practice is inefficient, costly and slow in control response. A better control of WTPs can be achieved by developing a robust mathematical tool for performance prediction. Due to their high accuracy and quite promising application in the field of engineering, Artificial Neural Networks (ANNs) are attracting attention in the domain of WWTP predictive performance modeling. This work focuses on applying ANN with a feed-forward, back propagation learning paradigm to predict the effluent water quality of the Habesha brewery WTP. Data of influent and effluent water quality covering approximately an 11-month period (May 2016 to March 2017) were used to develop, calibrate and validate the models. The study proves that ANN can predict the effluent water quality parameters with a correlation coefficient (R) between the observed and predicted output values reaching up to 0.969. Model architecture of 3-21-3 for pH and TN, and 1-76-1 for COD were selected as optimum topologies for predicting the Habesha Brewery WTP performance. The linear correlation between predicted and target outputs for the optimal model architectures described above were 0.9201 and 0.9692, respectively.


2018 ◽  
Vol 68 (12) ◽  
pp. 2752-2755
Author(s):  
Carmen Tociu ◽  
Tania Zaharia ◽  
Elena Diacu ◽  
Cristina Maria ◽  
Florica Marinescu ◽  
...  

This paper depicts the research conducted at a micro-pilot scale on autochthonous cultures in order to develop adequate technological solutions for the treatment of wastewater resulting from shrimp cultures (Palaemonidae) that would ensure the protection of the Black Sea ecosystem and constitute an applicable tool for the development of aquaculture in Romania. The proposed objectives were attained by adopting an integrated system of marine cultures shrimps-mussels-macrophyte algae, followed by a conventional chemical treatment step using aluminium sulphate recovered from metallurgical slags. This system together with wastewater treatment ensures an optimum development of species and a minimum load of pollutants in the aquatic environment.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.


2002 ◽  
Vol 2 (4) ◽  
pp. 145-150
Author(s):  
T. Pavón Silva ◽  
S.G. Hoyos ◽  
C. Chávez Guerra

The design and operation of floc blanket clarification plant, embodying coagulation, flocculation and floc blanket sedimentation is still very much an art, mainly because there has been no adequate scientific explanation of the mechanisms of the floc blanket sedimentation process. This study aims to provide an explanation based on the floc blanket formation with CPL (hydroxyl chlorine of aluminium) coagulant. The theoretical parameters results were: Gcoagulation: 1,500 s-1; Gflocculation: 397 s-1, and for sedimentation G×θ×c 2476.8. The solid removal in the floc blanket was 65.28% expressed by residual turbidity. The water quality obtained at the end of the treatment satisfied the values of official Mexican standards.


1992 ◽  
Vol 25 (9) ◽  
pp. 85-92 ◽  
Author(s):  
I. Ozturk ◽  
T. Zambal ◽  
A. Samsunlu ◽  
E. Göknel

Metropolitan Istanbul Wastewater Treatment System contains 14 marine outfalls, seven of which include secondary stage biological treatment processes. The others have only mechanical treatment units including bar screens and grit chambers. Only one mechanical pre-treatment and marine disposal system, Yenikapi plant, has been operated since 1988 among these 14 plants and six of them are ready for construction. In this paper, the environmental impact of Yenikapi pretreatment and marine disposal system on the water quality of the Bosphorus and the Sea of Marmara has been investigated. Long term water quality measurements which were performed in pre-and post-dischange applications have been evaluated. Water quality parameters including pH, DO, BODs, TKN, P and total coliforms were measured at various sampling stations around the discharge points. A general evaluation of marine outfall systems to be constructed in the scope of Istanbul wastewater treatment project, on the water quality of the Sea of Marmara and the Bosphorus has been presented.


1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.


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