Long-Term Effluent Absorption Rates of a Serially Loaded Septic Tank Filter Field

2009 ◽  
pp. 63-63-9
Author(s):  
PR Owens ◽  
EM Rutledge ◽  
C Roark ◽  
M Gross ◽  
D Wolf ◽  
...  
Keyword(s):  
Septic Tank

scholarly journals Long-term flow rates and biomat zone hydrology in soil columns receiving septic tank effluent

2006 ◽  
Vol 40 (12) ◽  
pp. 2327-2338 ◽  
Author(s):  
C.D. Beal ◽  
E.A. Gardner ◽  
G. Kirchhof ◽  
N.W. Menzies
Keyword(s):  
Septic Tank ◽  
Soil Columns ◽  
Flow Rates ◽  
Septic Tank Effluent

scholarly journals Effluent flux prediction in variably saturated soil zones within a septic tank—soil absorption trench

Soil Research ◽  
2006 ◽  
Vol 44 (7) ◽  
pp. 677 ◽  
Author(s):  
Cara D. Beal ◽  
Ted Gardner ◽  
David W. Rassam ◽  
Alison M. Vieritz ◽  
Neal W. Menzies
Keyword(s):  
Hydraulic Conductivity ◽  
Hydraulic Properties ◽  
Septic Tank ◽  
Flow Rates ◽  
Unsaturated Hydraulic Conductivity ◽  
Order Of Magnitude ◽  
Magnitude Variation ◽  
Limiting Surface ◽  
Underlying Soil

The treatment and hydraulic mechanisms in a septic tank–soil absorption system (SAS) are highly influenced by the clogging layer or biomat zone which develops on bottom and lower sidewall surfaces within the trench. Flow rates through the biomat and sub-biomat zones are governed largely by the biomat hydraulic properties (resistance and hydraulic conductivity) and the unsaturated hydraulic conductivity of the underlying soil. One- and 2-dimensional models were used to investigate the relative importance of sidewall and vertical flow rates and pathways in SAS. Results of 1-dimensional modelling show that several orders of magnitude variation in saturated hydraulic conductivity (Ks) reduce to a 1 order of magnitude variation in long-term flow rates. To increase the reliability of prediction of septic trench hydrology, HYDRUS-2D was used to model 2-dimensional flow. In the permeable soils, under high trench loading, effluent preferentially flowed in the upper region of the trench where no resistant biomat was present (the exfiltration zone). By comparison, flow was more evenly partitioned between the biomat zones and the exfiltration zones of the low permeability soil. An increase in effluent infiltration corresponded with a greater availability of exfiltration zone, rather than a lower resistance of biomat. Results of modelling simulations demonstrated the important role that a permeable A horizon may play in limiting surface surcharge of effluent under high trench hydraulic loading.

scholarly journals Guidelines for Tourism Sustainability in Ultra-Peripheral Territories: A Research Based on the Azores Region’s Touristic Companies’ Analysis

2021 ◽  
Vol 13 (7) ◽  
pp. 3895
Author(s):  
Gualter Couto ◽  
Rui Alexandre Castanho ◽  
Carlos Santos ◽  
Pedro Pimentel ◽  
Áurea Sousa ◽  
...  
Keyword(s):  
Environmental Conservation ◽  
Hazardous Substances ◽  
Septic Tank ◽  
Final Destination ◽  
Goods And Services ◽  
Tourism Activity ◽  
Conservation Principles ◽  
Cultural Conservation ◽  
Waste Separation

Tourism is an important activity to achieve territorial sustainability. In fact, a properly planned long-term tourism activity is critical for the regional planning to reach the desired living conditions capable of attracting new residents in the future. Thereby, the present research aims to assess the perceptions of the managers of tourist companies in the Azores on sustainability actors about the sustainability of tourism activity in the archipelago. Contextually, throughout an exploratory methodology, it was possible to assess the Azores Touristic Companies managers’ perceptions. Hence, this paper shows that the sustainable practices most frequently adopted by the surveyed companies are the following: prioritize the purchase of regional goods and services (94.7%); selective waste separation (94.5%); minimize the use of hazardous substances or replace them with less hazardous products (92.3%); ensure the proper final destination of wastewater (public sanitation, septic tank) (88.8%); and adopt purchasing criteria that take into account environmentally friendly products or services (88.6%). This research also recognizes that 67% of the respondents consider that the respective participating companies have their goals aligned with environmental conservation principles, 66.7% aligned with environmental conservation principles, 36.9% aligned with social conservation principles and 26.4% aligned with cultural conservation principle.

Enhancement of a UASB-septic tank performance for decentralised treatment of strong domestic sewage

2011 ◽  
Vol 64 (4) ◽  
pp. 923-929 ◽  
Author(s):  
Nidal Mahmoud ◽  
Jules B. van Lier
Keyword(s):  
Domestic Sewage ◽  
Cod Removal ◽  
Septic Tank ◽  
Anaerobic Sludge ◽  
Reactor Performance ◽  
Removal Efficiencies ◽  
The Difference ◽  
Long Term Performance ◽  
Term Performance

The possibility of enhancing the process performance of the UASB-septic tank for treating strong sewage in Palestine by means of inoculating the reactor with well adapted anaerobic sludge and/or adding a packing media to the upper part of the reactor, creating an anaerobic hybrid (AH)-septic tank, was investigated. To achieve these objectives, two community onsite UASB-septic tank and AH-septic tank were operated in parallel at 2 days HRT for around 8 months overlapping the cold and hot periods of the year in Palestine. The achieved removal efficiencies of CODtot in the UASB-septic tank and AH-septic tank during the first months of operation, coinciding with the cold period and the subsequent hot period, were respectively 50(±15)% and 48(±15)% and 66(±8)% and 55(±8)%. This shows that the UASB-septic tank performed significantly better (p < 0.05) than the AH-septic tank after rather long periods of operation. The difference in the CODtot removal efficiency was mainly due to the better CODss removal efficiencies in the UASB-septic tank. The removal efficiencies over the last 50 days of operation for CODtot, CODsus, CODcol and CODdis were 70, 72, 77 and 55% and 53, 54, 78 and 45% for the UASB-septic tank and AH-septic tank, respectively. Comparing the here achieved COD removal efficiencies with previously reported efficiencies of UASB-septic tanks operated in Palestine shows that the reactor performance in terms of COD removal and conversion, during the first 8 months of operation, has improved substantially by being started with well adapted anaerobic sludge, simulating and predicting long-term performance. Adding packing media did not lead to an improvement.

Long Term Performance of a Septic Tank - Rock Filter System

2002 ◽  
Vol 2002 (10) ◽  
pp. 111-122
Author(s):  
D. M. Griffin ◽  
X. Yan ◽  
H. Xiang ◽  
C Fletcher ◽  
R. Crawford
Keyword(s):  
Septic Tank ◽  
Filter System ◽  
Long Term Performance ◽  
Term Performance

Batch studies on septic tank effluent treatment using peat

1989 ◽  
Vol 16 (2) ◽  
pp. 157-161 ◽  
Author(s):  
T. Viraraghavan ◽  
A. Ayyaswami
Keyword(s):  
Oxygen Demand ◽  
High Water ◽  
Effluent Treatment ◽  
Septic Tank ◽  
Column Studies ◽  
Batch Studies ◽  
Indicator Microorganisms ◽  
Filtration System ◽  
Septic Tank Effluent

Batch studies were conducted to determine the efficiency of Saskatchewan horticultural peat to remove biochemical oxygen demand (BOD), chemical oxygen demand (COD), phosphorus, nitrogen, and indicator microorganisms from septic tank effluent. Results of the studies showed that peat was effective in adsorbing 35–50% of dissolved BOD, COD, and organic carbon from the septic tank effluent and in removing indicator microorganisms to the extent of 45–70%. The studies showed that peat has the potential to be used as a medium for septic tank effluent treatment in areas with high water table and with bedrock at shallow depths. Because of leaching of pollutants from peat in the 2-h batch studies, it is necessary to conduct long-term column studies to observe the length of time up to which leaching continues and to evaluate the performance of a peat filtration system under dynamic conditions. Key words: batch studies, septic tank effluent, treatment, peat, adsorption isotherms, indicator microorganisms.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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