The development of a Code of Practice for single house on-site wastewater treatment in Ireland

2011 ◽  
Vol 64 (3) ◽  
pp. 677-683 ◽  
Author(s):  
L. W. Gill
Keyword(s):  
Wastewater Treatment ◽  
Septic Tank ◽  
Secondary Effluent ◽  
Indicator Microorganisms ◽  
Hydraulic Loading ◽  
Code Of Practice ◽  
Treated Effluent ◽  
Lower Permeability ◽  
Septic Tank Effluent ◽  
Treatment And Disposal

The performance of six separate percolation areas was intensively monitored to ascertain the attenuation effects of unsaturated subsoils with respect to on-site wastewater effluent: three sites receiving septic tank effluent, the other three sites receiving secondary treated effluent. The development of a biomat across the percolation areas receiving secondary treated effluent was restricted on these sites compared to those sites receiving septic tank effluent. This created significant differences in terms of the hydraulic loading on the percolation areas with implications for the transport and attenuation of indicator microorganisms and nitrogen down through the subsoils and into the groundwater. The results of this work have formed a large input into the production of a new Code of Practice Wastewater Treatment and Disposal Systems Serving Single Houses. This has led to changes in the design of on-site hydraulic loading from 180 L per capita per day (L/c.d) down to 150 L/c.d. The range of acceptable subsoils receiving septic tank effluent has narrowed for more highly permeable subsoils following a series of tracer studies using bacteriophages. However, the range has been extended for lower permeability subsoils (range 0.08 down to 0.06 m/d) receiving secondary treated effluent in order to encourage the effluent to spread further along the trenches. The maximum individual length of percolation trenches receiving secondary effluent has also been reduced to 10 m to encourage dispersion on a wider area. This paper thus highlights how research can directly feed into a Code of Practice.

scholarly journals Woven-Fiber Microfiltration (WFMF) and Ultraviolet Light Emitting Diodes (UV LEDs) for Treating Wastewater and Septic Tank Effluent

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1564
Author(s):  
Sara Beck ◽  
Poonyanooch Suwan ◽  
Thusitha Rathnayeke ◽  
Thi Nguyen ◽  
Victor Huanambal-Sovero ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Light Emitting Diodes ◽  
Domestic Wastewater ◽  
Septic Tank ◽  
Uv Disinfection ◽  
Small Community ◽  
Photochemical Process ◽  
Light Emitting ◽  
Decentralized Wastewater Treatment ◽  
Septic Tank Effluent

Decentralized wastewater treatment systems enable wastewater to be treated at the source for cleaner discharge into the environment, protecting public health while allowing for reuse for agricultural and other purposes. This study, conducted in Thailand, investigated a decentralized wastewater treatment system incorporating a physical and photochemical process. Domestic wastewater from a university campus and conventional septic tank effluent from a small community were filtered through a woven-fiber microfiltration (WFMF) membrane as pretreatment for ultraviolet (UV) disinfection. In domestic wastewater, WFMF reduced TSS (by 79.8%), turbidity (76.5%), COD (38.5%), and NO3 (41.4%), meeting Thailand irrigation standards for every parameter except BOD. In septic tank effluent, it did not meet Thailand irrigation standards, but reduced TSS (by 77.9%), COD (37.6%), and TKN (13.5%). Bacteria (total coliform and Escherichia coli) and viruses (MS2 bacteriophage) passing through the membrane were disinfected by flow-through UV reactors containing either a low-pressure mercury lamp or light-emitting diodes (LEDs) emitting an average peak wavelength of 276 nm. Despite challenging and variable water quality conditions (2% < UVT < 88%), disinfection was predictable across water types and flow rates for both UV sources using combined variable modeling, which enabled us to estimate log inactivation of other microorganisms. Following UV disinfection, wastewater quality met the WHO standards for unrestricted irrigation.

Influence of Hydraulic Loading Rate on Horizontal Zeolite Wetland Effluent Quality

2012 ◽  
Vol 573-574 ◽  
pp. 659-662
Author(s):  
Hao Wang
Keyword(s):  
Wastewater Treatment ◽  
Loading Rate ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Hydraulic Loading Rate ◽  
Effluent Quality ◽  
Hydraulic Loading

In Tangshan area, the secondary effluent of wastewater treatment plants was used for this study. Horizontal zeolite wetland was carried out treating it. Hydraulic loading rate was the parameters for analyzing the nitrogen and phosphorus removal efficiency of pollutants from the secondary effluent of wastewater treatment plant. Zeolite constructed wetlands showed different behaviors for nitrogen and phosphorus removals.Under the optimum hydraulic loading rate, the primary pollutions were removed to a large extent.

Planted Soil Filter – A Wastewater Treatment System for Rural Areas

1993 ◽  
Vol 28 (10) ◽  
pp. 133-140 ◽  
Author(s):  
Robert Netter
Keyword(s):  
Wastewater Treatment ◽  
Rural Areas ◽  
Removal Rate ◽  
Extended Period ◽  
Bacterial Count ◽  
Subsurface Water ◽  
Septic Tank ◽  
Total Bacterial Count ◽  
Surface Loading ◽  
Septic Tank Effluent

Three planted soil filters for wastewater treatment (constructed wetlands with subsurface water flow) were investigated over an extended period of time. Each of them was filled with different kinds of soil. The filters were planted with helophytes, and loaded with septic tank effluent, with pre-treated combined sewage respectively. The hydraulic surface loading varied from 4 to 60mm/d and the specific BOD5 mass loading from 0.9 to 8.7g per square metre per day. The purification efficiency varied between 61 and 99% with respect to BOD5 and COD. The elimination of nutrients (Ntot and Ptot) varied between 5 and almost 100%. The removal rate of the total bacterial count, conforms, faecal coliforms and faecal streptococci was significant.

Nitrogen loading on groundwater from the discharge of on-site domestic wastewater effluent into different subsoils in Ireland

2008 ◽  
Vol 57 (12) ◽  
pp. 1921-1926 ◽  
Author(s):  
L. W. Gill ◽  
C. O'Suilleabhain ◽  
B. D. R. Misstear ◽  
P. Johnston ◽  
T. Patel ◽  
...  
Keyword(s):  
Domestic Wastewater ◽  
Nitrogen Loading ◽  
Wastewater Effluent ◽  
The Other ◽  
Septic Tank ◽  
Treated Effluent ◽  
Septic Tank Effluent ◽  
Per Capita ◽  
Suction Lysimeters

The performance of six separate percolation areas has been intensively monitored to ascertain the attenuation effects of the unsaturated subsoil with respect to on-site wastewater effluent. Septic tank effluent on three sites and secondary treated effluent on the other three sites was discharged into subsoils of varying percolation values. Samples of the percolating effluent were taken using suction lysimeters installed to nominal depths of 0.3, 0.6 and 1.0 m below the invert of the percolation trenches. The results clearly showed that the development of a biomat across the percolation areas receiving secondary treated effluent was muted on these sites compared to the sites receiving septic tank effluent. Significant differences were found between the sites receiving septic tank and secondary treated effluent in terms of the potential nitrogen loading to groundwater. The average nitrogen loading after 1.0 m depth of unsaturated subsoil per capita equated to 5.5, 3.3 and 3.2 gTotal-N/d for the sites receiving secondary treated effluent compared to 4.2, 1.7 and 0.3 gTotal-N/d for the sites receiving septic tank effluent. The noticeably higher nitrogen loading on one of the septic tank sites corresponded to the effluent percolating through highly permeable subsoil that counteracted any significant denitrification.

Treatment of Septic Tank Effluent in a Subsurface Biofilter

1993 ◽  
Vol 28 (10) ◽  
pp. 117-124 ◽  
Author(s):  
Robert Netter ◽  
Eckhard Stübner ◽  
Peter A. Wilderer ◽  
Ivan Sekoulov
Keyword(s):  
Bacterial Count ◽  
Septic Tank ◽  
Residential Areas ◽  
Negative Effects ◽  
Septic Tanks ◽  
Treated Effluent ◽  
Septic Tank Effluent ◽  
Per Capita ◽  
Private Homes ◽  
Complete Nitrification

A horizontal flow biofilter to be buried in the backyard of private homes and residential areas was developed to treat effluents of septic tanks. Pilot and full scale experiments have been conducted to study the efficiency of the biofilter. A tank volume of about 0.6 m3 per capita is needed to achieve advanced COD removal, complete nitrification and up to 60 per cent nitrogen removal. The bacterial count was reduced by 2 to 3 orders of magnitude. The treated effluent may be used for irrigation or toilet flushing. Percolation is possible without negative effects on groundwater quality.

scholarly journals Characterisation of Organic Matter and Its Transformation Processes in On-Site Wastewater Effluent Percolating through Soil Using Fluorescence Spectroscopic Methods and Parallel Factor Analysis (PARAFAC)

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2627
Author(s):  
Donata Dubber ◽  
Jan Knappe ◽  
Laurence W. Gill
Keyword(s):  
Factor Analysis ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Domestic Wastewater ◽  
Parallel Factor Analysis ◽  
Septic Tank ◽  
Secondary Effluent ◽  
Significant Difference ◽  
Septic Tank Effluent ◽  
Parallel Factor

This research has used fluorescence spectroscopy and parallel factor analysis (PARAFAC) in order to characterize dissolved organic matter in septic tank effluent, as it passes through the biomat/biozone, infiltrating into the unsaturated zone beneath domestic wastewater treatment systems (DWWTSs). Septic tank effluent and soil moisture samples from the percolation areas of two DWWTSs have been analyzed using fluorescence excitation–emission spectroscopy. Using PARAFAC analysis, a six-component model was obtained whereby individual model components could be assigned to humified organic matter, fluorescent whitening compounds (FWCs), and protein-like compounds. This has shown that fluorescent dissolved organic matter (FDOM) in domestic wastewater was dominated by protein-like compounds and FWCs and that, with treatment in the percolation area, protein-like compounds and FWCs are removed and contributions from terrestrially derived (soil) organic decomposition compounds increase, leading to a higher degree of humification and aromaticity. The results also suggest that the biomat is the most important element determining FDOM removal and consequently affecting DOM composition. Furthermore, no significant difference was found in the FDOM composition of samples from the percolation area irrespective of whether they received primary or secondary effluent. Overall, the tested fluorometric methods were shown to provide information about structural and functional properties of organic matter which can be useful for further studies concerning bacterial and/or virus transport from DWWTSs.

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.

scholarly journals Effectiveness and Energy Requirements of Pasteurisation for the Treatment of Unfiltered Secondary Effluent from a Municipal Wastewater Treatment Plant

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2100
Author(s):  
Peter Sanciolo ◽  
Paul Monis ◽  
Justin Lewis ◽  
Greg Ryan ◽  
Andrew Salveson ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Heat Exchangers ◽  
Municipal Wastewater ◽  
Waste Heat ◽  
Treatment Plant ◽  
Economic Feasibility ◽  
Secondary Effluent ◽  
Heat Sensitivity ◽  
Municipal Wastewater Treatment ◽  
Treated Effluent

Pasteurisation was investigated as a process to achieve high microbial quality standards in the recycling of water from unfiltered secondary effluents from a wastewater treatment plants in Melbourne, Australia. The relative heat sensitivity of key bacterial, viral, protozoan and helminth wastewater organisms (Escherichia coli, Enterococcus, FRNA bacteriophage, adenovirus, coxsackievirus, Cryptosporidium, and Ascaris) were determined by laboratory scale tests. The FRNA phage were found to be the most heat resistant, followed by enterococci and E. coli. Pilot scale challenge testing of a 2 ML/day pasteurisation pilot plant using unfiltered municipal wastewater and male specific coliphage (MS2) phage showed that temperatures between 69 °C and 75 °C achieved log reductions values between 0.9 ± 0.1 and 5.0 ± 0.5 respectively in the contact chamber. Fouling of the heat exchangers during operation using unfiltered secondary treated effluent was found to increase the energy consumption of the plant from 2.2 kWh/kL to 5.1 kWh/kL. The economic feasibility of pasteurisation for the current municipal application with high heat exchanger fouling potential can be expected to depend largely on the available waste heat from co-generation and on the efforts required to control fouling of the heat exchangers.

Sign in / Sign up

Export Citation Format

Share Document