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 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.

Septic Tank Effluent Treatment by Subsurface Horizontal Flow Wetland

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
Ellina S. Pandebesie ◽  
Ni Wayan Budi Arie
Keyword(s):  
Ground Water ◽  
Removal Efficiency ◽  
Open Space ◽  
Loading Rate ◽  
Domestic Wastewater ◽  
Septic Tank ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Septic Tank Effluent ◽  
Bod Removal

Domestic wastewater treatment in Indonesia, mostly treat by using septic tanks. The use of septic tanks preferred by the public because of the design, construction, and maintenance are easy and more economical for the system of domestic wastewater disposal. Effluent from the septic tank still contains BOD about 100 mg /l, COD about 250 mg/l and TSS about 100 mg /l. This effluent is still dangerous to public health and is not fulfill wastewater effluent standards yet. If there is open space available, extended treatment of septic tank effluent can be done by field infiltration. This open space must suitable for infiltration without contaminating the ground water or well water. In urban areas with ground water level is high such as Surabaya, water infiltrate into the ground causing the problem. Problems that arise are due to pollution of ground water and surface water contaminated by effluent from the septic tank. Because of these problems, it would require an alternative treatment of septic tank effluent. Appropriate technology would be a simple, economical, easy in operation and maintenance. One of wastewater processing that can be applied to the septic tank effluent is a constructed wetland system. Previous research carried out by using Cyperus papyrus plant with sand media in batch experiments showed satisfactory results. In this study, experiments conducted by using Cyperus papyrus plant with sand media with continuous flow in a horizontal subsurface flow wetland method. Wastewater flows with varying flow 90 ml /min and 180 ml /min. The objective of this research is to determine the ability of a horizontal subsurface flow wetland for treating septic tank effluent. The parameters analyzed were BOD and TSS. The results show the relation of organic loading rate with BOD removal efficiency. The highest organic loading rate of 0.051 kg BOD/m2.d on first day observations has BOD removal efficiency of 73.63% and the lowest organic loading rate of 0.029 kg BOD/m2.d with an efficiency of 70.82%. This shows that BOD removal efficiency is affected by organic loading rate. If BOD loading rate increase, it will decrease BOD removal efficiency. Organic loading rate recommended for domestic wastewater is 0.037-0.4 kg BOD5 /m2.d. Although in this study the organic loading rate exceeds the above recommendations, but efficiency is still good, above 70%.

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.

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.

Performance evaluation of package plant for treatment of single household domestic wastewater

2016 ◽  
Vol 11 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Meena Kumari Sharma ◽  
Absar Ahmad Kazmi
Keyword(s):  
Developing Countries ◽  
Removal Efficiency ◽  
Urban Areas ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Post Treatment ◽  
Pollutant Removal ◽  
Septic Tank ◽  
Efficient Technology ◽  
Treated Effluent

This study was carried out to evaluate the performance of an anaerobic packaged onsite system as an alternative to septic tank for the rural and semi-urban areas of developing countries where centralized sewerage facilities are not available. Potential application was identified on the basis of pollutant removal efficiency. The average per-capita wastewater generation was found to be 140 L/person/day with maximum contribution from the kitchen. The average removal efficiency of the system for chemical oxygen demand (COD), biochemical oxygen demand, total suspended solids, total nitrogen, total phosphate and fecal coliform was 70.9 ± 11.8%, 68.7 ± 8.5%, 78.1 ± 4.7%, 20.2 ± 8.4%, 13.8 ± 3.7% and 86.5 ± 1.6%, respectively. Despite a satisfactory performance, the anaerobically-treated effluent did not meet the disposal standards and required subsequent post treatment. An electrochemical reactor with aluminium electrodes, at a potential difference of 12 V, showed appreciable potential for use in actual households as a post treatment option for further removal of the pathogens and COD. The treated domestic wastewater, with electrocoagulation as a post-treatment measure, was successfully reused for non-potable purposes. Therefore, the package system, in conjugation with electrocoagulation process, promises to be a highly efficient technology for the onsite treatment of domestic wastewater in developing countries while facilitating reuse of the treated effluent for various recreational purposes as well as a safe discharge.

scholarly journals Scale up of Microbial Fuel Cell Stack System for Residential Wastewater Treatment in Continuous Mode Operation

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 217 ◽  
Author(s):  
Rodrigo Valladares Linares ◽  
Jorge Domínguez-Maldonado ◽  
Ernesto Rodríguez-Leal ◽  
Gabriel Patrón ◽  
Alfonso Castillo-Hernández ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Scale Up ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Septic Tank ◽  
Efficient Technology ◽  
Fuel Cell Stack ◽  
Treated Effluent

The most important operational expense during wastewater treatment is electricity for pumping and aeration. Therefore, this work evaluated operational parameters and contaminant removal efficiency of a microbial fuel cell stack system (MFCSS) that uses no electricity. This system consists of (i) septic tank primary treatment, (ii) chamber for secondary treatment containing 18 MFCs, coupled to an energy-harvesting circuit (EHC) that stores the electrons produced by anaerobic respiration, and (iii) gravity-driven disinfection (sodium hypochlorite 5%). The MFCSS operated during 60 days (after stabilization period) and it was gravity-fed with real domestic wastewater from a house (5 inhabitants). The flow rate was 600 ± 100 L∙d−1. The chemical oxygen demand, biological oxygen demand, total nitrogen and total phosphorous were measured in effluent, with values of 100 ± 10; 12 ± 2; 9.6 ± 0.5 and 4 ± 0.2 mg∙L−1, and removal values of 86%, 87%, 84% and 64%, respectively. Likewise, an EHC (ultra-low energy consumption) was built with 6.3 V UCC® 4700 µF capacitors that harvested and stored energy from MFCs in parallel. Energy management was programmed on a microcontroller Atmega 328PB®. The water quality of the treated effluent complied with the maximum levels set by the Mexican Official Standard NOM-001-SEMARNAT-1996-C. A cost analysis showed that MFCSS could be competitive as a sustainable and energy-efficient technology for real domestic wastewater treatment.

Economic Performance and Public Finance in Kenya, 1960-2010

2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Kempe Ronald Hope
Keyword(s):  
Public Finance ◽  
Economic Performance ◽  
Emerging Economy ◽  
The Other ◽  
Government Investment ◽  
The Past ◽  
Other Hand ◽  
Private Savings ◽  
Per Capita ◽  
Real Growth

Countries with positive per capita real growth are characterised by positive national savings—including government savings, increases in government investment, and strong increases in private savings and investment. On the other hand, countries with negative per capita real growth tend to be characterised by declines in savings and investment. During the past several decades, Kenya’s emerging economy has undergone many changes and economic performance has been epitomised by periods of stability, decline, or unevenness. This article discusses and analyses the record of economic performance and public finance in Kenya during the period 1960‒2010, as well as policies and other factors that have influenced that record in this emerging economy. 

scholarly journals A Preliminary Study on the Use of Xylit as Filter Material for Domestic Wastewater Treatment

2021 ◽  
Vol 11 (11) ◽  
pp. 5281
Author(s):  
Marcin Spychała ◽  
Tadeusz Nawrot ◽  
Radosław Matz
Keyword(s):  
Quality Indicators ◽  
Initial Period ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Filter Material ◽  
Stage I ◽  
Stage Ii ◽  
Septic Tank ◽  
Preliminary Stage ◽  
Wastewater Quality

The aim of the study was to verify two morphological forms (“angel hair” and “scraps”) of xylit as a trickling filter material. The study was carried out on two types of polluted media: septic tank effluent (STE) and seminatural greywater (GW). The basic wastewater quality indicators, namely, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), ammonium nitrogen (NNH4), and total phosphorus (Ptot) were used as the indicators of treatment efficiency. Filtering columns filled with the investigated material acted as conventional trickling filters at a hydraulic load of 376–472 cm3/d during the preliminary stage, 198–245 cm3/d during stage I, and 184–223 cm3/d during stage II. The removal efficiency of the two morphological forms of xylit did not differ significantly. The average efficiencies of treatment were as follows: for COD, over 70, 80, and 85% for preliminary stage, stage I and stage II, respectively; for BOD5, 77–79% (preliminary stage); for TSS, 42% and 70% during the preliminary stage, and 88, 91, and 65% during stage I; for NNH4, 97–99% for stage I and 36–49% for stage II; for Ptot, 51–54% for stage I and 52–56% for stage II. The study demonstrated that xylit was a material highly effective in wastewater quality indicators removal, even during the initial period of its use.

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