scholarly journals Improving phosphorus removal of conventional septic tanks by a recirculating steel slag filter

2015 ◽  
Vol 50 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Dominique Claveau-Mallet ◽  
Félix Lida ◽  
Yves Comeau
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Removal ◽  
Steel Slag ◽  
Domestic Wastewater ◽  
Septic Tank ◽  
Retention Capacity ◽  
Septic Tanks ◽  
P Retention

The objective of this project was to increase the phosphorus (P) retention capacity of a conventional septic tank by adding a recirculating slag filter. Two recirculation modes and recirculation ratios from 5 to 50% were tested in the laboratory with reconstituted domestic wastewater. The best system was recirculation from the end to the inlet of the second compartment of a septic tank with a 50% recirculation ratio in the slag filter, achieving 4.2 and 1.9 mg P/L at the effluent for total phosphorus (TP) and orthophosphate (o-PO4), respectively, and a pH of 8.8. The calculated size of the slag filter for a two-bedroom house application was 1,875 kg for an expected lifetime of 2 years. The 1 mg P/L level goal was not reached, but P precipitation may be favoured by the relatively high effluent pH reaching the infiltration bed.

scholarly journals Phosphorus Removal and Carbon Dioxide Capture in a Pilot Conventional Septic System Upgraded with a Sidestream Steel Slag Filter

2019 ◽  
Author(s):  
Dominique Claveau-Mallet ◽  
Hatim Seltani ◽  
Yves Comeau
Keyword(s):  
Carbon Dioxide ◽  
Phosphorus Removal ◽  
Carbon Dioxide Capture ◽  
Steel Slag ◽  
Experimental System ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Septic Tank ◽  
Septic System ◽  
Precipitated Calcium Carbonate

The objective of this work was to evaluate the removal of phosphorus and carbon dioxide capture of a conventional septic system upgraded with a sidestream steel slag filter used in recirculation mode. A pilot scale sidestream experiment was conducted with two septic tank and drainfield systems, one with and one without a sidestream slag filter. The experimental system was fed with real domestic wastewater. Recirculation ratios of 25%, 50% and 75% were tested. Limestone soils and silica soils were used as drainfield media. The phosphorus removal efficiency observed in the second compartment of the septic tank was 30% in the slag filter upgraded system, compared to -3% in the control system. The drainfield of silica soils achieved very high phosphorus removal in both control and upgraded systems. In the drainfield of limestone soil, the slag filtration reduced the groundwater phosphorus contamination load by up to 75%. Phosphorus removal in the septic tank with a slag filter was attributed to either sorption on newly precipitated calcium carbonate or precipitation of vivianite, or both. Recirculation ratio design criteria were proposed based on simulations. Simulations showed that the steel slag filter partly inhibited biological production of carbon dioxide in the septic tank. The influent alkalinity strongly influenced the recirculation ratio needed to raise the pH in the septic tank. The control septic tank produced carbon dioxide, whereas the slag filter upgraded septic tank was a carbon dioxide sink.

scholarly journals Characterizing phosphorus removal in passive waste stabilization ponds in Arctic communities

2016 ◽  
Vol 2 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Jordan J. Schmidt ◽  
Colin M. Ragush ◽  
Wendy H. Krkosek ◽  
Graham A. Gagnon ◽  
Rob C. Jamieson
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Removal ◽  
Organic Phosphorus ◽  
Domestic Wastewater ◽  
The Arctic ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
Fractionation Analysis ◽  
Arctic Communities

A majority of communities in the Canadian territory of Nunavut rely on passive waste stabilization ponds (WSPs) for domestic wastewater treatment. Little research has been conducted on the treatment performance of these systems. Therefore, in response to impending federal wastewater regulations, a research program was conducted in order to characterize contaminant removal, with phosphorus a contaminant of particular concern. The performance of WSPs in the Arctic communities of Kugaaruk, Pond Inlet, Grise Fiord, and Clyde River was evaluated from 2011 to 2014. Removal of total phosphorus was highly variable, ranging from 24% (Pond Inlet, 2014) to 76% (Grise Fiord, 2011). The average removal efficiency was 44%. Effluent total phosphorus concentrations generally exceeded 7 mg P/L, partly due to elevated raw wastewater concentrations. Over the course of the treatment season (defined as June to September, when the WSP is thawed), limited additional total phosphorus removal was observed. A fractionation analysis of WSP sediments showed that organic phosphorus and phosphorus bound to aluminum and iron were the predominant forms, which provided insight into primary treatment mechanisms. Further studies on these mechanisms are needed in order to optimize Arctic WSP treatment.

Comprehensive evaluation of substrates in vertical-flow constructed wetlands for domestic wastewater treatment

2015 ◽  
Vol 10 (3) ◽  
pp. 625-632 ◽  
Author(s):  
Junmei Wu ◽  
Dong Xu ◽  
Feng He ◽  
Jie He ◽  
Zhenbin Wu
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Evaluation System ◽  
Comprehensive Evaluation ◽  
Steel Slag ◽  
Domestic Wastewater ◽  
Vertical Flow ◽  
Substrate Selection ◽  
Comprehensive Evaluation System

Substrates are the important component of constructed wetlands (CWs), which have an effect on construction cost, purification capability and stable operation, so that substrate optimization is the key part of CWs design. The comprehensive evaluation system, including four layers, eleven indicators and nine schemes, for substrates in vertical-flow CWs treating domestic wastewater was established based on analytic hierarchy process. Then combined with Delphi method and fuzzy synthetic evaluation approach, zeolite, anthracite, shale, vermiculite, ceramic filter material, gravel, steel slag, bio-ceramic and combination substrate (isopyknic layered anthracite, bio-ceramic and zeolite) were evaluated from the viewpoints of purification effect, practical performance and economic analysis. The results showed that phosphorus removal, nitrogen removal, chemical stability were the main factors of substrate selection. Combination substrate was the best scheme among nine substrates. Zeolite was ideal substrate for nitrogen removal and biocompatibility, while anthracite and steel slag were ideal substrates for phosphorus removal. The comprehensive evaluation system of substrates was beneficial to comprehensive compare all aspects of performance for different substrates, and could be improved according to the actual situation of engineering applications, so as to provide guidance of substrate selection for CWs design.

Removal of nitrogen and phosphorus using a new biofilm-activated-sludge system

1996 ◽  
Vol 34 (1-2) ◽  
pp. 315-322 ◽  
Author(s):  
J. X. Liu ◽  
J. W. van Groenestijn ◽  
H. J. Doddema ◽  
B. Z. Wang
Keyword(s):  
Activated Sludge ◽  
Total Phosphorus ◽  
Phosphorus Removal ◽  
Domestic Wastewater ◽  
Optimum Conditions ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
The Mean ◽  
Scale Experiment ◽  
Biological Nitrogen

This paper describes a laboratory scale experiment using a combined biofilm and activated sludge process to enhance biological nitrogen and phosphorus removal. In the system, fibrous carriers were packed in an anoxic tank for the attached growth of denitrifying bacteria and the sludge of the clarifier was returned to the anaerobic tank to release phosphate. In this configuration, nitrification, denitrification and phosphorus removal could be performed at their respective optimum conditions. The influent was domestic wastewater; the mean concentrations of COD, NH4-N and total phosphorus in the influent were about 319 mg/l, 60 mg/l and 10 mg/l respectively. At a total HRT of the system of 20-30 hours, based on the influent flow of the system, and a temperature of 10-15°C, the mean concentrations of COD, NH4-N, NO3-N, NO2-N and total phosphorus in the effluent were about 39.4 mg/l, 1.3 mg/l, 13.4 mg/l, 0.6 mg/l, and 0.8 mg/l respectively.

Pre-treatment of domestic wastewater with pre-composting tanks: evaluation of existing systems

2004 ◽  
Vol 48 (11-12) ◽  
pp. 133-138 ◽  
Author(s):  
D.R. Gajurel ◽  
O. Benn ◽  
Z. Li ◽  
J. Behrendt ◽  
R. Otterpohl
Keyword(s):  
Constructed Wetland ◽  
New Technology ◽  
Domestic Wastewater ◽  
Solid Material ◽  
Septic Tank ◽  
Soil Conditioner ◽  
Septic Tanks ◽  
Decentralised Systems ◽  
Pre Treatment ◽  
Tanker Truck

A relatively new technology called pre-composting tank or Rottebehaelter, retaining solid material and draining water to a certain extent, has been found to be an interesting component of decentralised systems to replace the usual septic tank. Results of the investigation revealed that solid material which has been retained in the pre-composting tanks still contained a high percentage of water. However, there was no odour problem at and near the tanks. The pre-composted materials have to be further composted together with household and garden wastes for a year prior to their use as soil conditioner. The filtrate is further treated in a constructed wetland. One of the major advantages of this system compared to other systems, such as septic tanks, is that it does not deprive agriculture of the valuable nutrients and soil conditioner from human excreta and does not require an expensive tanker truck. It can be the most appropriate system for application in regions where there is a demand for local reuse of the end product. It has to be stated that maintenance is a crucial factor.

scholarly journals Phosphorus Removal and Carbon Dioxide Capture in a Pilot Conventional Septic System Upgraded with a Sidestream Steel Slag Filter

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 275 ◽  
Author(s):  
Dominique Claveau-Mallet ◽  
Hatim Seltani ◽  
Yves Comeau
Keyword(s):  
Carbon Dioxide ◽  
Phosphorus Removal ◽  
Carbon Dioxide Capture ◽  
Steel Slag ◽  
Calcareous Soils ◽  
Oxygen Demand ◽  
Experimental System ◽  
Septic Tank ◽  
Septic System ◽  
Precipitated Calcium Carbonate

The objective of this work was to demonstrate the removal of the phosphorus and carbon dioxide capture potential of a conventional septic system upgraded with a sidestream steel slag filter used in recirculation mode. A pilot scale sidestream experiment was conducted with two septic tank and drainfield systems, one with and one without a sidestream slag filter. The experimental system was fed with real domestic wastewater. Recirculation ratios of 25%, 50% and 75% were tested. Limestone soils and non-calcareous soils were used as drainfield media. The tested system achieved a satisfactory compromise between phosphorus removal and pH at the effluent of the septic tank, thus eliminating the need for a neutralization step. The phosphorus removal efficiency observed in the second compartment of the septic tank was 30% in the slag filter upgraded system, compared to −3% in the control system. The slag filter reached a phosphorus retention of 105 mg/kg. The drainfield of non-calcareous soils achieved very high phosphorus removal in both control and upgraded systems. In the drainfield of limestone soil, the slag filtration reduced the groundwater phosphorus contamination load by up to 75%. The removal of chemical oxygen demand of the drainfields was not affected by the pH rise induced by the slag filter. Phosphorus removal in the septic tank with a slag filter was attributed to either sorption on newly precipitated calcium carbonate, or the precipitation of phosphate minerals, or both. Recirculation ratio design criteria were proposed based on simulations. Simulations showed that the steel slag filter partly inhibited the biological production of carbon dioxide in the septic tank. The influent alkalinity strongly influenced the recirculation ratio needed to raise the pH in the septic tank. The recirculation mode allowed clogging mitigation compared to a mainstream configuration, because an important part of chemical precipitation occurred in the septic tank. The control septic tank produced carbon dioxide, whereas the slag filter-upgraded septic tank was a carbon dioxide sink.

scholarly journals Study of Steel Slag Filter Unit as a Secondary Treatment System for Removing Total Phosphorus from Textile Industry Wastewater

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
Nur Ain Nazirah Mohd Arshad ◽  
◽  
R. Hamdan ◽  
Keyword(s):  
Removal Efficiency ◽  
Total Phosphorus ◽  
Phosphorus Removal ◽  
Textile Industry ◽  
High Efficiency ◽  
Steel Slag ◽  
Industrial Effluent ◽  
Textile Wastewater ◽  
Secondary Stage ◽  
Industry Wastewater

Eutrophication is one of the global concerned due to algae bloom in the natural surface water such as lakes and swamp area. Industrial effluent with incomplete treatment discharged has become one of the main culprits to this phenomenon. Approximately, 0.3 – 13 mg/L of total phosphorus can be found in the final discharge of industrial effluent showing that the existing treatment including an activated carbon filter (ACF) has limitation in polishing the phosphorus. Therefore, this 16 week of study has been designed to study the alternative treatment phosphorus removal at secondary stage to replace the tertiary treatment by using steel manufacturing by-product as filter media for effective phosphorus removal from the textile industry wastewater. Two units of lab-scale vertical steel slag filter (SSF) systems under aerated and unaerated conditions have been developed for this study. The samples were collected and analysed biweekly for selected parameters including pH, alkalinity, DO and TP. The results obtained from this study show that the unaerated steel slag filter has a high efficiency of TP removal which ranged from 46% to 70% compared to the aerated SSF with removal efficiency ranged from 37% to 66%. Besides, the existing ACF removal efficiency was ranged from 36% to 54%. Thus, the use of steel slag in removing phosphorus from textile wastewater is possible with the used of both aerated and unaerated steel slag filter systems. Furthermore, the removal mechanism involved was likely to be precipitation and adsorption.

Basic Studies on Phosphorus Removal by the Contact Aeration Process Using Iron Contactors

1991 ◽  
Vol 23 (4-6) ◽  
pp. 641-650 ◽  
Author(s):  
S. Haruta ◽  
T. Takahashi ◽  
T. Nishiguchi
Keyword(s):  
Corrosion Rate ◽  
Phosphorus Removal ◽  
Domestic Wastewater ◽  
Small Scale ◽  
Combined Method ◽  
Sulfate Reducing ◽  
Biological Sludge ◽  
Aeration Process ◽  
Basic Studies ◽  
Volumetric Loading

The authors have developed what we call the submerged iron contactor process as a simple and inexpensive phosphorus removal method for small-scale plants disposing of domestic wastewater and household wastewater treatment tanks. In this method iron contactors are submerged in biological treatment tanks, where phosphate anions in wastewater are combined with iron cations produced through corrosion of the contactors, and the compound thus produced is precipitated and removed together with biological sludge. In these studies, laboratory experiments were made on the contact aeration process combined with the above-mentioned method, and the following findings were obtained. (1) It is desirable to treat wastewater by making use of corrosion by sulfate-reducing bacteria instead of corrosion by oxygen dissolved in wastewater, to conduct a stable phosphorus removal by this combined method. (2) The corrosion rate of iron contactors is affected by the volumetric loading of BOD in the tanks where they are submerged. (3) Assuming that an iron contactor continues to suffer corrosion evenly all over the surface when our combined method is applied, it is estimated that the corrosion rate is about 1mm or less in 30 years.

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.

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