Study of food waste degradation in a simulated septic tank

2019 ◽  
Vol 37 (12) ◽  
pp. 1199-1206
Author(s):  
Hongjian Lin ◽  
Yuchuan Wang ◽  
Leif van Lierop ◽  
Carlos Zamalloa ◽  
Casey Furlong ◽  
...  

Septic systems are typically designed to treat domestic wastewater from households without access to centralized facilities. The installation of a food waste disposer (FWD) may increase the discharge of food waste (FW) into the wastewater; therefore, the installation of a FWD is discouraged in households that have a septic system. This study was conducted to determine how a typical dose of FW from a FWD can affect the performance of a septic system in terms of sewage treatment and solids accumulation. A 20-L control tank was compared with an experiment tank to which FW was added, increasing the amount of total suspended solids (TSS) by 31.3% and total chemical oxygen demands by 46.3% for a period of 110 days. Although the influent water quality changed dramatically, the effluent from the experiment tank had a substantially lower percentage increase in water quality parameters compared with the effluent from the control. It was found that in the experiment tank, 75.8% of FW TSS was degraded, whereas only 36.7% of sewage TSS was degraded, and that 18.8% of FW TSS and 44.9% of sewage TSS accumulated in the experiment tank. The addition of FW increased the scum accumulation, even though the dry matter of the scum layer was much less in quantity than the sludge layer. It also increased the lipid content in the sludge. The increase in the scum layer was mainly due to the increase in protein from the addition of the FW. Overall, compared with sewage TSS, FW TSS tends to be more biodegradable, which indicates that the impact on pumping frequency from adding FW will be insignificant.

2018 ◽  
Vol 195 ◽  
pp. 05004
Author(s):  
Prihatiningsih Bekti ◽  
Zaenal Kusuma ◽  
Agus Suharyanto ◽  
Amin Setyoleksono

The degradation of water quality has become a major problem today. In Indonesia, the decline in water quality is caused by domestic wastewater which is a non-point source. In an effort to reduce the occurrence of environmental degradation due to domestic wastewater, it is necessary to give an idea and convince the public and the relevant parties of the importance of domestic wastewater management. Efforts are made by informing the pattern of distribution of domestic wastewater in a region and the impact of its distribution for its control and management. The research method uses a momentary sampling technique in accordance with SNI 6989.59:2008. The location of the water sampling is determined purposively. Sampling was conducted in two periods; the dry season in September and the rainy season in January. The observed parameters included BOD5 and E.coli. Determination of the distribution of domestic wastewater uses GIS. The distribution of domestic wastewater is determined based on pollution levels expressed as IP. The results show that pollution levels in Sawojajar and Sumbersari were lightly polluted with average IPs of 4.09 and 4.02 (dry season). While Kedungkandang is in the good category, IP = 0.32 (dry season).


2002 ◽  
Vol 46 (6-7) ◽  
pp. 105-112 ◽  
Author(s):  
M. Spanou ◽  
D. Chen

This paper presents the application of the object-oriented framework SMILE to the management of flows and water quality in the Upper Mersey river catchment. The design river flows are those exceeded for 95% of the time, and are estimated applying alternative methods. The influence of compensation reservoirs, surface-water abstractions, and continuous discharges on low river flows is quantified. The annual licensed abstraction volumes are further reviewed. The monitored river water quality is classified using the River Ecosystem scheme. The compliance of the sewage treatment works and trade effluents with their discharge-consent limits is also assessed. The impact of effluents on the variation of river water quality is evaluated through Monte Carlo simulations at the discharge points. The points where the downstream water quality fails to comply with proposed River Quality Objectives are identified. The consent limits of the corresponding discharges are assessed, and changes to the BOD and total ammonia limits are suggested.


2012 ◽  
Vol 16 (8) ◽  
pp. 2453-2467 ◽  
Author(s):  
J. E. Bremer ◽  
T. Harter

Abstract. Onsite wastewater treatment systems are common in rural and semi-rural areas around the world; in the US, about 25–30% of households are served by a septic (onsite) wastewater treatment system, and many property owners also operate their own domestic well nearby. Site-specific conditions and local groundwater flow are often ignored when installing septic systems and wells. In areas with small lots (thus high spatial septic system densities), shallow domestic wells are prone to contamination by septic system leachate. Mass balance approaches have been used to determine a maximum septic system density that would prevent contamination of groundwater resources. In this study, a source area model based on detailed groundwater flow and transport modeling is applied for a stochastic analysis of domestic well contamination by septic leachate. Specifically, we determine the probability that a source area overlaps with a septic system drainfield as a function of aquifer properties, septic system density and drainfield size. We show that high spatial septic system density poses a high probability of pumping septic system leachate. The hydraulic conductivity of the aquifer has a strong influence on the intersection probability. We find that mass balance calculations applied on a regional scale underestimate the contamination risk of individual drinking water wells by septic systems. This is particularly relevant for contaminants released at high concentrations, for substances that experience limited attenuation, and those that are harmful even at low concentrations (e.g., pathogens).


2011 ◽  
Vol 8 (3) ◽  
pp. 5701-5732
Author(s):  
J. E. Horn ◽  
T. Harter

Abstract. Onsite wastewater treatment systems such as septic systems are common in rural and semi-rural areas around the world; in the US, about 25–30 % of households are served by a septic system and a private drinking water well. Site-specific conditions and local groundwater flow are often ignored when installing septic systems and wells. Particularly in areas with small lots, thus a high septic system density, these typically shallow wells are prone to contamination by septic system leachate. Typically, mass balance approaches are used to determine a maximum septic system density that would prevent contamination of the aquifer. In this study, we estimate the probability of a well pumping partially septic system leachate. A detailed groundwater and transport model is used to calculate the capture zone of a typical drinking water well. A spatial probability analysis is performed to assess the probability that a capture zone overlaps with a septic system drainfield depending on aquifer properties, lot and drainfield size. We show that a high septic system density poses a high probability of pumping septic system leachate. The hydraulic conductivity of the aquifer has a strong influence on the intersection probability. We conclude that mass balances calculations applied on a regional scale underestimate the contamination risk of individual drinking water wells by septic systems. This is particularly relevant for contaminants released at high concentrations, for substances which experience limited attenuation, and those being harmful even in low concentrations.


Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 184 ◽  
Author(s):  
Anie Yulistyorini ◽  
Miller Camargo-Valero ◽  
Sukarni Sukarni ◽  
Nugroho Suryoputro ◽  
Mujiyono Mujiyono ◽  
...  

In order to assess the impact of the Sanitation by Communities (SANIMAS) program for community-led sanitation in Indonesia (established in 2002), this research work was conducted with the aim of characterizing the current performance of anaerobic baffled reactors (ABRs), which were deployed in high numbers for the provision of domestic wastewater treatment in densely populated urban areas in Malang (Indonesia). Small and decentralized sewage treatment facilities serve ≈3% of the total population in Malang, including 89 ABR treatment plants. Our findings reveal that only 14% of the 89 ABRs in Malang have an acceptable performance with regard to pollutant removal and integrity of their building structure, but the majority of them produce a treated effluent of poor quality, according to discharge consents set by the Ministry of Environment and Forestry of the Republic of Indonesia (Regulation No. P.68/2016). Clearly the lack of consistent operation and maintenance practices have had a detrimental effect on these decentralized sewage treatment systems, despite their robustness and buffer capacity to cope with changes in organic and hydraulic loading rates. Urbanization will continue to exert pressure on the provision of sanitation services in lower and middle economies, and the role of decentralized sewage management systems is expected to be prominent in the UN’s Sustainable Development Goals era (2015–2030); however, sustainable service delivery must be conceived beyond the provision of sanitation infrastructure.


Author(s):  
Dominique Claveau-Mallet ◽  
Hatim Seltani ◽  
Yves Comeau

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.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yulia Anggraini ◽  
Eka Wardhani

Cibaligo River is the polluted rivers in Cimahi City. The river that flows through three districts and 6 sub-districts in Cimahi City catchment  area of 666.19 hectares of watershed with a total length of 7 km. The land use of the district through which this river passes is domestic, trade, agriculture, livestock and industry whose waste will end into the Cibaligo River. The impact of these activities causes the river to be polluted and a decrease in water quality. The purpose of this study was to determine the status of water quality from upstream to downstream which represents the transition, dry, and rainy seasons. Knowledge of water quality status can be used as basic data for controlling water pollution in rivers. The pollutant index (IP) method used in this study is in accordance with the Decree of the State Minister for the Environment Number 115 of 2003 concerning guidelines for determining water quality status. The results showed that the water quality status of the Cibaligo River from upstream to downstream represented that each season was categorized as heavily polluted with the highest index value being in the rainy season at the downstream point. The main contributor that causes river water to be heavily polluted is domestic wastewater, especially the presence of total coliform and fecal coliform that exceed the established quality standards. Based on the results of the research, efforts to tackle domestic waste are needed to improve the quality of this river water.


2014 ◽  
Vol 687-691 ◽  
pp. 4339-4342
Author(s):  
Ying Zhang ◽  
Lei Zhu ◽  
Jie Fan

Fe2+ is widely used as a coagulant to enhance the primary SBR sewage treatment process. Based on SBR system, this paper studies the change trend of phosphate content in various stages by simulating the interaction between sewage and the precipitates produced with Fe2+ in the sediment as a coagulant. The results indicate that excluding the impact of activated sludge, the concentration of PO43+ increases in the end of the anaerobic stage with the increase of FePO4 cumulant in the sediment and there is an equimultiple relationship between the increase of the concentration of PO43+ in the effluent and the FePO4 dosage and that the accumulation of Fe (OH)3 can contribute to the subsequent sustainable phosphorus removal, but the cumulant increase of Fe (OH)3 has no significant influence on the effects of phosphorus removal.


2014 ◽  
Vol 70 (4) ◽  
pp. 634-641 ◽  
Author(s):  
Mary Keegan ◽  
Kate Kilroy ◽  
Daniel Nolan ◽  
Donata Dubber ◽  
Paul M. Johnston ◽  
...  

One of the key threats to groundwater and surface water quality in Ireland is the impact of poorly designed, constructed or maintained on-site wastewater treatment systems. An extensive study was carried out to quantify the impact of existing sites on water quality. Six existing sites, consisting of a traditional septic tank and soakaway system, located in various ranges of subsoil permeabilities were identified and monitored to determine how well they function under varying subsoil and weather conditions. The preliminary results of the chemical and microbiological pollutant attenuation in the subsoil of the systems have been assessed and treatment performance evaluated, as well as impact on local surface water and groundwater quality. The source of any faecal contamination detected in groundwater, nearby surface water and effluent samples was confirmed by microbial source tracking. From this, it can be seen that the transport and treatment of percolate vary greatly depending on the permeability and composition of the subsoil.


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