scholarly journals Mathematical Modeling of a Domestic Wastewater Treatment System Combining a Septic Tank, an Up Flow Anaerobic Filter, and a Constructed Wetland

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3019
Author(s):  
Alberto Fernández del Castillo ◽  
Marycarmen Verduzco Garibay ◽  
Carolina Senés-Guerrero ◽  
Carlos Yebra-Montes ◽  
José de Anda ◽  
...  

Systems combining anaerobic bioreactors with constructed wetlands (CW) have proven to be adequate and efficient for wastewater treatment. Detailed knowledge of removal dynamics of contaminants can ensure positive results for engineering and design. Mathematical modeling is a useful approach to studying the dynamics of contaminant removal in wastewater. In this study, water quality monitoring was performed in a system composed of a septic tank (ST), an up flow anaerobic filter (UAF), and a horizontal flow constructed wetland (HFCW). Biological oxygen demand (BOD5), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), NH3, organic nitrogen (ON), total suspended solids (TSS), NO2−, and NO3− were measured biweekly during a 3-month period. First-order kinetics, multiple linear regression, and mass balance models were applied for data adjustment. First-order models were useful to predict the outlet concentration of pollutants (R2 > 0.87). Relevant multiple linear regression models were found, which could be applied to facilitate the system’s monitoring and provide valuable information to control and improve biological and physical processes necessary for wastewater treatment. Finally, the values of important parameters (μmax, Ks,  and Yx/s) in mass-balance models were determined with the aid of a differential neural network (DNN) and an optimization algorithm. The estimated parameters indicated the high robustness of the treatment system since performance stability was found despite variations in wastewater composition.

Author(s):  
Tanveer Saeed ◽  
Rumana Afrin ◽  
Abdullah Al-Muyeed ◽  
Md Jihad Miah ◽  
Hasin Jahan

2021 ◽  
Vol 13 (1) ◽  
pp. 15
Author(s):  
Junior Pastor Pérez-Molina ◽  
Carola Scholz ◽  
Roy Pérez-Salazar ◽  
Carolina Alfaro-Chinchilla ◽  
Ana Abarca Méndez ◽  
...  

Introduction: The implementation of wastewater treatment systems such as constructed wetlands has a growing interest in the last decade due to its low cost and high effectiveness in treating industrial and residential wastewater. Objective: To evaluate the spatial variation of physicochemical parameters in a constructed wetland system of sub-superficial flow of Pennisetum alopecuroides (Pennisetum) and a Control (unplanted). The purpose is to provide an analysis of spatial dynamic of physicochemical parameters using R programming language. Methods: Each of the cells (Pennisetum and Control) had 12 piezometers, organized in three columns and four rows with a separation distance of 3,25m and 4,35m, respectively. The turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), ammoniacal nitrogen (N-NH4), organic nitrogen (N-org.) and phosphorous (P-PO4-3) were measured in water under in-flow and out-flow of both conditions Control and Pennisetum (n= 8). Additionally, the oxidation-reduction potential (ORP), dissolved oxygen (DO), conductivity, pH and water temperature, were measured (n= 167) in the piezometers. Results: No statistically significant differences between cells for TKN, N-NH4, conductivity, turbidity, BOD, and COD were found; but both Control and Pennisetum cells showed a significant reduction in these parameters (P<0,05). Overall, TKN and N-NH4 removal were from 65,8 to 84,1% and 67,5 to 90,8%, respectively; and decrease in turbidity, conductivity, BOD, and COD, were between 95,1-95,4%; 15-22,4%; 65,2-77,9% and 57,4-60,3% respectively. Both cells showed ORP increasing gradient along the water-flow direction, contrary to conductivity (p<0,05). However, OD, pH and temperature were inconsistent in the direction of the water flow in both cells. Conclusions: Pennisetum demonstrated pollutant removal efficiency, but presented results similar to the control cells, therefore, remains unclear if it is a superior option or not. Spatial variation analysis did not reflect any obstruction of flow along the CWs; but some preferential flow paths can be distinguished. An open-source repository of R was provided. 


2010 ◽  
Vol 62 (10) ◽  
pp. 2408-2418 ◽  
Author(s):  
C. Y. Wu ◽  
J. K. Liu ◽  
S. H. Cheng ◽  
D. E. Surampalli ◽  
C. W. Chen ◽  
...  

In Taiwan, more than 20% of the major rivers are mildly to heavily polluted by domestic, industrial, and agricultural wastewaters due to the low percentage of sewers connected to wastewater treatment plants. Thus, constructed or engineered wetlands have been adopted as the major alternatives to clean up polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems for the wastewater polishment to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before it is discharged into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks for organics and metals. In this study, water and sediment samples were collected from the major wetland basins in KRRBCW. The investigation results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g. total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g. Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2 d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TN). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that a variation in microbial diversity in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradual disappearance of E. coli was also observed along the flow courses through natural attenuation mechanisms.


2018 ◽  
Vol 16 (2) ◽  
pp. 155
Author(s):  
Euis Nurul Hidayah ◽  
Andrysah Djalalembah ◽  
Gina Aprilliana Asmar ◽  
Okik Hendriyanto Cahyonugroho

ABSTRAKPenanganan air limbah domestik Kota Surabaya selama ini dilakukan dengan 2 cara, yakni untuk blackwater dialirkan ke tangki septik dan greywater dialirkan ke drainase tanpa pengolahan. Hal ini menyebabkan peningkatan pencemar pada sungai sebagai air baku. Salah satu teknologi alternatif yang dapat diaplikasikan dengan mudah dan rendah biaya operasional dibanding pengolahan air limbah lainnya adalah constructed wetland dengan menggunakan tanaman Iris pseudoacorus sebagai kombinasi pengolahan biofilter dan proses fitoteknologi. Penelitian ini dilakukan untuk mengetahui efisiensi dari constructed wetland dengan tanaman Iris pseudoacorus untuk mengolah limbah domestik, serta menentukan bagaimana pengaruh dari adanya aerasi dan pengaruh waktu tinggal pada sistem constructed wetland dalam menurunkan bahan organik dan nitrogen pada air limbah. Penelitian ini dilakukan dalam skala uji laboratorium menggunakan reaktor berkapasitas 30 liter. Air limbah dialirkan pada reaktor dengan waktu tinggal 2 hari dan 3 hari, dengan variasi aerasi dan efisiensi pencemar diukur dengan parameter BOD, dan ammonia. Hasil penelitian ini menunjukan bahwa kemampuan penyisihan BOD, dan ammonia dari limbah air domestik oleh reaktor constructed wetland dengan tambahan aerasi dan waktu tinggal selama 4 hari sangat efektif. Reaktor ini mampu menurunkan nilai BOD hingga 96% dan nilai ammonia sebesar 97%.ABSTRACTWastewater domestic in Surabaya City has been treated in two methods, including septic tank for blackwater and directly discharged into drainage system for greywater. This caused an increasing pollutant loading in source water. Constructed wetland with Iris pseudoacorus, one of the alternative natural treatment technology through biofilter and phytotechnology process, could be applied easily and less costly to other treatment. This research was conducted to know the efficiency of constructed wetland with Iris pseudoacorus in domestic wastewater treatment, and to reveal the effect of aeration and detention time in reducing organic and nitrogen content in domestic wastewater. Experiment has been conducted on a laboratory scale of continue aerated reactor and without aeration as control reactor. Detention time (days) 2 and 3 was setup, then sample was taken for BOD and ammonia measurement. The results indicated that constructed wetland with aeration and detention time 4 days had a higher performance to remove BOD up to 96% and ammonia up to 97% than without aeration and less than 4 days process.Keywords: Domestic Wastewater, Constructed Wetland, Phytotechnology, Iris pseudoacorus, Aeration.Sitasi: Hidayah, E. N., Djalalembah, A., Asmar, G.A. dan Cahyonugroho, G.A. (2018). Pengaruh aerasi dalam constructed wetland pada pengolahan air limbah domestik. Jurnal Ilmu Lingkungan, 16(2),155-161, doi:10.14710/jil.16.2.155-161


2017 ◽  
Vol 75 (11) ◽  
pp. 2649-2658 ◽  
Author(s):  
Andrzej Jucherski ◽  
Maria Nastawny ◽  
Andrzej Walczowski ◽  
Krzysztof Jóźwiakowski ◽  
Magdalena Gajewska

The aim of the present study was to assess the technological reliability of a domestic hybrid wastewater treatment installation consisting of a classic three-chambered (volume 6 m3) septic tank, a vertical flow trickling bed filled with granules of a calcinated clay material (KERAMZYT), a special wetland bed constructed on a slope, and a permeable pond used as a receiver. The test treatment plant was located at a mountain eco-tourist farm on the periphery of the spa municipality of Krynica-Zdrój, Poland. The plant's operational reliability in reducing the concentration of organic matter, measured as biochemical oxygen demand (BOD5) and chemical oxygen demand (COD), was 100% when modelled by both the Weibull and the lognormal distributions. The respective reliability values for total nitrogen removal were 76.8% and 77.0%, total suspended solids – 99.5% and 92.6%, and PO4-P – 98.2% and 95.2%, with the differences being negligible. The installation was characterized by a very high level of technological reliability when compared with other solutions of this type. The Weibull method employed for statistical evaluation of technological reliability can also be used for comparison purposes. From the ecological perspective, the facility presented in the study has proven to be an effective tool for protecting local aquifer areas.


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).


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