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.

Combined Treatment of Domestic Wastewater using Anaerobic and Solar Photocatalytic Treatment

2009 ◽  
Vol 44 (4) ◽  
pp. 393-398 ◽  
Author(s):  
J. Rajesh Banu ◽  
Sudalyandi Kaliappan ◽  
Khac-Uan Do ◽  
Arthur James ◽  
Ick Tae Yeom
Keyword(s):  
Combined Treatment ◽  
Domestic Wastewater ◽  
Anaerobic Treatment ◽  
Stage I ◽  
Stage Ii ◽  
Photochemical Oxidation ◽  
Upflow Anaerobic Sludge Blanket ◽  
Treated Wastewater ◽  
Anaerobic Sludge ◽  
Working Volume

Abstract The present study utilizes anaerobic and solar photocatalytic methods to treat domestic wastewater. For stage I, a granulated hybrid upflow anaerobic sludge blanket reactor (HUASB) with a working volume of 5.9 L was used. It was run in a recirculation mode for 3 days called "one cycle," and 30 cycles were run to find out the stability of the anaerobic treatment. During stage I anaerobic treatment, 90% of the chemical oxygen demand (COD) was removed, and it increased with an increase in digestion period for each cycle. Volatile fatty acids did not cause any operational problems during the stage I anaerobic treatment, being in the range of 280 to 90 mg/L. Stage I treated wastewater was subjected to a stage II solar photocatalytic oxidation method. The optimum pH and catalyst loading for the solar photochemical oxidation were found to be 5 and 200 mg/L, respectively. Stage II, treatment at an optimized condition, removed 66% of organics from the stage I treated wastewater. The combined COD removal due to the combination of these two technologies was found to be 96%.

scholarly journals Machine Learning Algorithms for the Forecasting of Wastewater Quality Indicators

Water ◽  
2017 ◽  
Vol 9 (2) ◽  
pp. 105 ◽  
Author(s):  
Francesco Granata ◽  
Stefano Papirio ◽  
Giovanni Esposito ◽  
Rudy Gargano ◽  
Giovanni De Marinis
Keyword(s):  
Machine Learning ◽  
Support Vector Regression ◽  
Quality Indicators ◽  
Drainage Basin ◽  
Learning Algorithms ◽  
Oxygen Demand ◽  
Machine Learning Algorithms ◽  
Coefficient Of Determination ◽  
Support Vector ◽  
Wastewater Quality

Stormwater runoff is often contaminated by human activities. Stormwater discharge into water bodies significantly contributes to environmental pollution. The choice of suitable treatment technologies is dependent on the pollutant concentrations. Wastewater quality indicators such as biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), and total dissolved solids (TDS) give a measure of the main pollutants. The aim of this study is to provide an indirect methodology for the estimation of the main wastewater quality indicators, based on some characteristics of the drainage basin. The catchment is seen as a black box: the physical processes of accumulation, washing, and transport of pollutants are not mathematically described. Two models deriving from studies on artificial intelligence have been used in this research: Support Vector Regression (SVR) and Regression Trees (RT). Both the models showed robustness, reliability, and high generalization capability. However, with reference to coefficient of determination R2 and root‐mean square error, Support Vector Regression showed a better performance than Regression Tree in predicting TSS, TDS, and COD. As regards BOD5, the two models showed a comparable performance. Therefore, the considered machine learning algorithms may be useful for providing an estimation of the values to be considered for the sizing of the treatment units in absence of direct measures.

scholarly journals Management challenges for a more decentralized treatment and reuse of domestic wastewater in metropolitan areas

2017 ◽  
Vol 8 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Martín Alejandro Iribarnegaray ◽  
María Soledad Rodriguez-Alvarez ◽  
Liliana Beatriz Moraña ◽  
Walter Alfredo Tejerina ◽  
Lucas Seghezzo
Keyword(s):  
Urban Planning ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Septic Tank ◽  
Anaerobic Sludge ◽  
Social Perspectives ◽  
Open Debate ◽  
Filtration Step

Abstract In a case study located in suburban sectors of the metropolitan area of the Lerma Valley (Valle de Lerma), in the province of Salta (Argentina), 24 informal decentralized wastewater treatment systems (DWWTS) were evaluated. The analyzed systems had three general configurations: A, septic tank; B, septic tank combined with upflow anaerobic sludge blanket (UASB) reactor; C, septic tank combined with UASB and a final filtration step. Statistically significant differences (p < 0.05) were observed in effluent quality, measured as total coliforms, thermotolerant coliforms, and chemical oxygen demand (COD). Treatment A was the most inefficient, and was statistically different from B and C; there were no significant differences between the latter two. Thermotolerant coliform concentrations were high in all analyzed systems and did not comply with local discharge standards in soakaway pits or in the ground. The lack of a final disinfection step in these systems is thus a weakness that needs to be addressed. The formal inclusion of DWWTS in urban planning could reduce overall investment costs, as long as the best technologies are selected for each case. Incorporation of DWWTS in formal urban planning requires an open debate in which the social perspectives of all relevant users need to be considered.

Sludge accumulation and conversion to methane in a septic tank treating domestic wastewater or black water

2013 ◽  
Vol 68 (4) ◽  
pp. 956-964 ◽  
Author(s):  
Tarek Elmitwalli
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Septic Tank ◽  
Black Water ◽  
Operational Temperature ◽  
Filling Time ◽  
Pre Treatment ◽  
Sludge Accumulation

Although the septic tank is the most applied on-site system for wastewater pre-treatment, limited research has been performed to determine sludge accumulation and biogas production in the tank. Therefore a dynamic mathematical model based on the Anaerobic Digestion Model No. 1 (ADM1) was developed for anaerobic digestion of the accumulated sludge in a septic tank treating domestic wastewater or black water. The results showed that influent chemical oxygen demand (COD) concentration and hydraulic retention time (HRT) of the tank mainly control the filling time with sludge, while operational temperature governs characteristics of the accumulated sludge and conversion to methane. For obtaining stable sludge and high conversion, the tank needs to be operated for a period more than a year without sludge wasting. Maximum conversion to methane in the tank is about 50 and 60% for domestic wastewater and black water, respectively. The required period for sludge wasting depends on the influent COD concentration and the HRT, while characteristics of the wasted sludge are affected by operational temperature followed by the influent COD concentration and the HRT. Sludge production from the tank ranges between 0.19 to 0.22 and 0.13 to 0.15 L/(person.d), for the domestic wastewater and black water, respectively.

scholarly journals Effect of Chemical Oxygen Demand Concentration on Nutrient Removal in Simultaneous Nitrification, Denitrification and Phosphorus Removal System in High-Altitude Areas

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2656
Author(s):  
Yani Zhao ◽  
Liling Zhang ◽  
Meng Zhang ◽  
Jingya Wu ◽  
Shuping Li ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
High Altitude ◽  
Phosphorus Removal ◽  
Inorganic Nitrogen ◽  
Oxygen Demand ◽  
Stage I ◽  
Stage Ii ◽  
Removal Rates ◽  
Atmosphere Pressure ◽  
Total Phosphate

The application of biological nitrogen and phosphorus removal processes in high-altitude areas faces severe challenges due to low temperature, low atmosphere pressure and low oxygen concentration. In this study, a simultaneous nitrification, denitrification and phosphorus removal (SNDPR) system was operated under low atmosphere pressure. The chemical oxygen demand (COD) concentrations in influent were decreased from 300 mg/L (stage I) to 200 mg/L (stage II), corresponding to the low COD concentration of sewage in high-altitude areas. The removal of COD and total phosphate was efficient at the H1 reactor (72 kPa). The removal rates of COD and total phosphate were 94.08% (stage I), 90.66% (stage II) and 98.43% (stage I), 99.34% (stage II), respectively, which were similar to L1 (100 kPa). The removal rates of total inorganic nitrogen and simulation nitrification and denitrification were from 81.21% (stage I) and 59.48% (stage I) to 72.86% (stage II) and 31.95% (stage II), respectively, which were also improved compared to L1. Cycle experiment results indicated that the activity of phosphorus accumulating organisms was enhanced, while the ammonia oxidation process was inhibited under low atmosphere pressure.

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 Toxicity Abatement of Wastewaters from Tourism Units by Constructed Wetlands

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2623 ◽  
Author(s):  
Cristina S. C. Calheiros ◽  
Paula M. L. Castro ◽  
Ana Gavina ◽  
Ruth Pereira
Keyword(s):  
Lemna Minor ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Added Value ◽  
Septic Tank ◽  
Toxicity Tests ◽  
Before And After ◽  
Concomitant Reduction ◽  
Aliivibrio Fischeri ◽  
Rural Context

The present research intended to investigate the toxicity abatement of domestic wastewater after passing a biosystem composed of a constructed wetland (CW) followed by a pond. The wastewater was generated in a tourism house in a rural and mountainous context and passed through a septic tank before being diverted to a CW followed by a pond. A battery of ecotoxicological tests, comprising microalgae (Raphidocelis subcapitata), macrophytes (Lemna minor), cladocerans (Daphnia magna), and bacteria (Aliivibrio fischeri), was used to assess the toxicity of the wastewater collected before and after the CW and the water of the pond. Physicochemical parameters (pH, conductivity, chemical oxygen demand, biochemical oxygen demand, total suspended solids, phosphates, ammonium, and nitrate) were also determined. The CW was able to remove carbon and nutrients from the water with a concomitant reduction of its toxicity. This study, reinforced the added value of using toxicity tests as a complement to CW operational monitoring to validate the solution and to analyze possible readjustments that may be required to improve efficiency. This study lends further support to the claim that CWs can be a sustainable solution for treating small volumes of domestic wastewater in a rural context.

scholarly journals The efficiency of the economic septic tank in the treatment of domestic wastewater and black water in rural areas

2021 ◽  
Vol 10 (8) ◽  
pp. e22910817232
Author(s):  
Guilherme Franceschini ◽  
Nathalie Dyane Miranda Slompo ◽  
Sergio Augusto Rodrigues ◽  
Valéria Cristina Rodrigues Sarnighausen ◽  
Jorge Lucas Junior
Keyword(s):  
Rural Areas ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Septic Tank ◽  
Attractive Alternative ◽  
Single Family ◽  
Black Water ◽  
Removal Efficiencies

Wastewater treatment in rural areas is important to prevent the pollution of aquatic environments and to protect the health of the population. Centralized treatment systems present a high cost, making the use of decentralized systems attractive. The use of septic tanks for on-site treatment of residential (single-family) is an attractive alternative within the context of Brazilian sanitation. Thus, the main objective of this study was to analyze the efficiency of the Economic Septic Tank in the treatment of wastewater of two residences located in a rural area. Two systems were installed: the first treat sanitary wastewater of a residence with three residents (A) and the second treat only the water from the toilet of a residence with five residents (B) (Black Water). For both systems, A and B, removal efficiencies were obtained in relation to total suspended solid (75%), biochemical oxygen demand (58 and 55%), and chemical oxygen demand (61 and 60%), respectively. Removal efficiencies were close, indicating that the system works satisfactorily in both systems, considering values indicated in the literature.

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.

Load limit of a UASB fed septic tank-treated domestic wastewater

2015 ◽  
Vol 72 (8) ◽  
pp. 1455-1461 ◽  
Author(s):  
Sunil Prasad Lohani ◽  
Rune Bakke ◽  
Sanjay N. Khanal
Keyword(s):  
Chemical Oxygen Demand ◽  
Low Cost ◽  
Scale Up ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Septic Tank ◽  
Anaerobic Sludge ◽  
Combined System

Performance of a 250 L pilot-scale up-flow anaerobic sludge blanket (UASB) reactor, operated at ambient temperatures, fed septic tank effluents intermittently, was monitored for hydraulic retention time (HRT) from 18 h to 4 h. The total suspended solids (TSS), total chemical oxygen demand (CODT), dissolved chemical oxygen demand (CODdis) and suspended chemical oxygen demand (CODss) removal efficiencies ranged from 20 to 63%, 15 to 56%, 8 to 35% and 22 to 72%, respectively, for the HRT range tested. Above 60% TSS and 47% CODT removal were obtained in the combined septic tank and UASB process. The process established stable UASB treatment at HRT ≥ 6 h, indicating a hydraulic load design limit. The tested septic tank–UASB combined system can be a low-cost and effective on-site sanitation solution.

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