Wyniki wyszukiwania - Biblioteka Nauki

1

Membrane performance in the treatment of the effluent from a zirconium silicate production industry

100%

Pindea A. , Sancho M. , Lora J. , Arnal J. M. , Bes A. , Marti C.

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tom Vol. 31, nr 3-4

177-186

EN

Zirconium silicate sands are produced by different branches of industry for several applications in the ceramic industry. This production can be made by different milling processes: dry milling and wet milling. The wet milling yields a smaller particle size. This is a great yield process which implies more stages: addition and removal of water, sedimentation, and addition of alumina (Al2O3), NaOH and a coagulant, generally a polyelectrolyte, which are used to control the process and the quality of the wastewater. Polyelectrolyte allows formation of flocs for the separation of zirconium silicate solids from the water. This experimental study was made with two main purposes: 1) to reuse the polyelectrolyte in the process of coagulation and 2) to reuse the water in the milling process, therefore reducing the amount of wastewater. As a result, some environmental benefits will be obtained: reuse of the water and better quality of the wastewater; and also economical benefits: saving of polyelectrolyte and water, and greater yield in the production process. Membrane technologies are suitable for the removal of suspended solids and organic compounds, like a polyelectrolyte, from water. Some experimental tests were carried out in a pilot-plant scale in order to assess the viability of different membrane processes in the treatment of the effluent from a zirconium silicate production industry. This work presents the results of membrane performance obtained in these experiments.

2

Predicting Water Quality Parameters in a Complex River System

100%

Kurniawan I. , Hayder G. , Mustafa H. M.

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tom Vol. 22, nr 1

250--257

EN

This research applied a machine learning technique for predicting the water quality parameters of Kelantan River using the historical data collected from various stations. Support Vector Machine (SVM) was used to develop the prediction model. Six water quality parameters (dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), and suspended solids (SS)) were predicted. The dataset was obtained from the measurement of 14 stations of Kelantan River from September 2005 to December 2017 with a total sample of 148 monthly data. We defined 3 schemes of prediction to investigate the contribution of the attribute number and the model performance. The outcome of the study demonstrated that the prediction of the suspended solid parameter gave the best performance, which was indicated by the highest values of the R2 score. Meanwhile, the prediction of the COD parameter gave the lowest score of R2 score, indicating the difficulty of the dataset to be modelled by SVM. The analysis of the contribution of attribute number shows that the prediction of the four parameters (DO, BOD, NH3-N, and SS) is directly proportional to the performance of the model. Similarly, the best prediction of the pH parameter is obtained from the utilization of the least number of attributes found in scheme 1.

3

Treatment of Hospital Wastewater Using Activated Sludge with Extended Aeration

100%

Custodio M. , Cuadrado-Campó W. , Peñaloza R. , Vicuña-Orihuela C. , Torres-Gutiérrez E. , Orellana E.

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tom Vol. 23, nr 11

24--32

EN

Hospital wastewater is of a complex nature and is generally discharged into urban sewage systems. This study evaluated the removal efficiency of organic and biological contaminants from a hospital wastewater treatment plant using extended aeration activated sludge. The study was conducted at a treatment plant scale, with 14 hours of feed. The plant consists of a pre-filter, a collector and crumbler tank, a homogenization tank, two biological reactors of 80 000 liters capacity each, two settlers and a contact disinfection chamber. Three flow rates of 3 L/s, 4 L/s and 5 L/s were tested in each biological reactor, with application of three concentrations of residual chlorine with sodium hypochlorite to the effluent of the settling tanks (0.3 ppm, 0.4 ppm and 0.5 ppm). The removal efficiency of suspended solids varied according to flow rate. The reactor with a flow rate of 3 L/s and 0.5 ppm of residual chlorine achieved the highest removal of suspended solids (91.95%), biological oxygen demand (97.52%) and fecal coliforms (99.99%). Finally, the quality of the hospital wastewater is within the limits of the national and international environmental quality thresholds.

4

Analysis of suspended solids emissions from a combined sewage system using the Stormwater Management Model (SWMM)

86%

Sakson G.

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2023

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tom Vol. 49, no. 4

389--399

EN

The protection of water bodies requires the reduction of pollutant emissions from all major sources. In urbanized areas, these include: wastewater treatment plants (WWTPs) and (depending on the type of sewage system) combined sewer overflows (CSOs) and stormwater drainage outlets. WWTPs are usually monitored and emitted pollutant loads are known, but it is more difficult to assess the pollutant load discharged by CSOs and stormwater drainage systems. The article attempts to use the Stormwater Management Model (SWMM) to assess emissions of suspended solids from a large urban combined catchment. Suspended solids are the main pollutant of stormwater runoff in urban areas, and the dynamics of their emission from catchments is very diverse. The amount of suspended solids discharged by CSOs functioning in the given city was assessed in comparison with emissions from a wastewater treatment plant. The results show that CSOs discharge a pollutant load to the receiver which is comparable to WWTPs, but in a much shorter time and in a violent manner which can lead to the severe deterioration of receiving water quality. The modelling took into account the quality of dry weather sewage, the build-up of suspended solids, wash-off processes in the catchment area, and local precipitation characteristics. Factors affecting the quality of the obtained model and the accuracy of the emission level assessment were analysed.

5

Applying of water quality indices methods for assessment of 9-Nissan Water Treatment Plant

86%

Abdul-Hameed H. M. , Abdul-Hameed H. M.

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nr 47

6

New Approach to Modelling if Sand Filter Clogging by Septic Tank Effluent

86%

Nieć J. , Spychała M. , Zawadzki P.

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tom Vol. 17, nr 2

97--107

EN

The deep bed filtration model elaborated by Iwasaki has many applications, e.g. solids removal from wastewater. Its main parameter, filter coefficient, is directly related to removal efficiency and depends on filter depth and time of operation. In this paper the authors have proposed a new approach to modelling, describing dry organic mass from septic tank effluent and biomass distribution in a sand filter. In this approach the variable filter coefficient value was used as affected by depth and time of operation and the live biomass concentration distribution was approximated by a logistic function. Relatively stable biomass contents in deeper beds compartments were observed in empirical studies. The Iwasaki equations associated with the logistic function can predict volatile suspended solids deposition and biomass content in sand filters. The comparison between the model and empirical data for filtration lasting 10 and 20 days showed a relatively good agreement.

7

Hydraulic gradient prediction for solid-water mixture flow through horizontal pipelines of different diameters and roughness and solids concentrations

86%

Osra F. A.

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tom no. 49

267--272

EN

In wastewater treatment plants, large pumps are often used to accommodate unknown hydraulic properties of solid-water mixture flow. The use of large pumps translates into higher purchasing and operating costs. Wastewater mixture is pumped with solids of different types and concentrations through pipelines. The design of these ducts is mainly based on the hydraulic laws of solid-water mixture which is represented by a corrected friction coefficient corresponding to the concentration of solids in water. This paper experimentally studies hydraulic properties of solid-water mixtures in pipelines by the varying Froude number (Fr), which represents the velocity mixture, solid concentration, pipeline diameter and pipeline material type-roughness coefficient. The experiments have been conducted in the wastewater treatment plant where six solid concentrations can be found ranging from 2 to 12% by weight. The pipe diameter ranges between 100 to 300 mm. It has been found that both the friction coefficient and the hydraulic gradient ameliorate with the increase of the pipeline roughness and the solids concentration in the water mixture, whereas the Fr drop with the diameter of the pipeline. The results are translated into curves and equations to predict the corrected pipeline friction coefficient and the hydraulic gradient of the solid-water mixture flow through horizontal pipelines at various solids concentrations, roughness and diameters.

8

Influence of runoff of suspended solids on quality of surface water: Case study of the Szreniawa River

72%

Kowalczyk A. , Smoroń S. , Kopacz M.

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2019

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nr 41

9

Performance of subsurface vertical flow constructed wetlands receiving municipal wastewater

72%

Kowalik P. , Mierzejewski M. , Randerson P. F. , Williams H. G.

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tom Vol. 51, nr 4

349-370

EN

The efficiency of pollution removal from municipal sewage in two vertical flow constructed wetlands consisting of gravel filters with a surface area of 4 × 5 m, depth 60 cm, planted with reed (Phragmites) was assessed over a period of about two years. The flow of wastewater was 50 mm per day. Wastewater underwent only primary treatment before application to reed bed B, but reed bed A was supplied with wastewater after mechanical and biological treatment. Measurements were taken of sewage supply and discharge, precipitation and wastewater temperatures. The main indicator of efficiency was the elimination of suspended solids, BOD5, nitrogen and phosphorus from the wastewater during treatment. The elimination of the pollution load was 2-25g O2 per square meter per day for the BOD5 and 0-3.5 g per square meter per day for so-called "total nitrogen". Rates of pollution removal were between 2 and 4 times as high in bed B (after primary treatment) as in bed A (after biological treatment), but the loading rate of bed B was also substantially higher. The rate of BOD5 removal and the coefficient k for BOD5 were greatly dependent on temperature for reed bed B (primary treatment); less so for bed A (biological treatment). The difference between summer and winter temperatures indicates that the surface area of constructed wetland B with wastewater after mechanical treatment should be about 3 times greater during winter, to obtain the summer rate of BOD5 pollution removal in the climatic conditions of Northern Poland (54oN).

10

Analiza zmian ładunku metali śladowych transportowanych wraz z zawiesinami wzdłuż biegu rzeki

72%

Nocoń W. , Barbusiński K. , Nocoń K. , Kernert J.

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tom Vol. 35, nr 1

33--38

EN

The paper discusses potential use of changes in load of suspended solids and co-transported trace metal ions to define sectors of the river where increased sedimentation occurs as river bottom deposits. Therefore, flow rate of the river was being determined as well as content of total suspended solids and of selected metal ions (Zn, Cd, Cu, Mn, Pb, Cr, Ni, Fe) in suspended solids and bottom sediments. Changes in the load of suspended solids and of metals with suspended solids found along the course of the river (Klodnica, Upper Silesia) were estimated. It was established that under similar hydraulic conditions the load of metals associated with suspended solids was a function of change in the load of suspended matter. The results of the research allowed determination of sectors of the Klodnica River where sedimentation of the major part of suspended solids is observed and where the number of metal ions in the bottom sediments is increased. This will enable defining sectors of small and medium-sized rivers that require certain measures to be taken in order to improve their ecological state.

PL

Przedstawiono możliwości praktycznego wykorzystania zmian ładunku zawiesin i transportowanych wraz z nimi jonów metali śladowych do określenia odcinków koryta rzeki, na których następuje zwiększona sedymentacja zanieczyszczeń w postaci osadów dennych. W tym celu wyznaczano wartości strumienia objętości wody w rzece, zawartość zawiesin ogólnych oraz jonów wybranych metali (Zn, Cd, Cu, Mn, Pb, Cr, Ni, Fe) w zawiesinach i osadach dennych. Określono zmiany ładunku zawiesin oraz metali wraz z zawiesinami, jakie wystąpiły wzdłuż biegu rzeki (Kłodnica, Górny Śląsk). Stwierdzono, że ładunek metali śladowych związanych z zawiesinami, przy zbliżonych warunkach hydraulicznych, był funkcją zmian ładunku zawiesin. Wyniki badań pozwoliły na wskazanie odcinków rzeki, na których sedymentuje znaczna część zawiesin, a w osadach dennych występuje zwiększona zawartość związków metali śladowych. Umożliwi to wskazanie odcinków małych i średnich rzek, na których konieczne są zabiegi mające na celu poprawę ich stanu ekologicznego.

11

Zastosowanie programu SWMM do modelowania ilości i jakości ścieków deszczowych

72%

Szeląg B. , Górski J. , Bąk Ł. , Górska K.

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2015

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tom Vol. 9, No. 2

767--775

PL

Ze względu na stochastyczny charakter zjawisk opadowych, a także akumulacji oraz zmywania zanieczyszczeń zgromadzonych na powierzchni zlewni, prognoza jakości i ilości ścieków deszczowych jest bardzo złożona, co może prowadzić do znacznych błędów obliczeniowych na etapie doboru i projektowania ciągów technologicznych oczyszczalni wód deszczowych. Wytyczna ATV A-118 oraz norma PN-EN 752 zalecają do obliczeń hydraulicznych systemów kanalizacyjnych zastosowanie modelowania hydrodynamicznego dla zlewni o powierzchni przekraczającej 200 ha, ale również w przypadku występowania w sieci zjawiska wylania ścieków na powierzchnię terenu, co zdarza się na terenach miejskich stosunkowo często. Ponadto, ze względu na to, że w większości opracowane programy obliczeniowe (SWMM, Mouse, Mike Urban, Civil Storm) mają oprócz zaimplementowanych modułów do symulacji spływu także moduły określania jakości ścieków, wydaje się wskazane przeprowadzenie kompleksowych analiz w tym kierunku. Celem artykułu jest omówienie wyników symulacji numerycznych jakości i ilości ścieków uzyskanych przy pomocy programu SWMM dla zlewni kanału Si9 zlokalizowanej na terenie Kielc. W artykule wykonano obliczenia hydrogramów odpływu ze zlewni i stężeń zawiesiny przy założeniu stałego natężenia deszczu dla czasu trwania td = 15-180 min i prawdopodobieństwa wystąpienia opadu p = 20%. Ponadto opracowano model matematyczny oczyszczalni ścieków deszczowych, który pozwolił określić obciążenia ładunkiem zanieczyszczeń istniejącego ciągu technologicznego oraz ustalić objętość i ładunek zawiesiny ogólnej zrzucanej przelewem burzowym bezpośrednio do odbiornika. Przeprowadzone obliczenia wykazały nieznaczny wpływ jednostkowego spływu na masę zawiesiny ogólnej odpływającej z przedmiotowej zlewni zurbanizowanej.

EN

Due to the stochastic character of precipitation phenomena, and also accumulation of pollutants in the catchment area and their wash-off, predicting the quantity and quality of rainfall wastewater is a very complex task. That can lead to massive calculation errors at selection and design stages of technological lines in rainfall wastewater treatment plants. For hydraulic sewer systems, the guideline ATV A-118 and the PN-EN 752 standard recommend using hydrodynamic modelling for the catchment area of more than 200 ha, but also for cases where the surface flooding occurs, which happens quite often in urban areas. As a majority of computational software tools (SWMM, Mouse, Mike Urban, Civil Storm), in addition to modules for run-off simulations also have those dedicated to wastewater quality assessment, it is justifiable to conduct complex analyses. The paper aims to discuss the results of wastewater quality and quantity numerical simulations obtained with SWMM software for Si9 sewer catchment located in the area of Kielce. For the paper, hydrogram computations were made for the catchment run-off and the suspension concentrations at the assumption of constant intensity of the rainfall of the duration of td = 15-180 min and the precipitation occurrence probability of p = 20%. In addition, a mathematical model of rainfall wastewater treatment plant was developed. That allowed determination of the pollutant load of the existing technological line, and volume and load of suspended solids discharged by the stormwater overflow structure directly into the receiver. The computations that were conducted showed a limited impact of a unit runoff on the mass of suspended solids flowing in from the catchment under consideration.

12

Analiza statystycznej zmienności składu ścieków w mechaniczno-biologicznej oczyszczalni

58%

Płuciennik-Koropczuk E. , Wojciech M.

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2013

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tom nr 151 (31)

131--142

PL

W pracy przedstawiono wyniki analizy statystycznej zmienności składu ścieków w kolejnych procesach mechaniczno-biologicznego oczyszczania. Rozkład stężeń zanieczyszczeń oraz podstawowe wartości statystyk opisowych przedstawiono za pomocą wykresów pudełkowych. Wykonano również oceny współzależności między wskaźnikami ChZTCr, BZT5 i OWO dla próbek ścieków po kolejnych procesach oczyszczania.

EN

The paper presents the results of the statistical analysis of variability of the composition of the wastewater in the subsequent processes of treatment. Distribution of pollutant concentrations and the core values of descriptive statistics are presented in the form of graphs boxed. Also performed evaluation of the relationship between indicators COD, BOD5 and TOC in wastewater samples after subsequent treatment processes.

13

Upgrading the effluent quality of an aerated lagoon with horizontal roughing filtration

44%

Nabizadeh R. , Naddafi K. , Khazaei M. , Fard R. F. , Izanloo H. , Yavari Z.

Environment Protection Engineering

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2015

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tom Vol. 41, nr 3

121--136

EN

Removal of suspended solids and microorganisms from an aerated lagoon effluent with a horizontal roughing filter (HRF) was investigated. The aerated lagoon receives Qom municipal wastewater. The HRF was operated at three filtration rates of 0.5, 1.0 and 1.5 m3/(m2·h) during four month operation period. The measured values of turbidity, TSS, COD, pH, temperature and flow rate of HRF at the former filtration rate were 79±12 NTU, 100±11 mg/dm3, 190±12 mg/dm3, 7±0.1 °C, 17±8 °C and 0.82 dm3/min, respectively. The differences between inlet and outlet values of pH and temperature were not significant (P > 0.05). Measures turbidity, TSS and COD in HRF final effluent were 15±13.7 NTU, 37±295 mg/dm3, 64±39.7 mg/dm3, respectively, which corresponds to 81.1%, 63% and 66.3% removal efficiencies, respectively. A decrease of removal efficiency was observed upon increasing filtration rates. The Spearman correlation coefficients between the head-loss and removal efficiencies ranged from 0.578 to 0.968 pointing to a direct relationship. Results of modeling approach revealed appropriate compliance between the values of the observed and predicted TSS for higher filtration rates.