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Pilot-scale study of removal of anionic surfactants with trickling filterGuo, Feng 11 1900 (has links)
Anionic surfactants are wildly used in many industrial and household applications.
Because anionic surfactants are used so widely, significant attention has focused on
the removal of these contaminants from wastewater. Among various treatment
techniques, biofiltration, such as trickling filter technologies, has been employed in
many wastewater treatment plants (WWPTs) to remove anionic surfactants. However,
current knowledge of the efficacy of trickling filter to remove anionic surfactants
from wastewaters is limited. The present study characterized the performance of a
high rate (i.e. roughing) trickling filter to remove anionic surfactants both at lab-scale
and pilot-scale. Lab-scale tests investigated the biodegradation of anionic surfactants
under controllable conditions were compared with those from previous studies by
others. Pilot-scale tests investigated the efficacy of a trickling filter at removing
anionic surfactants from a wastewater over an extended period of time. The data from
the pilot-scale tests were used to model the performance of trickling filter at removing
anionic surfactants from the wastewater, using first order and modified Velz models.
The lab-scale tests indicated that high molecular weight anionic surfactants
degrade faster than the low molecular weight surfactants. The biodegradation rates
observed in the present study were similar to those from pervious studies by others.
The pilot-scale tests indicated that roughing trickling filter could remove 11% to 29%
of anionic surfactants and 4% to 22% of COD from the wastewater. Higher molecular
weight anionic surfactants were more degradable.
The experimental data could be accurately modeled using the modified Velz
model (R² value more than 0.9). The degradation rates of modified Velz model for
total anionic surfactants, high molecular weight anionic surfactants and COD were
0.053±0.0057, 0.088±0.0048 and 0.119±0.0111 (mIs)0.5 respectively.
The pilot-scale test results indicated that a high rate (i.e., roughing) trickling filter
was not capable of effectively removing anionic surfactants in the primary effluent at
Lions Gate WWTP because a relatively large trickling filter area would be required to
achieve the required surfactant removal efficiency.
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Pilot-scale study of removal of anionic surfactants with trickling filterGuo, Feng 11 1900 (has links)
Anionic surfactants are wildly used in many industrial and household applications.
Because anionic surfactants are used so widely, significant attention has focused on
the removal of these contaminants from wastewater. Among various treatment
techniques, biofiltration, such as trickling filter technologies, has been employed in
many wastewater treatment plants (WWPTs) to remove anionic surfactants. However,
current knowledge of the efficacy of trickling filter to remove anionic surfactants
from wastewaters is limited. The present study characterized the performance of a
high rate (i.e. roughing) trickling filter to remove anionic surfactants both at lab-scale
and pilot-scale. Lab-scale tests investigated the biodegradation of anionic surfactants
under controllable conditions were compared with those from previous studies by
others. Pilot-scale tests investigated the efficacy of a trickling filter at removing
anionic surfactants from a wastewater over an extended period of time. The data from
the pilot-scale tests were used to model the performance of trickling filter at removing
anionic surfactants from the wastewater, using first order and modified Velz models.
The lab-scale tests indicated that high molecular weight anionic surfactants
degrade faster than the low molecular weight surfactants. The biodegradation rates
observed in the present study were similar to those from pervious studies by others.
The pilot-scale tests indicated that roughing trickling filter could remove 11% to 29%
of anionic surfactants and 4% to 22% of COD from the wastewater. Higher molecular
weight anionic surfactants were more degradable.
The experimental data could be accurately modeled using the modified Velz
model (R² value more than 0.9). The degradation rates of modified Velz model for
total anionic surfactants, high molecular weight anionic surfactants and COD were
0.053±0.0057, 0.088±0.0048 and 0.119±0.0111 (mIs)0.5 respectively.
The pilot-scale test results indicated that a high rate (i.e., roughing) trickling filter
was not capable of effectively removing anionic surfactants in the primary effluent at
Lions Gate WWTP because a relatively large trickling filter area would be required to
achieve the required surfactant removal efficiency.
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Pilot-scale study of removal of anionic surfactants with trickling filterGuo, Feng 11 1900 (has links)
Anionic surfactants are wildly used in many industrial and household applications.
Because anionic surfactants are used so widely, significant attention has focused on
the removal of these contaminants from wastewater. Among various treatment
techniques, biofiltration, such as trickling filter technologies, has been employed in
many wastewater treatment plants (WWPTs) to remove anionic surfactants. However,
current knowledge of the efficacy of trickling filter to remove anionic surfactants
from wastewaters is limited. The present study characterized the performance of a
high rate (i.e. roughing) trickling filter to remove anionic surfactants both at lab-scale
and pilot-scale. Lab-scale tests investigated the biodegradation of anionic surfactants
under controllable conditions were compared with those from previous studies by
others. Pilot-scale tests investigated the efficacy of a trickling filter at removing
anionic surfactants from a wastewater over an extended period of time. The data from
the pilot-scale tests were used to model the performance of trickling filter at removing
anionic surfactants from the wastewater, using first order and modified Velz models.
The lab-scale tests indicated that high molecular weight anionic surfactants
degrade faster than the low molecular weight surfactants. The biodegradation rates
observed in the present study were similar to those from pervious studies by others.
The pilot-scale tests indicated that roughing trickling filter could remove 11% to 29%
of anionic surfactants and 4% to 22% of COD from the wastewater. Higher molecular
weight anionic surfactants were more degradable.
The experimental data could be accurately modeled using the modified Velz
model (R² value more than 0.9). The degradation rates of modified Velz model for
total anionic surfactants, high molecular weight anionic surfactants and COD were
0.053±0.0057, 0.088±0.0048 and 0.119±0.0111 (mIs)0.5 respectively.
The pilot-scale test results indicated that a high rate (i.e., roughing) trickling filter
was not capable of effectively removing anionic surfactants in the primary effluent at
Lions Gate WWTP because a relatively large trickling filter area would be required to
achieve the required surfactant removal efficiency. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
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Using a biotrickling filter for degradation of cypermethrin, an insecticide frequently used in Tahuapalca, BoliviaEnstedt, Henric January 2013 (has links)
The feasibility of using bench-scale biotrickling filter reactors inoculated with the fungus UBAF004, isolated from soil in Tahuapalca, for treatment of water contaminated with cypermethrin was investigated. Wood chips, gravel and ceramics were tested as packing materials for the reactors in batch experiments in small glass flasks. Wood proved to be the material on which the fungus grew best and was thus chosen as the packing material for the reactors. It was determined that UBAF004 had quite low competitive strength compared to other microorganisms when growing on wood and gravel but not necessarily on ceramics. UBAF004 grew slowly in the reactors leading to poor degradation performance. The results obtained indicate that it will be challenging to use UBAF004 for treatment of water contaminated with cypermethrin in Tahuapalca. The single largest issue is to find a way to establish a stable population of the fungus in the reactor and to protect it from being out competed by other microorganisms. / <p>Opponent: Veronika Granat</p>
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Removal of ammonia from drinking water by biological nitrification in a fixed film reactorvan den Akker, Ben, ben.vandenakker@flinders.edu.au January 2008 (has links)
The absence of water catchment protection often results in contamination of drinking water supplies. Waters in South East Asia have been exploited to support extensive agriculture, industry, power generation, public water supply, fisheries and recreation use. Ammonia has been identified as a significant contaminant of drinking water because of its ability to affect the disinfection efficiency of chlorine. The interference of ammonia with chlorination is a prevalent and expensive problem faced by many water treatment plants (WTPs) located throughout South East Asia. The conventional approach for ammonia removal was to pre-chlorinate using high concentrations of chlorine, which has a number of disadvantages including the formation of disinfection by-products and high chlorine consumption.
This thesis investigated the application of high rate nitrifying trickling filters (NTFs) as a means of ammonia removal from a polluted lowland water source as an alternative to pre-chlorination. NTFs are widely used for the biological remediation of ammonia rich wastewater, however their performance when required to operate under low ammonia concentrations for potable water applications was unknown.
A NTF pilot facility consisting of one large-scale, and three small-scale NTFs were constructed at Hope Valley WTP in South Australia. The NTFs were operated to simulate the raw water quality of a polluted catchment identified in Indonesia (Buaran WTP), including variations in ammonia, biological oxygen demand (BOD5), and turbidity. Results confirmed that plastic-packed NTFs were able to operate equally successfully under low ammonia-N concentrations, some 10- to 50-fold lower that that of conventional wastewater applications, where complete conversion of ammonia to nitrate was consistently observed under these markedly reduced loadings. Results also showed that when operated under mass loads equivalent to typical ammonia loading criteria for wastewater NTFs, by increasing hydraulic flow¬, comparable apparent nitrification rates were achieved. These results confirmed that mass transport limitations posed by low ammonia-N concentrations on overall filter performance were insignificant.
This thesis also investigated the impact of organic carbon quantity and biodegradability on the nitrification behaviour of the pilot NTF. Results demonstrated that organic carbon loading, rather than the C:N ratio, was an important regulator of filter nitrification capacity, where a linear decline in nitrification performance correlated well with sucrose and methanol augmented carbon loads. Extensive monitoring of inorganic nitrogen species down the NTF, to profile nitrification behaviour, showed sucrose-induced carbon loads greater than 870 mg sBOD5 m2 d1 severely suppressed nitrification throughout the entire filter bed. This study also confirmed that critical carbon loads for nitrification varied among carbon sources. In contrast to sucrose, when a more native-like carbon source was dosed (organic fertiliser), no significant decline in nitrification capacity was observed. This could be attributed to differences in carbon biodegradability.
This research has provided new insights into the microbial ecology of a potable water NTF. The combination of fluorescent in situ hybridisation (FISH) and scanning electron microscopy (SEM) for in situ analysis of biofilms was successful in identifying the spatial distribution of ammonia oxidising bacteria (AOB), nitrite oxidising bacteria (NOB) and heterotrophs. When the NTF was operated under low organic loads, clusters of AOB and NOB were abundant, and were located in close proximity to each other. Uniquely, the study identified not only Nitrospira spp but also the less common Nitrobacter spp within the NTF biofilm. Biofilm analysis showed that the type of carbon source also strongly influenced the biofilms characteristics in terms of biomass ecology, morphology, and polysaccharide composition, which was correlated with NTF performance. Results showed that an increase in sBOD5 via the addition of sucrose promoted the rapid growth of filamentous heterotrophic bacteria and production of large amounts of polysaccharide. Stratification of nitrifiers and heterotrophs, and high biofilm polysaccharide concentrations were observed at all filter bed depths, which coincided with the impediment of nitrification throughout the entire filter column. High biofilm polysaccharide concentrations also coincided with a significant increase (40 %) in filter hydraulic retention time, as determined by hydraulic tracer experiments. In contrast to sucrose-fed biofilms, organic fertiliser-fed biofilms had a more uniform and dense ultra-structure dominated by many rod shaped bacteria, and was significantly lower in polysaccharide composition. This observation was coupled with superior nitrification performance.
This study confirmed that a well functioning NTF is a viable, low cost alternative for ammonia removal from source water abstracted from poorly protected catchments found in many developing countries. Pre-treatment using NTFs has the potential to reduce the chlorine dose required for pre-chlorination. Thereby improving water quality by minimising the formation of disinfection by-products, and improving the control of chlorination. NTFs could also find ready application in other situations where ammonia interferes with chlorine disinfection.
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Wood Drying Condensate Treatment Using a Bio – Trickling Filter with Bark Chips as a Support MediumKristiono, Arie January 2009 (has links)
The kiln drying of wood produces huge amounts of vapour. The vapour is released to the environment when the process purges some of the saturated hot air. The main environmental issue regarding the use of kiln drying process are the release of the water vapour which contains organic contaminants. Some of them are hazardous to human health. In addition, there are some wood particles which may released with the water vapour purging process.
In this research, the vapour is condensed and analysed for its organic contaminants and their biodegradability. The result showed that the dominant contaminants present in the condensate were ethanol and methanol with the concentration of approximately 65 mg/L and 25 mg/L respectively. The average COD concentration of the condensate was 159 ± 40 mg/L. The analysis also showed that the contaminants were biodegradable.
In order to treat the wastewater, a trickling filter process using bark chips as a support medium was used to treat an artificial wastewater. The artificial wastewater contained the dominant contaminant present in the wood drying condensate. In the experiment, different sizes of bark chips were used. In addition, the loading rate of the treatment system was varied by changing the flow rate and contaminant concentration.
The 30 cm long trickling filter using bark chips varying between of 2.8 – 4 mm diameter as the support medium gave a maximum removal of 36.4 % with removal capacity of 8.34 kg COD/m³bed•day at a flow rate of 2.8 cm/min and average inlet COD load of 20.4 kg COD/m3bed•day. The trickling filter with bark chips varying between 5.6 – 8 mm diameter as the support medium was operated using variations in contaminant concentration and flow rate. The operation using different inlet concentration gave the highest removal rate of 13.5 kg COD/m3bed•day at average initial load of 84.9 kg COD/m³bed•day, flow rate of 2.8 cm/min and theoretical initial concentration of 680 mg/L. The trickling filter operated with flow rate variation showed the highest removal rate of 10 kg COD/m³bed•day at an average inlet load of 53.3 kg COD/m³bed•day and flow rate of 7.1 cm/min.
The removal rate of the contaminants in treatment was limited. There is a number of possible explanations. First is the active surface area, which indicating the area where the contact between the biofilm surface and feed happened. The active surface area increased as the flow rate increased. Second is the residence time of the feed in the bed. The residence time of the feed varied with the flow rate. It decreased as the flow rate increased. Third is the influence of the contaminants in the feed. The presence of methanol and methanol in the feed inhibited each other’s degradation.
The dimention of a full-scale biotrickling filter to be used in actual kiln was also estimated. The estimation was made based on the maximum removal rate and optimum flow rate obtained in the experiments. The result of the estimation showed to obtain significant removal, the required bed would have to be 2.35 m in diameter and 160 in height.
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Removing Algae From Stabilization Pond Effluents By Using Trickling FiltersKaya, Devrim 01 September 2005 (has links) (PDF)
The objective of this study is to remove turbidity originating from algae present
in oxidation ponds effluents by an easy and inexpensive method. For this reason,
a novel lab-scale Step Feed Dual Treatment (SFDT) process was constructed and
the efficiency of trickling filter (TF) to remove algae and organic matter was
investigated. SFDT process developed in this study is the unique, inexpensive
and new system to scavenge algae from oxidation pond effluents. In this system,
influent is first treated in a stabilization pond, and subsequently they directed to a
TF, so as to provide a dual treatment. Moreover, some fraction of the raw
influent was directly sent to TF to maintain a steady biofilm on the TF medium.
Stabilization pond was not simulated in the experimental set-up as the main
objective of the study is to observe TF ability to scavenge algae from pond effluent. To determine the magnitude of the effect of individual operational
parameters (hydraulic loading rate, influent COD and chlorophyll-a
concentration) and of their combinations on organics and particle removal
efficacy an experimental design was followed. Experiments consistent with twolevel
factorial design with three variables (23) were performed. Hydraulic
loading rate (HLR) (0.5-2 m3/m2.day), influent COD (150-550 mg/l) and influent
chlorophyll-a concentrations (Chl-a) (250-600 µ / g/l) were selected as
independent variables. The COD and algae removal (as Chl-a) were selected as
dependent variables. Data obtained from the experiments showed that when HLR
(m3/m2.day) was increased from 0.5 to 2, Chl-a, NTU, SS and COD removals
were decreased, however, more than 85 % removal was attained in each case,
except for COD. The lowest removal efficiencies were obtained for all the
quality parameters when hydraulic loading was increased to 4 m3/m2.day. It was
observed that in general removal percentages for turbidity, Chl-a, SS and COD
increased considerably with the decreasing hydraulic loading rate. Highest
removals were obtained at lowest HLR. The removal of algae in TF was
presumably due to both flocculation (due to algal and bacterial EPS production)
and degradation (through bacterial activity) of algae. In conclusion, trickling
filter produced clear effluents, with less than 2 NTU, for most of the cases.
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Biofiltracijos procesų taikymo nuotekų valymui tyrimai / Investigation of Wastewater Treatment Applying Biofiltration ProcessesStrazdauskas, Konstantinas 26 July 2012 (has links)
Biofiltraciniai įrenginiai - tai alternatyva standartiniams veikliojo dumblo valymo įrenginiams. Tinkamai įrengus ir naudojant šiuos filtrus galima ženkliai sumažinti eksploatacijos išlaidas bei pasiekti pageidaujamų išvalymo kokybės rezultatų. Biofiltrų efektyvumas labai priklauso nuo naudojamo užpildo tipo, todėl šiame darbe buvo nagrinėjama naujo užpildo nuotekų biofiltracijai tinkamumas. Atlikti tyrimai parodė, kad pasirinkti akmens vatos užpildai yra tinkami naudoti laistomuosiuose filtruose ir juose gali vykti organinių medžiagų šalinimas ir nitrifikacija. Organinių medžiagų šalinimo efektyvumas pagal BDS7 abiejuose filtruose siekė daugiau nei 95 %, o ištekančių nuotekų koncentracija neviršijo 5 mg O2/l. Pirmajame filtre, kuriame buvo naudojama specialiai apdorota akmens vata, skirta augalams auginti, vidutinis nitrifikacijos efektyvumas siekė 62,2 %, antrajame filtre, kuriame buvo naudojama statybinė priešvėjinė akmens vata, skirta pastatams apšiltinti, vidutinis nitrifikacijos efektyvumas buvo 61,6 %. Darbą sudaro šios dalys: įvadas, literatūros analizė, tiriamojo darbo metodika, tyrimų rezultatai, išvados, rekomendacijos, literatūros sąrašas bei priedai. Darbo apimtis – 64 p. teksto be priedų, 17 lent., 25 pav., 46 bibliografiniai šaltiniai. Atskirai pridedami 6 priedai. / Biofilters are an alternative for standard active sludge treatment plants. When used and installed properly, biofilters can significantly reduce operating costs and achieve the desirable cleaning quality results. The effectiveness of biofilters depends on the type of media used, so this paper discuses the suitability of new media for waste water biofiltration. Studies have shown that chosen stone wool media is suitable to use for trickling filters and it may also be used in organic matter removal and nitrification processes. In trickling filters, organic matter removal efficiency by BDS7 was more than 95 %, and wastewater outlet concentration was less than 5 mg O2/l. In the first filter, filled specially with treated stone wool for growing plants, average nitrification efficiency was 62,2 %; while in the second filter, filled with stone wool for buildings thermo isolation, average nitrification efficiency was 61,6 %. Thesis consists of: 64 pages of text without appendixes, 17 tables, 25 pictures, 46 bibliographical entries. Also there are 6 appendixes included.
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Pós-tratamento de efluente de lagoa facultativa visando à remoção de nitrogênio amoniacal. / Post treatment of facultative pond effluent aiming removal of ammonia nitrogen.Ruggeri Júnior, Humberto Carlos 08 April 2011 (has links)
Discute o pós-tratamento de efluente de lagoas facultativas visando à remoção de nitrogênio amoniacal. Para isso, foram utilizadas unidades terciárias em escala piloto. A escolha do tipo de unidades para o pós-tratamento do efluente levou em consideração a questão do baixo custo e simplicidade de operação. Desta forma, para o estudo, fez-se opção por lagoas rasas e filtros percoladores como unidades de pós-tratamento. O objetivo principal do trabalho foi associar as taxas de aplicação superficial e volumétricas com as remoções de nitrogênio amoniacal nessas unidades. Para lagoas em escala piloto, foram adotadas profundidades de 0,5 m e 1,0 m. As lagoas rasas foram submetidas a diferentes taxas de aplicação e TDH. Para os filtros percoladores, foram escolhidos dois materiais diferentes como meio suporte, pedra britada e anel plástico. Os filtros foram submetidos a diferentes condições operacionais. Para os dois tipos de unidades complementares de tratamento, foram verificados os efeitos das condições ambientais sobre as eficiências de remoção. Na lagoa de 0,5 m foram observadas concentrações de nitrogênio amoniacal abaixo de 20 mg-N/L para tempos de detenção de 5 dias e taxas de aplicação superficial de 50 kgDBO/ha.d. Na lagoa de 1,0 m, concentrações de nitrogênio amoniacal abaixo de 20 mg-N/L só foram possíveis com taxas de aplicação de 50 kgDBO/ha.d e TDH de 10 dias. A lagoa de 0,5 m apresentou uma eficiência maior na remoção de nitrogênio amoniacal do que a lagoa de 1,0 m. Os efluentes dos filtros apresentaram concentrações de nitrogênio amoniacal acima de 20 mg-N/L com taxas acima de 0,20 kgDBO/m³.d. Para taxas de aplicação hidráulica acima de 18 m³/m².d e 0,70 kgDBO/m².d houve o encerramento do processo de nitrificação nos filtros. Os valores de pH e as concentrações de NH3 no efluente da lagoa facultativa submeteram os filtros a operar dentro da faixa de inibição da nitratação, devido ao NH3, sendo observadas concentrações significativas de nitrito no seu efluente. Os filtros percoladores não foram adequados como unidades de pós-tratamento de efluente de lagoa. Embora as lagoas rasas não tenham atendido aos aspectos de múltiplas qualidades do efluente, elas foram mais adequadas ao pós-tratamento de efluente de lagoa facultativa do que os filtros percoladores. / This study discusses the post treatment of effluent ponds aiming at removing the ammonia nitrogen. To this end, tertiary units were used in a pilot scale. The choice of units for the post treatment of the effluent took into consideration the issue of low cost and simplicity of operation. Thus, for this study, we chose shallow ponds and trickling filters as post-treatment units. The main objective of this study was to associate the superficial and the volumetric application rates with the removal of ammonia nitrogen of these units. For the ponds on a pilot scale, two depths were adopted: a pond of 0.5 m and another one of 1.0 m depth. The shallow ponds were subjected to different loading rates and HRT. For the trickling filters, two different kinds of materials were chosen as a medium support: crushed stone and plastic ring. The filters were also subjected to different operating conditions. For both types of additional treatment units it was observed the effects of the environmental conditions on the removal efficiencies. In the pond of 0.5 m depth, it was observed concentrations of ammonia nitrogen below 20 mg-N/L for detention times of 5 days and superficial application rates of 50 kgBOD/ha.d. In the pond of 1.0 m depth, concentrations of ammonia nitrogen below 20 mg-N/L were only possible with application rates of 50 kgBOD/ha.d and HRT of 10 days. The 0.5m-depth pond showed a better efficiency in the removal of ammonia nitrogen than then1.0m-depth pond. The filters had concentrations above 20mg-N/L with rates above 0.20 kgBOD/m³.d. For hydraulic application rates above 18m³/m².d and 0.70kgBOD/m².d there was the cessation of the nitrification process in the filters. The pH values and the concentrations of NH3 in the effluent of the facultative pond made the filters operate within the range of inhibition of nitration, due to the NH3, and it was observed significant concentrations of nitrite in the effluent of the filters. The trickling filters were not suitable as units of post-treatment pond effluent. Although the shallow ponds have not met the multiple aspects of quality of the effluent, they were more adequately for facultative pond effluents post-treatment than trickling filters.
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Pós-tratamento de efluente de lagoa facultativa visando à remoção de nitrogênio amoniacal. / Post treatment of facultative pond effluent aiming removal of ammonia nitrogen.Humberto Carlos Ruggeri Júnior 08 April 2011 (has links)
Discute o pós-tratamento de efluente de lagoas facultativas visando à remoção de nitrogênio amoniacal. Para isso, foram utilizadas unidades terciárias em escala piloto. A escolha do tipo de unidades para o pós-tratamento do efluente levou em consideração a questão do baixo custo e simplicidade de operação. Desta forma, para o estudo, fez-se opção por lagoas rasas e filtros percoladores como unidades de pós-tratamento. O objetivo principal do trabalho foi associar as taxas de aplicação superficial e volumétricas com as remoções de nitrogênio amoniacal nessas unidades. Para lagoas em escala piloto, foram adotadas profundidades de 0,5 m e 1,0 m. As lagoas rasas foram submetidas a diferentes taxas de aplicação e TDH. Para os filtros percoladores, foram escolhidos dois materiais diferentes como meio suporte, pedra britada e anel plástico. Os filtros foram submetidos a diferentes condições operacionais. Para os dois tipos de unidades complementares de tratamento, foram verificados os efeitos das condições ambientais sobre as eficiências de remoção. Na lagoa de 0,5 m foram observadas concentrações de nitrogênio amoniacal abaixo de 20 mg-N/L para tempos de detenção de 5 dias e taxas de aplicação superficial de 50 kgDBO/ha.d. Na lagoa de 1,0 m, concentrações de nitrogênio amoniacal abaixo de 20 mg-N/L só foram possíveis com taxas de aplicação de 50 kgDBO/ha.d e TDH de 10 dias. A lagoa de 0,5 m apresentou uma eficiência maior na remoção de nitrogênio amoniacal do que a lagoa de 1,0 m. Os efluentes dos filtros apresentaram concentrações de nitrogênio amoniacal acima de 20 mg-N/L com taxas acima de 0,20 kgDBO/m³.d. Para taxas de aplicação hidráulica acima de 18 m³/m².d e 0,70 kgDBO/m².d houve o encerramento do processo de nitrificação nos filtros. Os valores de pH e as concentrações de NH3 no efluente da lagoa facultativa submeteram os filtros a operar dentro da faixa de inibição da nitratação, devido ao NH3, sendo observadas concentrações significativas de nitrito no seu efluente. Os filtros percoladores não foram adequados como unidades de pós-tratamento de efluente de lagoa. Embora as lagoas rasas não tenham atendido aos aspectos de múltiplas qualidades do efluente, elas foram mais adequadas ao pós-tratamento de efluente de lagoa facultativa do que os filtros percoladores. / This study discusses the post treatment of effluent ponds aiming at removing the ammonia nitrogen. To this end, tertiary units were used in a pilot scale. The choice of units for the post treatment of the effluent took into consideration the issue of low cost and simplicity of operation. Thus, for this study, we chose shallow ponds and trickling filters as post-treatment units. The main objective of this study was to associate the superficial and the volumetric application rates with the removal of ammonia nitrogen of these units. For the ponds on a pilot scale, two depths were adopted: a pond of 0.5 m and another one of 1.0 m depth. The shallow ponds were subjected to different loading rates and HRT. For the trickling filters, two different kinds of materials were chosen as a medium support: crushed stone and plastic ring. The filters were also subjected to different operating conditions. For both types of additional treatment units it was observed the effects of the environmental conditions on the removal efficiencies. In the pond of 0.5 m depth, it was observed concentrations of ammonia nitrogen below 20 mg-N/L for detention times of 5 days and superficial application rates of 50 kgBOD/ha.d. In the pond of 1.0 m depth, concentrations of ammonia nitrogen below 20 mg-N/L were only possible with application rates of 50 kgBOD/ha.d and HRT of 10 days. The 0.5m-depth pond showed a better efficiency in the removal of ammonia nitrogen than then1.0m-depth pond. The filters had concentrations above 20mg-N/L with rates above 0.20 kgBOD/m³.d. For hydraulic application rates above 18m³/m².d and 0.70kgBOD/m².d there was the cessation of the nitrification process in the filters. The pH values and the concentrations of NH3 in the effluent of the facultative pond made the filters operate within the range of inhibition of nitration, due to the NH3, and it was observed significant concentrations of nitrite in the effluent of the filters. The trickling filters were not suitable as units of post-treatment pond effluent. Although the shallow ponds have not met the multiple aspects of quality of the effluent, they were more adequately for facultative pond effluents post-treatment than trickling filters.
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