Influence of earthworm presence and hydraulic loading rate on the performance of vertical flow constructed wetlands.

In order to know the behaviour and performance of a vertical flow constructed wetland (VF-CW) operating with earthworm, this study evaluated the earthworm presence linked to hydraulic loading rates applied for domestic wastewater treatment. Two VF-CW units (710 cm², 0.75 m deep, with sand as filter media and planted with Heliconia rostrata) operated with a variable hydraulic and organic loadings rates (200 mm d-1/123 g COD m-2 d-1; 280 mm d-1/186 g COD m-2 d-1; 160 mm d-1/94 g COD m-2 d-1). Although the efficiency of COD load removal was similar (around 70%) for both CWs, the efficiency of total nitrogen load removal was around 95% throughout the evaluated period. The nitrification-denitrification process was identified with and without the presence of earthworm. VF-CW with earthworms showed higher hydraulic conductivity values (from 0.11 to 0.14 m h-1) compared with the VF-CW wetland without earthworms (0.07-0.09 m h-1). This study showed that the use of earthworms in CWs can be associated mainly with a preventive measure of clogging, which requires measures to maintain earthworms inside the bed media. Additionally, the earthworm presence has an ingestion mechanism of organic and inorganic solid particles in wastewater which excretes them as finer particles.

Methodology for hydraulic characterisation of the sand filter backwashing processes used in micro irrigation.

The correct operation of the backwashing process in sand filters used in micro irrigation determines directly the effectiveness of the subsequent filtration processes, and consequently the micro irrigation systems maintenance. As backwashing involves the filter bed expansion, the current sand filter design makes it impossible to measure the process. In this sense, this work aims to present a hydraulic characterization methodology of the backwashing process of sand filters used in micro irrigation, evaluating the influence of the sand particle size, the filter bed height, and the sand filter design. The proposed methodology can assist manufacturers in gathering equipment operating information, aiming at its presentation in the product catalogs.•This method article discusses a method of hydraulic evaluation of the backwashing process of sand filters used in micro irrigation.•The method can assist sand filter manufacturers in the correct definition of the equipment's operating parameters.•The method shows the effectiveness of using the filter media pressure loss evaluation in the indirect definition of the minimum fluidisation velocity.

Influence of nanoscale zero-valent iron on hydraulic conductivity of a residual clayey soil and modeling of the filtration parameter.

Contaminated clay soils pose problems to public health and the environment in several parts of the world. Very little is known about the transport of decontaminating agents used in remediation process under natural, undisturbed conditions. Nanomaterials, especially those made of nanoscale zero-valent iron (nZVI), have been most frequently used for remediation of contaminated soils because of their higher reactivity, lower toxicity, and lower cost than other metallic nanoparticles. Even though the nanoparticle size is smaller than soil pores, clogging may occur over time due to agglomeration of nanoparticles, which could reduce the soil's natural permeability and thereby cause filtration of the nanoparticles. The use of a stabilizer in the nanoparticles can modify the reactivity but improves their mobility in the soil system. Thus, the objective of this work was to evaluate the hydraulic conductivity of residual clay soil under the injection of different types and concentrations of nZVI with and without surfactant stabilizer (NANOFER 25, NANOFER 25S, and NANOFER STAR in powder at 1 g/L, 4 g/L, 7 g/L, and 10 g/L concentrations), and to model transport of these nZVI suspensions in this soil system. Undisturbed cylindrical soil samples collected from the field were used, and hydraulic conductivity tests were performed using a column apparatus. The results showed that the presence of the stabilizer in the nZVI influenced the nanoparticles' mobility. The nZVI concentrations of 1 and 4 g/L did not affect the natural soil hydraulic conductivity. However, higher concentrations reduced the hydraulic conductivity value, which retarded the migration of nZVI as reflected in the value of filtration parameter.

Combined microfiltration and adsorption process applied to public water supply treatment: water quality influence on pesticides removal.

Granular activated carbon (GAC) fixed bed adsorption technology was applied to remove carbamates carbaryl, methomyl and carbofuran from public water supply. In order to minimize the effect of clogging and to evaluate adsorbent saturation for carbamates, the microfiltration (MF) was previously used to adsorb and the backwash procedure of the GAC bed was carried out. The determination and quantification of the carbamates were performed by analytical technique in high performance liquid chromatography with post-column derivatization and fluorescence detector. The MF of the water previously adsorbed in the GAC fixed bed allowed the greater removal of 100% of the carbamates pesticides with an initial concentration of 25 µg L-1 during the first 48 h of operation. The saturation of the GAC fixed bed occurred in 240 h, due to the partial removal of the natural organic matter by the MF, consequently the competition for adsorptive sites of the GAC was smaller. The backwashing procedure contributed to the partial recovery of the performance of the hydraulic filtration and allowed to identify the saturation of the adsorption column, since the sealing phenomenon preceded the saturation. Finally, the use of public water supply was considered a relevant and positive aspect, since it allowed the identification of the performance of this technology in the removal of carbamates pesticides considering the presence of substances inherent to the public water supply.

Short-Term Effects on Agricultural Soils Irrigated with Reclaimed Water in Baja California, México.

In 2014 reclaimed water (RW) started to be used for agricultural irrigation of 200 ha in Maneadero Valley, Baja California, Mexico. The RW had relatively high electrical conductivity (4-5 dS m-1), and K+, Mg2+, PO43- and Cl- concentrations relative to irrigation guidelines. However, no accumulation of these elements, nor total nitrogen, was observed in the studied soils. The main effect of RW irrigation was the downcore leaching of Cl- and Na+ below 120 cm, causing an increase in electrical conductivity in the lower soil horizons. Al, Fe and Zn showed a twofold to eightfold accumulation in the top soil layer after 2 years. Moderate to severe chemical clogging of dripping systems and potential biological clogging are likely to occur. Mexican national guidelines for the reuse of RW do not take into account specific variables that could change the quality of agricultural soil or lead to clogging of drip irrigation systems.

Biosseguridade para sistemas de produção de peixes em tanque-rede em função da colmatação agravada por Limnoperna fortunei / Biosecurity for fishfarming cage systems due to the highly clogged screen aggravated by Limnoperna fortunei

Este trabalho avaliou a colmatação por Limnoperna fortunei em diferentes materiais para confecção de telas de arame, a dinâmica da colmatação pelo molusco e a relação custo-benefício dos materiais usados em tanques-rede. Utilizaram-se amostras de telas de simples torção de malha 19mm, de cinco tipos diferentes de revestimentos, colocadas na barragem de Salto Caxias, no Rio Iguaçu, estado do Paraná, entre julho de 2012 e julho de 2014. A cada seis meses, foi verificado o ganho de peso das telas em razão da colmatação, além da contagem do número de mexilhões aderidos. Após as coletas dos dados, foi realizado o teste estatístico de Kruskal-Wallis para se avaliar o ganho de peso das telas devido à colmatação. Realizou-se também uma pesquisa com 21 empresas para se obter o preço comercializado de telas para confecção de tanques-rede e se avaliar a expectativa de durabilidade dos materiais. Verificou-se que os diferentes materiais avaliados para as telas influenciam na colmatação e aderência do mexilhão-dourado; além disso, constatou-se que a tela mais eficiente quanto ao custo/ano é a de arame galvanizado plastificado e, para baixa colmatação, a de arame Bezinal.(AU)

This research evaluated degree of clogging by Limnoperna fortunei in different materials for wire mesh fabrication, the dynamics of mollusk sealing and the cost-benefit ratio of these materials used in tank-nets. Samples of single-twist screens of 19 mm mesh were used, from five different types of coatings were placed in the Salto Caxias dam on the Iguaçu River in the Paraná state, between July 2012 and July 2014. Every six months, it was verified the weight gain of the screens due to clogging and counting of the number of mussels adhered. After the data collection was performed Kruskal-Wallis statistical test to evaluate the weight gain of the screens due to clogging. In addition, a survey was carried out with 21 companies to obtain the commercialized price of screens for the production of net tanks and to evaluate the expected durability of the materials. The different materials evaluated for the screens influenced the sealing and adhesion of the golden mussel. In addition, the most cost-per-year screen is that of plastic-coated galvanized wire and for low clogging it is the Bezinal wire.(AU)

Biosseguridade para sistemas de produção de peixes em tanque-rede em função da colmatação agravada por Limnoperna fortunei / Biosecurity for fishfarming cage systems due to the highly clogged screen aggravated by Limnoperna fortunei

Este trabalho avaliou a colmatação por Limnoperna fortunei em diferentes materiais para confecção de telas de arame, a dinâmica da colmatação pelo molusco e a relação custo-benefício dos materiais usados em tanques-rede. Utilizaram-se amostras de telas de simples torção de malha 19mm, de cinco tipos diferentes de revestimentos, colocadas na barragem de Salto Caxias, no Rio Iguaçu, estado do Paraná, entre julho de 2012 e julho de 2014. A cada seis meses, foi verificado o ganho de peso das telas em razão da colmatação, além da contagem do número de mexilhões aderidos. Após as coletas dos dados, foi realizado o teste estatístico de Kruskal-Wallis para se avaliar o ganho de peso das telas devido à colmatação. Realizou-se também uma pesquisa com 21 empresas para se obter o preço comercializado de telas para confecção de tanques-rede e se avaliar a expectativa de durabilidade dos materiais. Verificou-se que os diferentes materiais avaliados para as telas influenciam na colmatação e aderência do mexilhão-dourado; além disso, constatou-se que a tela mais eficiente quanto ao custo/ano é a de arame galvanizado plastificado e, para baixa colmatação, a de arame Bezinal.(AU)

This research evaluated degree of clogging by Limnoperna fortunei in different materials for wire mesh fabrication, the dynamics of mollusk sealing and the cost-benefit ratio of these materials used in tank-nets. Samples of single-twist screens of 19 mm mesh were used, from five different types of coatings were placed in the Salto Caxias dam on the Iguaçu River in the Paraná state, between July 2012 and July 2014. Every six months, it was verified the weight gain of the screens due to clogging and counting of the number of mussels adhered. After the data collection was performed Kruskal-Wallis statistical test to evaluate the weight gain of the screens due to clogging. In addition, a survey was carried out with 21 companies to obtain the commercialized price of screens for the production of net tanks and to evaluate the expected durability of the materials. The different materials evaluated for the screens influenced the sealing and adhesion of the golden mussel. In addition, the most cost-per-year screen is that of plastic-coated galvanized wire and for low clogging it is the Bezinal wire.(AU)

Dryophthorinae weevils (Coleoptera: Curculionidae) of the forest floor in Southeast Asia: illustrated overview of nominal Stromboscerini genera.

All 13 Recent genera currently assigned to the tribe Stromboscerini are studied and illustrated based mainly on the type specimens of the type species. Nominal monotypic genus Parasynommatus Voss, 1956 from New Guinea is herein transferred to Cossoninae incertae sedis. The genus Nephius is notably dissimilar to the rest of the tribe and perhaps renders it paraphyletic. Besides the monotypic type genus endemic to Madagascar, the tribe is distributed in a triangle delimited by Japan, Sri Lanka and northern Australia; two new tribe records from continental Africa (Uganda) and the Western Hemisphere (Cuba) are reported and illustrated. Assignment of both fossil monotypic genera to the tribe was done outside of the cladistic framework and remains questionable. Judging by external similarity, the likeliest closest relative of Stromboscerini (with or without Nephius and, perhaps, Stromboscerus) is the tribe Dryophthorini with three Recent genera.

Hydraulic and hydrological aspects of an evapotranspiration-constructed wetland combined system for household greywater treatment.

Constructed wetlands systems demand preliminary and primary treatment to remove solids present in greywater (GW) to avoid or reduce clogging processes. The current paper aims to assess hydraulic and hydrological behavior in an improved constructed wetland system, which has a built-in anaerobic digestion chamber (AnC), GW is distributed to the evapotranspiration and treatment tank (CEvaT), combined with a subsurface horizontal flow constructed wetland (SSHF-CW). The results show that both the plants present in the units and the AnC improve hydraulic and volumetric efficiency, decrease short-circuiting and improve mixing conditions in the system. Moreover, the hydraulic conductivity measured on-site indicates that the presence of plants in the system and the flow distribution pattern provided by the AnC might reduce clogging in the SSHF-CW. It is observed that rainfall enables salt elimination, thus increasing evapotranspiration (ET), which promotes effluent reduction and enables the system to have zero discharge when reuse is unfeasible.

Gotejadores não autocompensantes usando efluente de esgoto tratado para irrigação / Non-pressure compensating emitters using treated sewage effluent for irrigation

This study aimed to evaluate the obstruction of non-pressure compensating emitters using treated sewage effluent (TSE) for irrigation. A drip irrigation system with six models of emitters (encoded) was installed in level field conditions. TSE coming from a sewage treatment station was used as irrigation water after being filtered through a disc filter (120 mesh). Seven flow rate evaluations of drippers operating at 100kPa were performed (0, 100, 200, 300, 400, 500 and 600h of operation). The experimental design was randomized in a 6×7 factorial arrangement (6 models and 7 times), with four repetitions, and Tukeys test was used to compare means. Relative flow rate (Qr), the flow rate coefficient of variation (CVQ) and degree of clogging (GE) were determined. There was a reduction in flow rate in five dripper models, which are susceptible to clogging. The model with rated flow stood out against the others, showing a Qr of 100.52%, CVQ of 2.76% and GE of 0.49%. The use of TSE changed the Qr of the drippers after 600h of operation.

Objetivou-se avaliar a obstrução de gotejadores não autocompensantes utilizando efluente de esgoto tratado (EET) para irrigação. Um sistema de irrigação por gotejamento com seis modelos de gotejadores (codificados) foi instalado em nível e em condições de campo. Como água de irrigação foi utilizado EET, originado de estação de tratamento de esgoto, filtrado por um filtro de disco (120 mesh). Foram realizadas sete avaliações da vazão dos emissores (0, 100, 200, 300, 400, 500 e 600h de funcionamento), operando a 100kPa. O experimento foi montado em delineamento casualizado, com arranjo fatorial 6x7 (6 modelos e 7 tempos), com 4 repetições e teste de Tukey para comparação das médias. Foram determinados a vazão relativa (Qr), o coeficiente de variação de vazão (CVQ) e o grau de entupimento (GE). Observou-se redução na vazão em cinco modelos de gotejadores, sendo estes suscetíveis ao entupimento. O modelo com maior vazão nominal destacou-se perante os demais, apresentando Qr de 100,52%, CVQ de 2,76% e GE de 0,49%. A utilização de EET alterou a Qr dos gotejadores após 600h de funcionamento.

Gotejadores não autocompensantes usando efluente de esgoto tratado para irrigação / Non-pressure compensating emitters using treated sewage effluent for irrigation

This study aimed to evaluate the obstruction of non-pressure compensating emitters using treated sewage effluent (TSE) for irrigation. A drip irrigation system with six models of emitters (encoded) was installed in level field conditions. TSE coming from a sewage treatment station was used as irrigation water after being filtered through a disc filter (120 mesh). Seven flow rate evaluations of drippers operating at 100kPa were performed (0, 100, 200, 300, 400, 500 and 600h of operation). The experimental design was randomized in a 6×7 factorial arrangement (6 models and 7 times), with four repetitions, and Tukeys test was used to compare means. Relative flow rate (Qr), the flow rate coefficient of variation (CVQ) and degree of clogging (GE) were determined. There was a reduction in flow rate in five dripper models, which are susceptible to clogging. The model with rated flow stood out against the others, showing a Qr of 100.52%, CVQ of 2.76% and GE of 0.49%. The use of TSE changed the Qr of the drippers after 600h of operation.(AU)

Objetivou-se avaliar a obstrução de gotejadores não autocompensantes utilizando efluente de esgoto tratado (EET) para irrigação. Um sistema de irrigação por gotejamento com seis modelos de gotejadores (codificados) foi instalado em nível e em condições de campo. Como água de irrigação foi utilizado EET, originado de estação de tratamento de esgoto, filtrado por um filtro de disco (120 mesh). Foram realizadas sete avaliações da vazão dos emissores (0, 100, 200, 300, 400, 500 e 600h de funcionamento), operando a 100kPa. O experimento foi montado em delineamento casualizado, com arranjo fatorial 6x7 (6 modelos e 7 tempos), com 4 repetições e teste de Tukey para comparação das médias. Foram determinados a vazão relativa (Qr), o coeficiente de variação de vazão (CVQ) e o grau de entupimento (GE). Observou-se redução na vazão em cinco modelos de gotejadores, sendo estes suscetíveis ao entupimento. O modelo com maior vazão nominal destacou-se perante os demais, apresentando Qr de 100,52%, CVQ de 2,76% e GE de 0,49%. A utilização de EET alterou a Qr dos gotejadores após 600h de funcionamento.(AU)

Non-pressure compensating emitters using treated sewage effluent for irrigation / Gotejadores não autocompensantes usando efluente de esgoto tratado para irrigação

ABSTRACT: This study aimed to evaluate the obstruction of non-pressure compensating emitters using treated sewage effluent (TSE) for irrigation. A drip irrigation system with six models of emitters (encoded) was installed in level field conditions. TSE coming from a sewage treatment station was used as irrigation water after being filtered through a disc filter (120 mesh). Seven flow rate evaluations of drippers operating at 100kPa were performed (0, 100, 200, 300, 400, 500 and 600h of operation). The experimental design was randomized in a 6×7 factorial arrangement (6 models and 7 times), with four repetitions, and Tukey’s test was used to compare means. Relative flow rate (Qr), the flow rate coefficient of variation (CVQ) and degree of clogging (GE) were determined. There was a reduction in flow rate in five dripper models, which are susceptible to clogging. The model with rated flow stood out against the others, showing a Qr of 100.52%, CVQ of 2.76% and GE of 0.49%. The use of TSE changed the Qr of the drippers after 600h of operation.

RESUMO: Objetivou-se avaliar a obstrução de gotejadores não autocompensantes utilizando efluente de esgoto tratado (EET) para irrigação. Um sistema de irrigação por gotejamento com seis modelos de gotejadores (codificados) foi instalado em nível e em condições de campo. Como água de irrigação foi utilizado EET, originado de estação de tratamento de esgoto, filtrado por um filtro de disco (120 mesh). Foram realizadas sete avaliações da vazão dos emissores (0, 100, 200, 300, 400, 500 e 600h de funcionamento), operando a 100kPa. O experimento foi montado em delineamento casualizado, com arranjo fatorial 6x7 (6 modelos e 7 tempos), com 4 repetições e teste de Tukey para comparação das médias. Foram determinados a vazão relativa (Qr), o coeficiente de variação de vazão (CVQ) e o grau de entupimento (GE). Observou-se redução na vazão em cinco modelos de gotejadores, sendo estes suscetíveis ao entupimento. O modelo com maior vazão nominal destacou-se perante os demais, apresentando Qr de 100,52%, CVQ de 2,76% e GE de 0,49%. A utilização de EET alterou a Qr dos gotejadores após 600h de funcionamento.

Drip irrigation with treated wastewater from cashew nut industry under service pressures / Irrigação por gotejamento com água residuária tratada da indústria da castanha de caju sob pressões de serviço

The agricultural use of wastewater generated in the processing of cashew nuts enables the rationalization of water use, as well as the minimization of pollution and environmental degradation. The study aimed to analyze the effect of service pressures in the distribution uniformity of drip irrigation units applying treated wastewater from cashew nut industry. The experiment was conducted in split-split plots scheme having the service pressures (70, 140, 210 and 280 kPa) on parcels, the emitters models (G1, G2 and G3) on subplots and the evaluation periods (0, 20, 40, 60, 80, 100, 120, 140 and 160 h of operation of the irrigation units) on subsubplots. The treatments were distributed in a completely randomized design with three replications. The coefficient of uniformity of distribution of irrigation units, as well as the physical, chemical and microbiological characteristics of the effluent were determined every 20 hours of operation the irrigation units to totalize 160 h. The combination of dripper G3 and service pressure of 140 kPa provided excellent levels of distribution uniformity of effluent on irrigation units operating with treated wastewater of cashew nut industry. For application of treated wastewater from cashew nut it is not recommended the use of drippers with low flow rate (? 1.6 L h-1) and labyrinth of greater length (? 58 mm).(AU)

O aproveitamento agrícola das águas residuárias geradas no processamento da castanha de caju possibilita a racionalização do uso da água, bem como a minimização da poluição e da degradação ambiental. O trabalho objetivou analisar o efeito de pressões de serviço na uniformidade de distribuição de unidades de irrigação por gotejamento aplicando água residuária tratada da castanha de caju. O experimento foi montado em esquema de parcelas subsubdivididas, tendo nas parcelas as pressões de serviço (70, 140, 210 e 280 kPa), nas subparcelas os modelos de gotejadores (G1, G2 e G3) e nas subsubparcelas os períodos das avaliações (0, 20, 40, 60, 80, 100, 120, 140 e 160 h de operação das unidades de irrigação). Os tratamentos foram distribuídos em delineamento inteiramente casualizado com três repetições. O coeficiente de uniformidade de distribuição das unidades de irrigação, bem como as características físicas, químicas e microbiológicas do efluente foram determinadas a cada 20 h de operação das unidades de irrigação até totalizar 160 h. A combinação gotejador G3 e pressão de serviço de 140 kPa proporcionou níveis excelentes da uniformidade de distribuição de efluente nas unidades de irrigação, operando com água residuária tratada da castanha de caju. Para aplicação de água residuária tratada da castanha de caju não é recomendada o uso de gotejadores de baixa vazão nominal (? 1,6 L h-1) e maior comprimento de labirinto (≥ 58 mm).(AU)

Drip irrigation with treated wastewater from cashew nut industry under service pressures / Irrigação por gotejamento com água residuária tratada da indústria da castanha de caju sob pressões de serviço

The agricultural use of wastewater generated in the processing of cashew nuts enables the rationalization of water use, as well as the minimization of pollution and environmental degradation. The study aimed to analyze the effect of service pressures in the distribution uniformity of drip irrigation units applying treated wastewater from cashew nut industry. The experiment was conducted in split-split plots scheme having the service pressures (70, 140, 210 and 280 kPa) on parcels, the emitters models (G1, G2 and G3) on subplots and the evaluation periods (0, 20, 40, 60, 80, 100, 120, 140 and 160 h of operation of the irrigation units) on subsubplots. The treatments were distributed in a completely randomized design with three replications. The coefficient of uniformity of distribution of irrigation units, as well as the physical, chemical and microbiological characteristics of the effluent were determined every 20 hours of operation the irrigation units to totalize 160 h. The combination of dripper G3 and service pressure of 140 kPa provided excellent levels of distribution uniformity of effluent on irrigation units operating with treated wastewater of cashew nut industry. For application of treated wastewater from cashew nut it is not recommended the use of drippers with low flow rate (? 1.6 L h-1) and labyrinth of greater length (? 58 mm).

O aproveitamento agrícola das águas residuárias geradas no processamento da castanha de caju possibilita a racionalização do uso da água, bem como a minimização da poluição e da degradação ambiental. O trabalho objetivou analisar o efeito de pressões de serviço na uniformidade de distribuição de unidades de irrigação por gotejamento aplicando água residuária tratada da castanha de caju. O experimento foi montado em esquema de parcelas subsubdivididas, tendo nas parcelas as pressões de serviço (70, 140, 210 e 280 kPa), nas subparcelas os modelos de gotejadores (G1, G2 e G3) e nas subsubparcelas os períodos das avaliações (0, 20, 40, 60, 80, 100, 120, 140 e 160 h de operação das unidades de irrigação). Os tratamentos foram distribuídos em delineamento inteiramente casualizado com três repetições. O coeficiente de uniformidade de distribuição das unidades de irrigação, bem como as características físicas, químicas e microbiológicas do efluente foram determinadas a cada 20 h de operação das unidades de irrigação até totalizar 160 h. A combinação gotejador G3 e pressão de serviço de 140 kPa proporcionou níveis excelentes da uniformidade de distribuição de efluente nas unidades de irrigação, operando com água residuária tratada da castanha de caju. Para aplicação de água residuária tratada da castanha de caju não é recomendada o uso de gotejadores de baixa vazão nominal (? 1,6 L h-1) e maior comprimento de labirinto (≥ 58 mm).

Desempenho de gotejadores utilizando água de baixa qualidade química e biológica / Drip lines performance using water of low chemical and biological quality

Esse trabalho objetivou identificar os principais fatores de entupimento em três modelos de tubogotejadores (M1, M2 e M3), caracterizar a qualidade da água utilizada na irrigação, bem como verificar os gêneros de bactérias causadoras de entupimento. Avaliou-se a uniformidade de aplicação de água, por meio da vazão e do Coeficiente de Uniformidade Estatístico (Us). Conclui-se que todos os parâmetros de qualidade da água analisados encontravam-se dentro dos padrões desejados, com exceção do ferro. Foram identificadas ferrobactérias dos gêneros Gallionella e Leptpthrix nos tubogotejadores. Após 700 h de funcionamento do sistema, a vazão dos tubogotejadores M1 e M2 reduziu 26,13 e 27,4%, respectivamente, e o modelo M3 apresentou um incremento de 1%. Os valores de Us apresentaram reduções de 28,35; 16,25 e 12,5% para os modelos M1, M2 e M3, respectivamente.

This work objectified to identify to the main causes of clogging in three models of drip lines (M1, M2 and M3), to characterize the quality of the water used in the irrigation, as well as verifying the gender of ironbacterias causing of clogging. The uniformity of application of water was evaluated, through the discharge and the Coefficient of Statistic Uniformity (Us). In accordance with the gotten results concluded that all of the parameters of quality of the water analyzed met inside of the wanted patterns, except for the iron. The gender Gallionella and Leptpthrix had been identified in drip lines. After 700 h of operation, the discharge of the drip lines M1 and M2 reduced 26,13 and 27,4%, respectively, and increased 1% for M3. The reductions in the values of Us for model M1, M2 and M3: 28,35; 16,25 and 12,5%.

Microaspersores entupidos devido a problemas de ferro na água / Microsprinkler clogged due to iron problems in the water

Um dos aspectos relevantes a ser considerado no manejo da irrigação é a uniformidade de distribuição de água pelo sistema. Este trabalho foi desenvolvido com o objetivo de avaliar a eficiência da cloração com a utilização de hipoclorito de sódio na desobstrução de microaspersores devido à utilização de águas com elevado teor de ferro. Um sistema com dez meses de uso apresentava setores com vazões de 5 por cento a 57 por cento menores que a vazão de projeto. Foi feito o tratamento químico da água de irrigação, utilizando-se hipoclorito de sódio com 12 por cento de cloro livre na dosagem de 100 mg L-1 e ácido sulfúrico, na concentração de 98 por cento, para manter o pH da água de irrigação em torno de 4,5. O resultado indicou que houve aumento significativo nas vazões médias dos microaspersores em todos os setores avaliados e diminuição na variação da vazão dos mesmos com relação à estimada no projeto.

An important aspect to be considered in irrigation managment is the uniformity distribution of water through the irrigation system. This research had the objective to evaluate the efficiency of chlorination in the use of sodium hypochlorite in clearing of microsprinkler due to the presence of high iron concentration in water. The equipment with less than a year of use presenting sectors with 5 percent and 57 percent lower flow than the original project flow. The chemical treatment of water irrigation utilized sodium hypochlorite with 12 percent free chlorine on 100mg L-1 concentration, and sulphuric acid 98 percent to maintain the pH of water irrigation about 4.5. The result demonstrated a significant increase in the average flow of the microsprinkler's variation in all evaluted setors, and decrease in their flow variation related to the estimated in the project.

Microaspersores entupidos devido a problemas de ferro na água / Microsprinkler clogged due to iron problems in the water

Um dos aspectos relevantes a ser considerado no manejo da irrigação é a uniformidade de distribuição de água pelo sistema. Este trabalho foi desenvolvido com o objetivo de avaliar a eficiência da cloração com a utilização de hipoclorito de sódio na desobstrução de microaspersores devido à utilização de águas com elevado teor de ferro. Um sistema com dez meses de uso apresentava setores com vazões de 5 por cento a 57 por cento menores que a vazão de projeto. Foi feito o tratamento químico da água de irrigação, utilizando-se hipoclorito de sódio com 12 por cento de cloro livre na dosagem de 100 mg L-1 e ácido sulfúrico, na concentração de 98 por cento, para manter o pH da água de irrigação em torno de 4,5. O resultado indicou que houve aumento significativo nas vazões médias dos microaspersores em todos os setores avaliados e diminuição na variação da vazão dos mesmos com relação à estimada no projeto.(AU)

An important aspect to be considered in irrigation managment is the uniformity distribution of water through the irrigation system. This research had the objective to evaluate the efficiency of chlorination in the use of sodium hypochlorite in clearing of microsprinkler due to the presence of high iron concentration in water. The equipment with less than a year of use presenting sectors with 5 percent and 57 percent lower flow than the original project flow. The chemical treatment of water irrigation utilized sodium hypochlorite with 12 percent free chlorine on 100mg L-1 concentration, and sulphuric acid 98 percent to maintain the pH of water irrigation about 4.5. The result demonstrated a significant increase in the average flow of the microsprinkler's variation in all evaluted setors, and decrease in their flow variation related to the estimated in the project.(AU)