Caracterização do efluente líquido no processo de beneficiamento do índigo têxtil

The great diversity of the textile industries activities causes the formation of wastewaters with high complex characteristics during the productive process, according to the industrial process used. The principal aim of the present work is the characterization of the wastewater from the textile industry that process the indigo, located in the Industrial District of Natal-RN, to know the contaminante load of each stage of the process and the framing of the wastewater with the standards of act of receiving of the System of Treatment of Wastewater of the Industrial District of Natal-RN SITEL-DIN, operated for the Company of Waters and Sewers of the RN CAERN. It was analyzed the following properties and pollutants agents: temperature; pH; alcalinity; color; COD (Chemical Oxygen Demand); total and suspended solids; heavy metals, thermotolerants coliformes, turbidity, dissolved oxygen and electrical conductivity. As conclusion it is distinguished that the wastewater did not get resulted satisfactory, according to comparisons with other sources, in only three parameters: turbidity, dissolved oxygen and electrical conductivity, however none of these parameters is criteria of acts of receiving of the SITEL-DIN,therefore the wastewater if finds inside of normality. After the analysis of the obtained results it was verified that SITEL-DIN is indispensable for completing the wastewater treatment

Degradação fotoquímica de hidrocarbonetos da gasolina em efluentes aquosos

Photo-oxidation processes of toxic organic compounds have been widely studied. This work seeks the application of the photo-Fenton process for the degradation of hydrocarbons in water. The gasoline found in the refinery, without additives and alcohol, was used as the model pollutant. The effects of the concentration of the following substances have been properly evaluated: hydrogen peroxide (100-200 mM), iron ions (0.5-1 mM) and sodium chloride (200 2000 ppm). The experiments were accomplished in reactor with UV lamp and in a falling film solar reactor. The photo-oxidation process was monitored by measurements of the absorption spectra, total organic carbon (TOC) and chemical oxygen demand (COD). Experimental results demonstrated that the photo-Fenton process is feasible for the treatment of wastewaters containing aliphatic hydrocarbons, inclusive in the presence of salts. These conditions are similar to the water produced by the petroleum fields, generated in the extraction and production of petroleum. A neural network model of process correlated well the observed data for the photooxidation process of hydrocarbons

Influência da intensidade de aeração na formação do floco de lodo ativado e na eficiência de remoção de matéria orgânica

In wastewater treatment, activated sludge systems have been a technology widely applied as secondary treatment. During this step, which has a strong biological aspect, it is necessary to introduce oxygen supply for the maintenance of metabolic activity of the bacteria through the aerators. Aeration devices are responsible for most of the energy consumption in this stage. In this background, the influence of three aeration intensities (atmospheric air flow 3.5, 7.0 and 10.5 L.min-1) and the concentration of dissolved oxygen (DO) on the dimension of activated sludge flocs as well as on the efficiency of organic matter removal were assessed using a traditional activated sludge system which was fed with synthetic domestic wastewater. Samples were taken weekly from the three units that make up the system feed, aeration and storage tank in order to verify the Chemical Oxygen Demand (COD). It was established the process efficiency through a comparison between the initial and final COD. Besides the parameters already mentioned, this monitoring work on activated sludge batch system was also observed by Mixed Liquor Suspend Solids (MLSS), Volatile Suspend Solids (VSS), pH and temperature measures. The results have showed a maximum removal efficiency around 75% in the first aeration sequence and approximately 85% for the second and third one. For the first aeration, the DO concentration remained higher than 3.0 mg.L-1 and a diameter range from 10 to 60 μm was observed. In the second e third sequence, the DO concentration remained higher than 4.0 mg.L-1 with a diameter range of 10 until 200 μm. Although the sequence 1 and 2 have presented similar performances for organic matter removal, the sequence 2 promoted a regular floc size distribution and with lower values of Sludge Volumetric Index (SVI) meaning a better flocculating ability. In addition, the results reaffirmed what the literature has reported: higher DO concentrations produce flocs with greater dimensions

Caracterização de Efluente Têxtil e Proposta de Tratamento

Textile industry deals with a high diversity of processes and generation of wastewaters with a high content of pollutant material. Before being disposed of in water bodies, a pre-treatment of the effluent is carried out, which is sometimes ineffective. In order to be properly treated, physical and chemical properties of the effluent must be known, as well as the pollutant agents that might be present in it. This has turned out to be a great problem in the textile industry, for there is a variety of processes and the pollutant load is very diversified. The characterization of the effluent allows the identification of most critical points and, as a consequence, the most appropriate treatment procedure to be employed, may be chosen. This study presents the results obtained after characterizing the effluent of a textile industry that comprises knitting, dyeing and apparel sections, processing mainly polyester/cotton articles. In this work, twenty samples of the effluent were collected, and related to the changes in production. From the results, a statistical evaluation was applied, determined in function of the rate of flow. The following properties and pollutants agents were quantitatively analysed: temperature; pH; sulfides; chlorine; alcalinity; chlorides; cianides; phenols; color; COD (Chemical Oxygen Demand); TOC (Total Organic Carbon); oil and grease; total, fixed and volatile solids; dissolved, fixed and volatile solids; suspended, fixed and volatile solids; setteable solids and heavy metals such as cadmium, copper, lead, chromium, tin, iron, zinc and nickel. Analyses were carried out according to ABNT NBR 13402 norm, based upon Standard Methods for the Examination of Water and Wastewater. As a consequence, a global treatment proposal is presented, involving clean production practices as contaminant load reducer, followed by conventional (biological) treatment

Estudo da influência de compostos recalcitrantes na remoção de matéria orgânica biodegradável no tratamento de efluente de refinarias de petróleo

Petroleum Refinery wastewaters (PRW) have hart-to-degrade compounds, such as: phenols, ammonia, cyanides, sulfides, oils and greases and the mono and polynuclear aromatic hydrocarbons: benzene, toluene and xylene (BTX), acenaphthene, nitrobenzene and naphtalene. It is known that the microrganisms activity can be reduced in the presence of certain substances, adversely affecting the biological process of wastewater treatment. This research was instigated due the small number of studies regarding to this specific topic in the avaiable literature. This body of work ims to evaluate the effect of toxic substances on the biodegradability of the organic material found in PRW. Glucose was chosen as the model substrate due to its biodegradable nature. This study was divided into three parts: i) a survey of recalcitants compounds and the removal of phenol by using both biological and photochemical-biological processes; ii) biomass aclimation and iii) evaluation of the inhibitory effect certain compounds have on glucose biodegradation. The phenol degradation experiments were carried out in an activity sludge system and in a photochemical reactor. The results showed the photochemical-biological process to be more effective on phenol degradation, suggesting the superioruty of a combined photochemical-biological treatment when compared with a simple biological process for phenol removal from industry wastewaters. For the acclimation step, was used an activated sludge from industrial wastewaters. A rapid biomass aclimation to a synthetic solution composed of the main inhibitory compouns fpund in a PRW was obtained using the following operation condition: (pH = 7,0; DO ≥ 2,0 mg/L; RS = 20 days e qH = 31,2 and 20,4 hours), The last part was consisted of using respirometry evaluation toxicity effects of selected compounds over oxygen uptake rate to adaptated and non adaptated biomass in the presence of inhibitory compounds. The adaptated sludge showed greater degration capacity, with lower sensibility to toxic effects. The respirometry has proved to be very practical, as the techiniques used were simple and rapid, such as: Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), and Volatile Suspended Solids (VSS). Using the latter it is possible to perform sludge selection to beggingthe process; thus allowing its use for aerobic treatment system`s behacior prediction

Macroalgas de riachos da Floresta Nacional de Irati, região centro-sul do Estado do Paraná, Sul do Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assessment of liquid disposal originated by uranium enrichment at Aramar Experimental Center São Paulo-Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desempenho de reatores aeróbios de leito fluidizado com circulação interna na remoção de matéria carbonácea tratando diferentes águas residuárias

The organic matter. (OM) removal efficiency in the biochemical oxygen demand (BOD) and chemical oxygen demand (COD) forms for domestic wastewater and semi-intensive fish culture effluents by using three phase aerobic fluidized bed reactors with circulation in concentric tubes was studied. Three different ratios between external and internal areas by different internal diameter configurations (100, 125 and 150mm) to the same external diameter of 250mm were used; sand for filters and granulated activated carbon were used as supporting media. The reactors were tested for three hydraulic retention times: 11.5min to the R100, and 3h for the R125 and R150 reactors. The results demonstrated that this kind of reactors had good performance in the BOD and COD removal for different concentrations of waste waters. BOD mean removal efficiencies obtained were: 47% at the R100 reactor, 57% and 93% of raw and filtered BOD respectively at R125, 48 and 89% of raw and filtered BOD at R150. The COD mean calculated removal efficiencies were: 75% at the R100 reactor, 56 and 86% of raw and filtered COD at R125, and 54 and 86% of raw and filtered COD at R150. In the case of domestic wastewater it is necessary to provide a solids removal system at the reactor outflow in order to increase the removal of suspended OM from the final effluent.

Aplicação da tecnologia eletroquímica como alternativa para a remoção de corante têxteis em efluentes sintéticos e reais utilizando anodos de platina e diamante

In this work, electrochemical technology was used to treat synthetic wastewater containing Methyl Red (MR) and Blue Novacron (BN) by anodic oxidation using anodes platinum (Pt) and real samples of textile effluents using DDB anodes and platinum (Pt). The removal of color from the galvanostatic electrolysis of synthetic wastewater MR and BN, and the actual sample has been observed under different conditions (different current densities and temperature variation). The investigation of these parameters was performed in order to establish the best conditions for removal of color and chemical oxygen demand (BOD). According to the results obtained in this study, the electrochemical oxidation processes suitable for the degradation process of color and COD in wastewater containing such textile dyes, because the electrocatalytic properties of Pt and BDD anodes consumption energy during the electrochemical oxidation of synthetic solutions AN and MR and real sample, mainly depend on the operating parameters of operation, for example, the synthetic sample of MR, energy consumption rose from 42,00kWhm-3 in 40 mAcm-2 and 25 C to 17,50 kWhm-3 in 40mAcm-2 and 40 C, from the BN went 17,83 kWhm-3 in 40mAcm and 40°C to 14,04 kWhm- 3 in 40mAcm-2 and 40 C (data estimated by the volume of treated effluent). These results clearly indicate the applicability of electrochemical treatment for removing dyes from synthetic solutions and real industrial effluents

Phototrophic growth of Rubrivivax gelatinosus in poultry slaughterhouse wastewater

Rubrivivax gelatinosus was grown in Pfennig's synthetic medium (PM) and in treated wastewater from poultry slaughterhouse (TW) to assess growth profiles for biomass production. Cultures inoculated at 1% (v/v) were grown under anaerobiosis at 30 +/- 2 degrees C and 1400 200 lux for 12 days. Regular absorbance curves for R. gelatinosus were found both on PM and TW. on PM, the highest dry weight of biomass, 0.39 g L-1. was achieved in the 216-h culture and the highest specific growth rate of 0.2960 h(-1) occurred in the 24-h culture. on TW, the highest biomass of 0.57 g L-1 was also obtained in the 216-h culture and the highest specific growth rate, 0.1970 h(-1), was achieved in the 48-h culture. For productivity and chemical oxygen demand investigations, the cultivation was accomplished in the TW under anaerobiosis at 32 +/- 2 degrees C and 4000 +/- 500 lux, for 10 days. Productivity was 0.085 g biomass (d.w.) L-1 day(-1), with a COD decrease of 91%. (c) 2007 Elsevier Ltd. All rights reserved.

Determinação da demanda química de oxigênio em águas por espectrofotometria simultânea dos íons crômio(III) e dicromato

Propõe-se metodologia analítica para a determinação da demanda química de oxigênio(DQO) em águas e efluentes pouco poluídos, pela espectrofotometria simultânea dos íons crômio(III) e dicromato, após a clássica oxidação sulfocrômica das amostras, à quente e catalisada por íons Ag+. Demonstra-se que a inter-relação entre as concentrações de DQO, de crômio(III) formado e de dicromato residual permite simplificar a resolução numérica do sistema - de multicomponente, envolvendo as concentrações desses dois íons, e medidas de absorbância em pelo menos dois comprimentos de onda para monocomponente, envolvendo diretamente a concentração em DQO, e medida de absorbância num único comprimento de onda.

Avaliação (em escala laboratorial) da aplicação do processo eletrolítico em efluente de lagoa de estabilização de esgoto urbano

Physico-chemical and microbiological parameters were evaluated before and after applying an electrolytic process to effluents of a stabilization lagoon, in the presence or absence of salt. Chlorine generation and bactericidal properties of the treatments were studied following two experiments. Effluent pH increased with electrolysis time. In the absence of salt, 20 min electrolysis resulted in a COD (Chemical Oxygen Demand) reduction of 44%, along with ca. 99.9% (3 log10 cfu/mL) reduction in total coliforms, heterotrophic bacteria and Escherichia coli. These results indicated that the electrolytic process is a promising complementary technology to improve effluent quality for stabilization lagoons.

Performance of an Anaerobic Baffled Reactor (ABR) in treatment of cassava wastewater

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribuição ecológica de comunidades de macroalgas de ambientes lóticos do Parque Nacional de Itatiaia (RJ, MG), Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microbiological and physicochemical treatments applied to metallurgic industry aiming water reuse

Estudou-se o reuso de água de um sistema composto por estação de tratamento de esgoto (ETE) com aeração prolongada e lodo ativado, e em uma estação compacta de tratamento de água (ECTA) de uma indústria metalúrgica. Os processos para obtenção da água de reuso foram: microbiológico e físico-químico. O esgoto doméstico foi bombeado para a ETE, onde houve formação de flocos biológicos e água clarificada. Avaliou-se a eficiência do processo microbiológico da ETE mediante a remoção de demanda bioquímica de oxigênio (DBO), demanda química de oxigênio (DQO) e sólidos sedimentáveis (SS). A eficiência do processo físico-químico de clarificação e desinfecção foi avaliada mediante análises de pH, turbidez, cor, contagem de bactérias heterotróficas aeróbias, cloro livre, dureza, alcalinidade, cloretos, sulfatos, sólidos totais dissolvidos (STD). Na água de reuso além desses parâmetros avaliou-se a toxicidade aguda ao microcrustáceo Daphnia similis.