Uso de quitina e quitosana como adsorventes de amônia de efluentes aquícolas: revisão de literatura / Use of chitin and quitosan as adsorvents of ammonia of aquaculture effluents: a literature review / Uso de quitina y quitosana como adsorbentes de amonia de efluentes acuícolas: revisión de literatura

Os resíduos provenientes da aquicultura são derivados da ração e da excreção dos peixes e podem estar sedimentados, suspensos ou dissolvidos, ocasionando elevados valores de DBO, DQO, nitrogênio e fósforo. A produção de camarões no Brasil tem gerado elevadas quantidades de resíduos sólidos, tendo em vista que os exoesqueletos dos camarões correspondem a cerca de 40% do seu peso total, resultando num forte impacto ambiental. Diversas pesquisas envolvendo a quitina estão sendo desenvolvidas na área de tratamento de água, devido principalmente a sua capacidade de formar filme, sendo utilizada em sistemas filtrantes. Este polissacarídeo também pode ser utilizado como agente floculante no tratamento de efluentes, como adsorvente na clarificação de óleos, e principalmente na produção de quitosana. Atualmente a quitosana possui aplicações multidimensionais, desde áreas como a nutrição humana, biotecnologia, ciência dos materiais, indústria farmacêutica, agricultura, terapia genética e proteção ambiental. A quitosana é muito eficiente na remoção de poluentes em diferentes concentrações. Apresenta alta capacidade e grande velocidade de adsorção, boa eficiência e seletividade tanto em soluções que possuem altas ou baixas concentrações. O uso da biotecnologia, através do processo de adsorção utilizando adsorventes naturais e baratos, como a quitina e quitosana, minimiza os impactos ambientais da aquicultura tanto em relação aos provocados pelo lançamento de efluentes no meio ambiente quanto aos causados pelo descarte inadequado dos resíduos do processamento de camarões.(AU)

Aquaculture residues are derived from fish feed and excretion and may be sedimented, suspended or dissolved, resulting in high BOD, COD, nitrogen and phosphorus values. Shrimp production in Brazil has generated high amounts of solid waste, since shrimp exoskeletons account for about 40% of their total weight, resulting in a strong environmental impact. Several researches involving chitin are being developed in the area of water treatment, mainly due to its ability to form film, being used in filter systems. This polysaccharide can also be used as a flocculating agent in the treatment of effluents, as an adsorbent in the clarification of oils, and especially in the production of chitosan. Currently, chitosan has multidimensional applications, from areas such as human nutrition, biotechnology, materials science, pharmaceutical industry, agriculture, gene therapy and environmental protection. Chitosan is very efficient in the removal of pollutants at different concentrations. It presents high capacity and high adsorption velocity, good efficiency and selectivity both in solutions that have high or low concentrations. The use of biotechnology, through the adsorption process using natural and cheap adsorbents such as chitin and chitosan, minimizes the environmental impacts of aquaculture both in relation to those caused by the release of effluents into the environment and those caused by the inappropriate disposal of processing residues of shrimps.(AU)

Los residuos procedentes de la acuicultura se derivan de la ración y de la excreción de los peces y pueden estar sedimentados, suspendidos o disueltos, ocasionando elevados valores de DBO, DQO, nitrógeno y fósforo. La producción de camarones en Brasil ha generado grandes cantidades de residuos sólidos, teniendo en cuenta que los exoesqueletos de los camarones corresponden a cerca del 40% de su peso total, resultando en un fuerte impacto ambiental. Varias investigaciones involucrando la quitina se están desarrollando en el área de tratamiento de agua, debido principalmente a su capacidad de formar película, siendo utilizada en sistemas filtrantes. Este polisacárido también puede ser utilizado como agente floculante en el tratamiento de efluentes, como adsorbente en la clarificación de aceites, y principalmente en la producción de quitosana. Actualmente la quitosana posee aplicaciones multidimensionales, desde áreas como la nutrición humana, biotecnología, ciencia de los materiales, industria farmacéutica, agricultura, terapia genética y protección ambiental. La quitosana es muy eficiente en la eliminación de contaminantes en diferentes concentraciones. Presenta alta capacidad y gran velocidad de adsorción, buena eficiencia y selectividad tanto en soluciones que poseen altas o bajas concentraciones. El uso de la biotecnología, a través del proceso de adsorción utilizando adsorbentes naturales y baratos, como la quitina y quitosana, minimiza los impactos ambientales de la acuicultura tanto en relación a los provocados por el lanzamiento de efluentes en el medio ambiente en cuanto a los causados por el descarte inadecuado de los residuos del procesamiento de camarones.(AU)

Bioflocculant production from Streptomyces platensis and its potential for river and waste water treatment

ABSTRACT A bacterium isolated from Sterkfontein dam was confirmed to produce bioflocculant with excellent flocculation activity. The 16S rDNA nucleotide sequence analyses revealed the bacteria to have 99% similarity to Streptomyces platensis strain HBUM174787 and the sequence was deposited in the Genbank as Streptomyces platensis with accession number FJ 486385.1. Culture conditions for optimal production of the bioflocculant included glucose as a sole carbon source, resulting in flocculating activity of 90%. Other optimal conditions included: peptone as nitrogen source; presence of Mg2+ as cations and inoculum size of 1.0% (v/v) at neutral pH of 7. Optimum dose of the purified bioflocculant for the clarification of 4 g/L kaolin clay suspension at neutral pH was 0.2 mg/mL. Energy Dispersive X-ray analysis confirmed elemental composition of the purified bioflocculant in mass proportion (%w/w): carbon (21.41), oxygen (35.59), sulphur (26.16), nitrogen (0.62) and potassium (7.48). Fourier Transform Infrared Spectroscopy (FTIR) indicated the presence of hydroxyl, carboxyl, methoxyl and amino group in the bioflocculant. The bioflocculant produced by S. platensis removed chemical oxygen demand (COD) in river water and meat processing wastewater at efficiencies of 63.1 and 46.6% respectively and reduced their turbidity by 84.3 and 75.6% respectively. The high flocculating rate and removal efficiencies displayed by S. platensis suggests its industrial application in wastewater treatment.

Aquaculture biological waste as culture medium to cultivation of Ankistrodesmus gracilis (Reinsch) Korshikov / Resíduos biológicos de aquicultura como meio de cultura para o cultivo de Ankistrodesmus gracilis (Reinsch) Korshikov

Abstract Current study investigated the effectiveness of different macrophytes as culture media for Ankistrodesmus gracilis in laboratory conditions. Significant difference (p < 0.05) was reported in cell density with regard to conventional culture medium (CHU12) and macrophytes culture media. Mean cell density in NPK, Eichhornia crassipes and E. azurea media was higher (p < 0.05) than in conventional culture medium. Chlorophyll-a was higher than 1 g.L-1, except in CHU12 (0.7 ± 0.4 g.L-1) and T. domingensis (0.8 ± 0.3 g.L-1) media. Nitrate decreased sharply as from the 7th-day of the experiment. Ammonium and total phosphorus were highest in culture media and ranged between 0.4 g.L-1 (P. cordata medium) and 1.7 g.L-1 (CHU12 medium) for ammonium, and between 0.8 g.L-1 (CHU12 medium) and 1.9 g.L-1 (T. domingensis medium) for total phosphorus. Results revealed inorganic fertilizer and macrophytes combined with vitamins may be effective as culture media and strongly supports the growth of Ankistrodesmus gracilis, since cell density and biochemical composition are similar to or higher than conventional culture medium (CHU12). Macrophyte is a tool for aquaculture since biological wastes may be used with nutrients to improve the cultivation of microalgae.

Resumo O presente estudo investigou a eficácia na utilização de diferentes macrófitas como meio de cultura para Ankistrodesmus gracilis em condições laboratoriais. Foi observada diferença significativa (p < 0,05) entre a densidade celular em relação aos meios de cultura convencional (CHU12) e de macrófitas. Os meios de cultura com Eichhornia crassipes, E. azurea e NPK apresentaram densidade celular maiores (p < 0,05) que o meio de cultura convencional. Os teores de clorofila-a foram superiores a 1 g.L-1, exceto nos meios de cultura CHU12 (0.7 ± 0.4 g.L-1) e de T. domingensis (0.7 ± 0.3 g.L-1). O nitrato diminuiu acentuadamente a partir do 7º dia de experimento. Dentre os nutrientes, amônia e o fósforo total foram os mais elevados nos meios de cultura, variando entre 0.4 g.L-1 (meio de P. cordata) a 1,7 g.L-1 (meio CHU12) para amônia e, entre 0.8 g.L-1 (meio CHU12) e 1,9 gL-1 (meio de T. domingensis) para o fósforo total. Os resultados do presente estudo mostraram que o uso de fertilizantes inorgânicos e macrófitas, combinados com vitaminas, pode ser eficaz como meio de cultura no crescimento de Ankistrodesmus gracilis, uma vez que a densidade celular e a composição bioquímica foram semelhantes ou superiores ao meio de cultura convencional (CHU12). As macrófitas são ferramentas a serem adotadas na aquicultura, desde que os resíduos biológicos podem ser usados como nutrientes para melhorar o cultivo de microalgas.

Potential of microalgae in the bioremediation of water with chloride content / Potencial de microalga na biorremediação da água com conteúdo de cloretos

Abstract In this work it was carried out the bioremediation of water containing chlorides with native microalgae (MCA) provided by the Centre for study and research in biotechnology (CIBIOT) at Universidad Pontificia Bolivariana. Microalgae presented an adaptation to the water and so the conditions evaluated reaching a production of CO2 in mg L-1 of 53.0, 26.6, 56.0, 16.0 and 30.0 and chloride removal efficiencies of 16.37, 26.03, 40.04, 25.96 and 20.25% for microalgae1, microalgae2, microalgae3, microalgae4 and microalgae5 respectively. Water bioremediation process was carried out with content of chlorides in fed batch system with an initial concentration of chlorides of 20585 mg L-1 every 2 days. The Manipulated variables were: the flow of MCA3 (10% inoculum) for test one; NPK flow for test two, and flow of flow of MCA3+0.5 g L-1 NPK. Chloride removal efficiencies were 66.88%, 63.41% and 66.98% for test one, two and three respectively, for a total bioprocess time of 55 days.

Resumo Neste trabalho avaliou-se a biorremediação da água com conteúdos de cloretos utilizando microalgas nativas (MCA) fornecidas pelo Centro de Estudos e Pesquisas em Biotecnologia (CIBIOT) da Universidad Pontifícia Bolivariana. As microalgas empregadas apresentaram uma adaptação ao meio de cultura e as condições operacionais avaliadas atingindo uma produção de CO2 em mg L-1 de 53,0, 26,6, 56,0, 16,0 e 30,0 e eficiências de remoção de cloretos de 16,37, 26,03, 40,04, 25,96 e 20,25% para MCA1, MCA2, MCA3, MCA4 e MCA5 respectivamente. A biorremediação da água com conteúdos de cloretos foi realizada em modo batelada alimentada (Feed Batch) com uma concentração inicial de cloretos de 20585 mg L-1. A alimentação foi realizada a cada 2 dias. A variável manipulada foi: ensaio um, uma vazão de MCA3 (10% de inoculo); ensaio dois, uma vazão de NPK e ensaio três, uma vazão de MCA3+0,5 g L-1 NPK. As eficiências de remoção foram 66,88%, 63,41% e 66,98% para os ensaios um, dois e três, respectivamente num tempo do bioprocesso total de 55 dias.

Decolorization of textile industry wastewater in solid state fermentation with Peach-Palm (Bactris gasipaes) residue / Decoloração de águas residuais da indústria têxtil em fermentação de estado sólido com resíduo de Pupunha (Bactris gasipaes)

Abstract In this work we have assessed the decolorization of textile effluents throughout their treatment in a solid-state fermentation (SSF) system. SSF assays were conducted with peach-palm (Bactris gasipaes) residue using the white rot fungus Ganoderma lucidum EF 31. The influence of the dye concentration and of the amounts of peach-palm residue and liquid phase on both the discoloration efficiency and enzyme production was studied. According to our results, independently of experimental conditions employed, laccase was the main ligninolytic enzyme produced by G. lucidum. The highest laccase activity was obtained at very low effluent concentrations, suggesting the existence of an inhibitory effect of higher concentrations on fungal metabolism. The highest percentage of color removal was reached when 10 grams of peach palm residue was moistened with 60 mL of the final effluent. In control tests carried out with the synthetic dye Remazol Brilliant Blue R (RBBR) decolorization efficiencies about 20% higher than that achieved with the industrial effluent were achieved. The adsorption of RBBR on peach-palm residue was also investigated. Equilibrium tests showed that the adsorption of this dye followed both Langmuir and Freundlich isotherms. Hence, our experimental results indicate that peach-palm residue is suitable substrate for both laccase production and color removal in industrial effluents.

Resumo Neste trabalho, avaliamos a descoloração de efluentes têxteis durante seu tratamento em um sistema de fermentação em estado sólido (SSF). Os ensaios foram conduzidos com resíduo de pupunha (Bactris gasipaes) utilizando o fungo de podridão branca Ganoderma lucidum EF 31. A influência da concentração de corante, as quantidades de resíduo e da fase líquida foram estudadas tanto na eficiência de descoloração como na produção de enzima. De acordo com os resultados, independentemente das condições experimentais utilizadas, a lacase foi a principal enzima ligninolítica produzida por G. lucidum. A atividade de lacase mais elevada foi obtida em baixas concentrações de efluentes, sugerindo um efeito inibitório no metabolismo fúngico. A maior remoção de cor foi obtida com 10 gramas de resíduo da pupunha e 60 mL do efluente final. Nos ensaios de controle realizados com o corante sintético RBBR, foram atingidos cerca de 20% mais descoloração do que os obtidos com o efluente industrial. A adsorção de RBBR no resíduo de pupunha também foi investigada. Os testes de equilíbrio mostraram que a adsorção deste corante seguiu as isotermas de Langmuir e Freundlich. Assim, os resultados experimentais indicam que o resíduo de pupunha é um substrato adequado tanto para a produção de lacase quanto para a remoção de cor em efluentes industriais.

Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater

Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide concentrations of up to 5 mM. Increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. The rate of cyanide removal by the strains depends on the initial cyanide and glucose concentrations. When initial cyanide and glucose concentrations were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by Bacillus pumilus and Pseudomonas putida. Metabolic products such as ammonia and formate were detected in culture supernatants, suggesting a direct hydrolytic pathway without an intermediate formamide. The study clearly demonstrates the potential of aerobic treatment with cyanide degrading bacteria for cyanide removal in cassava factory wastewaters.

Impact of physical and chemical characteristics of breeding sites on mosquito larval abundance at Ismailia governorate, Egypt

The distribution and monthly abundance of mosquito larvae in released water, drainage canals and sewage water tanks in Ismailia governorate were investigated. The results obtained indicated the presence of five culicine [Culex. pipiens, Cx. pusillus, Cx. perexiguus, Cx. theleri and Ochlerotatus. caspius] and two anopheline [Anopheles. multicolor and An. pharoensis] mosquito species. Significantly higher larval density was recorded in sewage water [n= 5534; 46.08%] as compared with released water [n= 2903; 24.17%] and drainage water [n= 3573; 29.75%]. Culex pipiens was the most dominant mosquito species in the three habitats. The effects of environmental parameters including pH, biological and chemical oxygen demands, day time water temperature, plant growth, salinity, total organic matter and concentrations of heavy metals on larval population density were investigated. The positive correlations observed between heavy metals concentrations in the three habitats suggested relative uniformity of the sources of metal pollutants. Culex pipiens larvae demonstrated high tolerance to elevated levels of heavy metals in sewage water and compensatory effects of high nutrient levels generally associated with sewage or domestic waste. High densities of culicine larvae were accompanied by low density of anopheline larvae. This was attributed to water chemistry and competitive interactions

Combined coagulation flocculation pre treatment unit for municipal wastewater

The potentials of using the hydraulic technique in combined unit for municipal wastewater treatment were studied. A combined unit in which processes of coagulation, flocculation and sedimentation, has been designed utilizing hydraulic mixing instead of mechanical mixing. Ajar test treatability study has been conducted to locate the optimum dose of the coagulants to be used. Alum, ferrous sulfate, ferric sulfate, a mixture of ferric and ferrous sulfates, and mixture of lime and ferrous sulfate were all tested. A pilot unit was constructed in the existing wastewater treatment plant at El Mansoura governorate located in north Egypt. The optimum dose of coagulants used in the combined unit gives removal efficiencies for COD, BOD, and total phosphorous as 65%, 55%, and 83%, respectively

Utilization and biodegradation of starch stillage (distillery wastewater)

Stillage (distillery wastewater) is the main by-product originating in distilleries, and its volume is approximately 10 times that of ethanol produced. It is not surprising that the utilization of the stillage raises serious problems, and that many attempts have been made all over the world to solve them. In Poland most of the ethanol (about 90 percent) is produced from starch-based feedstocks, i.e. grains and potatoes. Starch feedstocks are widely used for spirit production also in other European countries, as well as outside Europe. The manuscript provides an overview of global fuel ethanol production and information on methods used for starch-based stillage biodegradation and utilization. The methods presented in this paper have been classified into two major groups. One of these includes the mode of utilizing starch stillage, the other one comprises methods, both aerobic and anaerobic, by which the stillage can be biodegraded.

Macromolecular composition and anaerobic degradation of the sludge produced in a sequencing batch reactor

The effect of sequencing batch reactor (SBR) operating conditions on sludge macromolecular composition and the effect of sludge macromolecular composition on the anaerobic degradation of the sludge produced in SBR was investigated in this work. A SBR, fed with synthetic wastewater, was operated at different air flow rates. The resulting sludge was analyzed in terms of protein, carbohydrate, phospholipid and polyhydroxybutyrate concentrations. Methane production during anaerobic digestion of the sludge was also measured. Ammonium, nitrite, nitrate, dissolved oxygen and chemical oxygen demand (COD) track studies in the SBR were carried out in order to relate SBR performance and sludge macromolecular composition. The lowest air flow rate at which the SBR was operated was 2 l min-1, in which case the dissolved oxygen concentration was lower than 0.5 mg l-1 in the SBR and partial denitrification occurred during the feeding phase. An increased air flow rate caused a decrease in protein concentration, as well as an increase in carbohydrate concentration. Polyhydroxybutyrate (PHB) concentration in the sludge was independent of air flow rate. At different air flows, the methane production rates were similar, but the total volume of methane was greater during anaerobic digestion of the sludge produced at low air flow rates. These results indicate a strategy by which changes in sludge composition can optimize the operation of anaerobic sludge digesters.

Estimate of denitrifying microbiota in tertiary sewage treatment and kinetics of the denitrification process using different sources of carbon

A study of the kinetics of denitrification was carried out in the laboratory based on the quantification of N2O, the final product of the activity of denitrifying microorganisms, when the enzymatic reduction of N2O to N2 was blocked by acetylene. Concentrated mixed liquor (sludge from a reactor with intermittent aeration used for sewage treatment) was used as the inoculum, while methanol, acetic acid, glucose, effluent sewage from an anaerobic fluidized bed reactor and synthetic substrate simulating domestic sewage were used as carbon sources. The mean concentration of nitrate was 20 mg/L. Maxima of N2O production and NO3- consumption occurred between 0.5h and 2.0h of incubation using all the carbon sources, which characterized the denitrification process. Acetic acid and methanol were responsible for the highest rates of N2O production. The estimated number of denitrifying microorganisms in the reactor with intermittent aeration, using the MPN technique, varied from 10(9) to 10(10) MPN/g VSS, indicating a high potential for the occurrence of denitrification.

Alterações morfológicas em Bacillus subtilis pela eletrólise / Morfological alteration in Bacillus subtilis by electrolisys

O tratamento de águas de abastecimento é indispensável à saúde pública. Tradicionalmente, o tratamento de água implica adição de substâncias químicas que podem gerar compostos tóxicos afetando a saúde daqueles que a utilizam. A cloração, por exemplo, promove a formação de compostos tóxicos como os trialometanos, de reconhecido efeito carcinogênico, além de apresentarem outros efeitos toxicológicos. O tratamento eletrolítico pode ser uma alternativa na desinfecção de águas de abastecimento e residuárias. Além das vantagens para a saúde pública, o tratamento eletrolítico, por não requerer a adiçaõ de nenhuma substância ao processo, pode ser utilizado em indústrias de alta tecnologia que necessitem de águas extremamente puras em seus processos. O objetivo deste estudo foi observar o efeito do tratamento eletrolítitco com cátodo de carbono sobre a morfologia do Bacillus subtilis. Suspensões de B. subtilis em tampão fosfato 0,2M em pH 7,2 livre de cloreto foram eletrolisadas com cátodo de carbono verificado e ânodo de platina recorbeto membrana de diálise. A corrente aplicada ao processo foi de 0,60A DC por 30 min. As suspensões eletrolisadas foram coradas pelo método de Gram e observadas ao microscópio óptico; observadas ao microscópio eletrônico de varredura após sua preparação. Os resutados permitem concluir que a eletrólise promove alterações na estrutura da parede do B. subtilis além de extravasamento de material celular