Francisco Suetônio Bastos Mota

Treatment of a sanitary landfill leachate using combined solar photo-Fenton and biological immobilized biomass reactor at a pilot scale.

A solar photo-Fenton process combined with a biological nitrification and denitrification system is proposed for the decontamination of a landfill leachate in a pilot plant using photocatalytic (4.16 m(2) of Compound Parabolic Collectors - CPCs) and biological systems (immobilized biomass reactor). The optimum iron concentration for the photo-Fenton reaction of the leachate is 60 mg Fe(2+) L(-1). The organic carbon degradation follows a first-order reaction kinetics (k = 0.020 L kJ(UV)(-1), r(0) = 12.5 mg kJ(UV)(-1)) with a H(2)O(2) consumption rate of 3.0 mmol H(2)O(2) kJ(UV)(-1). Complete removal of ammonium, nitrates and nitrites of the photo-pre-treated leachate was achieved by biological denitrification and nitrification, after previous neutralization/sedimentation of iron sludge (40 mL of iron sludge per liter of photo-treated leachate after 3 h of sedimentation). The optimum C/N ratio obtained for the denitrification reaction was 2.8 mg CH(3)OH per mg N-NO(3)(-), consuming 7.9 g/8.2 mL of commercial methanol per liter of leachate. The maximum nitrification rate obtained was 68 mg N-NH(4)(+) per day, consuming 33 mmol (1.3 g) of NaOH per liter during nitrification and 27.5 mmol of H(2)SO(4) per liter during denitrification. The optimal phototreatment energy estimated to reach a biodegradable effluent, considering Zahn-Wellens, respirometry and biological oxidation tests, at pilot plant scale, is 29.2 kJ(UV) L(-1) (3.3 h of photo-Fenton at a constant solar UV power of 30 W m(-2)), consuming 90 mM of H(2)O(2) when used in excess, which means almost 57% mineralization of the leachate, 57% reduction of polyphenols concentration and 86% reduction of aromatic content.

Geography, Population, Demography, Socioeconomic, Anthropometry, and Environmental Status in the MAL-ED Cohort and Case-Control Study Sites in Fortaleza, Ceará, Brazil

The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort in the studys Fortaleza, Brazil, catchment area has a population of approximately 82 300 inhabitants. Most of the households (87%) have access to clean water, 98% have electricity, and 69% have access to improved toilet/sanitation. Most childbirths occur at the hospital, and the under-5 mortality rate is 20 per 1000 live births. The MAL-ED case-control study population, identified through the Institute for the Promotion of Nutrition and Human Development (IPREDE), serves 600 000 inhabitants from areas totaling about 42% of the city of Fortaleza. IPREDE receives referrals from throughout the state of Ceará for infant nutrition, and provides services including teaching activities and the training of graduate students and health professionals, while supporting research projects on child nutrition and health. In this article, we describe the geographic, demographic, socioeconomic, anthropometric, and environmental status of the MAL-ED cohort and case-control study populations in Fortaleza, Brazil.

Crescimento da cultura do girassol irrigado com diferentes tipos de água e adubação nitrogenada

The objective of the present study was to evaluate the growth of sunflower crop irrigated with different water sources (both treated wastewater and well water) and application of different rates of nitrogen fertilizer. The experiment was conducted at the Research Center of Treatment and Reuse of Sewer Water located in the municipality of Aquiraz in the State of Ceara, Brazil. The statistical design consisted of a randomized block in split-plots with four replications. In the plots, the effects of two types of irrigation water on sunflower growth parameters was evaluated and in the subplots the effects of the five irrigation levels; according to the percentage of Class A Evaporation Pan (ECA),corresponding to the multiplication of ECA by factors of 0.25, 0.50, 0.75, 1.00 and 1.25 levels were determined. In splitplots, the effects of the four rates of nitrogen (25, 50, 75 and 100 kg ha-1) on the same growth parameters were evaluated. The plant height, stem diameter and number of leaves increased lineaRLy as a function of the irrigation water levels. The parameter values obtained for wastewater were consistently higher than those obtained with well water. The capitulum diameter increased in a quadratic manner as a function of the irrigation water levels and nitrogen fertilizer rates.

Effect of dye structure and redox mediators on anaerobic azo and anthraquinone dye reduction

We investigated the biological decolourisation of dyes with different molecular structures. The kinetic constant values (k1) achieved with azo dye Reactive Red 120 were 7.6 and 10.1 times higher in the presence of RM (redox mediators) AQDS and riboflavin, respectively, than the assays lacking RM. The kinetic constant achieved with the azo dye Congo Red was 42 times higher than that obtained with the anthraquinone dye Reactive Blue 4. The effect of RM on dye reduction was more evident for azo dyes resistant to reductive processes, and ineffective for anthraquinone dyes because of the structural stability of the latter.

Applicability of anthraquinone-2,6-disulfonate (AQDS) to enhance colour removal in mesophilic UASB reactors treating textile wastewater

This work assessed the applicability of the redox mediator anthraquinone-2,6-disulfonate (AQDS) to enhance colour removal in mesophilic UASB reactors treating textile wastewater under different operational conditions, such as different electron donor (ethanol) concentrations and different HRT. The anaerobic reactors were able to remove reasonably well the colour of the textile wastewater (35-63%) even when operated with a relatively short HRT (6 h), being a good option for textile effluents pre-treatment. Aditionally, colour removal efficiency was positively influenced not only by the addition of ethanol as external electron donor, but also by the initial wastewater absorbance. Although the applicability of AQDS is reported in the literature to enhance remarkably colour removal from synthetic dye-containing wastewaters, especially for recalcitrant azo dyes, the same effect was not evident in the present study with the textile wastewater tested, since the reactors did not show significant differences on decolourisation capacity.

Descoloração redutiva de corantes azo e o efeito de mediadores redox na presença do aceptor de elétrons sulfato

We investigated the impact of sulphate and the redox mediator Anthraquinone-2,6-disulfonate (AQDS) on the decolorization of the azo dyes Congo Red (CR) and Reactive Black 5 (RB5). In anaerobic reactors free of extra sulphate dosage, the color removal efficiency decreased drastically when the external electron donor ethanol was removed. In presence of an extra dosage of sulphate, CR decolourisations were 47.8% (free of AQDS) and 96.5% (supplemented with AQDS). The decolourisations achieved in both reactors with RB5 were lower than the ones found with CR. Finally, the biogenic sulphide contribution on azo dye reduction was negligiable.

Índice de sustentabilidade agroambiental para o perímetro irrigado Ayres de Souza

Uma analise integrada do atual uso dos recursos naturais do Perimetro Irrigado de Ayres de Souza, localizado no Vale do Acarau, Ceara, foi realizada atraves do desenvolvimento de um indice de sustentabilidade agroecologica. Os dados dessa pesquisa foram oriundos de questionarios aplicados a 33 produtores agricolas beneficiados pelo projeto de irrigacao. Os indicadores de sustentabilidade foram estimados pelo emprego de analise fatorial, metodo da analise fatorial/analise de componentes principais. O indice de sustentabilidade estimado a partir dos indicadores selecionados registrou uma situacao de sustentabilidade fragilizada ou de insustentabilidade reversivel. As unidades produtivas apresentaram um porcentual de 60,6% com alguma sustentabilidade; e os demais 39,4% estao em condicoes de insustentabilidade. Os resultados tambem mostraram que os fatores dominantes do indice de sustentabilidade foram: nivel da atividade agricola praticada, agricultura familiar, condicoes atuais do sistema agua-solo e infra-estrutura, fontes alternativas de renda e experiencia em tratos culturais.

Efluente de esgoto doméstico tratado e reutilizado como fonte hídrica alternativa para a produção de cana-de-açúcar

Com base no consumo hidrico excessivo na producao agricola e da expansao do cultivo da cana-de-acucar impulsionada pela crescente demanda de etanol, tem-se questionado em relacao a um uso mais racional da agua de irrigacao e ao reuso de agua na producao agricola. Desta forma objetivou-se, com o presente trabalho, avaliar os efeitos do reuso de efluente de esgoto domestico tratado na irrigacao da cana-de-acucar. O estudo foi conduzido no Centro de Pesquisa sobre Tratamento e Reuso de Aguas Residuarias, em Aquiraz, CE. O delineamento experimental adotado foi o de blocos ao acaso, no esquema de parcelas subdivididas, com quatro repeticoes. Nas parcelas avaliaram-se os efeitos de dois tipos de agua (agua potavel e esgoto domestico tratado); e nas subparcelas se alocaram cinco lâminas de irrigacao baseadas em percentuais da evaporacao medida em um tanque do tipo classe A (ECA). Concluiu-se que a agua residuaria proporcionou o maior potencial produtivo de colmos (272,1 Mg ha-1) e a maior densidade de plantas (126.000 plantas ha-1). O aumento das lâminas de irrigacao proporcionou incrementos no potencial produtivo e na densidade de plantas, independente do tipo de agua.

Calculation method for charging water on shrimp farming

The increase of global water demand has stimulated the application of water charging to seek its rational use. However, the establishment of the water tariff for a certain use is not an easy task, given that this tariff must have an elevated value, sufficient to encourage the rational use, but not so elevated, in a manner that compromises or prevents the development of production activities. The present study aimed to evaluate different water tariff values proposed and applied to the shrimp farming industry in Ceara, from 2003 to 2016, and analyze the sensitivity of the industry to these values. The analyses considered the productive performance of the shrimp farming observed by the producers, production costs for the activity, and incomes earned by the producers in 2008. The present study demonstrated that the only tariff value that makes the sector financially attractive is R

Avaliação do risco de eutrofização em reservatórios da bacia do Acaraú, Ceará, Brasil.

1.00/1,000m3, a lower value than the one previously proposed by the state of Ceara (R