Amphiphilic catalysts for the treatment of oily wastewaters

The main objective of this study was to obtain an effective catalyst for removal of diazo dye - Sudan IV by Catalytic Wet Peroxide Oxidation (CWPO). For this purpose liquid phase treatment was used to increase the basicity of activated carbon surface favoring the adsorption of organic pollutants. Modified activated carbon catalysts were used in different types of experiments: 1) decomposition of H2O2 in aquatic media, 2) decomposition of H2O2 in organic media, 3) adsorption of Sudan IV, 4) Sudan IV removal by CWPO. As the result of all of these experiments the most effective catalyst was obtained and discussed. It was not observed removal of Sudan IV from biphasic system by CWPO. The obtained results in some cases show a slight increase in concentration of Sudan IV, which may be ascribed to experimental errors. Different factors could be the reason of those errors. For example, the high volatility properties of organic media used in experiments should be taken into account during experiments. Under settled reaction temperature the decrease of cyclohexane volume during experiment could give rise in Sudan IV concentration. The initial concentration of model diazo dye also should be reviewed more detailed for CWPO experiments. Despite of these experimental errors the behavior of our catalysts in different media was observed.

Levels of some heavy Metals in Cocoyam ( Colocasia esculentum ) grown on Soil receiving Effluent from a Paint Industry

The levels of some heavy metals in soil samples and tubers of cocoyam ( Colocasia esculentum ) grown on soil receiving paint wastes (PWS) has been investigated using Atomic Absorption spectrophotometer (Unicam 939/959 model). Similar analyses were carried out for the same plant from a control area. The studies revealed that although the P.W.S contained abnormally high levels of Pb (474.14mgkg-1) and Cu (137.85mgkg-1). The paint waste tuber (PWT) recorded low levels of these metals: Pb (2.13mgkg-1) and Cu (13.85mgkg-1) respectively. Correlation analysis tested at 0.05 level of significance show that no significant correlation existed between the metals levels in the soil and the level in the tuber. In all cases the levels of the metals in the tubers were well below the upper limit documented for unpolluted plant. The results however suggest the ineffectiveness of the use of Colocasia esculentum as a bioindicator for heavy metal pollution in soil.

Poly(Lactide-co-Glycolide) Nanocapsules Containing Benzocaine: Influence of the Composition of the Oily Nucleus on Physico-Chemical Properties and Anesthetic Activity

The aim of this work was to investigate the influence of the oily nucleus composition on physico-chemical properties and anesthetic activity of poly (lactide-co-glycolide) nanocapsules with benzocaine.Nanocapsules containing benzocaine were prepared with three different oily nucleus composition and characterized by mean diameter, polydispersivity, zeta potential, pH and stability were investigated as a function of time. In vitro release kinetics were performed in a system with two compartments separated by a cellulose membrane. Intensity and duration of analgesia were evaluated in rats by sciatic nerve blockade.The greatest stability, slower release profile and improvement in the local anesthetic activity of BZC were obtained with the formulation using USP mineral oil as component.Results from our study provide useful perspectives on selection of the primary materials needed to produce suspensions of polymeric nanocapsules able to act as carriers of BZC, with potential future application in the treatment of pain.

Utilization of macrophyte biofilter in effluent from aquaculture: I. Floating plant

O objetivo deste trabalho foi confeccionar um biofiltro de baixo custo constituído por macrófita flutuante (Eichhornia crassipes). Os estudos limnológicos foram realizados 7 dias depois de colocadas as macrófitas no biofiltro, durante um período de 30 dias consecutivos, com amostragens 3 vezes por semana nas épocas de chuva, seca e de alta produção de organismos cultivados. Quanto aos compostos nitrogenados, as menores concentrações foram observadas no período de jul./ago., correspondendo à época de baixa produção de peixes e baixa adição de alimento nos tanques e viveiros de cultivo. O pH manteve-se ligeiramente ácido a alcalino ao longo do período experimental, não apresentando oscilações com os maiores valores médios no período de abr./mai. Os valores de pH influenciaram diretamente a alcalinidade e a dominância de bicarbonato no meio. Quanto à microfauna associada, entre os fitoplanctônicos as Chlorophyta foram o grupo dominante e entre os zooplanctônicos foram os Rotifera. Recomenda-se, no período de alta produção, substituição das plantas aquáticas por brotos bem pequenos a cada 10 dias.

A comparative study of alginate beads and an ion-exchange resin for the removal of heavy metals from a metal plating effluent

The capacity of dry protonated calcium alginate beads to sorb metals from an industrial effluent was studied and compared with a commercial ion-exchange resin (Lewatit TP 207). Both sorbents decreased zinc, nickel, iron and calcium concentrations in the effluent, and released sodium during treatment. Alginate beads removed lower amounts of heavy metals than the resin, but exhibited faster uptake kinetics. Zinc desorption from the sorbents was achieved in 30 minutes using 0.1 M HCl or 0.1 M H(2)SO(4). Desorption ratios with these acids varied between 90 and 100% for alginate, and 98 to 100% for the ion-exchange resin. Reusability tests with HCl showed that alginate beads can stand acid desorption and recover binding capacity. Overall, the comparison of dry protonated alginate beads with the resin supports the potential of the biosorbent for the treatment of industrial effluents.

Aquatic Toxicity Of Dyes Before And After Photo-fenton Treatment.

This study evaluated the ecotoxicity of five dyes to freshwater organisms before and during their photo-Fenton degradation. EC50 (48h) of the five tested dyes ranged from of 6.9 to >1000mgL(-1) for Daphnia similis. In the chronic tests IC50 (72h) varied from 65 to >100mgL(-1) for Pseudokirchneriella subcapitata and IC50 (8 days) from 0.5 to 410mgL(-1) for Ceriodaphnia dubia. Toxicity tests revealed that although the applied treatment was effective for decolorization of the dye, the partial mineralization may be responsible for the presence of degradation products which can be either more toxic than the original dye, as is the case of Vat Green 3 and Reactive Black 5, lead to initially toxic products which may be further degraded to non toxic products (acid Orange 7 and Food Red 17), or generate non toxic products as in the case of Food Yellow 3. The results highlighted the importance of assessing both acute and chronic toxicity tests of treated sample before effluent discharge.

The Influence Of The Buffering Capacity On The Production Of Organic Acids And Alcohols From Wastewater In Anaerobic Reactor.

Some bacteria common in anaerobic digestion process can ferment a broad variety of organic compounds to organic acids, alcohols, and hydrogen, which can be used as biofuels. Researches are necessary to control the microbial interactions in favor of the alcohol production, as intermediary products of the anaerobic digestion of organic compounds. This paper reports on the effect of buffering capacity on the production of organic acids and alcohols from wastewater by a natural mixed bacterial culture. The hypothesis tested was that the increase of the buffering capacity by supplementation of sodium bicarbonate in the influent results in benefits for alcohol production by anaerobic fermentation of wastewater. When the influent was not supplemented with sodium bicarbonate, the chemical oxygen demand (COD)-ethanol and COD-methanol detected in the effluent corresponded to 22.5 and 12.7 % of the COD-sucrose consumed. Otherwise, when the reactor was fed with influent containing 0.5 g/L of sodium bicarbonate, the COD-ethanol and COD-methanol were effluents that corresponded to 39.2 and 29.6 % of the COD-sucrose consumed. Therefore, the alcohol production by supplementation of the influent with sodium bicarbonate was 33.6 % higher than the fermentation of the influent without sodium bicarbonate.

Avaliação da biodegradabilidade anaeróbia de resíduos da bovinocultura e da suinocultura

The biodegradability of animal wastes production was evaluated through a simplified methodology that allowed the verification of the applicability of anaerobic processes. The experiments were performed in bath reactors, with granular sludge of three origins: UASB reactor treating dairy effluent, UASB reactor treating swine effluent and UASB reactor treating effluent of slaughterhouse of poultry. The experiments (1) - dairy effluent and poultry slaughterhouse non-adapted sludge; (2) -swine effluent and poultry slaughterhouse non-adapted sludge; (3) - dairy effluent and poultry slaughterhouse adapted sludge; (4) - swine effluent and poultry slaughterhouse adapted sludge; (5) - dairy effluent and dairy sludge, and (6) - swine effluent and swine sludge were performed in Incubator Shaker, at a temperature of 35 °C, under agitation at a 150 rpm, for 5 minutes, every 1 hour. A substrat:biomass relationship of 0.5 was used. Kinetic models of Monod, Zero Order, First and Second Order were tested and it was verified that the First Order model provided the best adjustment. The apparent First Order kinetic parameter (k1) was estimated for the experiments 1; 2; 3; 4; 5, and 6, as 2.51 x 10-2; 2.49 x 10-2; 1.90 x 10-2; 3.09 x 10-2; 2.54 x 10-2; 4.09 x 10-2 h-1, respectively.

Evaluation of elephant grass silage with the addition of cassava scrapings

The objective of this experiment was to evaluate the effects of adding cassava scrapings on gas and effluent losses, dry matter recovery, pH, contents of N-NH3, organic acids and volatile fatty acids and the bromatological composition of elephant grass silages. It was used a randomized complete design, with four levels of cassava scrapings (0, 7, 15 or 30% natural matter) each one with four replications per level. The grass was cut at 50 days of regrowth and ensiled in 15-L silos, equipped with a Bunsen valve to allow gas outflow. The gas losses decreased quadratically with the addition of cassava scrapings, whereas effluent losses decreased linearly. Dry matter recovery increased quadratically with the addition of cassava scrapings. Dry matter (DM) concentration increased but crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose (HEM) decreased linearly with the addition of cassava scrapings. The pH value and lactic acid concentration increased quadratically with the addition of cassava scrapings. Contents of N-NH3 and butyric acid decreased quadratically with the addition of cassava scrapings, whereas acetic acid content decreased linearly. Addition of cassava scrapings reduced gas and effluent losses and improved the fermentation profile of elephant grass silages and the level of 7% already ensures this improvement.

Electrochemical degradation of the dye reactive orange 16 using electrochemical flow-cell

Electrochemical removals of color and organic load from solutions containing the dye reactive orange 16 (RO16) were performed in an electrochemical flow-cell, using a platinum working electrode. The influence of the process variables flow-rate, such as NaCl concentration, applied potential and solution pH, were studied. The best color removal achieved was 93% (λ = 493 nm) after 60 min at 2.2 V vs. RHE electrolysis, using 1.00 g L-1 NaCl as supporting electrolyte. The rises in the concentration of NaCl and applied potential increased the color removal rate. The best total organic carbon removal (57%) was obtained at 1.8 V, without the separating membrane, indicating that the ideal conditions for the color removal are not necessarily the same as those to remove the total organic carbon. The degradation efficiency decreased with the solution pH decrease.

Recovery of p-TBC from a butadiene washing stream in a pilot plant

Results obtained in a pilot-scale unit designed for COD removal and p-TBC (p-tert-butylcatechol) recovery from a butadiene washing stream (pH 14, 200,000 mg COD L-1, highly toxic) at a petrochemical industry are presented. By adding H3PO4, phase separation is achieved and p-TBC is successfully recovered (88 g L-1 of washing stream). Information (time for phase separation and organic phase characterization) was gathered for designing a future industrial unit. The estimated heat generation rate was 990 kJ min-1 and 15 min were enough to promote phase separation for a liquid column of approximately 1.15 m.

Impactos das atividades humanas sobre a dinâmica do fósforo no meio ambiente e seus reflexos na saúde pública

O fósforo é um nutriente com fontes finitas e não renováveis, cuja velocidade de exploração é atualmente muito superior às suas taxas de retorno ao seu ciclo natural, sendo que já existem previsões a respeito de um provável colapso nas suas fontes disponíveis e conhecidas, com impactos econômicos, sociais e ambientais graves e irreversíveis. Diante desse cenário, o presente trabalho busca apresentar informações sobre a dinâmica do fósforo no meio ambiente, avaliando os impactos causados pelas atividades humanas e verificando as ações que podem auxiliar na preservação do ciclo do nutriente. Visando contribuir para uma melhor visualização do assunto, foi analisada a evolução dos dados relativos à concentração populacional, número de industriais e extensão das áreas cultivadas em uma bacia hidrográfica, em relação às concentrações de fósforo nos compartimentos água e sedimento, ao longo de 22 anos. Para tanto, utilizou-se o rio Tietê como estudo de caso. Os resultados obtidos indicam que o controle das fontes domésticas, principalmente da quantidade de tripolifosfato de sódio (STPP) utilizada nos detergentes, é de grande importância para melhoria da qualidade das águas, proteção ao meio ambiente e garantia da saúde pública

Proteção da comunidade aquática em efluente tratado por tanques de estabilização de resíduos no rio São Lourenço em São Lourenço da Serra, Vale do Ribeira, estado de São Paulo

O tratamento de esgotos de pequenas cidades por lagoas de estabilização é uma maneira simples, eficiente e de baixo custo. Os esgotos são uma fonte de contaminação das águas e solos e, conseqüentemente, contribuem para a transmissão de doenças, além de serem uma ameaça à preservação do meio ambiente. Surge a necessidade de investigar as condições dos efluentes lançados nos cursos d´água. O presente trabalho tem como objetivo realizar uma investigação da qualidade das águas residuárias tratadas por lagoas de estabilização de uma estação de tratamento de esgoto localizadas no município de São Lourenço da Serra no Vale da Ribeira no Estado de São Paulo e verificar os riscos sanitários e a comunidade aquática no Rio São Lourenço da Serra. Foram realizadas amostragens para avaliar o conjunto de lagoas anaeróbia e facultativa da estação de tratamento de esgoto do Município de São Lourenço da Serra. Os parâmetros utilizados foram pH, temperatura do ar e da água, condições climáticas, demanda bioquímica de oxigênio e nitrogênio amoniacal, bactérias termotolerantes, pigmentos fotossintéticos e comunidade zooplanctônica. Verificou-se que s sistemas de lagoa anaeróbia e facultativa foram eficientes na produção de efluente e apresentou alguns valores de acordo com a Resolução Conama nº 357, que estabelecem os valores limites para lançamento em corpos d´água. O rio São Lourenço está localizado em uma área de proteção ambiental. Os dados são comparados aos limites estabelecidos na Classe 1 e 2 e demonstram processo de eutrofização, colocando em risco à biodiversidade aquática e a saúde da população

Biomass Refinery as a Renewable Complement to the Petroleum Refinery

Biomass Refinery is a sequential of eleven thermochemical processes and one biological process with two initial basic treatments: prehydrolysis for lignocellulosics and low temperature conversion for biomass with medium-to-high content of lipids and proteins. The other ten processes are: effluent treatment plant, furfural plant, biodiesel plant, cellulignin dryer, calcination, fluidized bed boiler, authotermal reforming of cellulignin for syngas production, combined cycle of two-stroke low-speed engine or syngas turbine with fluidized bed boiler heat recovery, GTL technologies and ethanol from cellulose, prehydrolysate and syngas. Any kind of biomass such as wood, agricultural residues, municipal solid waste, seeds, cakes, sludges, excrements and used tires can be processed at the Biomass Refinery. Twelve basic products are generated such as cellulignin, animal feed, electric energy, fuels (ethanol, crude oil, biodiesel, char), petrochemical substitutes, some materials (ash, gypsum, fertilizers, silica, carbon black) and hydrogen. The technology is clean with recovery of energy and reuse of water, acid and effluents. Based on a holistic integration of various disciplines Biomass Refinery maximizes the simultaneous production of food, electric energy, liquid fuels and chemical products and some materials, achieving a competitive position with conventional and fossil fuel technologies, as well as payment capacity for biomass production. Biomass Refinery has a technical economical capability to complement the depletion of the conventional petroleum sources and to capture its GHGs resulting a biomass + petroleum ""green"" combination.

Fractionation and interesterification of palm (Elaeis guineensis) oil from Peruvian Amazon

In the present work, the physical and chemical characteristics of the fruit of the oily palm coming from the river basin of the Manitf (Region Loreto - Peru) were studied. Also, the fractionation of the palm oil and the interesterification of mixtures of palm oil/estearin was carried out. Physico- chemical properties of the crude oil and of the products obtained and fatty acids were analysed by gas chromatography The level of saturated fatty acids increased from 51,17% in the palm oil to 54,31% in the stearin. The best products for the food industry were the interesterified samples as they had melting points close to 37 degrees C.