Biomedical subjects

J F Ortuño

Publications and source records attributed to J F Ortuño.

4 recordsLinked to original sources

PubMed2006

Removal of cadmium from aqueous solutions by adsorption onto orange waste.

The use of orange wastes, generated in the orange juice industry, for removing cadmium from aqueous solutions has been investigated. The material was characterized by Fourier transform infrared spectroscopy and batch experiments were conducted to determine the adsorption capacity of the biomass. A strong dependence of the adsorption capacity on pH was observed, the capacity increasing as pH value rose. Kinetics and adsorption equilibrium were studied at different pH values (4-6). The adsorption process was quick and the equilibrium was attained within 3h. The maximum adsorption capacity of orange waste was found to be 0.40, 0.41 and 0.43 mmol/g at pH 4-6, respectively. The kinetic data were analysed using various kinetic models - pseudo-first order equation, pseudo-second order equation, Elovich equation and intraparticle diffusion equation - and the equilibrium data were tested using four isotherm models - Langmuir, Freundlich, Sips and Redlich-Peterson. The data were fitted by non-linear regression and five error analysis methods were used to evaluate the goodness of the fit. The Elovich equation provides the greatest accuracy for the kinetic data and the Sips model the closest fit for the equilibrium data.

Adsorption↗

PubMed2005

Improvement of coagulation-flocculation process using anionic polyacrylamide as coagulant aid.

A physicochemical treatment (coagulation-flocculation) was applied to a slaughterhouse wastewater, using anionic polyacrylamide as coagulant aid to improve the settling velocity of the flocs formed with the coagulants used: ferric sulphate, aluminium sulphate and polyaluminium chloride. The optimum speed and stirring time for the flocculation stage were ascertained along with the optimum pH and coagulant and coagulant aid doses. The speed and coagulation time were initially set according to recommendations in the literature concerning the treatment of this type of water. Chemical oxygen demand (COD), biochemical oxygen demand at 5 days (BOD5) and total suspended solids (TSS) were recorded at the beginning and end of each experiment in order to monitor the process. Once the optimal conditions had been established, several parameters were measured in order to assess the coagulation-flocculation process: particle number and size, sludge volume, nutrients (ammonia nitrogen, total Kjeldahl nitrogen, albuminoid nitrogen, orthophosphate, total phosphorus) and the residual concentration of iron and aluminium in clarified water. Anionic polyacrylamide, when added with ferric sulphate or polyaluminium chloride led to a significant increase in the settling speed.

Acrylic Resins↗

PubMed2003

Microscopic observation of particle reduction in slaughterhouse wastewater by coagulation-flocculation using ferric sulphate as coagulant and different coagulant aids.

A coagulation-flocculation treatment has been applied to a slaughterhouse liquid effluent, using ferric sulphate as coagulant and activated silica, powdered activated carbon, cationic polyacrylamide, polyvinyl alcohol, polyacrylic acid and anionic polyacrylamide as coagulant aids in order to improve the settling time. Once the optimal conditions had been established (speed and time of stirring during flocculation step, pH, coagulant and coagulant aid doses), the efficiency of the coagulation-flocculation process was studied by comparing the particle size distribution before and after the addition of the coagulant. When ferric sulphate was used without the coagulant aids, particle removal efficiency varied with size, although overall efficiency was quite substantial (87%). The use of coagulant aids improved the removal efficiency, except in the case of activated silica, when it fell to 78%. In all other cases removal efficiency values between 93% (for polyvinyl alcohol) and 99% (for anionic polyacrylamide) were reached.

Abattoirs↗

PubMed2002

Nutrient removal and sludge production in the coagulation-flocculation process.

Nutrient removal and sludge production in the coagulation-flocculation process, applied to a slaughterhouse effluent, have been studied. Fe2(SO4)3, Al2(SO4)3 and polyaluminium chloride were used as coagulants. Inorganic products were used as coagulant aids: activated silica, powdered activated carbon and precipitated calcium carbonate and synthetic polyelectrolytes: cationic polyacrylamide, polyacrilic acid, anionic polyacrylamide and polyvinyl alcohol. Performances were measured under optimum conditions for the products used. They were found after studying the different variables which influence the process. Phosphorus removal is very high (approximately 100% for the orthophosphate and between 98.93% and 99.90% for the total phosphorus). Ammonia nitrogen removal is very low although appreciable performances are observed for albuminoid nitrogen (73.9-88.77%). The use of coagulant aids reduces the volume of the sludge produced up to 41.6%.

Abattoirs↗