Separation of emulsified crude oil in saline water by flotation with micro- and nanobubbles generated by a multiphase pump.

The flocculation-column flotation with hydraulic loading (HL, >10 m h-1) was studied for the treatment of oil-in-water emulsions containing 70-400 mg L-1 (turbidity = 70-226 NTU) of oil and salinity (30 and 100 g L-1). A polyacrylamide (Dismulgan, 20 mg L-1) flocculated the oil droplets, using two floc generator reactors, with rapid and slow mixing stages (head loss = 0.9 to 3.5 bar). Flotation was conducted in two cells (1.5 and 2.5 m) with microbubbles (MBs, 5-80 µm) and nanobubbles (NBs, 50-300 nm diameter, concentration of 108 NBs mL-1). Bubbles were formed using a centrifugal multiphase pump, with optimized parameters and a needle valve. The results showed higher efficiency with the taller column reducing the residual oil content to 4 mg L-1 and turbidity to 7 NTU. At high HL (27.5 m h-1), the residual oil concentrations were below the standard emission (29 mg L-1), reaching 18 mg L-1. The best results were obtained with high concentration of NBs (apart from the bigger bubbles). Mechanisms involved appear to be attachment and entrapment of the NBs onto and inside the flocs. Thus, the aggregates were readily captured, by bigger bubbles (mostly MBs) aiding shear withstanding. Advantages are the small footprint of the cells, low residence time and high processing rate.

Raw water clarification by flotation with microbubbles and nanobubbles generated with a multiphase pump.

Raw water clarification by flotation was studied by injecting air into a centrifugal multiphase pump to generate microbubbles (MBs) and nanobubbles (NBs). Measurements of gas dispersion parameters were performed and optimal conditions were obtained using a pump pressure of 4 bar. Values showed a bubble Sauter diameter of 75 µm, an air holdup of 1.2%, a bubble surface area flux of 34 s-1 and an NB concentration of 1 × 108 NBs mL-1 (measuring 220 nm). Then, a study compared flotation with bubbles formed with the multiphase pump (F-MP) to lamellar settling at the clarification stage of a water treatment plant (WTP), in Brazil. The F-MP showed a higher separation efficiency at high hydraulic loads (9-15 m h-1), even without the use of a polymer, reaching 2 NTU (10-25 NTU raw water feed), which was much lower than the technical goal of the WTP (5 NTU). The results and the technical aspects are discussed, and it is concluded that the employment of MBs and NBs with pumps widens new research lines and applications in modern flotation.

Car wash wastewater treatment and water reuse - a case study.

Recent features of a car wash wastewater reclamation system and results from a full-scale car wash wastewater treatment and recycling process are reported. This upcoming technology comprises a new flocculation-column flotation process, sand filtration, and a final chlorination. A water usage and savings audit (22 weeks) showed that almost 70% reclamation was possible, and fewer than 40 L of fresh water per wash were needed. Wastewater and reclaimed water were characterized by monitoring chemical, physicochemical and biological parameters. Results were discussed in terms of aesthetic quality (water clarification and odour), health (pathological) and chemical (corrosion and scaling) risks. A microbiological risk model was applied and the Escherichia coli proposed criterion for car wash reclaimed water is 200 CFU 100 mL(-1). It is believed that the discussions on car wash wastewater reclamation criteria may assist institutions to create laws in Brazil and elsewhere.

La agregación eritrocitaria en la fisiopatogenia de las lesiones cutáneas microangiopáticas diabéticas / Erythrocytic aggregation in the physiopathogenesis of diabetic microangiopasthic skin lesions

Introducción: La diabetes puede producir importantes lesiones cutáneas; algunas microangiopáticas (dermopatía diabética, púrpura pigmentaria, eritrosis, eritema símil erisipela, rubeosis facial y telengiectasias periungueales). Existe creciente evidencia de que las anormalidades hemorreológicas desempeñan un papel definido en esta enfermedad. En consecuencia, este trabajo analiza la agregación eritrocitaria en pacientes diabéticos con y sin lesiones cutáneas Pacientes y método: Se estudió clínica, dermatológica y hemorreológicamente a 86 pacientes con diabetes tipos 1 y 2, de ambos sexos y edades similares, con lesiones cutáneas (28) y sin ellas (58), y 20 controles sanos. La agregación eritrocitaria se midió mediante observación microscópica directa y procesamiento numérico de las imágenes digitalizadas recogidas a través del llamado Parámetro de Forma de los Agregados (ASP). Los datos se analizaron con ANOVA y las pruebas de la t de Student y de la *2. Resultados: El tiempo de evolución de los pacientes diabéticos con lesiones cutáneas fue más prolongado y su ASP (0,692 ± 0,066) excedió significativamente el de los controles (0,288 ± 0,134) (p = 0,65 fue superior en aquéllos que presentaban lesiones cutáneas (el 80 frente al 45%; p = 0,006). Conclusiones La agregación eritrocitaria puede participar en el desarrollo de la microangiopatía diabética y en la aparición de las citadas lesiones dermatológicas

Introduction: Diabetes can produce significant skin lesions. Some of them are linked to microcirculatory changes (diabetic dermopathy, pigmentary purpura, erythrosis, erysipela-like erythema, facial rubeosis, and perionychial telangiectases). There is increasing evidence that hemorheological abnormalities play a definitive role in diabetes mellitus. Consequently, the present study analyzed red blood cell aggregation in diabetic patients with and without skin lesions. Patients and method: Eighty-six type 1 and type 2 diabetic patients of both sexes and similar ages, with (28) and without (58) skin lesions and 20 healthy controls underwent clinical, dermatological and hemorheological studies. Red blood cell aggregation was measured using direct microscopic observation and the recorded digitized images were numerically processed through the aggregate shape parameter (ASP). ANOVA, Student's t-test and the chi-square test were employed. Results: Diabetic patients with skin lesions had longer disease duration than those without and their ASP (0.692 ± 0.066) significantly exceeded that of controls (0.288 ± 0.134) (p = 0.65 was higher in those with cutaneous lesions than in those without (80% versus 45%, p = 0.006). Conclusions: Red blood cell aggregation may participate in the development of diabetic microangiopathy and in the appearance of the above-mentioned dermatologic lesions

Forna inusual de presentación de un carcinoma basocelular de parpado / Inusual presentatiom form of the basal cell carcinoma in the eyelid

Se presenta un paciente que padece un epitelioma basocalular de párpado con una miasis sobreagragada que modifica la lesión primitiva y a su vez la vuelve más agresiva en cuanto a su evolución. Se destaca la importancia de la evaluación exasustiva de estos tipos de tumores situados en zonas de alto riesgo para decidir de esa manera la técnica quirúrgica o el tratamiento más seguro. Se enfatiza la importancia de la cirugía micrográfica para estos casos" dificiles", el tratam,iento previo de la parasitosis, la utilización de técnica por imágenes que orientarán posteriormente la conducta quirúrgica y sobre todo el trabajo en conjunto de dermatólogos, oftalmólogos y cirujanos

Forna inusual de presentación de un carcinoma basocelular de parpado / Inusual presentatiom form of the basal cell carcinoma in the eyelid

Se presenta un paciente que padece un epitelioma basocalular de párpado con una miasis sobreagragada que modifica la lesión primitiva y a su vez la vuelve más agresiva en cuanto a su evolución. Se destaca la importancia de la evaluación exasustiva de estos tipos de tumores situados en zonas de alto riesgo para decidir de esa manera la técnica quirúrgica o el tratamiento más seguro. Se enfatiza la importancia de la cirugía micrográfica para estos casos" dificiles", el tratam,iento previo de la parasitosis, la utilización de técnica por imágenes que orientarán posteriormente la conducta quirúrgica y sobre todo el trabajo en conjunto de dermatólogos, oftalmólogos y cirujanos(AU)