8,362 research outputs found
Chromium recovery by membranes for process reuse in the tannery industry
Leather tanning is a wide common industry all over the
world. In leather processing, water is one of the most
important medium, almost 40-45 L water kg-1 raw-hide or
skin is used by tanneries for processing finished leathers.
The composition of tannery wastewater presents
considerable dissimilarities in the concentration range of
pollutants both of inorganic (chlorides, with concentration
ranging from several hundred to over 10,000 mg L-1 Cl–;
sulphate (VI), ammonium ions and sulphide ions,
exhibiting concentration that ranges from tens to several
hundred mg L-1) and organic (the COD value is usually
several thousand mg L-1 O2). Throughout the years, many
conventional processes have been carried out to treat
wastewater from tannery industry: unfortunately, in this
case, biological treatment methods give rise to an
excessive production of sludge, whereas physical and
chemical methods are too expensive in terms of energy and
reagent costs. In this work, a membrane process based on
NF membrane modules was adopted to treat the tannery
feedstock after primary conventional treatment. In a first
step, the determination of all boundary flux parameters, in
order to inhibit severe fouling formation during operation,
were performed. After this, experimental work was carried
out to validate the approach. The target of water
purification was reached, that is the legal discharge to
municipal sewer system in Italy of 90% of the initial
wastewater stream volume. This allows having an
immediate cost saving of 21%. Moreover, the developed
process leads to a second benefit, that is the production of
5% of the initial volume as a highly chromium-rich
concentrate at no cost suitable to tannery process recycle
and reuse. In this case, cost saving rates exceeds 40%. At
the end, scale-up of the investigated process will be
discussed from technical and economic point of view
Tridactyl tracks from the Lavini di Marco dinosaur ichnosite (Hettangian, Southern Alps, NE Italy). Ichnotaxonomical review and palaeobiogeography
The use of aerial- and close-range photogrammetry for the mapping of the Lavini di Marco tracksite (Hettangian, Southern Alps, NE Italy)
(EXCERPT FROM ABSTRACT) Close-range photogrammetry was executed following the procedure proposed by Mallison & Wings (2014). More than seventy 3D models were obtained and interpreted by means of color-coded and contour line images, which allow to improve the ichno- logical knowledge of the tracksite. The 3D models of the best-preserved tracks were used for the osteological reconstruction of the trackmakers’ autopodia, supposing the arthral position of the phalangeal pads. Three indirect methods were used to correlate tracks and their trackmakers: (i) synapomorphy-based approach; (ii) phenetic correlation; (iii) coincidence correlation (see Carrano & Wilson, 2001)
The final map was produced with different level of knowledge due to the distribution of tracks and current state of site preservation. Furthermore, it represents a complete documentation that will be used for future work of enhancement, preservation and valorization of the tracksite.
The ichnotaxonomical review of the quadrupedal trackways led us to emend the diagnosis of Lavinipes cheminii Avanzini et al. (2003) and to assign several other sparse tracks and trackways to L. chemini. The skeletal reconstruction of fore and hind limbs points towards Gongxianosaurus sp. as the most suitable trackmaker of L. cheminii. The herein supposed Laurasian affinity of the Lavini di Marco dinosaur assemblage clashes with the previous hypotheses that always link the Southern Alps sector with the Gondwana mainland
Controle de surtos de tristeza parasitária bovina.
No Brasil, os agentes causadores da Tristeza Parasitária Bovina (TPB) são dois protozoários (Babesia bovis e Babesia bigemina) e uma rickettsia (Anaplasma marginale), sendo que a doença pode ser causada por um, dois ou os três agentes juntos.bitstream/item/55746/1/CR26-02.pd
Controle/profilaxia da tristeza parasitária bovina.
O complexo de doenças que inclui a babesiose e a anaplasmose é conhecido, no Brasil, como Tristeza Parasitária Bovina (TPB).bitstream/item/55745/1/ct38-2001.pd
Profilaxia da tristeza parasitária bovina: por quê, quando e como fazer.
A tristeza parasitária bovina - TPB, Ă© um sĂ©rio entrave econĂ´mico na pecuária bovina, pois alĂ©m de apresentar altos Ăndices de mortalidade e morbidade, Ă© motivo de perdas de oportunidade e de mercado tambĂ©m, por parte dos produtores, de desestĂmulo em melhorar a produção.bitstream/item/55691/1/CR28-02.pd
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