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1.
Indian J Public Health ; 66(1): 27-32, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35381710

RESUMO

Background: Extensive evidence of elevated chromium (Cr) in the surface and groundwater exists. However, the importance of exposure toward Cr-associated health risks in areas with tanneries is still often neglected. These situations prompted an independent research study to investigate the views of those close-knit communities who are being directly affected by this tannery village. Objectives: To establish an understanding of the local demographics and; exploratory data analysis (EDA) to discover patterns in the occurrence of diseases; measure the awareness of residents of the presence of Cr and its harmful health effects. Methods: The EDA technique was used to conduct survey studies on data to uncover patterns, identify anomalies, test hypotheses, and validate assumptions using summary statistics and graphical representations. Results: Out of 14 diseases directly linked to high Cr toxicity, the study reported high levels of diarrhea, epigastric pain, and moderate-to-severe cases of vertigo among those aged more than 22 years. With over 90 active tanneries and toxic Cr released to the environment in a town of <78 km2 area (1.2 tannery/km), there are only 15 hospitals (0.2 hospitals/km) for the population currently accommodating more than a quarter-million people daily (3205 people/km). Conclusion: New mitigation strategies must be put forth to alleviate the negative impacts of the tanneries on the residents and nature most affected as well as the population as a whole.


Assuntos
Cromo , Saúde Pública , Adulto , Cromo/análise , Cromo/toxicidade , Humanos , Índia/epidemiologia , Curtume , Águas Residuárias , Adulto Jovem
2.
Mymensingh Med J ; 31(2): 421-427, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35383761

RESUMO

Tanners are exposed to raw hides as well as to various toxic chemicals. The study was intended to find out the health problems among tannery workers. This descriptive cross-sectional study was conducted in 2019 among 223 workers working with raw hides and chemicals selected by stratified random sampling in ten tanneries of Leather Industry Area, Hemayetpur, Savar, Dhaka, Bangladesh. Data were collected by the principal investigator after taking informed written consent from the tanners using a pre-tested interview schedule and a check-list. Data were cross-checked for consistency and accuracy. All relevant ethical issues including approval from Institutional Review Board (IRB), and data quality assurance issues were taken into consideration. Analysis of data was carried out by using computer software SPSS version 20.0 with anonymity. Descriptive statistics were used to describe the data, while Chi-square test was carried out to measure statistical association. As many as 97(43.5%) workers were in age group of 15 to 24 years with a mean age of 28.4±9.5 years. An overwhelming majority 204(91.5%) were males, three-fifths 134(60.1%) of the workers were married, while 213(95.5%) tanners had religion Islam. Majority 122(54.7%) tanners had primary level of education, whereas 56(25.1%) had secondary level and 44(19.7%) had no formal schooling. The mean monthly family income was 13744.4±3485.5 Taka. More than three-fourths 170(76.2%) workers had more than four family members with over half 114(51.1%) of the workers were smokers. Of 223, over half 124(55.6%) of the workers were affected with at least one health problem. Majority of the workers suffered from skin diseases (51.6%), musculoskeletal disorders (33.1%), gastrointestinal problems (22.6%), chronic headache (14.5%) and respiratory problems (14.5%). Only 9(4.0%) workers had pre-placement orientation, while 196(66.4%) workers did not notice the necessity for pre-placement training. Of ten tanneries, cent per cent had foul smell, 80.0% each had poor lighting and discomfort temperature, 60.0% had intolerable noise, 50.0% were with poor ventilation system, and only 30.0% had adequate waste management facilities. The tanneries did not have medical facilities even for emergency conditions. Health problems are significantly associated with job duration (p<0.01), working sections (p<0.05) and smoking status (p<0.001) of the workers. The overall environment of the tanneries is far from satisfactory. Skin diseases, musculoskeletal disorders, gastrointestinal problems, chronic headache and respiratory diseases are the common identified health problems. A considerable number of workers are unconcerned for the pre-placement orientation, and do not use Personal Protective Equipments (PPEs). As a rule, Personal Protective Equipments (PPEs) are not made available to workers by the tannery authorities, and lack of treatment facilities of the tanneries is a common place.


Assuntos
Doenças Profissionais , Exposição Ocupacional , Adolescente , Adulto , Bangladesh , Estudos Transversais , Humanos , Masculino , Exposição Ocupacional/análise , Curtume , Adulto Jovem
3.
Toxicol Ind Health ; 38(2): 112-126, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35220806

RESUMO

In the leather industry, Cr (III) is used as a basic tanning agent. The wastewater discharged from the tannery industry contains a high concentration of chromium. Recent studies indicate the genotoxic effects especially DNA damage and oxidative stress of Cr (III) in tannery workers. Cr (III) interacts with DNA to form DNA cross-links and DNA strand breaks. It also modifies the oxidative DNA base through the Haber-Weiss reaction. The present study is based on an overview of scientific literature and previous observations regarding the effects of tannery chromium effluents on exposed workers and the population in the vicinity. This study strongly suggests for use of a non-toxic substitute of chromium to be used for the tanning process and placement of tannery industries on the outskirts of the city. In South Asian developing countries like India, Pakistan and Bangladesh where the economy is strongly dependent on leather manufacturing industries, there is a need to spread proper information regarding the harmful effects of chromium toxicity to the workforce employed in the tannery and also to the people living in the surrounding area. Workers should be provided with the required safety protections like gloves, aprons, foot/shoe covers, masks, etc. Last but most important on an immediate basis is the installation of the proper efficient waste treatment plant, so that, waste should be treated before moving out of the industry.


Assuntos
Exposição Ocupacional , Saúde do Trabalhador , Cromo/análise , Dano ao DNA , Países em Desenvolvimento , Humanos , Exposição Ocupacional/efeitos adversos , Estresse Oxidativo , Curtume
4.
Environ Sci Pollut Res Int ; 29(23): 35382-35395, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35060060

RESUMO

Increased concern over the use of metal salts such as chromium, zirconium, and aluminum for tanning of hides and skins has made the leather production industry to be constantly on the lookout for organic tanning agents in place of the inorganic system. Though glutaraldehyde has been looked at as a viable option, it still lags in imparting superior strength properties to the leather and also it has been reported to have inherent toxicity. With that concept in view, this research work focuses on the usage of glyoxal along with synthetic tanning agents as a replacement for glutaraldehyde and other inorganic tanning systems. The offer level and starting pH for the glyoxal tanning process was optimized as 6% (w/w) and 5.0, respectively, and the shrinkage temperature of the collagen was found to be around 80 °C. Additionally, the controlled shrunken grain effect of the aldehyde tanning system was explored by changing the pH of the process, which helped to improve the thickness of low-grade thinner raw materials by up to 40%. The mechanism for the shrunken grain effect has also been proposed in this work by studying the dimensional changes occurring in the leather matrix upon treating skin/hide with glyoxal at different pH levels. The mechanical and strength properties of the leather were found to be better than the glutaraldehyde tanning system. The BOD/COD ratio of wastewater generated from the glyoxal process was found to be greater than 0.3 making them easily treatable. Considering all these factors, compact glyoxal-based tanning along with synthetic tanning agents can be a game-changing technology for the leather processing industry.


Assuntos
Glioxal , Curtume , Cromo/análise , Glutaral , Resíduos Industriais/análise , Indústrias
5.
Environ Sci Pollut Res Int ; 29(19): 28180-28193, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34988824

RESUMO

The effluent generated by Merox unit of oil refinery was used instead of freshwater for bovine hide unhairing because of its proper composition and alkalinity. The effect of temperature, treatment period, sodium sulfide (Na2S), and calcium carbonate (CaCO3) dosage was investigated on unhairing efficiency using lutrom (unhairing slurry) prepared from the Merox effluent (effluent-based lutrom). Under similar operating conditions and chemicals' dosage, the effluent-based lutrom resulted in a higher efficiency (98.6%) than water-based lutrom (67.3%) indicating faster unhairing kinetics for the former lutrom. Moreover, an acceptable swelling (48%) and suitable mechanical properties were also observed. The experimental strategy can save 50 to 67% toxic chemicals and 100% of water consumption in unhairing, which is equivalent to US$ 34 per ton of hide, leading to zero discharge from Merox unit. Recycling of effluent-based lutrom after 3 consecutive runs was associated with a significant reduction in COD (55.6 kg/t hide) and BOD5 (11.6 kg/t hide) load. The effluent-based and conventional lutroms, before and after unhairing, were treated with ozone under moderate conditions. The FTIR results indicated a high-quality and low costly pelt benefits from the integration of wastewater treatment units of both industries in an environment-friendly manner.


Assuntos
Ozônio , Purificação da Água , Animais , Bovinos , Indústria de Petróleo e Gás , Reciclagem , Curtume , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias
6.
Environ Sci Pollut Res Int ; 29(21): 31374-31383, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35001265

RESUMO

Preservation or curing of hides/skins is performed as the primary step of leather processing to conserve them from putrefaction. Normally preservation is carried out using common salt (NaCl), which is discharged in the soak liquor contributing to ~ 70%, of total dissolved solids (TDS) load of entire leather manufacturing. In an attempt to reduce the TDS and chlorides, phyto-based preservation using garlic peel (Allium sativum) and white onion peel (Allium cepa) was carried out. Different concentrations of salt in combination with garlic peel and white onion peel were applied on freshly flayed goat skins based on its green weight and compared to control (40% salt). Sensory evaluation of the preserved skin was done by assessing different parameters like hair slip, putrefaction and odour. Estimation of hydroxyproline (HP) release, moisture content and microbial load were carried out at regular intervals. Skins that remained in good condition for 14 days were further processed into leather and properties were examined which were found comparable to the conventionally cured skins. Hence, this cleaner curing technique helps in reducing the TDS and chlorides in the effluent, thus controlling the pollution caused by tanneries through sustainable leather processing.


Assuntos
Dermatopatias , Curtume , Animais , Cloretos , Cabras , Salinidade , Pele , Cloreto de Sódio , Cloreto de Sódio na Dieta , Verduras
7.
Environ Sci Pollut Res Int ; 29(21): 31278-31292, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35006568

RESUMO

The regular practice of using sodium chloride to preserve raw animal skin triggers increasing salinity and total dissolved solids (TDS) in the surface and groundwater during rehydration soaking operations. The process disrupts the lives of animals, plants, and human beings. This paper is focused on the phyto-based short-term preservation of goatskin to reduce salinity in tannery soaking operations. The indigenous Persicaria hydropiper leaf was investigated to assess the preservation of animal skin to diminish salinity and TDS of tannery soaking wastewater. Methanol-extracted leaf was characterized by GC-MS and FTIR for chemical composition analysis and affiliated functional groups. Fresh goatskins were preserved at the preliminary, laboratory, and pilot-scale scenarios to establish the best possible mixture and monitor the moisture and nitrogen content, shrinkage temperature, microorganism analysis, and pollution load at each level. The processed leathers derived from the preserved skins with an optimal mixture of 10% leaf paste with 8% salt and conventional 50% salt were tested for their physical strength. Finally, the modification in fiber structure due to the varieties of preserving chemicals was evaluated through a scanning electron microscope (SEM) and detected insignificant variation of leather fibers. The findings reported in this study can be applied to the industrial level and remove certain amounts of salinity and TDS from tannery soaking wastewater.


Assuntos
Curtume , Águas Residuárias , Animais , Salinidade , Pele/química , Cloreto de Sódio/análise , Águas Residuárias/análise
8.
J Environ Manage ; 307: 114554, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35066203

RESUMO

Chrome-free leather manufacturing has been acknowledged as a desirable option to eliminate potential environmental and human health risks of conventional chrome tanning. This work applied a sequential bridging-induced densification strategy to produce high-performance chrome-free leather with high crosslinking density derived from the biomass-derived aldehyde (BAT) crosslinking (BAT tanning of leather), followed by terminal Al(III) crosslinking (TAC). The TAC conditions for BAT tanned leather were optimized and the results suggested that the optimized conditions were as follows: the fixation pH was 4.2, the pre-penetration time was 180 min, the fixation temperature was 40 °C, and the dosage of the aluminum tanning agent (ATA) was 0.5% (based on Al2O3). Under the optimized conditions, the resultant BAT-TAC crust leather exhibited favorable overall performances compared with BAT crust leather in terms of higher hydrothermal stability, mechanical strengths, more pleasant uniform color, and comparable smooth grain surface. The obtained high-performance chrome-free leather is scalable, providing an avenue for designing and rationalizing other engineering technology towards high-performance eco-leather production.


Assuntos
Aldeídos , Curtume , Biomassa , Cromo/análise , Humanos
9.
Int J Biol Macromol ; 200: 557-565, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35066021

RESUMO

As a kind of renewable biological resource, leather collagen is the raw material of leather industry. The chrome tanning modified collagen has high humidity and heat resistance, but there are some defects such as environmental pollution, harm to human health and shortage of chromium resources, so it is urgent to research chromium-free tanning to achieve clean modified colloidal. In the chromium-free tanning system, the modification of skin fibrin by bio-based material has the significance of environmental protection. Sodium alginate can be used as crosslinking agent to stabilize collagen. In this study, the polyhedral oligomeric silsesquioxane (POSS) grafted oxidized sodium alginate polymer composite (POSS-OSA-MAA) containing aldehyde group was prepared by two steps. Firstly, POSS grafted sodium alginate polymer composite (POSS-SAG-MAA) was prepared by graft polymerization with POSS, sodium alginate (SAG) and methacrylic acid (MAA) as raw materials. Then POSS-OSA-MAA was obtained by oxidation of POSS-SAG-MAA with sodium periodate. The aldehyde group highest concentration in POSS-OSA-MAA was 3.26 mmol•g-1, and the tanned leather shrinkage temperature was 73.1 °C. The X-ray photoelectron spectroscopy showed that POSS-OSA-MAA could form Schiff base structure with amino-containing substances and form multiple points crosslinking, and POSS-OSA-MAA could improve the shrinkage temperature and thermal stability of skin collagen.


Assuntos
Curtume
10.
Environ Sci Pollut Res Int ; 29(20): 30337-30347, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34997490

RESUMO

Owing to containing high fraction of organic matter, the tannery sludge seemed to be fit for composting. Actually, it was intensively harmful to the environment, due to containing chromium (Cr). So it might undergo a long time of storage until finding a proper way to dispose it. In the storage period, it would expose the surrounding environment a risk via releasing Cr. In this study, an approach was proposed to minimize the amount of released Cr, and reveal the mechanism on immobilizing Cr. Collagen protein waste (CPW) was adopted to immobilize Cr, and it was evaluated via leaching experiment. The lowest leaching concentration of Cr was 12 mg/L, meeting the limits of related standard in China (GB 5085.3-2007, Tcr < 15 mg/L). Moreover, the compositions and functional groups of the optimum sample (12 mg/L) were also characterized, confirming that the dominant functional groups cross-linking with Cr were hydroxyl (-OH), carboxyl (-COOH), and epoxy (-COC). Importantly, density functional theory (DFT) calculation was also employed, suggesting that Cr was restrained by accepting electrons from O atoms donating by functional groups.


Assuntos
Cromo , Esgotos , Cromo/análise , Colágeno , Resíduos Industriais/análise , Curtume
11.
Environ Sci Pollut Res Int ; 29(3): 3763-3772, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34392486

RESUMO

Sodium chloride (NaCl) is commonly used as a curing/preservative agent for raw hides and skins in tanneries and is removed through a soaking process with total dissolved solids (TDS) and other organic pollutants in effluent, causing significant pollution load to the environment. Hence, the present study evaluated to apply dried neem leaf powder (DNL) as an additive to reduce the usage of salt in skin processing and preservation. To make certain of DNL antimicrobial properties, solvent extracts were performed against proteolytic bacteria isolated from raw skins. Initial characterization of DNL revealed the presence of bioactive compounds nimbolide and dehydro salannol and acetone extract with 16.9-mm, 10-mm and 8-mm zone of inhibition against Salmonella sp., E. coli sp. and Bacillus sp. identified using phenotypic conventional biochemical screening method. Further, skin curing experiments were carried out using four different treatments of DNL (10% 15%, 20% and 25% w/w) along with 15% w/w of conventional salt to obtain an optimum concentration for pilot-scale studies. Thus, the application of optimal DNL (15%) and salt (15%) resulted in no physical changes such as smell and hair slip and was taken for further studies for hydroxyproline activity, pollution load and organoleptic properties along compared with control 40% salt. DNL-aided salt less preservation of freshly flayed goat skins at ambient condition showed no hair slip or putrefaction during the preservation period with significant reduction of TDS (86%) and chloride (71%) in soak liquors compared to conventional salt preservation and enhanced organic load requiring additional treatment. However, the application of the organoleptic, physical and hydrothermal properties of resulting leathers produced from the DNL applied skins was on par with results of leather obtained from conventional salt. Thus, our results demonstrate DNL-aided salt less preservation method is able to reduce the amount of salt for preservation of goat skins significantly, leading to reduced salinity issues during leather processing.


Assuntos
Cloreto de Sódio , Curtume , Animais , Escherichia coli , Folhas de Planta , Pós , Pele
12.
Environ Sci Pollut Res Int ; 29(5): 7732-7742, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34480312

RESUMO

Leather manufacturing is the process of transforming animal skin into high value-added commodity. As a crucial step in the leather producing process, conventional chrome tanning could lead to discharge of chromium contaminant due to the low efficiency of chromium uptake. In this paper, a series of polyethylene glycol triazine derivatives' tanning agent (PT) with different molecule weight was synthesized with one-step method and applied in the main tanning of hide. The chemical structure of the PT was detected by FT-IR and 1H-NMR. The application experimental results indicated that after 16% of PT tanning at pH of 6, the wet-white was endowed with shrinkage temperature over 80°C and thickening rate over 108%. The experimental results indicated that the PT tanning leather not only have a better physical and mechanical properties than commercial triazine derivatives tanning agent, but also the leather is endowed with the effects of outstanding thermal properties. Considering that the pickling process became unnecessary, a large number of neutral salts could be avoided, the chromium load in spent liquor decreased from 1288 mg/L to 0, and the total dissolved chlorine in spent liquor decreased from 15,360 to 9581 mg/L; no toxic and harmful substances such as chromium and aldehyde are introduced into the tanning process. Compared with the leather tanned with commercial triazine derivatives' tanning agent, the leather tanned with PT showed a similar overall tanning properties and better environmental friendliness, which makes PT matches the integral requirements of the modern sustainable leather industry.


Assuntos
Curtume , Triazinas , Animais , Cromo/análise , Resíduos Industriais/análise , Polietilenoglicóis , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Environ Technol ; 43(9): 1285-1293, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32941110

RESUMO

The removal of anionic and cationic dyes from aqueous solutions was investigated by different leather shavings, which are solid wastes generated in the leather industry. Wet-blue leather shavings (WB), vegetable-tanned leather shavings (VT), pickled hide (not tanned) shavings (PIC) and wet-white leather (pre-tanned) shavings (WW) were used. The cationic dye was Basic Red 2 and the anionic dye was Acid Brown 414. Point of zero charge, functional groups, shrinkage temperature and adsorbent surface area were characterized. The point of zero charge was 4.0, 6.0, 3.9 and 4.1 for WB, VT, PIC and WW, respectively. The specific surface area showed low values which was expected for this type of material. Tanning agent influence was verified through shrinkage temperature analysis of leather shavings. Main functional groups of the acid dye and the collagen structure of the solid wastes were determined. The tests with Basic Red 2 solutions showed only VT had a considerable removal for this cationic dye (96.7%). The tests with Acid Brown 414 were carried out with different contact times and adsorbent mass. Results showed high efficiency of WW and PIC, whose percentages of dye removal were above 96% at contact time of 30 min and above 90% using 20 mg of adsorbent. In this way, the final dye removal was 98.1% and 98.3% for contact time tests and 97.7% and 98% for adsorbent mass tests for WW and PIC, respectively. These results highlight the promising use of leather shavings as alternative adsorbents for the treatment of wastewater containing dyes.


Assuntos
Resíduos Sólidos , Curtume , Corantes , Resíduos Industriais/análise , Águas Residuárias
14.
Carbohydr Res ; 511: 108501, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35045386

RESUMO

Highly-oxidized starch (HOS) is an excellent ligand for zirconium tanning in leather making. However, oxidation reaction can only be undertaken in diluted solution due to the high viscosity of starch, which leads to high oxidant consumption and low solid content of HOS, and therefore greatly limits its industrial application. Starch was predegraded by using HCl followed by H2O2 oxidation for preparing a practical oxidized starch (OST) ligand with high solid content. HCl (5%) remarkably reduced the viscosity of starch and simplified the subsequent oxidation, resulting in a decrease in H2O2 dosage from 60% to 40% and an increase in solid content from 10% to 38%. HCl broke the α-(1-4) glycosidic bond between glucose units, and H2O2 oxidation led to the generation of abundant carboxyl groups in OST. The OST with moderate molecular weight (Mw 5609 g/mol) and carboxyl content (6.48 mmol/g) made the tanning performance of OST-Zr comparable to those of HOS-Zr and chrome tanning agents. Therefore, this work gives new insights into the crop-polysaccharides based ligands application and exhibits huge potential for promoting industrial applications of zirconium tanning.


Assuntos
Amido , Curtume , Peróxido de Hidrogênio/química , Ligantes , Oxirredução , Amido/química , Zircônio
15.
J Environ Manage ; 302(Pt A): 114029, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34872177

RESUMO

Accumulation of hair waste is a major burden to the leather industry, causing a negative impact on the industry's sustainable development. The industry is already bogged down by the usage of synthetic re-tanning agents that are not only extremely challenging for biodegradation but also release free-form of formaldehyde in the final leather stage. This research work focuses on developing a formaldehyde-free bio-based re-tanning agent from hair waste. In order to do so, hair waste is subjected to alkali hydrolysis and subsequently graft-copolymerized with methacrylic acid (MAA). These treatments were optimal using 20 % (w/w) sodium hydroxide and thermal activity at 90 °C. This resulted in effective hydrolysis of red sheep hair, which was the ideal candidate in this study. The hydrolysate was subjected to monomer in situ polymerization (using MAA) with potassium per sulfate/sodium meta-bisulphite redox system, leading to the development of keratin hydrolysate-g-methacrylic acid (KH-g-MA) copolymer (this was noted both at a laboratory level and pilot scale). The obtained KH-g-MA copolymer exhibited ideal characteristics such as increased protein content (78.3 ± 1.2), appropriate particle size (1516 nm), suitable pH (5) and required viscosity of 512 cP. The developed KH-g-MA copolymer was then applied as a re-tanning agent in the leather manufacturing process. Significant improvement in leather's mechanical strength characteristics was observed. In addition, the organoleptic properties of leather such as fullness, softness and grain tightness showed much improvement. Scanning electron microscopy (SEM) showed an enhanced surface smoothness and filling of the voids in experimental leather in comparison to the control leather. This recycle and reuse strategy of hair waste not only helps resolve issues with handling of hair solid waste but also results in producing an eco-friendly re-tanning agent in leather manufacturing, thereby paving the way for cyclic economic utilization and cleaner environment.


Assuntos
Cabelo , Curtume , Animais , Biodegradação Ambiental , Hidrólise , Ovinos , Resíduos Sólidos
16.
Environ Sci Pollut Res Int ; 28(40): 55905-55914, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34494189

RESUMO

The leather industry converts the hide, a byproduct of slaughterhouses, into leather, a value-added product. This old industry generates wastes, causing environmental pollution. However, nanomaterials can help to decrease this problem. These tiny particles (1-100 nm) can replace chemicals in various steps of leather processing. This paper aims at giving an overview of the fundamentals of classical leather process and how nanomaterials can be applied in each step to obtain a more sustainable manufacturing. After a comprehensive literature review of journal articles, six steps were identified for potential for application of nanomaterials: unhairing, tanning, retanning, dyeing, fatliquoring, and finishing. With nano-oxides, polymers, and metals, it is feasible to reduce the amount of chemical products and also improve the properties of leather. Thus, it is possible to reach a more eco-friendly and effective process with the use of nanomaterials to turn hide/skins into finished leather.


Assuntos
Nanoestruturas , Curtume , Resíduos Industriais , Óxidos , Pele
17.
Chemosphere ; 285: 131503, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34265720

RESUMO

The prosperity and development of tannery industry have brought about rapid economic growth. However, the tannery landfill without anti-seepage measures in the early stage has generated masses of environmental hazards owing to the lack of awareness in environmental protection. Therefore, it is imperative to pay much attention to the understanding of environmental hazards from tannery waste. In this study, solid samples and groundwater samples were collected from a tannery landfill to study the effect of the characteristic pollutants produced by tanning on chromium distribution with other coexisting substances. The results showed that significant correlations were demonstrated between multiple coexisting substances (total organic carbon, total petroleum hydrocarbons, total nitrogen, Cr, F, Ca, Cu and Pb), indicating the possible same source or they coming from the same tannery production stage. The weights of positive effects and negative effects of coexisting substances on total Cr distribution in the profile decreased in the order: total nitrogen > Cu > Ca > Pb > total organic carbon > F > SO42-> Cd, and Ni > Cl > Hg, respectively. Moreover, the simulation of Visual MINTEQ showed that the cations were mainly bound to Cr as CrO42-, while the anions were bound to Cr3+. This study provided a new perspective on the selection of remediation strategies for Cr-contaminated sites to avoid secondary environmental pollution caused by the release of coexisting heavy metals.


Assuntos
Poluentes do Solo , Poluentes Químicos da Água , Cromo/análise , Resíduos Industriais/análise , Solo , Poluentes do Solo/análise , Curtume , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise
18.
Environ Sci Pollut Res Int ; 28(45): 64295-64306, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34304356

RESUMO

The process of composting has been proposed as a biological alternative to improve the quality of tannery sludge (TS) by the action of microbial communities. However, there is limited knowledge about the dynamic of these microbial communities during the composting process. This study assessed the responses of bacterial and archaeal communities during TS composting using the 16S rRNA sequencing. The composting process occurred within 90 days, and samples of compost were collected on day 7 (d7; mesophilic stage), 30 (d30; thermophilic stage), 60 (d60; cooling stage), and 90 (d90; maturation stage). The results showed a succession of microbial phyla during the composting with enrichment of Synergistetes, WS1, and Euryarchaeota at the mesophilic stage, while at the thermophilic stage, there was an enrichment of Hydrogenedentes, WPS-2, Chloroflexi, and Deinococcus-Thermus. At the cooling stage, there was an enrichment of Kiritimatiellaeota, and at the maturation stage, there was an enrichment of Entotheonellaeota, Dadabacteria, Nitrospirae, Dependiatiae, and Fibrobacteres. When analyzing the drivers influencing microbial communities, Cr and pH presented more negative correlations with general phyla. In contrast, S, C, K, temperature, and N presented more positive correlations, while Ni, Cd, and P showed fewer correlations. According to niche occupancy, we observed a decreased proportion of generalists with a consequently increased proportion of specialists following the composting process. This study showed that different stages of the composting present a specific microbial community structure and dynamics, which are related to some specific composting characteristics.


Assuntos
Archaea , Bactérias , Compostagem , Resíduos Industriais , Archaea/genética , Bactérias/genética , RNA Ribossômico 16S/genética , Esgotos , Solo , Curtume
19.
Molecules ; 26(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34072101

RESUMO

The tannery industry is one of the economic sectors that contributes to the development of different countries. Globally, Europe and Asia are the main producers of this industry, although Latin America and Africa have been growing considerably in recent years. With this growth, the negative environmental impacts towards different ecosystem resources as a result of the discharges of recalcitrated pollutants, have led to different investigations to generate alternative solutions. Worldwide, different technologies have been studied to address this problem, biological and physicochemical processes have been widely studied, presenting drawbacks with some recalcitrant compounds. This review provides a context on the different existing technologies for the treatment of tannery wastewater, analyzing the physicochemical composition of this liquid waste, the impact it generates on human health and ecosystems and the advances in the different existing technologies, focusing on advanced oxidation processes and the use of microalgae. The coupling of advanced oxidation processes with biological processes, mainly microalgae, is seen as a viable biotechnological strategy, not only for the removal of pollutants, but also to obtain value-added products with potential use in the biorefining of the biomass.


Assuntos
Resíduos Industriais/análise , Microalgas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Biocombustíveis , Análise da Demanda Biológica de Oxigênio , Biomassa , Biotecnologia , Cianobactérias , Ecossistema , Eletroquímica , Geografia , Metais Pesados , Oxirredução , Oxigênio/química , Curtume , Purificação da Água/métodos
20.
Contact Dermatitis ; 85(5): 514-522, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34185877

RESUMO

BACKGROUND: In March 2014, the European Commission issued a new regulation restricting the content of hexavalent chromium (Cr) in leather to no more than 3 mg/kg. We previously performed a questionnaire study in January 2014 to characterize our patients with Cr contact allergy prior to regulatory intervention. OBJECTIVES: To assess whether clinical characteristics, self-reported sources of Cr exposure, and burden of disease changed in patients with Cr allergy over time. METHODS: A questionnaire study was performed among 172 adult dermatitis patients with Cr allergy and 587 age- and sex-matched dermatitis patients without Cr allergy. A questionnaire was sent to all dermatitis patients patch tested from 2003 to 2018 in August 2019. RESULTS: The overall response rate was 61.2% (759/1241). Patients with Cr allergy were still more commonly affected by current foot dermatitis (odds ratio [OR] 3.82, 95% confidence interval [CI] 2.07-7.08) and hand dermatitis (OR 1.98, 95% CI 1.13-3.49) compared with controls diagnosed during 2013 to 2018. The proportion of patients with Cr allergy reporting dermatitis caused by leather exposure did not change during 2003 to 2012 vs 2013 to 2018 (71.0% vs 66.2%, P = .5). Furthermore, estimates on occupational performance and disease severity (eg, current dermatitis), number of anatomical locations with dermatitis, worst-case dermatitis, and effect on work were similar in patients with Cr allergy for 2003 to 2012 vs 2013 to 2018. CONCLUSION: No immediate sign of improvement was found in patients with Cr allergy concerning severity of disease and dermatitis from leather exposures 5 years after adoption of the regulation against hexavalent Cr in leather. The regulation may have to be revised for better protection of those already sensitized.


Assuntos
Carcinógenos Ambientais/efeitos adversos , Cromo/efeitos adversos , Corantes/efeitos adversos , Dermatite Alérgica de Contato/prevenção & controle , Dermatite Ocupacional/prevenção & controle , Saúde do Trabalhador/legislação & jurisprudência , Adulto , Dermatite Alérgica de Contato/etiologia , Dermatite Ocupacional/etiologia , Governo Federal , Feminino , Humanos , Masculino , Saúde Pública/legislação & jurisprudência , Medição de Risco , Curtume
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