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1.
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
2.
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
3.
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
4.
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
5.
Chemosphere ; 280: 130959, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34162114

RESUMO

Water pollution caused by tannery wastewater is an important issue in developing countries. Most studies have focused on inorganic chemicals represented by chromium as a tannery-related main pollutant. This is the first study in which pollution of water by tannery-related organic chemicals was assessed by a combination of qualitative and quantitative analyses. Our quantitative analysis showed that the maximum concentration of total phenolic compounds (phenols), consisting of phenol, bisphenol F, p-cresol and chlorocresol, in canal water in a tannery built-up area in Bangladesh was >67-fold higher than the Environmental, Health and Safety (EHS) guideline value. Mapping of our results indicated tanneries as the sources of phenols pollution. Our original depurative, a hydrotalcite-like compound consisting of magnesium and iron (MF-HT), could adsorb all kinds of phenols and exhibited the highest phenol adsorption ability (115.8 mg/g) among reported hydrotalcite-like compounds. The levels of phenols in canal water samples were reduced to levels below the guideline value by using MF-HT with assistance of a photocatalytic reaction. Moreover, the mean level of chromium (112.2 mg/L) in canal water samples was decreased by 99.7% by using the depurative. Thus, the depurative has the potential for solving the problem of tannery-related water pollution by phenols and chromium.


Assuntos
Poluentes Químicos da Água , Poluentes da Água , Bangladesh , Cromo/análise , Fenóis , Curtume , Águas Residuárias , Poluentes Químicos da Água/análise
6.
J Environ Manage ; 294: 113003, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34111598

RESUMO

Leather post-tanning is responsible for producing effluents that are difficult to treat due to several recalcitrant pollutants. Dyes, tannins, and fatliquoring agents are mainly related to this characteristic. This study, as the state-of-the-art, attempts to systematically review treatment technologies applied in recent years to the post-tanning effluents. The Scopus database was used to identify articles related to post-tanning pollutants removal. Through the review, Advanced Oxidation Processes (AOPs) and adsorption proved to be good alternatives to increase the effluent biodegradability when applied before biological treatment. AOPs and adsorption were also efficient for the final polishing of the effluents, to reach the regulation standards for disposal, as well as enzymatic treatment. Furthermore, Membrane Separation Processes demonstrated good applicability when the reuse of the treated effluent is aimed.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Corantes , Oxirredução , Curtume , Eliminação de Resíduos Líquidos , Águas Residuárias/análise
7.
Bull Environ Contam Toxicol ; 106(6): 1024-1032, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33991212

RESUMO

Tannery wastewater is a significant cause of chromium (Cr) contamination in land and water. This study assessed Cr contamination caused by the discharge of tannery wastewater in the Dhaleshwari River and identified possible native plants for phytoremediation of Cr. Water, soil and sediments samples were collected from upstream and downstream of the wastewater discharge channel of Savar tannery industrial estate situated on the bank of the river. Samples of root, stem, leaf and fruit of four selected plants (i.e., Eichhornia crassipes, Xanthium strumarium L., Cynodon dactylon, Croton bonplandianum Baill.) were also collected from those sampling points. The total Cr in acid digested samples were determined by flame atomic absorption spectrometry. High concentrations of Cr were detected in the water, soil and sediment samples collected near the wastewater discharge channel. Of all the plant species, Xanthium strumarium L. exhibited high translocation factors (TF) and bioconcentration factors (BCF) for Cr. Based on the findings of this study Xanthium strumarium L. is preferable as a native species for phytoremediation of Cr.


Assuntos
Poluentes do Solo , Poluentes Químicos da Água , Bangladesh , Biodegradação Ambiental , Cromo/análise , Resíduos Industriais/análise , Rios , Poluentes do Solo/análise , Curtume , Poluentes Químicos da Água/análise
8.
J Environ Manage ; 288: 112441, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33823454

RESUMO

The pollution in soils and groundwater caused by the tannery have attracted public attention. However, few studies have been done on the migration and species distribution of Cr and coexisting ions produced by tanning in the vadose zone. In this paper, an in-production tannery and a suspended tannery were selected to compare the migration of Cr and other inorganic ions from tanneries in the vadose zone. Results showed that the sewage treatment station and the temporary waste storage site had the highest concentration of pollutants. Cr exhibited a cumulative effect in the middle soil layer (100-300 cm) in the suspended tannery. However, in the in-production tannery, the cumulative effect occurred only at the temporary waste storage site. The distribution of pollutants in the soils at different depths was fixed in the suspended tannery field. But in the in-production tannery field, it was closely related to daily production. Visual MINTEQ showed that the saturation index of a species of Cr was positive or negative simultaneously in the two sites, indicating that (1) the change of saturation index of Cr had no relationship with operation of tannery. (2) the influence of Cr precipitation or dissolution was related to the source strength, the coexisting ions, and pH. This study contributed to understanding the migration of characteristic pollutants caused by tanneries in the vadose zone under different external environments, and provided a reference for the quantification calculation of the source load of pollutants caused by industrial infiltration into the groundwater.


Assuntos
Poluentes do Solo , Poluentes Químicos da Água , Cromo/análise , Resíduos Industriais/análise , Íons , Poluentes do Solo/análise , Curtume , Poluentes Químicos da Água/análise
9.
Environ Sci Pollut Res Int ; 28(29): 39014-39025, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33743156

RESUMO

In this study, a cleaner approach to a 'sandwich' chrome-less tanning for cattle hide upper suede leather based on polycarboxylate/montmorillonite nanocomposite (PCM) has been developed. The chromium was reduced both in tanning process and retanning process. Hydrothermal stability, mechanical strength, and organoleptic properties of the leather were closed to traditional chrome tanning. The important advantage of the cleaner tanning approach is that the chromium load in wastewater decreased from 2302 mg/L in tanning process and 2919 mg/L in retanning process to 131 and 257 mg/L, respectively. Moreover, SEM analyses demonstrated that the leather tanned by PCM achieved loose fiber structure and flaky montmorillonite deposition both in intra-triple and inter-triple helix. XRD results suggested that basic chromium sulfate and PCM may form more complexation with the helix chain of collagen fiber, resulting in structural distortion of collagen molecules without destroying the triple helical structure. EDS liner scanning indicated the distribution of chromium on the cross section of the leather. Trypsin degradation curves revealed the cleaner approach might increase the degradation of leather, and the economic analysis results showed that the tanning costs could be reduced and increased the economic benefits.


Assuntos
Nanocompostos , Curtume , Animais , Bentonita , Bovinos , Cromo/análise , Colágeno , Resíduos Industriais/análise
10.
Bull Environ Contam Toxicol ; 106(3): 493-500, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33527147

RESUMO

Many leather processing industries in Sialkot, Pakistan, discharge their wastes freely into the environment which then enters nearby water bodies. Irrigation practices with these polluted waters pose a great threat to the soil quality. Hence, the soils and effluent waters of five famous leather processing sites were evaluated for the presence of As, Cr, Cd, Ni, Zn, Mn, Mg, Na, K, and Ca. High mean concentrations of As (112.6 mg kg-1), Cr (45.9 mg kg-1), Cd (2.0 mg kg-1), Ni (58.2 mg kg-1), Zn (117.6 mg kg-1), Mn (12.8 mg kg-1), Mg (34,511 mg kg-1), Na (16,292 mg kg-1), K (1765 mg kg-1), and Ca (4387 mg kg-1) were found in soils at our study sites. Effluents were found to be highly acidic with high TDS content and high EC values. Index of Geoaccumulation (Igeo) confirmed the extremely toxic nature of these soils. Plants growing at these sites also showed high concentrations of As, Cr, and Cd in their leaves.


Assuntos
Metais Pesados , Poluentes do Solo , Monitoramento Ambiental , Metais/análise , Metais Pesados/análise , Paquistão , Solo , Poluentes do Solo/análise , Curtume
11.
J Hazard Mater ; 413: 125425, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33626472

RESUMO

Chrome-free metal tanning agent has been considered as eco-friendly in the leather industry. However, extensive crosslinking reactions of metal species on the leather surface restrain their uniform penetration into the hierarchical nanoscale leather matrix. Thus, masking agents with appropriate coordination ability are needed. Herein, the selective degradation of hemicellulose in corncob was achieved with 92.5% of conversion in an AlCl3-H2O system, obtaining oligosaccharides masking agent with high purity and leaving cellulose and lignin in the solid residue for other valuable use. Subsequently, H2O2 oxidation was performed to introduce -CHO/-COOH into oligosaccharides and reduce their molecular weights, thereby enhancing coordination ability and reducing ligand dimension. The post-oxidized reaction fluids together with additional Zr species were subjected to leather tanning, in which the oligosaccharides could coordinate with Al/Zr species and promote the penetration of metal species into the leather matrix. By controlling the hemicellulose degradation and oligosaccharide oxidation, an appropriate concentration of oligosaccharides with proper -CHO/-COOH contents allowed the efficient masking effect of the oligosaccharides. As a result, a uniform distribution of Al/Zr species was observed on the cross section, and 83.5 °C of shrinkage temperature was obtained for the chrome-free tanned leather.


Assuntos
Curtume , Zea mays , Biomassa , Peróxido de Hidrogênio , Oligossacarídeos , Polissacarídeos
12.
Chemosphere ; 271: 129552, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33453488

RESUMO

The tannery industry is an integral part of economic development in many developing countries, and the environmental pollution caused by the tannery industry cannot be ignored. In this study, soil and groundwater samples at different depths were collected from an abandoned tannery to investigate the temporal and spatial distribution of characteristic pollutants produced by tanning. The concentrations of Cr, Cl, F and NH4+-N in the soil from the sludge temporary storage area were higher than those from the liming and unhairing workshop, chrome tanning workshop, wastewater outlet, and around wastewater pond. The concentration of Cr(VI) in all sampling sites was below the detection limit. The main species of Cr in the groundwater were Cr(NH3)6Cl2+ and CrO42- based on the simulation of Visual MINTEQ. The saturation index was negative and changed with time indicating that Cr existed in the dissolved phase. The proportion of Cr(VI) to total Cr was negatively correlated with the saturation index in village 1 and village 3. The simulation results from Visual MODFLOW and MT3DMS showed that the migration of Cr, NH4+-N, Cl- and F- mainly occurred in the Quaternary system. The coverage of the pollution plume of pollutants in villages 1 and 3 was as follows: Cr > NH4+-N > Cl- > F-. Two decay rate calculation methods of pollutants with migration time and distance were put forward to provide a basis for the actual investigation of the pollution migration scope and time determination.


Assuntos
Poluentes Ambientais , Água Subterrânea , Poluentes do Solo , Poluentes Químicos da Água , Cromo/análise , Resíduos Industriais/análise , Solo , Poluentes do Solo/análise , Curtume , Poluentes Químicos da Água/análise
13.
Environ Geochem Health ; 43(2): 995-1008, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32696200

RESUMO

The main objective of the present study is evaluation of groundwater aptness for crops and chromium concentration in vegetables from an industrial (leather tanning) sector of South India using geospatial techniques. Seventy groundwater samples were collected from the open and tube wells during November 2017, February 2018, May 2018 and September 2018 to represent northeast (NE) monsoon (October-December), post-monsoon (winter) (January-February), pre-monsoon (summer) (March-May) and southwest (SW) monsoon (June-September) seasons, respectively. In addition, vegetables were also collected during the above-mentioned seasons from the market to assess the level of chromium content in them. All the groundwater samples were tested in the chemical laboratory using the American Public Health Association norms for various physicochemical parameters, viz. TDS, pH, sodium, potassium, calcium, magnesium, bicarbonate, chloride, sulfate, nitrate, fluoride and chromium. Northeast and southwest monsoon season samples mostly represented 'high to very high saline' and 'low alkaline' categories of irrigation water. However, post- and pre-monsoon samples represented 'high to very high saline' and 'low to medium alkaline' categories. 'High saline and low alkaline' water could be used for irrigation in all types of soil with less problem of exchangeable sodium. However, 'very high saline' water should not be applied for the crops having poor salt tolerance and soils having poor internal drainage. The concentration of chromium in groundwater and vegetables was within the permissible limits for human intake prescribed by the World Health Organization standards.


Assuntos
Cromo/análise , Água Subterrânea/química , Curtume , Verduras/química , Poluentes Químicos da Água/análise , Irrigação Agrícola , Humanos , Índia , Estações do Ano , Solo/química
14.
Environ Sci Pollut Res Int ; 28(10): 12889-12897, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33094461

RESUMO

Preservation of raw hide/skin is the prime technique to stop bacterial deterioration. Universally, salt curing is the most prevalent technique for hide/skin preservation. In this study, extracted oil from Aphanamixis polystachya seed was evaluated for the preservation of goatskin to reduce the chloride in tannery wastewater. The oil-induced goatskin preservation method was assessed observing diverse factors, e.g., hair slip, odor, moisture content, bacterial colony counting, total Kjeldahl nitrogen, and hydrothermal stability in evaluation to the conventional salt curing method. Results indicate that 15% oil-induced preservation technique could preserve the goatskin for 30 days. A small-scale experiment was performed for the preservation of goatskins. The preserved goatskins both monitoring and study samples were processed for shoe upper leather. The leather quality was evaluated by examining physical properties and fiber structure by a scanning electron microscope (SEM). Pollution load generated during leather making was determined in terms of total dissolved solids (TDS), chloride (Cl-), chemical oxygen demand (COD), and biochemical oxygen demand (BOD). The proposed oil-induced preservation method reduced Cl-, TDS, and BOD by 98.3%, 82.3%, and 86.8%, respectively, in the soaking liquor. The leather readied from the empirical goatskin shows the equipotential properties of leather from conventional goatskin. The oil-induced preservation method is substantiated to be favorable nonconventional preservation instead of conventional wet-salting for the contraction of pollution from soaking operation.


Assuntos
Curtume , Águas Residuárias , Análise da Demanda Biológica de Oxigênio , Cloretos , Óleos Vegetais
15.
Chemosphere ; 263: 127987, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32835980

RESUMO

The high value-added use of tannery solid waste and elimination of tannery liquid waste in the leather-making industry have attracted widespread attention. In this study, a MgO-doped biochar (MgO/BC) adsorbent was successfully prepared by utilizing tannery solid waste (i.e., non-tanned hide wastes) as the biomass material for dye removal from tannery wastewater. Characterization results indicated that MgO was uniformly embedded into the porous BC structure. The adsorption capacity of acid orange II by MgO/BC reached up to 448.4 mg g-1, which drastically exceeded the pure BC and other reported adsorbents. The adsorption behavior of acid orange II by MgO/BC matched nicely with Langmuir isotherm and pseudo-second-order kinetic model. This satisfactory adsorption capacity of MgO/BC for acid orange II was mainly due to the large specific surface area and the enhanced electrostatic interaction. According to the BET, zeta potential and XPS analysis, the possible mechanism towards acid orange II removal was attributed to the pore filling, surface complexation, electrostatic attraction and π-π interaction. In addition, MgO/BC showed the efficient removal towards anionic dyes from actual tannery wastewater. This work could provide guidance for the value-added utilization of tannery solid waste and a practical way to remove dyes from tannery wastewater.


Assuntos
Corantes/análise , Curtume , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Adsorção , Compostos Azo , Carvão Vegetal , Cinética , Naftalenos , Resíduos Sólidos , Águas Residuárias/química
16.
Cancer ; 127(4): 560-568, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33170961

RESUMO

BACKGROUND: Patients with primary cutaneous melanoma are at increased risk for subsequent new primary melanomas. Indoor tanning is a recognized risk factor for melanoma. This study was aimed at determining the association between indoor tanning and the occurrence of multiple primary melanoma. METHODS: This was a retrospective case-control study of cases with multiple primary melanoma and sex-matched controls with single primary melanoma retrieved at a 1:2 ratio from the Biological Sample and Nevus Bank of the Melanoma Center of the University of Pittsburgh Cancer Institute. Logistic regression models were used to examine the association between multiple primary melanoma and risk factors. RESULTS: In total, 330 patients (39.1% men) with a median age of 51 years were enrolled. Compared with patients who had a single primary melanoma, patients with multiple melanomas were younger at the diagnosis of their first primary melanoma and were more likely to be discovered at stage 0 or I and to have had indoor tanning exposure, a family history of melanoma, atypical moles, dysplastic nevi, and a Breslow thickness less than 1 mm. Compared with patients' first melanomas, subsequent melanomas were more likely to be thinner or in situ. The estimated probability of the locus for the second primary being the same as that for the first primary melanoma was 34%. In a multivariate analysis after adjustments for age, a family history of melanoma, the presence of atypical and dysplastic nevi, and recreational sun exposure, indoor tanning remained significantly associated with the occurrence of multiple primary melanoma (odds ratio, 2.75; 95% confidence interval, 1.07-7.08; P = .0356). CONCLUSIONS: Indoor tanning is associated with an increased risk of second primary melanoma. Subsequent melanomas are more likely to be thin or in situ and to occur in different anatomic locations.


Assuntos
Melanoma/epidemiologia , Neoplasias Primárias Múltiplas/epidemiologia , Neoplasias Induzidas por Radiação/epidemiologia , Nevo Pigmentado/epidemiologia , Neoplasias Cutâneas/epidemiologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Modelos Logísticos , Masculino , Melanoma/etiologia , Melanoma/patologia , Pessoa de Meia-Idade , Neoplasias Primárias Múltiplas/etiologia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Induzidas por Radiação/patologia , Nevo Pigmentado/etiologia , Nevo Pigmentado/patologia , Fatores de Risco , Pele/patologia , Pele/efeitos da radiação , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/patologia , Banho de Sol , Curtume
17.
Water Environ Res ; 93(5): 658-669, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32474980

RESUMO

Tanneries are an important industrial sector in Ethiopia; consequently, gaps in wastewater treatment process performance need to be identified as the country increases its emphasis on compliance. A case study was conducted to evaluate physicochemical and microbial water quality at a tannery near Addis Ababa. The treatment process was designed for the following: sulfide oxidation; biological oxygen demand reduction; and chromium removal. While some of Ethiopia's standards for industrial wastewater treatment were met through treatment, effluent COD, sulfide, total nitrogen, and total chromium guidelines were not. 16S rRNA gene analysis was used to evaluate the microbial community composition across the treatment train. The results show that common ruminant phyla were dominant throughout, with Firmicutes and Bacteroidetes comprising 77% to 82% relative abundance. The Firmicutes Clostridium increased consistently in relative abundance with treatment, comprising 39% to 61% of the total bacterial community in the effluent. Improved treatment is needed to meet environmental and public health goals. PRACTITIONER POINTS: Case Study of tannery wastewater treatment in Ethiopia shows ineffective treatment of chemical pollutants. Microbiological pollutants from tannery wastewater systems can introduce agents of importance to public health The microbiological composition of tannery influent, mixed liquor and effluent contains mostly four bacterial phyla lead by Firmicutes. Most pathogenic bacterial genera found in the tannery wastewater treatment system became a decreasing percentage of the total population. Clostridium comprises up to 61% of the effluent bacterial population and deserves further evaluation to better understand the consequences of its dominance.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Análise da Demanda Biológica de Oxigênio , Etiópia , Resíduos Industriais , RNA Ribossômico 16S/genética , Curtume , Águas Residuárias/análise , Poluentes Químicos da Água/análise
18.
Workplace Health Saf ; 69(1): 22-31, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32689923

RESUMO

Background: Few studies have reported associations between occupational exposure to tannery chemicals with breathing difficulty and skin diseases and none have been conducted in Bangladesh. The aim of this study was to investigate the associations of health complaints with types of work and length of employment among tannery workers in Bangladesh, where occupational health and safety regulations are less restricted compared with the developed world. Methods: One hundred sixty-seven (n = 167) workers from 10 tanneries were interviewed using a questionnaire adapted from the European Community Respiratory Health Survey (ECRHS) and the Tasmanian Longitudinal Health Study (TAHS) to collect information on occupational exposures and health outcomes. Workers' length of employment was examined, as well as their areas of work including beamhouse, wet finishing, dry finishing, and miscellaneous. Univariate and multivariate logistic regressions were performed to investigate potential associations while controlling for confounders. Results: Length of employment was positively associated with breathing difficulty (odds ratio [OR]: 1.32, 95% confidence interval [CI]:1.07-1.64). Workers involved in the wet finishing (OR: 11.75, 95% CI: 2.12-65.10) and dry finishing (OR: 13.38, 95% CI: 1.00-181.70) had higher odds of breathing difficulty; while, working in the beamhouse was associated with an increased risk of developing skin diseases (OR: 4.36, 95% CI: 1.10-17.32). Conclusion/Application to Practice: Length of employment and types of work were associated with increased risk of health complaints, including breathing difficulty and skin disease among tannery workers. Stronger regulations with regular enforcement, regular health surveillance, and worker and employer education are necessary for reducing these exposures and improving the health outcomes of the tannery workers.


Assuntos
Exposição Ocupacional/efeitos adversos , Doenças Respiratórias/epidemiologia , Dermatopatias/epidemiologia , Curtume , Adulto , Bangladesh/epidemiologia , Feminino , Humanos , Icterícia/epidemiologia , Masculino , Doenças Profissionais/epidemiologia , Traumatismos Ocupacionais/epidemiologia , Inquéritos e Questionários
19.
Molecules ; 25(22)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33228107

RESUMO

This paper presents the results of research on the granulation process of leather industry waste, i.e., tanning shavings. It is economically justified to granulate this waste together with mineral additives that are useful in the processes of their further processing. Unfortunately, the granulation of raw, unsorted shavings does not obtain desired results due to their unusual properties. In this study, the possibilities of agglomeration of this waste were examined by a new method consisting of the production and then the granulation of wet pulp. During granulation, no additional binding liquid is added to the granulated bed. As part of this work, the specific surface of granulated shavings, the granulometric composition of the obtained agglomerates, and their strength parameters were determined. The use of a vibrating disc granulator, the addition of a water glass solution (in the pulp), dolomite, and gypsum made it possible to obtain durable, mechanically stable granules.


Assuntos
Minerais/química , Curtume , Resíduos/análise , Água/química , Carbonato de Cálcio/química , Sulfato de Cálcio/química , Magnésio/química , Tamanho da Partícula
20.
Environ Monit Assess ; 192(11): 732, 2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33123797

RESUMO

Biodegradation of organic compounds would reveal important information on the final fate of a chemical in the environment. However, establishing biodegradability and fate of a chemical is cumbersome. In this scenario, the use of multimedia models help in predicting the fate and half-life of any compound to establish biodegradability. The study commenced with collection of wastewater samples, after primary and secondary treatment, from a Common Effluent Treatment Plant (CETP) treating tannery wastewater. The samples were subjected to gas chromatography-mass spectrometry (GC-MS) analysis. The GC-MS analysis identified that polyphenolic compounds were detected after biological treatment. The identified compounds emanated from tanning, dyeing, and fatliquoring process of leather making. Estimation Program Interface (EPI) Suite BIOWIN 3 and BIOWIN 4 model prediction revealed that while the primary biodegradation time-frame ranged from days to weeks, the ultimate biodegradation took weeks in the case of all the detected compounds. This study established that BIOWIN model could be used as a screening tool to determine biodegradability of complex chemicals used in tanneries and help to design better treatment facility with enhanced efficiency for removal of polyphenolic compounds. This methodology can also be applied to other industrial wastewaters containing recalcitrant chemicals, and with the help of BIOWIN model, information on biodegradability of chemicals present in the wastewater can be obtained.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Biodegradação Ambiental , Corantes , Monitoramento Ambiental , Compostos Orgânicos , Curtume , Eliminação de Resíduos Líquidos
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