Green Coffee-Mediated Biofabrication of silver Nanoparticles: Process optimization for heavy metal removal coupled antimicrobial applications in tannery wastewater

Tanning, crucial for leather production, relies heavily on chromium yet poses risks due to chromium’s oxidative conversion, leading to significant wastewater and solid waste generation. Physico-chemical methods are typically used for heavy metal removal, but they have drawbacks, prompting interest in eco-friendly biological remediation techniques like biosorption, bioaccumulation, and biotransformation. The EU Directive (2018/850) mandates alternatives to landfilling or incineration for industrial textile waste management, highlighting the importance of environmentally conscious practices for leather products’ end-of-life management, with composting being the most researched and viable option. This study aimed to isolate microorganisms from tannery wastewater and identify those responsible for different types of tanned leather biodegradation. Bacterial shifts during leather biodegradation were observed using a leather biodegradation assay (ISO 20136) with tannery and municipal wastewater as the inoculum. Over 10,000 bacterial species were identified in all analysed samples, with 7 bacterial strains isolated from tannery wastewaters. Identification of bacterial genera like Acinetobacter, Brevundimonas, and Mycolicibacterium provides insights into potential microbial candidates for enhancing leather biodegradability, wastewater treatment, and heavy metal bioremediation in industrial applications.

Aims: This research aims to determine the ability of Lemna sp. as a phytoremediation agent in absorbing chromium (Cr) in tannery wastewater.
 Study Design: A total of 20 fiber tubs with size 80 x 80 x 40 cm3 and volume of 256 L were prepared and filled with 30 L each of the tannery wastewater and 1.75% bio-slurry added with a volume of wastewater as a source of nutrition for Lemna sp.. The number of Lemna sp. which is used for culture was 180 g for each fiber tube.
 Place and Duration of Study: Culturing Lemna sp. in tannery wastewater were carried out in Ciparanje Land Fisheries Area of ​​the Faculty of Fisheries and Marine Sciences Universitas Padjadjaran and for chromium analysis were carried out in Center for Natural Resources and Environment Research of Universitas Padjadjaran, between February and March 2019.
 Methodology: This research was carried out by culturing Lemna sp. in tannery wastewater for five days with 20 replications and comparing Cr concentrations in tannery wastewater and Lemna sp. at the end and beginning of the research. Chromium analysis results on the tannery wastewater and Lemna sp. the beginning and end of the research on each sample was tested by paired t-test.
 Results: by culturing Lemna sp. in the tannery wastewater as phytoremediation agent for five days the results obtained Cr concentration at the beginning of research each for tannery wastewater and Lemna sp. ranged from 0.180 to 0.194 mg/L with an average of 0.187±0.0034 mg/L and 0 mg/kg. While at the end of the research the concentration of Cr in tannery wastewater and Lemna sp. respectively ranged from 0.057-0.075 mg/L with an average of 0.068±0.0044 mg/L and 2.292-2.333 mg/kg with an average of 2.314±0.0101 mg/kg. There was a decrease in Cr concentration by an average of 64.01±1.96% in tannery wastewater and an increase in Lemna sp.. Paired t-test results showed that Lemna sp. which was cultured in tannery wastewater had a significant influence on Cr concentrations in both tannery wastewater and Lemna sp so that there were significant differences in Cr concentrations at the beginning (day 0) and at the end of the research (day 5).
 Conclusion: Average ability of Lemna sp. in absorbing and accumulating chromium in the tannery wastewater in the tissue was 2.314±0.0101 mg/kg and the average reduction in Cr concentration in liquid waste was 64.01±1.96%. Utilization of Lemna sp. containing chromium is possible to be used as a food supplement for fish to increase growth due to reduced Cr toxicity by Lemna sp.

The main focus of this research work is to investigate the possibility of applying Moringa oleifera seed extract for the removal of heavy metals from tannery wastewater. Samples were collected from effluent discharge points of the GB tannery, Muhaza tannery and Z-tannery which are located in Challawa Industrial Area, Kano, Nigeria. The samples analyzed for physico-chemical parameters are pH, temperature, hardness, conductivity, turbidity, alkalinity, total suspended solid, total dissolved solid, calcium, magnesium, chloride, nitrates, sulphates and sulphide and heavy metals such as cadmium, chromium, copper, cobbalt, iron, lead, manganese and zinc. The results show that the final levels of heavy metals after the application of Moringa Oliefera seed extracts were within NESREA acceptable limits. The heavy metal removal efficiencies were as follows; 99.29% for cadmium, chromium and iron while 96.03%, 95.56%, 96.84%, 87.41%, 91.35% for copper, cobalt, lead, manganese and zinc, respectively. The cheap, easy and environmentally friendly material called Moringa oleifera could be recommended to tannery companies for effective removal of heavy metals so as to have a safe, non-polluting environment and also prevent endangering the lives of aquatic organisms andHUMANS Keywords: Moringa Oleifera, tannery, wastewater, heavy metal, wastewater

Rapid industrialization is potentially contaminating the environment. Tannery is one of the industries producing very high amount of effluents, having a significant quantity of chromium (Cr) along with other pollutants. Due to a water shortage in Pakistan, farmers are using wastewater from tanneries for irrigation, which markedly reduces plant growth and biomass. Irrigation of crops with tannery wastewater is one of the main sources of Cr entry into the food web, which is a major threat to human beings. The present study was planned to investigate the effect of tannery wastewater on wheat plants and the role of fulvic acid (FA) in Cr toxicity alleviation. Results showed that application of tannery wastewater reduced plant growth, biomass, and photosynthetic pigments. Application of wastewater induced oxidative damage and lipid peroxidation in wheat plants. The application of FA played a very beneficial role in Cr toxicity alleviation in wheat plants irrigated with wastewater. Fulvic acid enhanced plant growth, biomass, and photosynthetic pigments, while reducing oxidative damage, lipid peroxidation, and Cr accumulation in stressed plants. It is concluded that application of FA in crops, irrigated with tannery wastewater, is one of the best strategies to mitigate Cr toxicity in plants.

Tannery wastewater is considered to be one of the most polluting effluents due to it containing a large variety of toxic heavy metals that range from chromium, cadmium, cobalt, lead, nickel, selenium to arsenic. As consequence of most tannery wastewater treatments, the tannery sludge that is produced contains considerable amounts of heavy metals, which are harmful to the environment and human health. Hence, tannery wastewater and sludge treatments have become a serious environmental issue. At present, the conventional options for sewage sludge disposal, such as fertilizers and soil amendment materials for the land and landfill, are widely applied. However, heavy metals in the tannery sludge often outweigh the soil's heavy metal content, and the application of sludge can indeed increase the concentration of heavy metals in the agricultural soil and affect the crop production owing to uptake of the metals. Research on devising appropriate treatment technologies for tannery wastewaters has gone through various phases of development over the past decades following developments in processes related to the leather manufacturing industry. This chapter attempts to revise environmental concerns and future challenges related to the management of tannery wastewater and sludge.

Industrial developments led to environmental pollution with toxic heavy metals which spreading all over the world. Heavy metal pollution, characterized by its heightened toxicity, resistance to biodegradation, and biological accumulation, has significantly jeopardized both human health and ecological stability. Microbial activities offer a potential avenue for immobilizing, removing, and detoxifying active heavy metal ions in the natural environment. This research aimed to study the ability of Pseudomonas aeruginosa in reducing the amount of Cd, Ni, Cr, Zn and Pb that found in tannery wastewater and to investigate its survivability in high concentrations of these metals. In this study Pseudomonas aeruginosa, was isolated from tannery effluents wastewater. Pseudomonas aeruginosa has been incubated in medium contained 50, 100, 300, 500 and 1000 ppm of Cd, Ni, Cr, Zn and Pb for 6, 12 and 24hrs at 37 °C. Results showed that Pseudomonas aeruginosa was able to cause a significant reduction of Cd, Ni, Cr, Zn and Pb at incubation time of 24 hours at concentration of 50, 100 and 300 ppm ,the reduction level for Ni were (96.5%, 96.2% and 96.4 %) respectively, Cd (76.4%, 82.1% and 83.8 % )respectively, Cr showed reduction rates of ( 97.7% , 99.4% and 99.1%) respectively, Pb ( 87.3% ,91.9% and 89.6%) respectively, and (82%, 87.6% and 80.1 %) respectively for Zn, Pseudomonas aeruginosa was not able to grow at concentration level of 500 and 1000 ppm for Cd, Ni, Cr, Zn and Pb. These results indicated that Pseudomonas aeruginosa is able to survive in tannery effluents wastewater containing high levels of Cd, Ni, Zn, Cr and Pb. Therefore, more research is recommended to study the ability of this species to remove Cd, Ni, Cr, Zn and Pb in different conditions.

The present study was conducted in a lab-scale constructed wetland to investigate the extraction potential of Typha latifolia and Lemna minor for heavy metals (HMs) from tannery wastewater (TWW), supplemented with citric acid (CA) as a chelator. After 6 weeks of treatment, harvesting was followed by a recording of agronomical trait data. The data indicated a significant (p < 0.05) decline in the morpho-physiological and biochemical attributes of the plants, which correlated increase in TWW concentration. Maximum accumulation of selected HMs including chromium (Cr), cadmium (Cd), and lead (Pb), in L. minor was observed at 100% TWW, with respective values of 148.4%, 129.4%, and 85.6% as compared to 25% TWW. In T. latifolia, a significant increase in Cr (143.8%), Cd (148.3%), and Pb (126.8%) in the roots was also observed at 100% TWW as compared to 25% TWW. CA amendment under TWW conditions significantly enhanced Cr uptake in L. minor by 61% and accumulation by 94%. Similarly, in the roots of T. latifolia, Cr uptake was elevated by up to 11%, with accumulation increasing by 117%. These findings indicate that phytoextraction of heavy metals can serve as an efficient strategy for the remediation of tannery wastewater using Lemna minor and Typha latifolia in constructed wetlands.

BACKGROUNDThe commercial production of zeolite A mainly involves costly synthetic chemicals. However, cheaper raw materials such as clay minerals, coal ashes, natural zeolites, solid wastes and industrial sludge have been tested. Based on this, the objective of the present study is synthesis of zeolite A from two sources of raw kaolins (Ansho and Bombowha) from Ethiopia and evaluation of its application in tannery wastewater treatment.RESULTSThe synthesis result indicated high crystallinity (&gt;90%) of zeolite A using Ansho kaolin. Lower grade Bombowha kaolin yielded zeolite A with crystallinity of 80%. In the tannery wastewater treatment study, a real sample having chromium concentration of 2036 mg L−1 was treated, obtaining 99.8% removal and about 200 mg g−1 adsorption capacity of Cr(III) using 100 g L−1 and 5 g L−1 adsorbent dose, respectively. This indicated that the synthesized zeolite A has great potential for Cr(III) removal from tannery wastewater.CONCLUSIONIn this study, zeolite A has been synthesized from two sources of kaolin from Ethiopia and has been evaluated in tannery wastewater treatment. The synthesis result indicated the formation of crystals of zeolite A with optimum crystallinity of 91% and the material exhibited chromium removal efficiency of 99.8%. © 2017 Society of Chemical Industry

En este estudio se comparó la capacidad de adsorción de cromo VI en quitosano modificado con cobre (Quitosano–Cu) y en quitosano modificado con cinc (Quitosano–Zn), y su aplicación en aguas residuales de tenería. Este trabajo incluyó el estudio del pH de máxima capacidad de adsorción en un rango de 3 a 6 y el equilibrio de adsorción de Cr (VI) a diferentes concentraciones (de 1.0 a 750.0 mg/l) y diferentes masas de bio-adsorbentes modificados (5 y 2 g). Los resultados muestran que la adsorción del ion metálico en los dos bio-adsorbentes modificados depende fuertemente del pH de la solución, donde el mayor porcentaje de remoción de cromo VI se alcanzó a pH 3. Por su parte, la evaluación de los datos experimentales del equilibrio de adsorción de Cr (VI), aplicando los modelos de Langmuir y Freundlich, mostró que en todos los casos hubo un mejor ajuste de los datos al modelo de Freundlich y que la capacidad máxima de adsorción fue alcanzada en el adsorbente Quitosano–Cu. Así también, los resultados indicaron que el adsorbente Quitosano–Cu fue más efectivo en la remoción de Cr VI de las aguas residuales de tenería con un 98%.

With the vigorous development of the leather industry, the environmental pollution problem originating from tannery wastewater is becoming increasingly serious, which can be solved by using advanced adsorption technology. As a biodegradable natural biomaterial, starch has a wide range of sources and has gradually become one of the best choices for preparing superabsorbent polymers. The excellent characteristics of starch‐based superabsorbent polymer make it widely applied in wastewater treatment. Therefore, this paper reviews the research progress of starch‐based superabsorbent polymer in recent years by removing metal ions and typical organic compounds from tannery wastewater. Firstly, the synthesis methods and characteristics of starch‐based superabsorbent polymers are discussed. Secondly, the main factors influencing the adsorption performance of starch‐based superabsorbent polymer have been introduced. Thirdly, the present situation of treating tannery wastewater with starch‐based superabsorbent polymer is summarized. Finally, some problems existing in the practical application of starch‐based superabsorbent polymer are proposed. Although starch‐based superabsorbent polymer shows excellent adsorption properties, there remain several issues such as recycling that needed to be addressed. This review is of benefit for the high‐value utilization of starch‐based superabsorbent polymers in reducing environmental pollution caused by tannery wastewater.

Heavy metal pollution in the environment has become one of the major concerns worldwide due to its long persistency in the environment and highly toxic nature in living beings. Heavy metals are often non-biodegradable in nature and hence persist for a long time in the environment, cause serious soil and water pollution, and create severe health hazards in humans and animals. Among heavy metals, chromium has been considered as the highly toxic inorganic pollutant, which is disposed off in the environment through various natural and anthropogenic sources. Chromium has been also listed as the priority pollutant by many environment and health protection agencies such as the US Environmental Protection Agency and Agency for Toxic Substances and Disease Registry. Hexavalent form of chromium has been reported to cause genotoxic, carcinogenic, and mutagenic effects in living beings. Hence, the removal of chromium from tannery wastewater is urgently required. The physicochemical approaches are currently applied for the removal of chromium from tannery wastewater, which are not eco-friendly in nature and use a huge amount of chemicals to treat tannery wastewater. However, biological approaches can be an eco-friendly alternative to treat and detoxify the chromium-containing tannery wastewater prior to its disposal in the environment. This chapter provides a detailed information about the sources of chromium contamination in the environment and their toxic effects in human, animal, plants, as well as in microbes and bioremediation approaches for its detoxification from tannery wastewater for environmental and public health safety.

The leather-making process necessitates large amounts of water and consequently generates tons of liquid waste as leather tannery wastewater (TWW) is disposed of directly in the open environment. Open disposal of untreated TWW into the natural environment causes an accumulation of various polluting compounds, including heavy metals, dyes, suspended solids inorganic matter, biocides, oils, tannins, and other toxic chemicals. It thus poses potential hazards to the environment and human health. This study primarily focuses on providing in-depth insight into the characteristics, treatment strategies, and regulatory frameworks for managing TWW in leather processing industries. Different technologies of conventional physico-chemical (equalization, coagulation, and adsorption), advanced approaches (Fenton oxidation, ozonation, cavitation), thermo-catalytic and biological treatments available to treat TWW, and their integrative approaches were also highlighted. This review also sheds light on the most frequently applied technologies to reduce contaminant load from TWW though there are several limitations associated with it such as being ineffective for large quantities of TWW, waste generation during treatment, and high operational and maintenance (O&M) costs. It is concluded that the sustainable alternatives applied in the current TWW technologies can minimize O&M costs and recirculate the treated water in the environment. The exhaustive observations and recommendations presented in this article are helpful in the industry to manage TWW and recirculate the water in a sustainable manner.

ABSTRACTIn this investigation, we report on the treatment of tannery wastewater using microalgae Chlorella species to produce lipid and fatty acid as well as changes in antioxidant metabolism during the treatment. The variation in growth, production of pigments, antioxidant metabolism, lipid and fatty acids, and nutrient removal from wastewater during the remediation were observed. Surprisingly, a profuse growth was found in 50% diluted tannery wastewater (TW), which supported to accumulate high yield of lipid (18.5%) and unsaturated fatty acids (50.05%). The antioxidant activity of microalgae in both the concentrations (50% and 100% TW) were viz., lipid peroxidation 1.6 ± 0.1 and 2.3 ± 0.02nmol MDA mg−1 protein, SOD 10.3 ± 0.4 and 15.7 ± 0.9 U mg−1 protein, CAT 0.17 ± 0.036 and 0.52 ± 0.06 U mg−1 protein, and APX 7.2 ± 0.8 and 11.2 ± 09 U mg−1 protein respectively, which point out that the free radical scavenging mechanism against heavy metal stress. Maximum phycoremediation of heavy metals observed from both concentrations during the healthy growth period were Cr – 73.1, 45.7%, Cu – 90.4, 78.1%, Pb – 92.1, 52.2%, and Zn – 81.2, 44.6%, respectively. This study proved the potential use of Chlorella for heavy metal and nutrient removal from tannery wastewater. Moreover, an unaffected growth with high antioxidant activity of this species promises a sustainable lipid and fatty acid contents for biofuel production.

Sequential treatment of tannery wastewater using microalgae and microwave-prepared anodes.

Heavy metal pollution released into the surface environment poses a significant threat, being hazardous to both the environment and living organisms. Phytoremediation thus appears as a viable technique to address heavy metal pollution in soils impacted by industrial effluents. To identify the growth performance of sunflower and cotton seeds under various concentrations of arsenic and chromium present in the tannery industrial wastewater in the Chengalpattu region, and to identify the accumulation of Arsenic(As)As and chromium (Cr) in the roots, shoots, and soil of these plants. This paper examined the usefulness of sunflower (Helianthus annuus) and cotton (Gossypium herbaceum) in eradicating Cr and As-polluted soils originating from tannery wastewater. In this experiment, Completely Randomized Block Design (CBRD) testing was performed, and the samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The accumulation of Cr in sunflowers was 120 mg.kg-1 in the roots and 25 mg.kg-1 in the above-ground parts. As accumulated to 85 mg.kg-1 in the roots and 15 mg.kg-1 in the above-ground parts. Similarly, cotton plants accumulated 90 mg.kg-1 of Cr in the roots and 20 mg.kg-1 in the above-ground parts. As accumulation in cotton plants was 100 mg.kg-1 in the roots and 30 mg.kg-1 in the aboveground parts. The study inferred that, in comparison to the other plants, the concentrations of Cr in sunflower roots were significantly higher, but cotton was found to have a better ability to take up As in the roots as well as in the aerial parts of the plant. It hence demonstrates the applicability of sunflower and cotton to support phytoremediation efforts sustainably within industrial environments to mitigate pollution and improve the quality of the soil.