Heavy Metals In Industrial Effluents Research Articles

Bioremoval of tannins and heavy metals using immobilized tannase and biomass of Aspergillus glaucus

BackgroundThe presence of inorganic pollutants and heavy metals in industrial effluents has become a serious threat and environmental issues. Fungi have a remarkable ability to exclude heavy metals from wastewater through biosorption in eco-friendly way. Tannase plays an important role in bioconversion of tannin, a major constituent of tannery effluent, to gallic acid which has great pharmaceutical applications. Therefore, the aim of the current study was to exploit the potential of tannase from Aspergillus glaucus and fungal biomass waste for the bioremediation of heavy metals and tannin.ResultsTannase from A. glaucus was partially purified 4.8-fold by ammonium sulfate precipitation (80%). The enzyme was optimally active at pH 5.0 and 40 °C and stable at this temperature for 1 h. Tannase showed high stability at different physiological conditions, displayed about 50% of its activity at 60 °C and pH range 5.0–6.0. Immobilization of tannase was carried out using methods such. as entrapment in Na-alginate and covalent binding to chitosan. The effects of Na-alginate concentrations on the beads formation and enzyme immobilization revealed that maximum immobilization efficiency (75%) was obtained with 3% Na-alginate. A potential reusability of the immobilized enzyme was showed through keeping 70% of its relative activity up to the fourth cycle. The best bioconversion efficiency of tannic acid to gallic acid by immobilized tannase was at 40 °C with tannic acid concentration up to 50 g/l. Moreover, bioremediation of heavy metal (Cr3+, Pb2+, Cu2+, Fe3+, and Mn2+) from aqueous solution using A. glaucus biomass waste was achieved with uptake percentage of (37.20, 60.30, 55.27, 79.03 and 21.13 respectively). The biomass was successfully used repeatedly for removing Cr3+ after using desorbing agent (0.1 N HCl) for three cycles.ConclusionThese results shed the light on the potential use of tannase from locally isolated A. glaucus in the bioremediation of industrial tanneries contained heavy metals and tannin.

Isolation and Characterization of Heavy Metal-Tolerant Bacterial Isolates from Industrial Effluents in Uttar Pradesh, India

Industrial activities over the past century have significantly increased human exposure to pollutants such as heavy metals. Industrial emissions of heavy metals, which are carcinogenic, mutagenic and toxic, contaminate natural water supplies and the agricultural environment. Due to the high concentration of heavy metals in industrial effluents, the bacteria present there naturally develop resistance to heavy metals. The aim of this study is to isolate and characterize bacteria resistant to heavy metal, lead (Pb), copper (Cu), chromium (Cr), cadmium (Cd), and nickel (Ni) from sites contaminated by industrial effluents in Uttar Pradesh, India. A total of 58 bacterial isolates were isolated from 9 samples according to their various morphological parameters and 32 isolates were found positive for all heavy metals, which revealed that samples contained metal-resistant bacterial diversity. Two isolates were identified up to species level based on their physiological, biochemical and molecular characterization as Comamonas testosteroni (S4C1) and Bacillus cereus (S5C3). Both isolates are highly resistant to lead (Pb), copper (Cu), chromium (Cr), cadmium (Cd), and nickel (Ni) and they show different MICs against the above heavy metals at different levels. A growth experiment showed that the presence of heavy metals concentration had no discernible impact on the growth rate among the isolates. Gel analysis showed interesting patterns of protein expression were observed in the presence of various heavy metals. MALDI-TOF analysis found that specific proteins (S layer protein, F0F1ATP synthase subunit b, Flagellin, 50S ribosomal protein L4, Molecular chaperone) were overexpressed in the presence of heavy metals. As a result, identifying the heavy metal resistance bacteria and their proteins study could be useful as a preliminary investigation for the development of prospective bioremediation agents of potentially hazardous waste treatment technology.

Comprehensive pollution and ecological risk of heavy metals in an industrial region of south-west Bangladesh

Deterioration of water, soil and sediment due to industrial operation is well known. This study aimed to evaluate physicochemical properties of surface water and heavy metals in industrial effluent (n = 13), river water (n = 14), pond water (n = 5), soil (n = 11) and sediment (n = 19) collected from an industrial zone in south-west Bangladesh. Among the physicochemical parameters, pH and dissolved oxygen (DO) indicated relatively higher values in most of the samples than their respective lower guideline values of 6 and 4.5 mg L-1 and showed significant variation across environments. Based on the average concentration, none of the heavy metals in any environment surpassed the guideline values in the study area, except, Cr in both industrial effluent (0.034 ± 0.055 mg L-1) and river water (0.011 ± 0.005 mg L-1), Cd in both soil (1.11 ± 0.47 mg kg−1) and sediment (1.41 ± 1.04 mg kg−1). Possibly, continuous discharge of industrial effluents might increase the heavy metal concentrations in the effluent receiving environment. Concentration of others heavy metals were below the respective guideline values but varied significantly among the environments. Depth-wise variation was negligible which might be dependent on metal chemistry in soil and sediment. A very high pollution and ecological risk were observed for Cd, specifically in soil and sediment. Multivariate statistics showed strong correlation among heavy metals, which indicated considerable contribution from industrial effluent. Industrial operations control physicochemical properties of surface water, but temperature is dependent of meteorological conditions. This study concludes that the lower concentrations of heavy metals than guideline values in environmental samples still pose significant levels of pollution and ecological risks.

Physicochemical characterization and heavy metals analysis from industrial discharges in Upper Awash River Basin, Ethiopia

The recent expansion of industries in Addis Ababa is causing additional environmental pollution through wastewater discharges; this is becoming a critical concern. Addis Ababa is located in the upper Awash River basin, and is the main source of industrial pollutants to the river. In this study, physicochemical parameters, nutrients and heavy metal content of wastewaters released from 16 factories, 6 tanneries, 6 beverages and 4 diverse factories, and the Akaki-Kality central wastewater treatment plant in Addis Ababa, were sampled to assess the level of pollutants. Heavy metals were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Analysis of nutrients were conducted using Palintest Photometer. Physicochemical characteristics were measured either in situ using a portable micro meter or in the laboratory. Among the measured physicochemical properties, critical issues were observed with electrical conductivity, total dissolved solids and total hardness. Effluents from all of the tanneries, and a number of other factories, were found at levels higher than the maximum limits of various guideline standards. In addition, samples from two of the tanneries (T1 and T5), two beverage factories (B3 and B6) and the central wastewater treatment plant showed elevated concentrations of PO4 3-, which violated the limit (10mg/l) set by Environmental Protection Agency of Ethiopia (ETHEPA). The two tanneries (T1 and T5) also contained higher SO4 2- than the guideline limit of 1000mg/l. On the other hand, only one factory, one brewery (B3), exhibited NO3 - above the standard limit of 20mg/l. Whereas NH3, NH4 +, Cl-, S2- and NO2 - were within the limits in all of the samples. Severe pollution was found in wastewaters from tanneries, where half of them (T1, T5 and T6) contained Cr beyond the maximum limit of 2000µg/l. Furthermore, a third of the tanneries (T1 and T5) and a beverage factory (B5) contained Fe, Mn, Zn and Cu, higher than the ETHEPA limits of 10000, 5000, 5000 and 2000µg/l, respectively. Waste disposal from factories without proper treatment can cause great harm to the local people and the environment. Hence, the results of this study call for regulatory bodies to pay close attention to factories, particularly tanneries, in Addis Ababa in implementing adequate treatments of their wastewater discharges.

Bioremoval of Different Heavy Metals in Industrial Effluent by the Resistant Fungal Strain Aspergillus niger

Developing countries are increasingly concerned with pollution due to toxic heavy metals in the environment. Unlike most organic pollutants which can be destroyed, toxic metal ions released into the environment often persist indefinitely circulating and eventually accumulating throughout the food chain thus posing a serious threat to mankind. The use of biological materials for heavy metal removal or recovery has gained importance in recent years due to their good performance and low cost. Among the various sources, both live and inactivated biomass of organisms exhibits interesting metal binding capacities. Their complex cell walls contain high content of functional groups like amino, amide, hydroxyl, carboxyl, and phosphate which have been implicated in metals binding. In the present study, Aspergillus niger was used to analyze the metal uptake from an aqueous solution. The determination of Cu+2, Pb+2, Cd+2, Zn+2, Co-2 and Ni+2 in samples was carried out by differential Pulse Anodic Voltammetry (DPASV) and the Voltammograms. Production of oxalic acid was carried out by submerged fermentation. The organism used in the present study has the ideal properties to sequester toxic metals and grow faster.

First principle investigation of boron functionalized graphene to detect the presence of “arsenic” in water

Heavy metals in industrial effluents create severe water pollution, leading to adverse effects on human beings. Thus, to save mankind from the ill effects of these heavy metals and to monitor its’ concentration within the permissible limits, effective sensors are required to be marked in terms of sensitivity, selectivity, and simplicity. In this work, boron functionalized graphene (BG) has been examined for its sensing ability towards Arsenic (As) by analyzing its band structure, density of states, and current–voltage characteristics in both vacuum and aqueous environments. The findings of the vacuum environment reveal that the arsenic interacts strongly with BG sheet owing to its high binding energy −2.63eVthat results in an opening of a bandgap of ~0.206 eV, infers the sensing ability of the sheet towards arsenic. Further, to comprehend the effect of an aqueous environment on the sheet's sensitivity, calculations are carried out in the presence of water molecule. The findings show that the BG sheet can detect the As in water with a sensitivity of ~15% at a low applied voltage of 400 mV.

A highly efficient nanoscale tapioca starch prepared by high‐speed jet for Cu2+ removal in simulated industrial effluent

AbstractBACKGROUNDNanoscale tapioca starch (NTS) was successfully developed by high‐speed jet in our previous study. In this study, the adsorption capacity of Cu2+ onto NTS was further discussed. The optimal adsorption conditions (pH, contact time, contact temperature, initial Cu2+ concentration, and adsorbent concentration), adsorption kinetics, isotherms, and thermodynamic were also evaluated.RESULTSThe results showed that NTS exhibited excellent performance in adsorption of Cu2+, with adsorption capacities of 122.31 mg g−1 for Cu2+ (pH 7, 0.04 g L−1, 0.2 g L−1, 313.15 K and 10 min). The pseudo‐second‐order and Langmuir isotherms models could be used to explain the adsorption kinetics and adsorption equilibrium, respectively. The thermodynamic results showed that the adsorption process was spontaneous and endothermic with an increase in entropy. Cu2+ was adsorbed onto NTS, which was confirmed by energy dispersive spectrometry analysis.CONCLUSIONThese findings indicated that NTS might be an effective, environment‐friendly and renewable bio‐resource adsorbent for removing heavy metals in industrial effluent. © 2021 Society of Chemical Industry

Influence of Operating Environments on Adsorptive Removal of Lead (Pb (II)) Using Banana Pseudostem Fiber: Isotherms and Kinetic Study

ABSTRACT Natural fiber as adsorbents is an emerging trend in effluent treatments as the fibers are environmental friendly, abundantly available and superior to polymeric-based materials. In this study, fiber extracted from the banana pseudostem was tested as an adsorbent. The lead (Pb (II)) removal was assessed with various parameters, namely, pH, agitation speed, adsorbent dosage and contact time. Removal efficiency was found maximum in alkaline conditions (pH 10) with a contact time of 140 min. Its efficiency was further optimized for adsorbent dosage and agitation speed. Between the isothermic model and Temkin isotherm model predicted the conditions better by providing the highest respective coefficient of determination (R2 – 0.9942). Similarly, the kinetics for adsorption was fitted well with pseudo-second-order kinetic model. Banana pseudostem fiber (BPF) could be a promising source and low-cost adsorbent to remove toxic heavy metals in industrial effluents.

Reduction of toxic elements in marine environment using nano adsorbent materials

Due to large scale industrialisation and indiscriminate discharge of effluents with high BOD, sulphuric acid, oil, toxic metals and particulate matter reach the aquatic environment, either directly or indirectly. Living organisms consist less than one percent of heavy metals, and their different density cause to some disorders. Surface waters and also acidic rains can transfer these metals to oceans via washing polluted environment. Heavy metals naturally exist in very little amount in watery places. Metal pollution of the sea is less than other types of water pollution but its effects on marine ecosystems and humans are very extensive. Industrial wastes in aquaculture because toxic effects in aquatic organisms especially in fishes. Aquatic organisms absorb the pollutants directly from water and indirectly from food chains. Some of the toxic effects of heavy metals on fishes and aquatic invertebrates are; reduction of the developmental growth, increase of developmental anomalies, reduction of fishes survival- especially at the beginning of exogenous feeding or even cause extinction of entire fishes population in polluted reservoirs. The objective of this project is to investigate the heavy metals in industrial effluents and reducing it by using Nano Adsorbent of Vetiveriazizanioides. This method is more efficient than any other method for reducing heavy metals from industrial effluents, because it is biodegradable. The results obtained from this attempt shows that heavy metals reduction by this Nano adsorbent is in the range of decreases like Hg > As > Cd > Pb.

Effect of Industrial Effluents on Rice Growth, Yield and Soil Chemical Properties

Toxic pollutants and heavy metals in industrial effluents and city waste water are massive concern among the researchers, development worker, media personnel and policy makers. Keeping this in view-a pot experiment was conducted at the Bangladesh Rice Research Institute (BRRI), net house during T. Aman 2010 (wet season) and Boro 2011 (dry season) rice aimed to determining the effect of different industrial effluents on rice growth, yield and soil chemical properties. The irrigation effect of industrial effluents on rice production was more prominent in dry season (Boro) rice than wet season (T. Aman) rice. Perceptible changes in soil properties occurred through the effluents irrigation in rice-rice cropping pattern. Pharmaceutical and tannery effluents increased soil pH, EC, total N (%) available P (mg/kg). Exchangeable K, Ca, Mg and Na (cmol/kg) were increased due to irrigation with dyeing, pharmaceutical and tannery effluents. Dyeing, beverage, tannery and city waste water reduced percent soil organic carbon. Micronutrients (Zn, Fe, Cu and Mn) were increased significantly by the irrigation with dyeing, pharmaceutical and tannery effluents in both wet and dry season rice. Heavy metals like Pb, Cd, Ni and Cr in soils were increased significantly through irrigation with effluents in rice-rice cropping pattern.

Hexavalent Chromium Removal Using Filamentous Fungi: Sustainable Biotechnology

To advance sustainable, safe biotechnologies for removal of heavy metals in industrial effluents, we evaluated two filamentous fungi isolated from chromium-contaminated soil (Aspergillus fumigatus ...

Photocatalytic Reduction of Nickel using Synthesized nano Titanium Oxide - Acidified neem saw dust Composite from Battery waste

The heavy metals, present in the battery waste water released from industries are extremely toxic and pose a serious threat to public health. The physical adsorption methods are effective, but require an additional adsorbent regeneration step. The degradation of heavy metals in industrial effluents through chemical remediation has also gained tremendous attention due to its enormous applications. Photo catalytic degradation using renewable UV / sun light is one of the most promising techniques due to its simplicity and economy. Till date, various metallic/bimetallic oxides such as TiO2, ZnO, Fe2O3 have been tested for degradation of photo catalytic components due to their superior activity, low price. Attempts have been made to study the photo catalytic degradation of heavy metals using nano Titanium Oxide and Acidified neem saw dust (nTO/ANSD) composite as a photo catalyst.In this present research, nTO/ANSD composite was synthesized and assessed for photo-chemical degradation of nickel in presence of UV light. It was observed that 96.4% Nickel was reduced using photo catalytic process. The X-Ray Diffraction(XRD) and Scanning Electron Microscopy (SEM) for nTO/ANSD studies were also performed. The recovery process of the nTO/ANSD composite photo catalyst is easier and reusability studies shows that the catalyst can be reused to remove the traces of heavy metals with slight reduction in efficiency.

Heavy Metal Toxicity, Health Hazards and their Removal Technique by Natural Adsorbents: A Short Overview

Environmental pollution particularly from heavy metals and minerals in the wastewater is the most severe problem in India. Due to extensive anthropogenic activities such as industrial operations particularly mining, agricultural processes and disposal of industrial waste materials; their concentration has increased to dangerous levels. Heavy metals in industrial effluent include Copper, nickel, chromium, lead, zinc, arsenic, cadmium, selenium and uranium. So far, a number of efficient methods have been reviewed for the removal of heavy metals such as chemical precipitation, ion exchange, reverse osmosis, electro dialysis, ultra filtration, nanofiltration, coagulation, flocculation, floatation, etc. However these methods have several disadvantages such as high reagent requirement, unpredictable metal ion removal, generation of toxic sludge etc. Adsorption process being very simple, economical, effective and versatile has become the most preferred methods for removal of toxic contaminants from wastewater. This paper reviews the use of various readily available natural materials as adsorbents of heavy metals from industrial wastewater. Various natural adsorbents reviewed includes sand, waste tea leaves eggshell, rice husk, activated carbon, zeolites, olive stones, wood sawdust etc.

XANTHATION OF SAWDUST WASTE FOR ADSORPTION OF LEAD IONS FROM AQUEOUS SOLUTIONS

Heavy metals in industrial effluents have contaminated natural waters compromising the health of humans and animals. Traditional methods eliminate these metals from wastewater but they are costly or ineffective at low metal concentrations for which alternative methods are required. We investigated the adsorption of lead on xanthated sawdust (CS2 treatment). Kinetic and pH tests, adsorption isotherms and infrared spectroscopy were performed. Kinetic studies indicated that adsorption equilibrated at 120 min following a kinetic model of pseudo-second order. The adsorption capacity was 72 mg Pb2+ g-1 (maximum at pH 5, Freundlich type isotherm, 98% adsorption). This product obtained from raw materials without commercial value, can be used for environmental remediation as an alternative to its expensive dumping into landfills.

Simultaneous removal of Pb(II), Cd(II) and Cu(II) from aqueous solutions by adsorption on Triticum aestivum - a green approach

The presence of heavy metals in industrial effluents as a single component is generally very rare. The present study provides information about adsorption behaviour of lead, cadmium and copper in single and multi-component system using triticum aestivum (wheat straw) as adsorbent. It has been shown that adsorption of a certain metal ion is greatly affected by the presence of other metal ions. Effects of process parameters (adsorbent dose, contact time, pH, agitation speed etc.) have been studied. pH 4-6 have been found suitable for metal removal. Adsorption mechanism has been evaluated using five adsorption isotherm models (Langmuir, Freundlich, Temkin, Harkin- Jura and Halsey Isotherms). Removal of cadmium in multi-component system is greater as compared in single component system indicating the metal competition for adsorption sites. Kinetic and thermodynamic parameters have also been calculated and obtained results were found closely related to the reported literature. Positive values of ?H° for lead, cadmium and copper shows feasibility of the process and the spontaneous nature of adsorption.

Vulnerabilidade Sócio Ambiental de Pescadores e Marisqueiras em S. Francisco do Conde/Ba

A partir da identificação dos determinantes socioambientais em saúde, este estudo tem como objetivo mapear aspectos relativos aos riscos e vulnerabilidade social e ambiental de um grupo de pescadores e marisqueiras no município de São Francisco do Conde, região metropolitana de Salvador, Ba. Com o propósito de colaborar na formulação de políticas públicas voltadas a promoção da qualidade de vida das marisqueiras e pescadores artesanais, tomou-se como base 2 diagnósticos complementares: o ambiental e sócio demográfico. Foi verificado a qualidade microbiológica das águas, presença de metais pesados nos sedimentos, mariscos e peixes; contaminantes microbiológicos do esgoto doméstico e 6 metais pesados mais comuns nos efluentes industriais. O diagnóstico sócio demográfico levantou as condições de trabalho e habitação além de aspectos relativos à saúde. Aliados à observação de campo e estudos similares, constatou-se que o oficio da pesca e coleta de mariscos, vem sofrendo declínio enquanto atividade ligada a tradição, despertando pouco interesse das gerações mais jovens, além das características artesanais que restringem sua inserção no modo de produção capitalista. Resultados indicam comprometimento do ecossistema costeiro, o manguezal, pela contaminação por metais pesados e coliformes fecais que potencializam os agravos de ordem ocupacional, decorrentes da ergonomia e exposição à contaminação. Refere-se ainda as condições de habitabilidade destes sujeitos e sua condição de invisibilidade que recorrentemente fortalece e amplia o grau de vulnerabilidade social e ambiental. Assim, as raízes negras do município, manifestadas na composição da população, encontra-se ameaçada face a vulnerabilidade social das comunidades, grupos remanescentes e seus descendentes.

Bioremoval of heavy metals by bacterial biomass

Heavy metals are among the most common pollutants found in the environment. Health problems due to the heavy metal pollution become a major concern throughout the world, and therefore, various treatment technologies such as reverse osmosis, ion exchange, solvent extraction, chemical precipitation, and adsorption are adopted to reduce or eliminate their concentration in the environment. Biosorption is a cost-effective and environmental friendly technique, and it can be used for detoxification of heavy metals in industrial effluents as an alternative treatment technology. Biosorption characteristics of various bacterial species are reviewed here with respect to the results reported so far. The role of physical, chemical, and biological modification of bacterial cells for heavy metal removal is presented. The paper evaluates the different kinetic, equilibrium, and thermodynamic models used in bacterial sorption of heavy metals. Biomass characterization and sorption mechanisms as well as elution of metal ions and regeneration of biomass are also discussed.

The ability of crab and cockle shell to adsorb lead and chromium from industrial effluent

The ability of crab shell (Scylla serata) and cockle shell (Anadara granosa) to remove Pb, and Cr from industrial effluent was examined to determine its removal efficiency. This research was conducted under constant pH around 4 under room temperature and all samples were shacked to 150 rpm. Other factors like amount of adsorbent, types of adsorbent and time equilibrium was examined along this research. The highest uptake of heavy metals recorded is by crab shells compare to cockle shells. All heavy metals except chromium reached equilibrium after 60 minutes time. The most of heavy metals was adsorbed by amount of 1.0 g compare to other amount of adsorbent (0.5 g and 1.0 g). The amount of adsorbent and type of adsorbent were strongly correlated by amount of heavy metals adsorption. (p < 0.001). Chromium was the highest heavy metals that were removed in industrial effluent. The highest reading was recorded as 97.45%. CaCO3 and chitin play an important role to adsorb heavy metals in industrial effluent. Although, there are many other particles existed in industrial effluent but still crab shells and cockles can be used as biomass adsorbent to remove heavy metals in industrial effluent.

Síntese de zeólita tipo NaA a partir de caulim para obtenção de zeólita 5A através de troca iônica

A síntese de zeólitas com o intuito de utilizá-las posteriormente como materiais adsorventes exige rigoroso controle das variáveis de processamento. Para cada tipo diferente de zeólita, existem variáveis de processo distintas para obtenção do tipo específico desejado. Neste trabalho os objetivos foram obter zeólita NaA partindo de caulim, para posteriormente obter zeólita 5A por meio de troca iônica com esta zeólita anteriormente sintetizada. Estas zeólitas, por sua vez, podem ser usadas como adsorventes altamente seletivos para adsorver, por exemplo, metais pesados de efluentes industriais. Os resultados obtidos foram satisfatórios, a metodologia utilizada mostrou-se eficiente. A partir do metacaulim comercial utilizado, obteve-se com sucesso zeólita tipo NaA, e por meio de trocas iônicas obteve-se zeólita 5A. A porcentagem de sódio trocada na zeólita final foi 61,4%.

Biosorptive performance of an Escherichia coli biofilm supported on zeolite NaY for the removal of Cr(VI), Cd(II), Fe(III) and Ni(II)

One of the major environmental concerns of nowadays is the presence of heavy metals in industrial effluents. Aiming a solution for this problem, various efforts have been made towards research and implementation of economic and easily adaptable processes to remove heavy metals. The ability of a biofilm of Escherichia coli supported on NaY zeolite to biosorb Cr(VI), Cd(II), Fe(III) and Ni(II) was investigated in batch experiments aiming the treatment of wastewater with low metal concentrations. The biosorption performance, in terms of uptake, followed the sequence: Fe(III) > Ni(II) > Cd(II) > Cr(VI). The equilibrium data in batch systems were described by Langmuir, Sips and Toth isotherms. The best fit for chromium was obtained with the Toth model isotherm and for cadmium and nickel the best fit was the obtained with the Sips model. The presence of functional groups on the cell wall surface of the biomass that may interact with the metal ion, was confirmed by FTIR. The whole study showed that the biofilm tested is very promising for the removal of metal ions from effluents.