Heavy metal accumulation by aquatic fungi and reduction in viability of Gammarus pulex fed Cd2+ contaminated mycelium

The addition of Pb²⁺ (1.0 and 2.5 μg ml^?1) and Cd²⁺ (2.5 and 5.0 μg ml^?1) to growth medium decreased the growth of aquatic fungi, while Zn²⁺ even at a concentration of 10 μg ml^?1 had no inhibitory effect. Low concentrations of Cd²⁺ and Zn²⁺ on the other hand stimulated mycelial growth. The fungi accumulated considerable amounts of metal from the growth medium, generally in the order Zn²⁺ > Pb²⁺ > Cd²⁺ · Cd²⁺ was also accumulated by fungi from successive changes of medium containing low concentrations of the metal. Application of Langmuir and Freundlich isotherms to the results showed that the metals were accumulated largely by adsorption to the surface of the mycelium.Three species of aquatic fungi supported the growth of the freshwater shrimp. Gammarus pulex when provided as sole food source, sustaining from 30 to 60% of shrimps fed for a period of 21 days. A marked reduction in shrimp viability occurred however, when G. pulex was fed Pythium sp. containing Cd²⁺ (150–170 μg g^?1), with none of the shrimps surviving beyond 13 days, compared with a survival rate of 60% after 21 days for shrimps fed uncontaminated mycelium. Bodies of poisoned shrimps sampled on day 13 were found to contain Cd²⁺ (22.03 μg g^?1) showing that the metal can be transferred from aquatic fungi to G. pulex, the first step in a food chain involving freshwater fish and higher organisms.     

Adsorption of Cu(II), Cd(II) and Pb(II) from aqueous single metal solutions by succinylated twice-mercerized sugarcane bagasse functionalized with triethylenetetramine

This study describes the preparation of two new chelating materials, MMSCB 3 and 5, derived from succinylated twice-mercerized sugarcane bagasse (MMSCB 1). MMSCB 3 and 5 were synthesized from MMSCB 1 using two different methods as described by Gurgel and Gil (2009). In the first method MMSCB 1 was activated with 1,3-diisopropylcarbodiimide and in the second with acetic anhydride (to form an internal anhydride) and later both were reacted with triethylenetetramine in order to obtain MMSCB 3 and 5. New obtained materials were characterized by mass percent gain, concentration of amine groups, FTIR, and elemental analysis. MMSCB 3 and 5 showed mass percent gain of 19.9 and 57.1%, concentration of amine groups of 2.0 and 2.1 mmol/g, and nitrogen content of 5.8 and 4.4%. The capacity of MMSCB 3 and 5 to adsorb Cu²⁺, Cd²⁺, and Pb²⁺ from aqueous single metal ion solutions was evaluated at different contact times, pHs, and initial metal ion concentrations. Adsorption isotherms were well fitted by Langmuir model. Maximum adsorption capacities of MMSCB 3 and 5 for Cu²⁺, Cd²⁺, and Pb²⁺ were found to be 59.5 and 69.4, 86.2 and 106.4, 158.7 and 222.2 mg/g, respectively.     

Influences of pH, heavy metals and phosphate and their co-influences on the sorption of pentachlorophenol on cyanobacterial biomass

Influences of pH, two types of ions of transition metals (Cu²⁺, Cd²⁺), Na₃PO₄ and their co-influences on the sorption of pentachlorophenol (PCP) on cyanobacterial biomass derived from natural bloom were studied. Sorption of PCP significantly decreases with pH in the range of 3.25-9.00. Although sorption coefficient of ionized PCP is 8.51 times lower than that of neutral species, it is the dominant species at environmentally relevant pH and contributes more to the total sorption of PCP. In the presence of low concentration of Cu²⁺ (≤40 μmol L⁻¹), sorption of PCP was much lower than that of the blank. However, it increased gradually with Cu²⁺, and overpassed the blank when concentration of Cu²⁺ was higher than 50 μmol L⁻¹. Compared with the sole influence of pH, coexisted Cu²⁺ inhibited the sorption of PCP at pH of 3.25 and 4.35, but enhanced it in the pH range of 5.00-9.00. In the presence of Cd²⁺, sorption of PCP first increased then decreased rapidly and finally increased slightly again with Cd²⁺. Except for at pH of 9.00, sorption of PCP at other pH in the presence of Cd²⁺ was much lower than that solely affected by pH. In the presence of Na₃PO₄, sorption of PCP increased rapidly then maintained with Na₃PO₄. Under the influence of both Na₃PO₄ and pH, sorption of PCP at pH from 3.25 to 5.00 was lower than that solely affected by pH, while it increased with pH in the range of 5.00-9.00 and was higher than that solely affected by pH in the range of 6.00-9.00. Ion pairs of pentachlorophenolate-metal facilitated the sorption of PCP, which was largely dependent on pH illustrated by UV-visible and FTIR spectra. Speciations of metals and PCP and the stability constants of ion pairs of pentachlorophenolate-metal greatly affected the sorption. Ionic strength also played an important role for the sorption of PCP.     

Effect of selected metal ions on the photocatalytic degradation of bog lake water natural organic matter

Herein we report the photocatalytic degradation of natural organic matter from a bog lake (Lake Hohloh, Black Forest, Germany) in the presence of 0, 5, and 10 μmol L⁻¹ of added Cu²⁺, Mn²⁺, Zn²⁺ and Fe³⁺. The reactions were followed by size exclusion chromatography with organic carbon detection (SEC-DOC) and by measurements of low molecular weight organic acids. Addition of Cu²⁺ had the largest effect of all four studied metals, leading to a retardation in the molecular size changes in NOM: degradation of the larger molecular weight fraction was inhibited leading to reduced production of smaller molecular weight metabolites. Similarly, addition of Cu²⁺ reduced the production of formic and oxalic acids, and reduced the bioavailability of the partially degraded NOM.     

Monitoring of polychlorinated biphenyls (PCBs) and hexachlorocyclohexanes (HCH) in freshwater using the aquatic moss Cinclidotus danubicus

Concentrations of PCBs and α-, β, and γ-HCH have been measured in the aquatic moss Cinclidotus danubicus to examine its potential use an indicator of chlorinated organic pollutants in freshwaters. Samples of Cinclidotus were collected from an uncontaminated stretch of the Saône R. (France) and transplanted in the Durance R., which receives effluents of an insecticide factory. Mosses were sampled 13, 24 and 51 days after the transplant and analysed by capillary column gas chromatography. Concentrations in Cinclidotus transplanted 4 km downstream from the factory reached 0.30 μg g^?1 for PCBs, 2.37 μg g^?1 for α-HCH, 1.29 μg g^?1 for β-HCH and 0.50 μg g^?1 for γ-HCH; mean accumulation factors were 616 for α-HCH, 493 for β-HCH, 294 for γ-HCH and 4867 for PCBs. The preponderence of α- and β-HCH over the other pollutants investigated was also observed in water samples, which shows that aquatic mosses can be used as indicators of chlorinated organic pollutants in freshwaters.     

Studies on the use of inorganic gels in the removal of heavy metals

Chromium ferrocyanide gel shows a great affinity for Ag⁺, Cu²⁺, Tl⁺, Zn²⁺, Co²⁺, Cd²⁺, Mn²⁺ and Fe³⁺ and has been used to separate and recover some heavy metal ions viz. Tl⁺, Hg²⁺, Mg²⁺, Fe³⁺ etc. Some of these can be completely eluted from the columns of this exchanger material and the compound can be used to treat waste water rich in heavy metal ions.     

Water purification from metal ions using carbon nanoparticle-conjugated polymer nanocomposites

The paper deals with a novel method of obtaining nanocarbon-conjugated polymer nanocomposites (NCPC) using nanocarbon colloids (NCC) and polyethylenimine (PEI) for water purification from metal ions. Size of NCC, process of NCPC synthesis, its chemical characteristics, ratio of NCC and PEI in NCPC, speed of coagulation of NCPC, mechanism of interaction of metal ions with NCPC, ability of removing metal ions from water by NCPC against pH have been studied. NCPC has a bonding capacity of 4.0-5.7 mmol/g at pH 6 for most of the divalent metal ions. Percent of sorption of Zn²⁺, Cd²⁺, Cu²⁺, Hg²⁺, Ni²⁺, Cr⁶⁺ ions is higher than 99%. Lifetime of NCPC before coagulation in the treated water is 1 s-1000 min and depends on the ratio of polymeric molecules and carbon nanoparticle concentrations. Results of laboratory tests of the method are described.     

Laboratory and field analysis of pentachlorophenol (PCP) accumulation by salmonids

Rainbow trout were fed diets containing 10–3000 μg kg^?1 pentachlorophenol (PCP) for up to 110 days to examine its accumulation. Fish fed the 10 μg kg^?1 diet maintained whole body levels of 2 μg kg^?1 PCP over the study period, while PCP levels in those fed the 3000 μg kg^?1 diet increased to 40 μg kg^?1 after 40 days, then decreased thereafter to 20 μg kg^?1 at the end of the study. The biological half-life ($\text{T}\text{1}\text{2}$) of PCP in trout was estimated to be approx. 7 days. PCP levels in six species of fish representing two trophic levels from Lake Ontario were also monitored, most species contained 1–10 μg kg^?1 PCP. The results of these and other studies would suggest PCP accumulation in fish is primarily through direct uptake from water rather than accumulation through the food-chain.     

Sewage sludge conditioning by Fe(II)‐activated persulphate oxidation combined with skeleton builders for enhancing dewaterability

In this study, a joint application of Fe(II)‐activated persulphate oxidation and skeleton builders is used to condition sewage sludge for subsequent dewatering. The study mainly focuses on their efficacies and the optimization of the major operational parameters. The experimental results show that the joint application for conditioning sewage sludge is effective, especially using lime and ordinary Portland cement (OPC) as skeleton builders. Additionally, it is revealed that Fe(II)‐activated persulphate oxidation needs sufficient reaction time (20 min) to degrade organics in the sludge. The optimal conditions of this process are at Fe²⁺ = 47.6 mg g^?1 (dry solids), S₂ = 119.1 mg g^?1, lime = 446.4 mg g^?1, and OPC = 297.6 mg g^?1, under which the water content of dewatered sludge cake is 54.8% and the specific resistance to filtration (SRF) is 4.3 × 10¹¹ m kg^?1 with a reduction efficiency of 96.6%.     

A comprehensive study on the biological treatabilities of phenol and methanol—II the effects of temperature,pH, salinity and nutrients

The effects of temperature, pH, salinity, and nutrients on bacterial activities were investigated and evaluated using a statistical method. The substrate utilization rate coefficient (k) decreased as pH deviated from neutral and as salinity increased, and the unfavorable pH and salinity alleviated the temperature effect on k. The modified Arrhenius equation, $\text{k}{}_{\mathrm{<mtext>T2</mtext>}}\text{= k}{}_{\mathrm{<mtext>T1</mtext>}}\text{θ(}{}^{\mathrm{T2?T1}}\text{)}$, was not effective in describing the temperature effect on k: the temperature coefficient (θ) ranged between 1.0–1.4 depending on the temperature range, pH, salinity, and substance (phenol or methanol). The endogeneous respiration activity was affected by various environmental factors such as pH, temperature, and salinity; however, the cell decay coefficient (k_d) turned out to be correlated to a single parameter, k. Thus, k_d = 0.066 k^0.87 and k_d = 0.0115 k^0.634, where k and k_d are based on the unit of h^?1, were proposed for the prediction of cell decay coefficient for phenol and methanol acclimated activated sludge, respectively. In batch treatment of 770 mg l^?1 of phenol and 1000 mg l^?1 of methanol as TOC, nitrogen and phosphorus did not have any recognizable effect on k, while trace elements such as Fe²⁺, Mg²⁺, Mn²⁺, Ca²⁺, and Zn²⁺, etc. showed a slightly perceptible effect on it. The absence of extra-cellular nitrogen and phosphorus resulted in a greater cell yield; however, the cells in this condition decayed more rapidly than normal cells. The primary factor affecting the substrate decomposition rate in natural systems was pH: phenol decomposition resulted in a considerable decrease in pH so that the buffering capacity of the water was the most important factor, and methanol decomposition did not affect pH significantly so that the initial pH of the water was the most important factor. An initial lag phase was observed in 8 out of 115 phenol batch tests and 31 out of 66 methanol batch tests.     

Batch metal removal by peat. Kinetics and thermodynamics

Peat moss, a natural inexpensive material, is able to play an important rôle in treatment processes of metal-bearing industrial effluents since it adsorbs, complexes or exchanges various metal cations. This paper presents kinetics and thermodynamics of batch metal removal reactions by 50 g l⁻¹ (dry wt) eutrophic or oligotrophic peat particles using Cu²⁺, Cd²⁺, Zn²⁺ and Ni²⁺ concentrations ranging from 0.01 to 100 mM.Metal cation removal reactions are moderately rapid in 10 mM metal unbuffered solutions: the forward kinetic constant ranges between 0.005 and 0.17 M⁻¹s⁻¹, and equilibrium is reached within about 1 h. Under these conditions of pH (2.2–4.2) and concentrations, apparent binding equilibrium constants were found to range between 2 and 3150 M⁻¹ depending upon the peat origin and the metal cation.In 0–6.5 pH-buffered metal cation solutions, the four cations binding reactions behaved differently demonstrating that metal binding equilibrium constant decrease in the order Ni²⁺ > Cu²⁺ > Cd²⁺ = Zn²⁺. When pH is higher than 6.7, more than 90% of a 10 mM metal cation solution is removed by 50 g 1⁻¹ peat particles and metal binding capacities equal 200 mmol kg⁻¹ dry wt, whatever the metal nature and the peat origin. Except for nickel cation which is very strongly bound to peat, all metal cations are completely released when pH is fixed below 1.5.     

Metal sorption on blast-furnace slag

The removal of Cu, Ni and Zn-ions from water solution by ungranulated blast-furnace slag has been studied depending on contact time, initial ion concentration, pH and solution temperature. The polymineral composition and the slag specific properties determine its high sorption activity in metal salts solutions. In the range of the concentrations studied (10⁻⁴–10⁻³ M), the sorption data for Cu²⁺, Ni²⁺ and Zn²⁺ have been described using Freundlich's parabolic equation. The material's own alkalizing activity creates conditions for effective metal ions sorption in a wide pH range. With the temperature increase the hydrolysis of the sorption matrix intensifies which leads to the sorption improvement. On the basis of both literature data and the author's own data the mechanism of metal ions removed by blast-furnace slag has been discussed.     

Accumulation de quelques metaux lourds (Cd,Cu, Pb et Zn) chez l'eperlan (Osmerus mordax) preleve sur la rive Nord de l'Estuaire du Saint-LaurentHeavy metal accumulation (Cd,Cu, Pb and Zn) by smelt (Osmerus mordax) from the North shore of the St Lawrence estuary

Heavy metals in trace amounts are normal constituents of marine organisms. At sufficiently high concentrations, heavy metals are toxic to living organisms and so it is important to know by how much their concentration may be increased before effects on marine or estuarine populations can be detected or commercial species become unsuitable as food. A method of removing metals is by storage in a particular tissue. Several different sites for storing metals were investigated and concentrations of Cd, Cu, Pb and Zn were examined in muscle, liver and gonads of the smelt (Osmerus mordax) from the North shore of the St Lawrence estuary. Copper and zinc are constituents of several enzymes and are absolutely essential for normal growth and development, while cadmium and lead are not known to have necessary physiological function. A modified wet digestion procedure was used to prepare biological samples for the determination of trace elements by flameless atomic absorption spectrophotometry procedure, using calibration standards made up in a matrix of similar acidity (Table 1). NBS reference material bovine liver was analyzed along with the samples and the results were within the specified tolerance (Table 2). Analyses were reported on a dry weight basis (Table 3) and the correlations with total body weight were determined by regression analysis. Copper (range 0.3–3.3 μg g^?1) and zinc (range 19–38 μg g^?1) in muscle fillets were found to be negatively correlated with total body weight (Fig. 1). Apparent decreasing concentrations in these two metal levels in muscle sample with increasing body weight were possibly due to factor such as dilution with growth. Growth may dilute metal concentrations in an organism if tissue is added faster than metal. Livers and gonads contained greater levels of the four metals than somatic muscle. Liver metal concentrations of Zn (range 29–108 μg g^?1) and Cd (range 0.06–0.37 μg g^?1) increased with total body weight. All equations fit data at P < 0.01 (Fig. 2). Positive correlations between size and metal concentrations suggest that net uptake may occur. Inessential, slowly exchanging metals such as Cd appear to reflect an uptake which tend to become a cumulative process (age dependence of concentrations). The occurrence of insignificant correlation between liver concentrations of Cu (mean value: 4 μg g^?1) and environmental concentrations of this metal was consistent with equilibration. Since fish are known to possess the metal binding protein metallothionein, a sequestering agent, detoxification of these metals in fish liver may be by sequestration rather than elimination. Increasing metal concentrations in liver may represent storage of sequestered products in that organ. In the gonads, no significant relationship exists between total body weight and trace metal contents. Results of t-test indicated that females had significantly greater Cu and Zn concentrations, but no significant difference existed between males and females for Cd concentrations (Figs 3 and 4). Thus, the relation between concentration and total body weight appears to be specific as to the species, tissues analyzed and environmental conditions. The comparison of metal concentrations in fish to assess variations in contamination levels requires understanding the relationship between metal concentration and body size within each population.     

Determination of trialkyl and triaryl phosphates in environmental samples

Analytical methods of trialkyl and triaryl phosphate esters in water and sediment were developed. An environmental survey of them was performed using developed methods. The extract with dichloromethane (water sample) or acetone (sediment sample) was analyzed with a gas chromatograph equipped with a flame photometric detector and a gas chromatograph/mass spectrometer after clean-up through Florisil column. The separation of gas chromatography was good with 2% OV-17 + 2% PZ-179 on Uniport HPS. Recoveries fortified with 0.3–3 μg were 71–98% for water sample and 78–95% for sediment sample. In the environmental survey, tributyl phosphate (5–36 ng l^?1), Tris (3-chloropropyl) phosphate (16–176 ng l^?1), Tris (2-chloroethyl) phosphate (TCEP) (14–347 ng l^?1), Tris (2,3-dichloropropyl) phosphate (CRP) (23–136 ng l^?1), triphenyl phosphate (13–31 ng l^?1), and tricresyl phosphate (67–259 ng l^?1) were detected in river water and seawater, and TCEP (13-28 ng g^?1) and CRP (9–17 ng g^?1) were detected in sediment.     

Heavy metal accumulation by aquatic fungi and reduction in viability of Gammarus pulex fed Cd contaminated mycelium

The addition of Pb²⁺ (1.0 and 2.5 μg ml⁻¹) and Cd²⁺ (2.5 and 5.0 μg ml⁻¹) to growth medium decreased the growth of aquatic fungi, while Zn²⁺ even at a concentration of 10 μg ml⁻¹ had no inhibitory effect. Low concentrations of Cd²⁺ and Zn²⁺ on the other hand stimulated mycelial growth. The fungi accumulated considerable amounts of metal from the growth medium, generally in the order Zn²⁺ > Pb²⁺ > Cd²⁺ · Cd²⁺ was also accumulated by fungi from successive changes of medium containing low concentrations of the metal. Application of Langmuir and Freundlich isotherms to the results showed that the metals were accumulated largely by adsorption to the surface of the mycelium.Three species of aquatic fungi supported the growth of the freshwater shrimp. Gammarus pulex when provided as sole food source, sustaining from 30 to 60% of shrimps fed for a period of 21 days. A marked reduction in shrimp viability occurred however, when G. pulex was fed Pythium sp. containing Cd²⁺ (150–170 μg g⁻¹), with none of the shrimps surviving beyond 13 days, compared with a survival rate of 60% after 21 days for shrimps fed uncontaminated mycelium. Bodies of poisoned shrimps sampled on day 13 were found to contain Cd²⁺ (22.03 μg g⁻¹) showing that the metal can be transferred from aquatic fungi to G. pulex, the first step in a food chain involving freshwater fish and higher organisms.     

Temporal and spatial inhibitory effects of zinc and copper on wastewater biofilms from oxygen concentration profiles determined by microelectrodes

To understand the temporal and spatial toxic effect of heavy metals on the microbial activities of biofilms, microelectrodes were used to measure the inhibitory oxygen (O₂) concentration profiles resulted from the effects of zinc (Zn²⁺) and copper (Cu²⁺). Using the O₂ microprofiles as bases, the spatial distributions of net specific O₂ respiration were determined in biofilms with and without treatment of 5 mg/L Zn²⁺ or 1 mg/L Cu²⁺. Results show that microbial activities were inhibited only in the outer layer (∼400 μm) of the biofilms and bacteria present in the deeper sections of the biofilms became even more active. The inhibition caused by the heavy metals was evaluated by two methods. One was derived from the oxygen influx at the interface and the other was based on the integral of the oxygen consumption calculated from the entire O₂ profile. The two methods yielded significantly different results. We argue that the integral method results in more accurate assessment of toxicity than the surface flux determination.     

Photodegradation of selected β-blockers in aqueous fulvic acid solutions: kinetics, mechanism, and product analysis

The photodegradation of the widely used β-blockers atenolol and metoprolol were investigated in the presence of fulvic acid (FA) under simulated sunlight. Both atenolol and metoprolol undergo indirect photodegradation in the FA solutions. The triplet excited state of FA (³FA^∗) was verified to be main reactive species responsible for the photosensitized degradation of β-blockers. An electron transfer mechanism for the interaction between β-blockers and ³FA^∗ was proposed on the basis of a series of experiments. Magnetic property of metal ions exhibited significant impact on photosensitized degradation. Diamagnetic metal ions such as Mg²⁺, Ca²⁺, Zn²⁺, and Al³⁺ negligibly affected the degradation. In contrast, paramagnetic metal ions including Mn²⁺, Cu²⁺, Fe³⁺, and Cr³⁺ markedly inhibited the reactions in the order of Cr³⁺ < Fe³⁺ < Cu²⁺ < Mn²⁺. The inhibition was related to the complexation ability with FA. By LC-ESI-MS/MS analysis, deisopropyl-atenolol (metoprolol) was identified as the main photosensitized product. The degradation pathways of β-blockers involving electron transfer processes were proposed. This finding strongly suggests that ³FA^∗ was important reactive species for the degradation of β-blockers in natural waters.     

Removal of Cu(II), Ni(II), and Co(II) from aqueous solutions using layered double hydroxide intercalated with EDTA

A sample of a layered double hydroxide intercalated by EDTA has been synthesized and its chemical formula [Zn₄Al₂(OH)₁₂](EDTA) · 8H₂O was determined. The possibility of applying such sorbent for the extraction of Cu(II), Ni(II), and Co(II) from aqueous solutions was investigated. Comparative investigation of the sorption capacity of carbonate and chelate forms of layered double hydroxides was performed. It is shown that the degree of extraction of metals on sorbent [Zn₄Al₂(OH)₁₂](EDTA) · 8H₂O completely correlates with the stability of complex compounds of these metals in the solution.     

Releasing behavior of zinc in recirculated bioreactor landfill

The purpose of this research was to determine the releasing behavior of zinc in municipal solid waste (MSW) in landfill site with respect to refuse and leachate as an inseparable system. Two simulated bioreactor landfills, one with leachate recirculation and the other without, were operated in room temperature for 320 days. Results showed that the content of zinc in MSW could amount to 591.29 ± 31.33-632.14 ± 18.98 µg g ^− 1 dry weight ^− 1 (DW ^− 1). It exceeded the set standard for “Environmental quality standard for soil” (≤ 500 µg g ^− 1 DW ^− 1) and had high potential environmental risk. The releasing behavior of zinc in refuse mainly experienced speciation of solid-Zn, Zn²⁺, ZnHCO₃⁺, ZnCO₃, Zn(OH)⁺, Zn(OH)₂, Zn(NH₃)₄²⁺, ZnS, etc. Zinc in refuse showed behaviors of staggered migration and retention, which corresponded with the degradation process of refuse in bioreactor landfill. The Zn²⁺ concentration in leachate, which varied correspondingly with releasing behavior of zinc in refuse, were 0.75 mg L ^− 1 to 3.13 mg L ^− 1 and had no great difference in landfill with different operation modes (CL and RL). However, the amount of Zn²⁺ leached out from refuse, which accounted for 28.70 mg and 130.67 mg after 320 day's operation, respectively. More attention should be paid to the inseparable system including refuse and leachate together.     

Uptake of metal ions by chemically treated human hair

The uptake capacity of chemically treated human hair waste for the various metal ions can be arranged in the following decreasing order: Hg²⁺ (Hg⁺), Ag⁺, Pb²⁺, Cd²⁺, Cu²⁺ (Cu⁺), Cr⁶⁺, Ni²⁺, Cr³⁺.The uptake capacity is significantly affected by the presence of other metal ions. Anionic effect was found to be more pronounced for a mixed ions system than for a single ion system.