A field study investigating the potential use of phosphorus combined with organic amendments on cadmium accumulation by wheat and subsequent rice

A field study was performed to determine the efficiency of diammonium phosphate (DAP) applied alone or combined with biochar, lignite, and farmyard manure (FYM) on growth and cadmium (Cd) accumulation in wheat and rice. Before crop sowing, different treatments were applied in the field such as a control (T₁), DAP alone (0.1%, T₂), DAP + lignite (0.05% each, T₃), DAP + FYM (0.05% each, T₄), and DAP + biochar (0.05% each, T₅). Afterwards, the wheat seeds were sown in the soil. At wheat postharvest, rice was sown without any further treatment. Raw effluent was applied as an irrigation source during the whole growth period of both crops since it is the common practice of the farmers of study area. It was revealed that the use of amendments enhanced the yield and photosynthesis but lowered the Cd contents in straw as well as grains of both crops. In both crops, the highest yield of straw and grain was found in DAP + FYM whereas the lowest Cd concentration was found in DAP alone. The ammonium bicarbonate-DTPA extractable Cd of post wheat and post rice soils were decreased while the soil pH and immobilization index were increased in all treatments as compared with the control. The present field study highlighted that the DAP + FYM can be effective in increasing yield with decreased Cd concentrations in crop grains.     

Dispersion model and bioaccumulation factor validating trace metals in sea bream inhabiting wastewater drain outfalls

Our study was based on the recent increase in wastewater pollution and its deleterious effects to the marine ecosystem. Using numerical simulation (DESCAR-3.2 software program), we investigated the orientation and quantification of trace metals in wastewater discharges from permanent and semi-permanent drain outfalls constructed along the Kuwait Coastline encompassing six Kuwait Governorates (GI-GVI). This study was related to trace metals toxicity and bioaccumulation effects on the commercial yellow fin Sea bream, Acanthopagrus latus fish using probit program and bioaccumulation factor (BAF), respectively. Observations from wastewater discharges showed high trace metals concentrations in the sequence of Zn > Cr > Cu > Fe > Ni > Pb > Hg during winter compared to summer and in GI and GIV compared to drain outfalls in the other Governorates. Seasonally, trace metals in A. latus revealed the sequence of Zn > Fe > Cu > Ni > Cr > Pb > Hg in GI, GII and GIV indicating the significance of toxic metals that bioaccumulated from their surrounding untreated wastewater. Toxicity test revealed A. latus highly sensitive to Hg even at low lethal concentrations (LC₁₅) compared to other metals. BAF in A. latus body parts was >1 indicating significant accumulation of trace metals from wastewater. However, BAF was <1 in Cr suggesting that A. latus could absorb trace metals from multiple sources over lengthy exposure period and not necessarily from wastewater containing rich Cr levels. Thus, the present findings validate A. latus as bioindicator to pollution more authentically by numerical simulation, toxicity and bioaccumulation tests compared to the traditional method of labeling A. latus as a pollution indicator.     

Assessing cadmium risk in wheat grain using soil threshold values

At present, the prior-established threshold values are widely used to classify contaminated agricultural soils with heavy metals under the cultivation of a variety of crops, without considering the different sensitivity of plants to heavy metals. Evaluation of the characteristics of cadmium transfer from a polluted calcareous soil to cultivated wheat crop and assessment of the efficiency of using the threshold values to reflect the soil pollution risk by cadmium in Zanjan Zinc Town area at the northwest of Iran were the goals of this study. Totally, 65 topsoil (0–20 cm) and corresponding wheat samples of an agricultural region in the proximity of a metallurgical factory were collected and analyzed for cadmium concentration. The results revealed that industrial activities strongly control cadmium distribution in the studied soils. Relatively high bioavailable cadmium contents (mean 0.77 mg kg^?1) were found in the soils, notwithstanding their alkalinity. It was observed that just 22.5% of the studied area around the Zinc Town is covered by polluted soils with the cadmium concentration exceeding the maximum permissible concentration of 5 mg kg^?1, whereas cadmium concentration in wheat grains of 19 sampled plants is higher than the threshold value of 0.2 mg kg^?1. Among these polluted plants, a total of eight samples were grown in areas classified as unpolluted soils with cadmium, based on the soil threshold value. It seems that this misclassification of polluted soils is mainly related to the crop sensitivity to heavy metals uptake from the soil which should be considered.     

Heavy metal exposure from co-processing of hazardous wastes for cement production and associated human risk assessment

This study was carried out to determine the concentration of heavy metals (Cd, Ni, Pb, Cr, Ni and Zn) in ordinary Portland cement (OPC) produced from the co-processing with hazardous waste in comparison with OPC produced using natural raw materials. The results showed that the concentration of heavy metals in cement produced from natural raw material was in the order of Zn > Pb > Cr > Ni > Cu > Cd. Zn and Cd were the highest and the lowest concentrations, respectively, in cements produced from the co-processing activity. The difference between heavy metals concentrations in OPC produced with and without co-processing was found to be statistically significant. The concentration of heavy metals in the cement produced is generally factory dependent. The human risk assessment associated with the heavy metals for non-carcinogenic and carcinogenic risks has been evaluated. The calculated hazard index (HI) and total lifetime cancer risks (LCR) were lower than the acceptable threshold reference values, HI < 1 and LCR < 1 × 10^?4, respectively. Thus, it is anticipated that there is no potential of non-carcinogenic and carcinogenic risks for both adult and children. However, the findings indicated that there is a need for regulatory monitoring. The exposure pathway for both non-carcinogenic and carcinogenic risks are both in the order of ingestion > dermal > inhalation.     

Assessment of the selected trace metals in relation to long-term agricultural practices and landscape properties

Understanding of the landscape response to agricultural practices mainly in relation to soil trace metals requires particular attention. Consistent with this, the trend and possible pollution of total and DTPA fraction of Mn, Zn, Cu, and Cd in the agricultural soils developed on different landscape positions involving piedmont alluvial plain (PAP), river alluvial plain (RAP), plateau (PL), and lowland (LL) were investigated. The content of the metal in different soil profiles, grouped by landscape positions, varied in the following orders: total and DTPA-Mn as LL > PAP > RAP > PL, total Zn and Cu as PAP > RAP > LL > PL, total Cd as RAP > PAP > PL > LL, DTPA-Zn as RAP > PAP > PL > LL, and DTPA-Cu as RAP > LL > PL > PAP. A wide variation in the total fraction of Mn (89–985 mg kg^?1), Zn (24–152 mg kg^?1), Cu (8–27 mg kg^?1), and Cd (0.6–1.7 mg kg^?1) and in the DTPA fraction of Mn (1.2–11 mg kg^?1), Zn (0.3–4.4 mg kg^?1), Cu (0.3–3 mg kg^?1), Cd (0.03–0.09 mg kg^?1) observed as a result of the effects of agricultural practices and landscape properties. The values of both total and DTPA-extractable Mn, Zn, and Cu were enriched in the AP horizon probably due to anthropogenic activities particularly successive use of agrochemical compounds and manure during numerous years. Using soil pollution indices [single pollution (PI) and comprehensive pollution (PIN)], the study soils were categorized mainly as low to moderate pollution and Zn was identified as the major element affecting on the yield of these indices.     

Comparison of different methods for assessing heavy metal contamination in street dust of Xianyang City, NW China

Street dust is one of the important indicators that reflect the status of urban environmental pollution. There are many studies of heavy metals contamination of street dust in capital cities; however, little attention has been paid to this kind of study in medium cities, including China. The dust samples were collected in the district of traffic crossroads in Xianyang city, Shaanxi Province. Pb, Cd, Cu, Ni, Zn, Cr and Mn concentrations were determined using atomic absorption spectrometry (AAS). The results indicate that the concentrations of heavy metals are higher than the background values of soils in Shaanxi Province. The contamination level of heavy metals is assessed by potential ecological risk index (E _r), geoaccumulation index (I _geo), enrichment factor (EF) and pollution index (Pi). The low I _geo, EF, E _r, Pi and PI_n (integrated pollution index) for Mn in street dusts indicate an absence of distinct Mn pollution. The high EF, Pi and PI_n of Cu and Zn indicate that there is considerable Cu and Zn pollution. It is suggested that more attention should be paid to heavy metals contamination of Cu and Zn. The assessment results of Pi and PI_n suggest that Pb, Ni and Cr present strong pollution; however, their EFs indicate that they cause moderate pollution and their I _geo indicates that they are unpolluted to moderately polluted. The contamination class value with different assessing methods is of the order: Pi ≈ PI_n > EF > I _geo > E _r.     

Phytoremediation assessment of native plants growing on Pb–Zn mine site in Northern Tunisia

Pollution by heavy metals presents an environmental concern, and their toxicity threats soil, water, animals and human health. Phytoremediation can be used as a solution to remediate contaminated soils. The aim of this study was to identify native plants collected from tailings: material of Pb–Zn mine sites of Fedj Lahdoum and Jebel Ressas (two abandoned mines located, respectively, in the northwest of Tunisia and in the south of Tunis City). The tolerance of plant to heavy metals (lead, zinc and cadmium) is evaluated. Soil samples were collected and analyzed for Pb, Zn and Cd concentration. The total soil Pb, Zn and Cd are, respectively, reached 6132 mg kg^?1, 11,052 mg kg^?1 and it doesn’t exceed 479 mg kg^?1 for Cd. The highest content of Zn in plants was detected in shoots of Rumex bucephalophorus (1048 mg kg^?1), and the highest Pb concentration was detected in roots of Chrysopogon zizanioides (381 mg kg^?1), while for Cd Silene colorata it accumulated the highest content in roots (51 mg kg^?1). From all plants, only 12 have a translocation factor for Pb which is higher than one. Among all plants, only 17 have a translocation factor that is higher than one for Zn, while for Cd only 13 plants indicate TF > 1. As for the biological absorption coefficient, all samples indicate a rate which is lower than one. These plants can be primarily hyper accumulators and useful in remediation of lead- and zinc-contaminated soils after further biochemistry researches in mechanism of accumulation and translocation of heavy metals in plants.     

Potential ecological risk assessment of heavy metal contamination in sediment and water body around Dhaka export processing zone,Bangladesh

Sediments and surface water contamination by the industrial effluents containing heavy metals is the most detrimental environmental impact. Therefore, the present work attempts to determine the status of eight heavy metal distribution in sediments and water samples, and their ecological risks’ assessment in the studied area. The distribution pattern of heavy metals in the water and sediment follows the sequences: Zn > Cu > Pb > Cr > Mn > Ni > As > Cd and Mn > Zn > Cr > Pb > Cu > Ni > As > Cd, respectively. Gross water pollution is observed at different sampling points of Dhalai Beel and Bangshi River. The comparison of sedimentary mean metal concentrations with several environmental contamination monitoring parameters, viz, threshold effect level (TEL), probable effect level (PEL), and severe effect lever (SEL) indicates that the metal levels are less than PEL except Cr. Moreover, the level of contamination degree (C _d) and modified degree of contamination (mC _d) indicates ‘low’ and ‘nil to low’ degree of contamination, respectively. Pollution load indices (PLI) of the studied area are lower than unity, indicates no pollution. Furthermore, a toxic-response factor is applied to assess the potential ecological risk of these heavy metals into the water body. The results of this study exhibit a low potential ecological risk of heavy metals. The Pearson’s correlation and cluster analysis are also performed to assess the heavy metal interactions in water and sediment samples.     

Spatial and temporal variations of physicochemical and heavy metal pollution in Ramganga River—a tributary of River Ganges,India

The River Ganges being the most sacred river and lifeline to millions of Indians in serving their water requirements is facing excessive threat of pollution. Under various river management and conservation strategies for its protection, the assessment of water quality of its main tributary Ramganga River is lacking. This study focuses on assessment of physicochemical and heavy metal pollution of the Ramganga River by application of multivariate statistical techniques. Sampling of Ramganga River at sixteen sampling sites was carried out in three seasons (summer, monsoon and winter) of 2014. The collected water samples were analyzed for physicochemical parameters and heavy metals. Results from cluster analysis (CA) of the data divided the whole stretch of the river into three clusters as elevation from 1304 to 259 m as less polluted, from 207 to 154 m as moderately polluted and from elevation 154 to 139 m as high-polluted stretches with anthropogenic as main sources of pollution in high-polluted stretch. Principal component analysis of the seasonal dataset resulted in three significant principal components (PC) in each season explaining 72–8% of total variance with strong loadings (>0.75) of PC1 on fluoride (F^?), chloride (Cl^?), sodium (Na⁺), calcium (Ca²⁺), magnesium (Mg²⁺), bicarbonate (HCO₃ ^?), total dissolved solids and electrical conductivity. Temporal variation by one-way ANOVA (Analysis of Variance) showed significant seasonal variation was in the pH, chemical oxygen demand, biochemical oxygen demand, turbidity, HCO₃ ^?, F^?, Zn, cadmium (Cd) and Mn (p < 0.05). Turbidity showed approximately a twofold increase in monsoon season due to rainfall in the catchment area and subsequent flow of runoff into the river. Concentration of HCO₃ ^?, F^? and pH also showed similar increase in monsoon. The concentration of Zn, Cd and Mn showed an increasing trend in summers compared to monsoon and winter season due to dilution effect in the monsoon season and its lasting effect in winters.     

Phosphorus speciation and changes with depth in the sediment of Lake Illawarra,New South Wales,Australia

In order to better understand phosphorus (P) cycling and origins in the sediment of the Lake Illawarra, two sediment cores were extracted in November, 2010 and a modified sequential extraction scheme (SEDEX) was used to profile the exchangeable P (P_ex), reactive Fe/Al-bound P (P_reac), reductive Fe/Al-bound P (P_redu), authigenic apatite P (P_auth), detrital P (P_det), organic P (P_org) and residual P (P_resi). The total sedimentary P (TP) ranged from 93 to 437 μg g^?1, and was dominated by inorganic P. The average percentage of each fraction of P in the sediment followed the sequence: P_reac (28.6 %) > P_resi (23.5 %) > P_auth (19.1 %) > P_redu (17.0 %) > P_org (4.9 %) > P_ex (4.7 %) > P_det (2.2 %). The profiles of TP and P_org showed two peak values with depth, which were matched to land use history in the Lake Illawarra catchment. The sediment depth profiles indicated that Fe oxyhydroxides play a predominant role in the P cycle in the sediments of the lagoon. This is supported by significant positive correlation between P_reac and reactive Fe and a negative correlation between P_auth and Fe. P_auth and P_reac concentrations were also well negatively correlated, possibly a result of competitive equilibrium between Fe and Ca for P. The estimated P burial efficiency was up to 82 % for this lagoon, which is likely related to the high sediment accumulation rate and the high value of R _Fe-P. In addition, the bioavailable P, which consists of P_ex, P_reac, and P_org, represented a significant proportion of the sedimentary P pool, accounting, on average, for 38 % of the TP. This result indicates that the sediment is a potential internal source of P for this lake ecosystem.     

Contamination assessment and health risk of heavy metals in dust from Changqing industrial park of Baoji,NW China

The contents of Co, Cr, Cu, Mn, Ni, Pb and Zn in the dust samples collected from Changqing industrial park of Baoji city, NW China, were measured by XRF, while As and Hg in the dust samples were analyzed by AFS. Geo-accumulation index (I _geo), pollution index (PI) and integrated pollution index (IPI) were calculated to evaluate the heavy metal contamination level of dust. The health risk due to exposure to heavy metals in dust was analyzed by the Health Risk Assessment Model of US EPA. The results show that the arithmetic means of As, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn are 23.3, 16.4, 1591.8, 178.2, 0.243, 346.5, 40.2, 1,586.2 and 1,918.8 mg kg^?1, respectively, which are higher than the background values of Shaanxi soil, especially for Cr, Cu, Hg, Pb, and Zn. The mean values of I _geo reveal the order of Pb > Zn > Cr > Hg > Cu > As > Co > Ni > Mn. The high I _geo of Cr, Cu, Hg, Pb and Zn in dust indicates that there is considerable pollution from Cr, Cu, Hg, Pb and Zn, while the low I _geo of As, Co, Mn and Ni presents no pollution in dust. The assessment results of PI support the results of I _geo, and IPI indicates heavy metals in dust polluted seriously. The health risk assessment shows that ingestion of dust particles is the route for exposure to heavy metals from dust, followed by dermal adsorption. Exposure to As, Cr and Pb from dust may pose a potential health threat to children and adults. The risk of cancer from As, Co, Cr and Ni due to dust exposure is low.     

Assessment of spatial distribution and possible sources of heavy metals in the soils of Sariseki-Dörtyol District in Hatay Province (Turkey)

In this study, total heavy metal content of soil and their spatial distribution in Sar?seki-Dörtyol district were analyzed and mapped. Variable distance grids (0.5, 1.0 and 2.0 km) were established, with a total of 102 soil samples collected from two different soil depths (0–5 and 5–20 cm) at intersections of the grids (51 sampling point). Soil samples were analyzed for heavy metals (Cd, Co, Cr, Cu, Pb, Zn, Mn, Fe, and Ni). The most proper variogram models for the contents of all heavy metal were spherical and exponential ones. The ranges of semivariograms were between 1.9 and 31.1 km. According to the calculated geoaccumulation (I _geo) values, samples from both soil depths were classified as partly to highly polluted with Cd and Ni and partly polluted with Cr and as partly polluted-to-not polluted with Pb and not polluted with Cu, Fe and Mn. Similar results were also obtained when evaluated by the enrichment factor. The contamination levels of the heavy metals were Ni > Cd > Cr > Pb > Zn > Cu > Co > Fe > Mn in decreasing order. The soils in the study area are contaminated predominantly by Cd and Ni, which may give rise to various health hazards or diseases. Cadmium pollution results primarily from industrial activities and, to a lesser extent, from vehicular traffic, whereas Ni contents in the study area result from parent material, phosphorus fertilizer, industries, and vehicles.     

Thermal expansion and high-temperature P21/c–C2/c phase transition in clinopyroxene-type LiFeGe2O6 and comparison to NaFe(Si,Ge)2O6

A synthetic clinopyroxene with composition LiFe³⁺Ge₂O₆, monoclinic s.g. P2₁/c, a = 9.8792(7), b = 8.8095(5), c = 5.3754(3) Å, β = 108.844(6)°, V = 442.75(16) ų, has been studied by in situ low- and high-temperature single-crystal X-ray diffraction. The variation of lattice parameters and the intensity of the b-type reflections (h + k = 2n + 1, only present in the P-symmetry) with increasing temperature showed a displacive phase transition from space group P2₁/c to C2/c at a transition temperature T _tr = 789 K, first order in character, with a sudden volume increase of 1.6% and a decrease of β by 1° at the transition. This spontaneous dilatation is reversible, shows a limited hysteresis of ±10°C, and corresponds to the vanishing of the b-type reflections, thus indicating a symmetry increase to space group C2/c. Below T _tr an expansion is observed for all the cell parameters, while the β angle remained almost constant; at T > T _tr the thermal volume expansion is due to dilatation of the structure in the $(\bar{1}\,0\,1) A synthetic clinopyroxene with composition LiFe³⁺Ge₂O₆, monoclinic s.g. P2₁/c, a = 9.8792(7), b = 8.8095(5), c = 5.3754(3) ?, β = 108.844(6)°, V = 442.75(16) ?³, has been studied by in situ low- and high-temperature single-crystal X-ray diffraction. The variation of lattice parameters and the intensity of the b-type reflections (h + k = 2n + 1, only present in the P-symmetry) with increasing temperature showed a displacive phase transition from space group P2₁/c to C2/c at a transition temperature T _tr = 789 K, first order in character, with a sudden volume increase of 1.6% and a decrease of β by 1° at the transition. This spontaneous dilatation is reversible, shows a limited hysteresis of ±10°C, and corresponds to the vanishing of the b-type reflections, thus indicating a symmetry increase to space group C2/c. Below T _tr an expansion is observed for all the cell parameters, while the β angle remained almost constant; at T > T _tr the thermal volume expansion is due to dilatation of the structure in the ([`1] 0 1)(\bar{1}\,0\,1) plane, mostly along [0 1 0], and pure shear in the (0 1 0) plane due to the decrease of β. From comparison with silicate analogues, the germanate clinopyroxenes are more expansible, while the P2₁/c expands more than the C2/c phase. The evolution of Q ² (calculated as the normalized intensity of b-type reflections) with T in the framework of the Landau theory has been done using a standard expression for a first order phase transition. We observe a jump of Q ₀² = 0.538(2) at T _tr, with T _c of 481(7) K, b/a = −2,290 K, and c/a = 3,192 K, and thus far from being tri-critical point. A closely related composition (LiFe³⁺Si₂O₆) shows an equivalent phase transition at 228 K, which is very close to the tri-critical point and 561 K cooler. This result indicates that a change in the composition of tetrahedral sites can have dramatic effects on the P2₁/c ↔ C2/c displacive phase transition in clinopyroxenes. The major changes observed in the evolution of the crystal structure with T are observed in the M2 polyhedron, with a volume decrease by ca. 13.3%, compared to ca. 1.3% observed in the M1 polyhedron. The tetrahedra behave as rigid units with neither a significant change of volume at T > T _tr (<1‰), nor a change of tilting of the basal plane. No change in coordination is observed at T > T _tr in the M2 polyhedron, which remains sixfold coordinated although a strong deformation of this polyhedron is observed. This deformation is related to a strong change by 51.4° at T _tr of the kinking angle (O3–O3–O3 angle) of the B-chain of tetrahedra, which switches from O-rotated to S-rotated [from 143.3(5)° to 194.7(6)°]. The A-chain is S-rotated at T < T _tr [206.8(5)° at 703 K] and extends by 12° at the transition.     

Impact of biochar,bentonite, and compost on physical and chemical characteristics of a sandy soil

In this study, bentonite (Ben), compost (Com), and biochar (Bio) were used as soil amendments to enhance sandy soil physical properties. A soil column experiment was conducted in a laboratory. Application rates were 3% (weight/weight) of Bio (T₁), Ben (T₂), and Com (T₃). Furthermore, mixtures 1.5% and 1.5% of Bio and Ben (T₄), Ben and Com (T₅), and Bio and Com (T₆), and a mixture 1%, 1%, and 1% of Bio, Ben, and Com (T₇) in addition to control treatment were adopted. The mixtures of amendments and sandy soil were concentrated at the top 10 cm of columns. Results revealed that the cumulative evaporation was reduced by 2.3% and 5.7% as a result of using T₃ and T₅, respectively. However, the remaining treatments enhanced the cumulative evaporation. The application of amendments increased the capacity of the soil to maintain water by 35.4%, 24.4%, 13.3%, and 10.2%, for soils treated with T₅, T₃, T₇, and T₄, respectively. The water content at field capacity had the highest increase in the top 10 cm when treatment T₃ was used. Although T₃ (compost) was the most efficient for enhancing soil physical properties, this study recommends T₅ and T₇ to improve hydraulic properties of sandy soils. This is due to the fact that biochar and bentonite remain in the soil for a longer period and resist biodegradation while compost overcomes the negative impact of soil chemical properties as a result of biochar and bentonite additions.     

Composition of selected heavy metals in road dust from Kuala Lumpur city centre

This study was carried out in order to determine the concentration of heavy metals, e.g., lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), nickel (Ni) and chromium (Cr) in road dust in Kuala Lumpur’s city centre. Samples were collected from four sampling locations, each of which had four sampling points and three replications. Heavy metals from different fractions of particles separated by different diameter sizes: d < 63 μm (Fraction A), 63 < d < 125 μm (Fraction B) and 125 < d < 250 μm (Fraction C) were analyzed using inductively coupled plasma mass spectrometry. The results from this study showed that concentration of heavy metals was dominated by the smallest particle size: <63 μm and that Fe was the most abundant heavy metal overall, followed by Cu > Mn > Zn > Pb > Ni > Cr > Cd. The fact that Cd had the highest enrichment factor value (EF) for all particle sizes indicates that anthropogenic activities contributed to the presence of this metal. There was also a higher EF value for heavy metals in small particle (Fraction A), compared to Fraction B and C, which suggests that fine particles were being produced through anthropogenic activities. Cluster analysis and principal component analysis demonstrated the likelihood of the heavy metals detected in the road dust, originating from road traffic and industrial activities.     

Characterization of PM10 in the ambient air during Deepawali festival of Rajnandgaon district, India

Deepawali is one of the main festivals for Hindu religion which falls in the period October–November every year with great fireworks display. In this study, we investigated the levels of water soluble ions and heavy metals—during the fireworks festival in Rajnandgaon, Central India. The chemical compositions and noise level distributions are reported from the sampling site. First time during Deepawali, air quality was studied in this area, The Aerosol samples of PM₁₀ (particle aerodynamic diameter <10 μm) are collected in October 24–28, 2011. Aims of the present studies are (1) To describe the particulate concentrations and associated chemical species during Deepawali festival, (2) To recognize the noise level in Deepawali festival. For study, the samples were collected in glass fiber filter paper and analyzed for the major water soluble ions F^?, Cl^?, NO₃ ^?, SO₄ ^2?, Na²⁺, NH₄ ⁺, K⁺, Ca²⁺, and Mg²⁺ employing ion chromatograph. Concentration of heavy metals was analyzed by ICP-MS and was observed to occur in order Fe > Zn > Pb > Ni > Cr > Cd. The result revels that all concentration are above the permissible limit fixed by CPCB, USPEA, and WHO standard. It is concluded that the burning of fireworks during Deepawali festival was the main source of heavy metals and ion.     

Contamination and ecological risk assessment of heavy metals in street dust of Tehran,Iran

Heavy metals are introduced in human tissue through breathing air, food chain and human skin. They can cause damage to the nervous system and internal organs. In the present study, sixty street dust samples were collected from the central area of Tehran and were digested in the laboratory to determine the content of Zn, Ni, Cd, Cr, Cu and Pb, using inductively coupled plasma optical emission spectrometry (ICP-OES). The level of contamination with the analyzed metals was determined according to the following indices: geo-accumulation index (I _geo), enrichment factor (EF), pollution index (PI), integrated pollution index (IPI) and potential ecological risk index (RI). The average concentration of heavy metals found was in the order of Zn > Cu > Pb > Ni > Cr > Cd. The average I _geo values for Cd, Cr, Cu, Ni, Pb and Zn were 1.53, ?1.88, 2.68, ?0.67, 1.62 and 2.70, respectively. Among the investigated heavy metals, zinc and copper had the maximum average EF values and were placed into the “very severe enrichment” class. Potential ecological risk factor (E _r) also indicated that Cd had the highest risk, and it was classified as of considerable potential ecological risk. Therefore, it is necessary to pay more attention to the appearance of Cd in the human environment. The calculated potential ecological risk index values also illustrated that the street dust samples presented a “moderate ecological risk.” The calculated IPI values showed that the pollution levels of the street dust samples ranged from high to extremely high.     

Sorption of heavy metals from aqueous solution by dehydrated powders of aquatic plants

Ruppia maritima and Echinodorus amazonicus were prepared in a dehydrated powder form. The characteristics and mechanisms of adsorption of heavy metals were studied under various pH values, reaction times, and heavy metal ion concentrations. The results showed that under different pH and reaction time conditions, heavy metal adsorption was lead > cadmium > zinc > copper. The adsorption of lead increased linearly with the lead concentration. For cadmium, zinc and copper, the adsorption was saturated when metal ion concentration exceeded 200 mg/L. When a Freundlich model was applied, R ² values for the heavy metal adsorption by the aquatic plants mostly exceeded 0.9. The adsorption of heavy metal ions by these two aquatic plant powders was better explained by the Lagergren second-order equation than the first-order equation. From the Fourier Transform Infrared spectra, there was an adsorption peak at 2,115 cm^?1 for R. maritima. The peak shape did not change with metal affiliation except there was a shift of peak wavelength before adsorption. The results indicate that the mechanism of heavy metal adsorption by the two species is not simply on the mono-molecular layer level, and that intra-particulate dispersal is the dominant process. Heavy metal pollution does not affect the basic chemical components, and major substances involved in heavy metal adsorption including carbohydrates, cell wall pectin, and protein functional groups.     

Serpentine geology links to water quality and heavy metals in sediments of a stream system in central Queensland,Australia

Serpentinite soils, common throughout the world, are characterized by low calcium-to-magnesium ratios, low nutrient levels and elevated levels of heavy metals. Yet the water quality and heavy metal concentrations in sediments of streams draining serpentine geology have been little studied. The aim of this work was to collect baseline data on the water quality (for both wet and dry seasons) and metals in sediments at 11 sites on the Marlborough Creek system, which drains serpentine soils in coastal central Queensland, Australia. Water quality of the system was characterized by extremely hard waters (555–698 mg/L as CaCO₃), high dissolved salts (684–1285 mg/L), pH (8.3–9.1) and dissolved oxygen (often >110% saturation). Cationic dominance was Mg > Na > Ca > K and for anions HCO₃ > Cl > SO₄. Al, Cu and Zn in stream waters were naturally high and exceeded Australian and New Zealand Environment and Conservation Council guidelines. Conductivity displayed the highest seasonal variability, decreasing significantly after wet season flows. There was little seasonal variation in pH, which often exceeded regional guidelines. Stream sediments were enriched with concentrations of Ni, Cr, Co and Zn up to 35, 21, 10 and 2 times the world average for shallow sediments, respectively. Concentrations for Ni and Cr were up to 60 and 16 times those of the relevant Interim Sediment Quality Guidelines Low Trigger Values, respectively. The distinctive nature of the water and sediment data suggests that it would be appropriate to establish more localized water quality and sediment guidelines for the creek system for the water quality parameters conductivity, Cu and Zn (and possibly Cr and Cd also), and for sediment concentrations of Cd, Cr and Ni.     

Mapping potential risks of long-term wastewater irrigation in alluvial soils,Egypt

In Egypt, wastewater has been used for irrigation in areas with fresh water scarcity; however, continuous applications may cause potential risks. Thus, the current study aims to map the spatial distribution of soil contamination and human risks of long-term wastewater irrigation due to the exposure of heavy metals. Soils from nine sites in Al-Qalyubia Governorate, Egypt, were sampled and analyzed. Wastewater irrigation resulted in a buildup of heavy metals in soils compared to Nile fresh water-irrigated soil. The pollution index (PI) showed the decreasing order of Cd?>?Zn?>?Ni?>?Cu?>?Co?>?Pb?>?Cr. The soils were out of the safe domain, as the integrated pollution index of Nemero’s (IPIN) exceeded the safe limit of 0.7. The enrichment factor (EF) exceeded 1.0, proving anthropogenic effects. The geo-accumulation index (I_geo) indicated high threats associated with Cd. The calculated hazard index (HI) indicated that humans exposed to such contaminated soils would have a potential health risk, particularly children. It is recommended to perform a treatment to the wastewater used in irrigation to avoid such threats.