Influence of Lanthanum on Phosphorus Uptake and Its Chemical Fractions in Rice Crop (Oryza Sativa)

The effects of lanthanum on rice growth, phosphorus uptake and phosphorus chemical fractions in rice were studied with split root solution culture. Results show that low concentration of La (0.05～1.5 mg·L -1 ) significantly increases rice yield while high La concentration (9～30 mg·L -1 ) markedly decreases rice yield. When La concentration is 0.05～0.75 mg·L -1 , La increases stem and root dry weight, but the difference is not statistically significant. La significantly increases EDTA P and inorganic P content in the stem and root. More than 80% of the increase of phosphors content in roots attributing to increase of EDTA P and inorganic P. Low La concentration (0.05～0.75 mg·L -1 ) increases nucleic P content in root, but high La concentration (30 mg·L -1 ) decreases nucleic P and ester P content in root. The residue P content increases in the root and stem. Also the relationship between the chemical fractions of phosphorus and its uptake by rice was discussed.

Chemical fractions and potential mobility of lead in soils irrigated by sewage in Pearl River Delta,South China

The chemical fractions,i.e.,water soluble(WS),exchangeable(Ex),carbonate(Car),weakly organic(WO),Fe-Mn oxide(FMO),strongly organic(SO),residual(Res) fraction,of Pb in irrigated soils in South China were investigated by a modified Tessier sequential extraction technique.The results show that the chemical fraction of Pb in soil is mainly the Res fraction and followed by FMO fraction,and the WS,WO,FMO,and SO fractions in topsoils(0-10 cm) are higher than those in subsoils(30-40 cm).The sum of contents of WS and Ex fractions(SWE) in topsoils is significantly positively related with that in subsoils,indicating the strong mobility of Pb in WS and Ex fractions in soils,and the SWE in soils is higher than the German trigger value for the transfer path soil-plant,indicating the high bioavailability of Pb in soils of this area.Fortunately,SWE and the ratio of WS and Ex fractions(RWE) to the sum of all fractions generally decrease with the soil depth in soil profile and the RWE in soil profile is lower than 0.5%,indicating the low pollution risk for Pb in groundwater.In addition,soil particles,pH and Fe2O3 play an important role in the impact of mobility and chemical fractions of Pb in soils.

Disinfection byproduct precursor removal by enhanced coagulation and their distribution in chemical fractions

Raw water from the Songhua River was treated by four types of coagulants, ferric chloride （FeC13）, aluminum sulfate （A12（504）3）, polyaluminum chloride （PACl） and composite polyaluminum （HPAC）, in order to remove dissolved organic matter （DOM）. Considering the disinfection byproduct （DBP） precursor treatability, DOM was divided into five chemical fractions based on resin adsorption. Trihalomethane formation potential （THMFP） and haloacetic acid formation potential （HAAFP） were measured for each fraction. The results showed that hydrophobic acids （HoA）, hydrophilic matter （HIM） and hydrophobic neutral （HoN） were the dominant fractions. Although both HoN and HoA were the main THM precursors, the contribution for THMFP changed after coagulation. Additionally, HoA and HiM were the main HAA precursors, while the contribution of HoN to HAAFP significantly increased after coagulation. HoM was more easily removed than HiM, no matter which coagulant was used, especially under enhanced coagulation conditions. DOC removal was highest for enhanced coagulation using FeCl3 while DBPFP was lowest using PAC1. This could indicate that not all DOC fractions contained the precursors of DBPs. Reduction of THMFP and HAAFP by PAC1 under enhanced coagulation could reach 51% and 59% respectively.

Effects of Feed Fermentation on Chemical Fractionation of Trace Elements in Feed and Pig Manure and Skatole Content in Pig Manure

[Objective] This study aimed to promote the combination of cultivation and livestock farming, and to explore an environment-protecting farming style. [Method]The effects of anaerobically fermented complete compound sow feed, added with Lactobacillus and Bacillus subtilis, on the chemical fractionation of copper, iron, zinc and manganese in feed and pig manure and skatole content in pig manure were investigated. [Result] Compared with those in the non-fermented feed, in the fermented feed and pig manure, the acetic acid-extractable copper, iron, zinc and manganese contents increased significantly（P0.05）, the reduced copper and iron contents increased significantly（P 0.05）, the oxidized copper and iron contents reduced significantly（P0.05）, and the residual copper contents remained unchangeable（P0.05）. The pH value of fermented feed decreased significantly（P0.05）, and that of pig manure increased significantly（P0.05）. The skatole content in pig manure decreased significantly（P 0.01）. The Lactobacillus abundance and amylase and cellulase activity increased significantly（P 0.05）. [Conclusion] The fermentation of feed changed the chemical fractionation of copper, iron, zinc and manganese in feed and pig manure, and reduced the manure odor.

Extraction of copper and zinc from naturally contaminated copper mine soils： Chemical fractionation analysis and risk assessment

The leaching behaviour of Cu and Zn from contaminated soils at a copper mine was investigated using four extractants： citric acid （CA）, oxalic acid （OA）, ethylenediaminetetraacetic acid （EDTA） and nitrilotriacetic acid （NTA）. Six soil samples were characterized for the distribution of four chemical fractions of Cu or Zn （acid-soluble, reducible, oxidizable and residual）. For the extraction of Cu, EDTA is more effective than other extmctants when the concentration is less than 0.02 mol/L. The leaching efficiency for Cu was at least 15% higher for EDTA than for the other extractants at the same concentrations. Similar leaching behaviour was observed in the extraction of Zn. After extraction by CA, OA, EDTA or NTA, the acid-soluble fractions and the reducible fractions of Cu were the main fractions extracted. The potential environmental risks related to speciation were evaluated, and after extraction these risks were reduced.

Effects of phosphorus fertilizer application on phosphorus fractions in different organs of Cordia trichotoma

The application of phosphorus(P)to soil can increase its availability to plants and alter P fractions in annual and perennial organs of Cordia trichotoma.If a portion of P accumulates in perennial organs in organic fractions it can be used in the next growth season,possibly decreasing plant dependence on P derived from soil fertilization.However,if P is preferentially accumulated in inorganic fractions in annual organs,plants will be more dependent on phosphate fertilization.This study aimed to evaluate the distribution of P fractions in organs of C.trichotoma grown on sandy soil treated with 120 and 360 kg P2O5 ha^(−1).The control was a zero application.After 24 months following fertilization,C.trichotoma seedlings were cut and separated into leaves,branches,stems and roots,dried,ground and subjected to chemical fractionation of P,which estimates fractions of total soluble P,soluble inorganic and organic P,lipid P,P associated ribonucleic acid and deoxyribonucleic acid,and residual P.P in annual organs,as leaves,accumulated preferentially in the soluble inorganic fraction in both treatments.In perennial organs such as stems and branches,P accumulated preferentially in the soluble organic fraction.The application of 300%of the recommended dosage(360 kg P2O5 ha^(−1))promoted the accumulation of P in soluble organic fractions which may contribute to annual growth the following season and be a strategy to reduce the dependence of 2-year-old stands on soil-derived P and on fertilizers.

Heavy Metals and PAHs in Sewage Sludge from Twelve Wastewater Treatment Plants in Zhejiang Province

Objective To investigate the heavy metals （HMs） and polycyclic aromatic hydrocarbons （PAHs） in sludge of twelve wastewater treatment plants （WWTPs） in Zhejiang province of China, and to assess their potential for land application. Methods Sludge was collected from 12 WWTPs within the province. GC-MS and AAS were used to measure PAHs and HMs contents in sludge. Results Concentrations of HMs in most of the sludge samples were below the regulatory limits for the sludge to be used in agriculture in China with the exception of Zn in 2 sludge samples and Cd in 1 sample. All 16 PAHs, targeted by the USEPA agency, were found in the sludge from the twelve plants with a total concentration ranging from 33.73 mg kg^-1 to 82.58 mg kg^-1 （dry weight, d.w.）. The levels of Σ9 PAHs varied from 13.87 mg kg^-1 to 61.86 mg kg^-1 （d.w.） in the sludge, far exceeding the limitation value recommended by the Europe Union. The concentration and composition of PAHs in sewage sludge varied and depended mainly on the quantity and type of industrial wastewater accepted by the WWTPs. A significant relationship between the proportion of industrial wastewater received by WWTPs and the total content of 16 PAHs in the sludge was observed. Conclusion PAHs have become one of the primary pollutants in sludge of Zhejiang WWTPs instead of HMs. It is, therefore, essential to reduce the contents of PAHs before the sludge can be used in agriculture through proper treatment.

Impacts of Power Density on Heavy Metal Release During Ultrasonic Sludge Treatment Process

The impact of ultrasonic power density on changes of heavy metals during sludge sonication was inves-tigated. Results showed that ultrasound could release heavy metals from sludge into the supernatant. There existed an effective power density range of 0.8-1.6 W·ml?1 for the release of the total heavy metal; there was little release below 0.8 W·ml?1 and too high power density was adverse to the release. Furthermore, sonication showed selective release of heavy metal from sludge to the supernatant; copper, cadmium and lead were not released by sonication, while arsenic and nickel were released easily and their release ratio could reach 40%. The effective energy range for each heavy metal was also different that 0.8-1.2 W·ml?1 for arsenic, 0.5-1.6 W·ml?1 for nickel, and 0.8-1.6 W·ml?1 for mercury and chrome. The differences among heavy metal release during sonication might be explained by the different distribution of chemical fractions of each metal in sludge. Such selectivity could be used to control heavy metal release during sludge treatment.

MSWI Fly Ash Based Novel Solidification/Stabilization Matrices for Heavy Metals

The possibilities of MSWI fly ash as a major constituent of novel solidification/stabilization matrices for secure landfill were investigated by mixing MSWI fly ash with rich aluminum components, which was added as bauxite cement or metakaolinite instead, to form Friedel and Ettringite phases with high fixing capacities for heavy metals. The physical properties, heavy metals-fixing capacity, mineral phases and its vibration bands in the novel matrices were characterized by compressive strength, TCLP（toxic characteristic leaching procedure）, XRD （x-ray diffraction） , DTG （derivative thermogravimetry）, and FTIR （fourier transform infrared spectroscopy）, respectively. The Tessier＇s five-step sequential extraction procedure was used to analyze the fractions of chemical speciation for Pb, Cd and Zn ions. The experimental results indicate that Friedel-Ettringite based novel solidification/stabilization matrices can incorporate Pb, Cd and Zn ions effectively by physical encapsulation and chemical fixation, and it exhibits a great potential in co-landfill treatment of MSWI fly ash with some heavy metals-bearing hazardous wastes.

Integration of chemical fractionation, Mosbauer spectrometry, and magnetic methods for identification of Fe phases bonding heavy metals in street dust

Street dust is one of the most important carriers of heavy metals(HMs)originating from natural and anthropogenic sources.The main purpose of the work was to identify which of Fe-bearing phases bind HMs in street dust.Magnetic parameters of the Fe-bearing components,mainly magnetically strong iron oxides,are used to assess the level of HM pollution.Chemical sequential extraction combined with magnetic methods(magnetic susceptibility,magnetization,remanent magnetization)allowed determining the metal-bearing fractions and identifying the iron forms that aremostly associated with traffic-related HMs.The use of Mossbauer spectrometry(MS)supplemented bymagnetic methods(thermomagnetic curves and psarameters of hysteresis loops)enabled precise identification and characterization of iron-containing minerals.The classification of HMs into five chemical fractions differing in mobility and bioaccessibility revealed that iron is most abundant(over 95%)in the residual fraction followed by the reducible fraction.HMs were present in reducible fraction in the following order:Pb>Zn>Mn>Cr>Ni>Fe>Cu,while they bound to the residual fraction in the following order:Fe>Ni>Cr>Mn>Pb>Cu>Zn.The signature of the anthropogenic origin of street dust is the presence of strongly nonstoichiometric and defected grains of magnetite and their porous surface.Magnetite also occurs as an admixture with maghemite,and with a significant proportion of hematite.A distinctive feature of street dust is the presence of metallic iron and iron carbides.Magnetic methods are efficient in the screening test to determine the level ofHMpollution,while MS helps to identify the iron-bearing minerals through the detection of iron.

Pollution characteristics and source apportionment of heavy metal(loid)s in soil and groundwater of a retired industrial park

Heavy metal(loid)s(HMs)pollution has become a common and complex problem in industrial parks due to rapid industrialization and urbanization.Here,soil and groundwater were sampled from a retired industrial park to investigate the pollution characteristics of HMs.Results show that Ni,Pb,Cr,Zn,Cd,and Cu were the typical HMs in the soil.Source analysis with the positive matrix factorization model indicates that HMs in the topsoil stemmed from industrial activities,traffic emission,and natural source,and the groundwater HMs originated from industrial activities,groundwater-soil interaction,groundwater-rock interaction,and atmosphere deposition.The sequential extraction of soil HMs reveals that As and Hg were mainly distributed in the residue fraction,while Ni,Pb,Cr,Zn,Cd,and Cu mainly existed in the mobile fraction.Most HMs either in the total concentration or in the bioavailable fraction preferred to retain in soil as indicated by their high soil-water partitioning coefficients(K_(d)),and the K_(d) values were correlated with soil pH,groundwater redox potential,and dissolved oxygen.The relative stable soil-groundwater circumstance and the low active fraction contents limited the vertical migration of soil HMs and their release to groundwater.These findings increase our knowledge about HMs pollution characteristics of traditional industrial parks and provide a protocol for HMs pollution scrutinizing in large zones.

Chemical profile of the active fraction of Yi-Gan San by HPLC–DAD–Q-TOF–MS and its neuroprotective effect against glutamate-induced cytotoxicity

Yi-Gan San(YGS), a traditional Chinese medicine for dementia-related symptoms, was previously fractionated. One active fraction, YGS40 exhibited a neuroprotective effect against glutamate-induced cytotoxicity. In the present study, high-performance liquid chromatography, coupled with diode-array detection and quadrupole time-of-flight mass spectrometry, was applied for the identification of its chemical constituents and for quantification studies. The chemical profile of YGS40 consisted of sixty-four identified or tentatively characterized compounds. The levels of the major marker compounds increased significantly in the mixed decoction compared with those in the single plant decoction. The results suggest the high precision of the analyses of most of the constituents in YGS40 and establish the quantitative variations of the major marker compounds between the single and mixed decoction processes.

Chemical signature and fractionation of trace elements in fine particles from anthropogenic and natural sources

The health effects of trace metal elements in atmospheric fine particulate matter(PM_(2.5))are widely recognized,however,the emission factor profiles and chemical fractionation of metal elements in different sources were poorly understand.In this study,sixteen metal elements,including Cd,Pb,V,Zn,Ba,Sb,As,Fe,Sr,Cr,Rb,Co,Mn,Cu,Ni and Sn frombiomass burning,bituminite and anthracite combustion,as well as dust,were quantified.The results showdifferent emission sourceswere associated with distinct emission profiles,holding important implications for source apportionment of ambient particulate metals.Specifically,Fe was the dominant metal species(28-1922 mg/kg)for all samples,and was followed by different metals for different samples.For dust,Mn(39.9 mg/kg_(dust))had the second-highest emission factor,while for biomass burning,itwas Cr and Ba(7.5 and 7.4mg/kg_(biomass),respectively).For bituminous coal combustion,the emission factor of Zn and Ba was 6.2 and 6.0 mg/kg_(bituminous),respectively,while for anthracite combustion the corresponding emission factor was 5.6 and 4.3 mg/kg_(anthracite),respectively.Moreover,chemical fractionation(i.e.,the exchangeable,reducible fraction,oxidizable,and residual fraction)and the bioavailability index(BI)values of the metal elements from different sources were further investigated to reveal the link between different emission sources and the potential health risk.The findings from this study hold important implications for source apportionment and sourcespecific particulate metal-associated health effects.

Lead stabilization in a polluted calcareous soil using cost-effective biochar and zeolite amendments after spinach cultivation

Biochar has been shown to be an effective organic soil amendment for the in-situ immobilization of lead(Pb).Little research has been done on the effects of biochar and zeolite interactions on Pb immobilization in contaminated calcareous soils.Therefore,the aim of this study was to investigate the effects of different levels of zeolite(2%and 4%,weight:weight)and biochars(3%,weight:weight)prepared from green compost(GB),poultry manure(PB),and municipal waste(MB)on the content of Pb in spinach shoots and Pb stabilization in a greenhouse experiment conducted using a Pb-contaminated calcareous soil.Application of GB and PB significantly decreased the Pb mobility factor(MF)from 2.8%to 4.6%and the cumulative Pb release(diethylenetriamine pentaacetate(DTPA)extraction)from 16.8%to 20.1%in the calcareous soil,which were further enhanced by the combined addition of zeolite,with Pb MF reduction from 4.4%to 8.4%and cumulative Pb release reduction from 24.8%to 28.6%.The enhancement of soil Pb immobilization was attributed to the properties of the amendments,such as high pH,ash content,and phosphorus content(10.5^(-1)1.0,390-435 g kg^(-1),and 2.5-4.3 g kg^(-1),respectively).Results of the soil Pb sequential extraction and Pb release kinetics were highly and significantly correlated with spinach shoot Pb content.Soil chemical data showed that the application of MB with 4%zeolite was the most effective treatment for immobilizing Pb(8.4%reduction in Pb MF and 28.6%reduction in cumulative DTPA-extractable Pb),which is in agreement with the results of the spinach shoot Pb(89.0%reduction in Pb uptake).

Mineral materials as feasible amendments to stabilize heavy metals in polluted urban soils

Four minerals, agricultural limestone （AL）, rock phosphate （RP）, palygorskite （PG）, and calcium magnesium phosphate （CMP）, were evaluated by means of chemical fractions of heavy metals in soils and concentrations of heavy metals in leachates from columns to determine their ability to stabilize heavy metals in polluted urban soils. Two urban soils （calcareous soil and acidic soil） polluted with cadmium, copper, zinc and lead were selected and amended in the laboratory with the mineral materials） for 12 months. Results indicated that application of the mineral materials reduced exchangeable metals in the sequence of Pb, Cd Cu Zn. The reduction of exchangeable fraction of heavy metals in the soils amended with different mineral materials followed the sequence of CMP, PG AL RP. Reductions of heavy metals leached were based on comparison with cumulative totals of heavy metals eluted through 12 pore volumes from an untreated soil. The reductions of the metals eluted from the calcareous soil amended with the RP, AL, PG and CMP were 1.98%, 38.89%, 64.81% and 75.93% for Cd, 8.51%, 40.42%, 60.64% and 55.32% for Cu, 1.76%, 52.94%, 70.00% and 74.12% for Pb, and 28.42%, 52.74%, 64.38% and 49.66% for Zn. Those from the acidic soil amended with the CMP, PG, AL, and RP were 25.65%, 68.06%, 78.01% and 79.06% for Cd, 26.56%, 49.64%, 43.40% and 34.68% for Cu, 44.44%, 33.32%, 61.11% and 69.44% for Pb, and 18.46%, 43.77%, 41.98% and 40.68% for Zn. The CMP and PG treatments were superior to the AL and RP for stabilizing heavy metals in the polluted urban soils.

Land Use Effects on the Distribution and Speciation of Heavy Metals and Arsenic in Coastal Soils on Chongming Island in the Yangtze River Estuary, China

The reclamation of tidal fiats has been one of the important approaches to replenish the arable lands in the coastal areas; pollution status of reclaimed soils has received wide attention recently, especially for the study of heavy metals due to the relative high pollutant concentrations in wetlands. To understand the impact of land use change on heavy metal and arsenic （As） geochemistry by the reclamation of wetlands for agriculture, surface soils and soil profiles were collected from the agricultural land reclaimed in the 1990s and the intertidal flat wetland at Dongtan on Chongming Island in the Yangtze River Estuary, China. The soil samples were analyzed for total concentrations and chemical speciation of chromium （Cr）, zinc （Zn）, copper （Cu）, lead （Pb）, nickel （Ni）, cadmium （Cd） and As using inductively coupled plasma mass spectrometry （ICP-MS）. Results showed that soil properties （salinity, total organic carbon and grain-size distribution） and the concentrations of heavy metals and As in the soils differed under the different land use types. The conversion of wetland to forest had caused obvious losses of all the measured heavy metals. In paddy field and dryland with frequent cultivation, the concentrations of Cr, Zn, Cu, Ni and As were higher when compared to forest land which was disturbed rarely by human activities. Speciation analysis showed that Cr, Zn, Cu, Ni and As were predominated by the immobile residual fraction, while Pb and Cd showed relatively higher mobility. In general, metal （except Ni） and As mobility decreased in the following order： wetland 〉 dryland 〉 paddy field 〉 forest land, which suggested that the reclaimed soils had lower metal and As mobility than the intertidal fiat wetland. The results of this study contribute to a better understanding of the effects of land use on heavy metals and As in the reclaimed soils of the study area and other similar coastal areas.

Heavy metals in a typical city-river-reservoir system of East China:Multi-phase distribution,microbial response and ecological risk

The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the aquatic environment of a typical system composed of main watersheds in Suzhou and Jinze Reservoir in Shanghai.Results shown that Mn,Zn and Cu were the dominant metals detected in multiple phases.Cd,Mn and Zn were mainly presented in exchangeable fraction and exhibited high bioavailability.Great proportion and high mobility of metals were found in suspended particulate matter(SPM),suggesting that SPM can greatly affect metal multi-phase distribution process.Spatially,city system(Ci S)exhibited more serious metal pollution and higher ecological risk than river system(Ri S)and reservoir system(Re S)owing to the diverse emission sources.Ci S and Re S were regarded as critical pollution source and sink,respectively,while Ri S was a vital transportation aisle.Microbial community in sediments exhibited evident spatial variation and obviously modified by exchangeable metals and nutrients.In particular,Bacteroidetes and Firmicutes presented significant positive correlations with most exchangeable metals.Risk assessment implied that As,Sb and Ni in water may pose potential carcinogenic risk to human health.Nevertheless,Re S was in a fairly safe state.Hg was the main risk contributor in SPM,while Cu,Zn,Ni and Sb showed moderate risk in sediments.Overall,Hg,Sb and Ci S were screened out as priority metals and system,respectively.More attention should be paid to these priority issues to promote the sustainable development of the watershed.

Effect of cultivation time on soil heavy metal accumulation and bioavailability in Phyllostachys praecox stands

Phyllostachys praecox is a bamboo species cultivated for edible shoots under intensive management.However,the potential pollution risk of heavy metals in bamboo soils is not clear under the intensive management for a long term.The objective of this study was to evaluate the effect of cultivation time on soil heavy metal accumulation and bioavailability in bamboo stands subjected to intensive management.Soil samples were collected from a chronosequence of bamboo stands which had been cultivated for 0,1,2,4,8,and 10 years in Lin’an,Zhejiang Province of China.Eight heavy metals(Cu,Zn,Pb,Ni,Cr,Cd,As,and Hg)present in the soil were selected,and their potential pollution risk was evaluated by chemical speciation analysis.Possible heavy metal sources were explored using multivariate and cluster analysis.Our results showed that Zn,Cu,Hg,and Cd contents in the soil increased with the cultivation time,while Ni,Cr,Pb,and As levels were similar among all stands.Furthermore,the bioavailabilities of all analyzed heavy metals increased with the cultivation time.Multivariate and cluster analysis showed that sources of Ni,Cr,Pb,and As were likely lithogenic in origin,whereas input of Zn,Cu,Hg,and Cd was mainly due to cultivation practices.Current bamboo management strategies raised the potential risks of heavy metal pollution in bamboo shoots in the long term.Soil acidification in P.praecox stands induced by intensive cultivation should be controlled since it stimulated and improved the bioavailability of heavy metals.Appropriate management strategies should thus be adopted to ensure safe and sustainable production of bamboo shoots.

Forms of potassium and chlorine from oxy-fuel co-combustion of lignite coal and corn stover

In this work,the forms of potassium and chlorine from oxy-fuel co-combustion of lignite coal and corn stover under atmospheric pressure were investigated.In order to check transitional stage,the feedstocks were combusted stepwise,first by pyrolysis to form coke under N2 environment and later by coke combustion into the ash at 850℃ in O_(2)/CO_(2) atmosphere.The results show that an increase in blend ratio from 15%to 40%results in an increase in water-soluble potassium in the feedstock and the ashes from 0.15%to 0.4%and 0.015%to 0.038%in weight respectively.The water-soluble potassium is present mainly as KCl and K2SO4.For ammonium acetate soluble potassium,a similar trend to water-soluble potassium is presented but with a much lower content of potassium.The bound potassium in the fuel matrix exists,likely in the form of AlKSi_(2)O_(6).Chlorides are present mainly in the form of KCl which is the dominant water-soluble compound.