Metal mobility at an old, heavily loaded sludge application site

This study was undertaken to determine the present distribution and mobility of sludge-applied metals at an old land application site. Trace metals concentrations were determined for soils (using 4 M HNO3 extracts), soil leachates (collected with passive wick lysimeters over a 2.5-year period), and plant tissue from a field site which received a heavy loading of wastewater sludge in 1978 and an adjacent control plot. Blue dye was used to indicate preferential percolate flowpaths in the sludge plot soil for sampling and comparison with bulk soil metals concentrations. After nearly 20 years, metals in the sludge plot leachate were found at significantly greater concentrations than in the control plot, exceeding drinking water standards for Cd, Ni, Zn, and B. Annual metals fluxes were only a fraction of the current soil metal contents, and do not account for the apparent substantial past metals losses determined in a related study. Elevated Cd, Cu, and Ni levels were found in grass growing on the sludge plot. Despite heavy loadings, fine soil texture (silty clay loam) and evidence of past and ongoing metals leaching, examination of the bulk subsoil indicated no statistically significant increases in metals concentrations (even in a calcareous subsoil horizon with elevated pH) when comparing pooled sludge plot soil profiles with controls. Sampling of dyed preferential flow paths in the sludge plot detected only slight increases in several metals. Preferential flow and metal complexation with soluble organics apparently allow leaching without easily detectable readsorption in the subsoil. The lack of significant metal deposition in subsoil may not be reliable evidence for immobility of sludge-applied metals.     

Synthetic fibers as an indicator of land application of sludge

Synthetic fabric fibers have been proposed as indicators of past spreading of wastewater sludge. Synthetic fiber detectability was examined in sludges (dewatered, pelletized, composted, alkaline-stabilized) and in soils from experimental columns and field sites applied with those sludge products. Fibers (isolated by water extraction and examined using polarized light microscopy) were detectable in sludge products and in soil columns over 5 years after application, retaining characteristics observed in the applied sludge. Concentrations mirrored (within a factor of 2) predictions based on soil dilution. Fibers were detectable in field site soils up to 15 years after application, again retaining the characteristics seen in sludge products. Concentrations correlated with residual sludge metal concentration gradients in a well-characterized field site. Fibers found along preferential flow paths and/or in horizons largely below the mixed layer suggest some potential for translocation. Synthetic fibers were shown to be rapid and semi-quantitative indicators of past sludge application.     

Effect of four alcohols on adsorption, desorption, and movement of cadmium, nickel, and zinc through soils

Miscible-displacement experiments were conducted to compare the effects of aqueous soil solutions with ethyl alcohol, ethylene glycol, diethylene glycol, and triethylene glycol on the movement of metals through soils. Aqueous or alcohol solutions containing 1 mM each Cd, Ni, and Zn and 5 mM Ca were perfused through columns containing River Sand, Canelo loam (Canelo 1) or Mohave sandy clay loam (Mohave scl) until effluent metal concentrations (C) equaled influent concentrations (C₀) or CC₀⁻¹ = 1. In general, the order of sorption was Zn > Ni > Cd in aqueous-perfused columns, while in alcohol-perfused columns sorption of Ni Cd ≥ Zn. In comparison to aqueous solutions, alcohols reduced total metal sorption by at least 25%. Metal sorption was best correlated to cation exchange capacity of the soil, sorption of metals being greatest in the Mohave scl and least in the River Sand. After CC₀⁻¹ = 1 was reached, columns were leached with deionized water. While leaching did not affect the sorption of metals in columns which had been perfused with aqueous solvents, sorption behavior of metals changed significantly in columns which had been perfused with alcohol solvents. Leaching caused desorption of 5 to 30% of the sorbed Ni. In general, Cd was desorbed (up to 45%) from the soils tested. The exceptions were River Sand columns perfused with diethylene and triethylene glycol in which additional Cd was sorbed to the soil from the soil solution. Additional Zn was sorbed in all columns tested with the exception of the Canelo 1 column perfused with ethyl alcohol.     

Impact of lime-stabilized biosolid application on Cu,Ni, Pb and Zn mobility in an acidic soil

A soil column leaching study was conducted on an acidic soil in order to assess the impact of lime-stabilized biosolid on the mobility of metallic pollutants (Cu, Ni, Pb and Zn). Column leaching experiments were conducted by injecting successively CaCl₂, oxalic acid and ethylenediaminetetraacetic acid (EDTA) solutions through soil and biosolid-amended soil columns. The comparison of leaching curves showed that the transport of metals is mainly related to the dissolved organic carbon, pH and the nature of extractants. Metal mobility in the soil and biosolid-amended soils is higher with EDTA than with CaCl₂ and oxalic acid extractions, indicating that metals are strongly bound to solid-phase components. The single application of lime-stabilized biosolid at a rate ranging from 15 to 30 t/ha tends to decrease the mobility of metals, while repeated applications (2?×?15 t/ha) increase metal leaching from soil. This result highlights the importance of monitoring the movement and concentrations of metals, especially in acid and sandy soils with shallow and smaller water bodies.     

Effects of sewage sludge biochar on plant metal availability after application to a Mediterranean soil

Pyrolytic conversion of sewage sludge into biochar could be a sustainable management option for Mediterranean agricultural soils. The aim of this work is to evaluate the effects of biochar from sewage sludge pyrolysis on soil properties; heavy metals solubility and bioavailability in a Mediterranean agricultural soil and compared with those of raw sewage sludge. Biochar (B) was prepared by pyrolysis of selected sewage sludge (SL) at 500 °C. The pyrolysis process decreased the plant-available of Cu, Ni, Zn and Pb, the mobile forms of Cu, Ni, Zn, Cd and Pb and also the risk of leaching of Cu, Ni, Zn and Cd. A selected Mediterranean soil was amended with SL and B at two different rates in mass: 4% and 8%. The incubation experiment (200 d) was conducted in order to study carbon mineralization and trace metal solubility and bioavailability of these treatments. Both types of amendments increased soil respiration with respect to the control soil. The increase was lower in the case of B than when SL was directly added. Metals mobility was studied in soil after the incubation and it can be established that the risk of leaching of Cu, Ni and Zn were lower in the soil treated with biochar that in sewage sludge treatment. Biochar amended samples also reduced plant availability of Ni, Zn, Cd and Pb when compared to sewage sludge amended samples.     

Dynamic chemical characteristics of soil solution after pig manure application: a column study

When manures from intensive livestock operations are applied to agricultural or vegetable fields at a high rate, large amounts of salts and metals will be introduced into soils. Using a column leaching experiment, this study assessed the leaching potential of the downward movement of Cu and Zn as well as some salt ions after an intensive farm pig manure at rates of 0%, 5% and 10% (w/w) were applied to the top 20 cm of two different textured soils (G soil -sandy loam soil; H soil-silty clay loam soil), and investigated the growth of amaranth and Cu and Zn transfer from soil to amaranth (Amaranthus tricolor). Soil solutions were obtained at 20, 40 and 60 cm depth of the packed column and analyzed for pH, electrical conductivity (EC), dissolved organic matter (DOC) and Cu and Zn concentrations. The results indicated that application of pig manure containing Cu and Zn to sandy loam soil might cause higher leaching and uptake risk than silty clay loam soil, especially at high application rates. And manure amendment at 5% and 10% significantly decreased the biomass of amaranth, in which the salt impact rather than Cu and Zn toxicity from manures played more important role in amaranth growth. Thus the farmer should avoid application the high rate of pig manure containing metal and salt to soil at a time, especially in sandy soil.     

Microbial acidification and pH effects on trace element release from sewage sludge

Leaching of sludge-borne trace elements has been observed in experimental and field studies. The role of microbial processes in the mobilization of trace elements from wastewater sludge is poorly defined. Our objectives were to determine trace element mobilization from sludge subjected to treatments representing microbial acidification, direct chemical acidification and no acidification, and to determine the readsorption potential of mobilized elements using calcareous sand. Triplicate columns (10-cm diameter) for incubation and leaching of sludge had a top layer of digested dewatered sludge (either untreated, acidified with H2SO4, or limed with CaCO3; all mixed with glass beads to prevent ponding) and a lower glass bead support bed. Glass beads in the sludge layer, support layer or both were replaced by calcareous sand in four treatments used for testing the readsorption potential of mobilized elements. Eight sequential 8-day incubation and leaching cycles were operated, each consisting of 7.6 d of incubation at 28 degrees C followed by 8 h of leaching with synthetic acid rain applied at 0.25 cm/h. Leachates were analyzed for trace elements, nitrate and pH, and sludge layer microbial respiration was measured. The largest trace element, nitrate and S losses occurred in treatments with the greatest pH depression and greatest microbial respiration rates. Cumulative leaching losses from both microbial acidification and direct acidification treatments were > 90% of Zn and 64-80% of Cu and Ni. Preventing acidification with sludge layer lime or sand restricted leaching for all trace elements except Mo. Results suggested that the primary microbial role in the rapid leaching of trace elements was acidification, with results from direct acidification being nearly identical to microbial acidification. Microbial activity in the presence of materials that prevented acidification mobilized far lower concentrations of trace elements, with the exception of Mo. Trace elements mobilized by acidification were readsorbed by calcareous sand when present.     

Effect of soil amendments on sorption and mobility of metribuzin in soils

Metribuzin (4-amino-6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazin-5-one), is weakly sorbed to soil therefore, leaches easily to lower soil profiles. Soil amendments play a significant role in the management of leaching losses of pesticides. Therefore, present study reports the effect of organic manure and fly ash amendments on metribuzin downward mobility in sandy loam soil columns. Application of animal manure [T-1(OM) and T-2(OM)] and fly ash [T-1(FA) and T-2(FA)] at 2.5% and 5.0% levels increased the metribuzin retention in the soil. Freundlich constant [K(f)(1/n)] values of metribuzin for treatments T-1(OM) and T-2(OM) were 0.70 and 1.11, respectively, which were significantly higher than the value (0.27) in natural soil (T-0). The respective values for treatments T-1(FA) and T-2(FA) were 1.80 and 4.61. Downward mobility of metribuzin was studied in packed soil columns [300 mm (l)x59 mm (i.d.)]. Both the amendments significantly reduced the downward mobility of metribuzin and affected breakthrough time and maximum concentration of metribuzin in the leachate. Leaching losses of metribuzin were decreased from 97% in natural soil (T-0) column to 64% [T-1(OM)] and 42% [T-2(OM)] for animal manure-amended columns and 26% [T-1(FA)] to 100% [T-2(FA)] for fly ash-amended columns, as metribuzin did not leach out of 5% fly ash-amended column. Study indicates that both animal manure and fly ash were quite effective in reducing the downward mobility of metribuzin in packed soil columns of a sandy loam soil.     

Effects of sewage sludge biochar on plant metal availability after application to a Mediterranean soil

Pyrolytic conversion of sewage sludge into biochar could be a sustainable management option for Mediterranean agricultural soils. The aim of this work is to evaluate the effects of biochar from sewage sludge pyrolysis on soil properties; heavy metals solubility and bioavailability in a Mediterranean agricultural soil and compared with those of raw sewage sludge. Biochar (B) was prepared by pyrolysis of selected sewage sludge (SL) at 500 °C. The pyrolysis process decreased the plant-available of Cu, Ni, Zn and Pb, the mobile forms of Cu, Ni, Zn, Cd and Pb and also the risk of leaching of Cu, Ni, Zn and Cd. A selected Mediterranean soil was amended with SL and B at two different rates in mass: 4% and 8%. The incubation experiment (200 d) was conducted in order to study carbon mineralization and trace metal solubility and bioavailability of these treatments. Both types of amendments increased soil respiration with respect to the control soil. The increase was lower in the case of B than when SL was directly added. Metals mobility was studied in soil after the incubation and it can be established that the risk of leaching of Cu, Ni and Zn were lower in the soil treated with biochar that in sewage sludge treatment. Biochar amended samples also reduced plant availability of Ni, Zn, Cd and Pb when compared to sewage sludge amended samples.     

矿区炼金废渣的固化/稳定化处理

通过对金矿矿区炼金废渣的酸中和能力、净产酸量及浸出毒性实验，测定了废渣的产酸潜力及重金属砷、镉、铅、锌的总量和它们的浸出量。为了合理处置矿区炼金废渣，并为矿区重金属污染土壤的修复提供技术支持，采用石灰、粉煤灰、堆肥化污泥作为添加剂对废渣进行固化/稳定化处理；通过浸出毒性实验对固化/稳定化处理效果进行综合分析，试图寻求一种最佳的稳定剂。结果表明，无论是单独添加石灰、粉煤灰或者堆肥化污泥还是两两组合混合添加，样品浸出液的pH都有升高，As、Cd的浸出浓度都有明显下降，而且两两组合添加比单独添加的固化/稳定化处理效果更好。在两两组合添加中，粉煤灰混合堆肥化污泥的处理效果最好，浸出液的pH值达到7.82，As、Cd的浸出率分别下降72.0%和72.2%。说明粉煤灰混合堆肥化污泥处理炼金废渣效果最佳，同时具有以废治污的资源化生态效能。     

Effects of soil amendments at a heavy loading rate associated with cover crops as green manures on the leaching of nutrients and heavy metals from a calcareous soil

The potential risk of groundwater contamination by the excessive leaching of N, P and heavy metals from soils amended at heavy loading rates of biosolids, coal ash, N-viro soil (1:1 mixture of coal ash and biosolids), yard waste compost and co-compost (3:7 mixture of biosolids to yard wastes), and by soil incorporation of green manures of sunn hemp (Crotalaria juncea) and sorghum sudangrass (Sorghum bicolor x S. bicolor var. sudanense) was studied by collecting and analyzing leachates from pots of Krome very gravelly loam soil subjected to these treatments. The control consisted of Krome soil without any amendment. The loading rate was 205 g pot(-1) for each amendment (equivalent to 50 t ha(-1) of the dry weight), and the amounts of the cover crops incorporated into the soil in the pot were those that had been grown in it. A subtropical vegetable crop, okra (Abelmoschus esculentus L.), was grown after the soil amendments or cover crops had been incorporated into the soil. The results showed that the concentration of NO3-N in leachate from biosolids was significantly higher than in leachate from other treatments. The levels of heavy metals found in the leachates from all amended soils were so low, as to suggest these amendments may be used without risk of leaching dangerous amounts of these toxic elements. Nevertheless the level of heavy metals in leachate from coal ash amended soil was substantially greater than in leachates from the other treatments. The leguminous cover crop, sunn hemp, returned into the soil, increased the leachate NO3-N and inorganic P concentration significantly compared with the non-legume, sorghum sudangrass. The results suggest that at heavy loading rates of soil amendments, leaching of NO3- could be a significant concern by application of biosolids. Leaching of inorganic P can be increased significantly by both co-compost and biosolids, but decreased by coal ash and N-viro soil by virtue of improved adsorption. The leguminous cover crop, sunn hemp, when incorporated into the soil, can cause the concentration of NO3-N to increase by about 7 fold, and that of inorganic P by about 23% over the non-legume. Regarding the metals, biosolids, N-viro soil and coal ash significantly increased Ca and Mg concentrations in leachates. Copper concentration in leachate was increased by application of biosolids, while Fe concentration in leachates was increased by biosolids, coal ash and co-compost. The concentrations of Zn, Mo and Co in leachate were increased by application of coal ash. The concentrations of heavy metals in leachates were very low and unlikely to be harmful, although they were increased significantly by coal ash application.     

Use of bone meal amendments to immobilise Pb, Zn and Cd in soil: A leaching column study

The aim of this study is to test the stabilisation of metals in contaminated soils via the formation of low-solubility metal phosphates. Bone apatite, in the form of commercially available bone meal, was tested as a phosphate source on a mine waste contaminated made-ground with high levels of Pb, Zn and Cd. Triplicate leaching columns were set up at bone meal to soil ratios of 1:25 and 1:10, in addition to unamended controls, and were run for 18 months. The columns were irrigated daily with a synthetic rain solution at pH of 2, 3, and 4.4. After 100 days, the leachate Pb, Zn and Cd concentrations of all amended columns were significantly reduced. For 1:10 treatments, release of these metals was suppressed throughout the trial. For 1:25 treatments, Zn and Cd concentrations in the leachates began to increase after 300 days. DTPA and water extractions showed that Pb and Cd were more strongly held in the amended soils. This study concludes that the complexity of soil processes and the small quantities of metals sequestered precluded determination of a metal immobilisation mechanism.     

Release of metals from homogeneous soil columns by wastewater from an agricultural industry

The effect of discharging olive mill wastewater (OMW) in soils on the release of metals previously retained by them is simulated by leaching homogeneous soil columns with a solution of the residue after passing solutions of Cu or Zn through the columns. The effect of other residues, previously added to the soil as composts in field experiments, on the behaviour observed in the laboratory is also discussed. OMW shows a strong power for releasing the metals retained. Previous addition of a compost made from olive mill sludge and plant refuse to the soil causes a significant reduction of the release of retained metal by liquid OMW. Previous addition of concentrated sugarbeet vinasse causes much less significant effects.     

Impact of sewage sludge spreading on nickel mobility in a calcareous soil: adsorption–desorption through column experiments

A soil column adsorption–desorption study was performed on an agricultural calcareous soil to determine the impact of sewage sludge spreading on nickel mobility. Ni adsorption experiments were followed by desorption tests involving the following liquid extractants: water, calcium (100 mg/L), oxalic acid (525 mg/L equivalent to 100 mg carbon/L), and sludge extracts (0.5 and 2.5 g/L). Desorption tests were also conducted after sewage sludge spreading at three application rates (30, 75, and 150 t/ha). According to the breakthrough curve, Ni adsorption was irreversible and occurred mainly through interactions with calcite surface sites. Nickel desorption from the soil column was promoted in presence of significant dissolved organic carbon (DOC) concentration as observed with oxalic acid elution and sludge extract at 2.5 g/L. In sludge-amended soil columns, the maximum Ni levels occurred in first pore volumes, and they were positively correlated to the sludge application rate. The presence of DOC in leaching waters was the main factor controlling Ni desorption from the sludge-amended soil columns. This finding implies that DOC generated by sludge applied on calcareous soils might facilitate the leaching of Ni due to the formation of soluble Ni–organic complexes. Thus, sludge application can have potential environmental impacts in calcareous soils, since it promotes nickel transport by decreasing Ni retention by soil components.     

Dolomite phosphate rock (DPR) application in acidic sandy soil in reducing leaching of phosphorus and heavy metals—a column leaching study

A column leaching study was designed to investigate the leaching potential of phosphorus (P) and heavy metals from acidic sandy soils applied with dolomite phosphate rock (DPR) fertilizers containing varying amounts of DPR material and N-Viro soils. DPR fertilizers were made from DPR materials mixing with N-Viro soils at the ratios of 30, 40, 50, 60, and 70 %, and applied in acidic sandy soils at the level of 100 mg available P per kilogram soil. A control and a soluble P chemical fertilizer were also included. The amended soils were incubated at room temperature with 70 % field water holding capacity for 21 days before packed into a soil column and subjected to leaching. Seven leaching events were conducted at days 1, 3, 7, 14, 28, 56, and 70, respectively, and 258.9 mL of deionized water was applied at each leaching events. The leachate was collected for the analyses of pH, electrical conductivity (EC), dissolved organic carbon (DOC), major elements, and heavy metals. DPR fertilizer application resulted in elevations up to 1 unit in pH, 7–10 times in EC, and 20–40 times in K and Ca concentrations, but 3–10 times reduction in P concentration in the leachate as compared with the chemical fertilizer or the control. After seven leaching events, DPR fertilizers with adequate DPR materials significantly reduced cumulative leaching losses of Fe, P, Mn, Cu, and Zn by 20, 55, 3.7, 2.7, and 2.5 times than chemical fertilizer or control. Even though higher cumulative losses of Pb, Co, and Ni were observed after DPR fertilizer application, the loss of Pb, Co, and Ni in leachate was <0.10 mg (in total 1,812 mL leachate). Significant correlations of pH (negative) and DOC (positive) with Cu, Pb, and Zn (P?<?0.01) in leachate were observed. The results indicated that DPR fertilizers had a great advantage over the soluble chemical fertilizer in reducing P loss from the acidic sandy soil with minimal likelihood of heavy metal risk to the water environment. pH elevation and high dissolved organic carbon concentration in soils after DPR fertilizer application are two influential factors.     

Mobility of Zn, Cd and Pb in soils as affected by poultry litter extract--I. Leaching in soil columns

Application of poultry litter to cropland may increase metal mobility, because the soluble organic ligands in poultry litter can form water-soluble complexes with metals. In this study, one uncontaminated soil and two metal-contaminated soils were sampled. A portion of the uncontaminated soil was amended with Zn, Pb, and Cd at rates of 400, 200, and 8 mg kg(-1), respectively. Packed soil columns were leached with H2O, EDTA, CaCl2, and poultry litter extract (PLE) solutions separately. No leaching of Zn, Cd, and Pb with the PLE was found in the uncontaminated soil. The retention of PLE-borne Zn indicated the potential for Zn accumulation in the soil. A large portion of the metals was leached from the metal-amended soil, and EDTA solubilized more Zn, Cd, and Pb than CaCl2 and PLE. In the metal-contaminated soils, the leaching of Zn and Cd with PLE was consistently larger than that for CaCl2, indicating that these metals were mobilized by organic ligands. The PLE did not mobilize Pb in these soils. The utilization of poultry litter in metal-contaminated soils might accelerate the movement of Zn and Cd in soil profiles.     

Heavy metal concentrations in plants and different harvestable parts: A soil-plant equilibrium model

A mathematical interaction model, validated by experimental results, was developed to modeling the metal uptake by plants and induced growth decrease, by knowing metal in soils. The model relates the dynamics of the uptake of metals from soil to plants. Also, two types of relationships are tested: total and available metal content. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality with a satisfactory approach. Data are taken from soils treated with Cd and Ni for ryegrass (Lolium perenne, L.) and oats (Avena sativa L.), respectively. Concentrations are measured in the aboveground biomass of plants. In the latter case, the concentration of metals in different parts of the plants (tillering, shooting and earing) is also modeled. At low concentrations, the effects of metals are moderate, and the dynamics appear to be linear. However, increasing concentrations show nonlinear behaviors.     

Relationship of surface changes to metal leaching from tungsten composite shot exposed to three different soil types

Physical changes that occur on the surface of fired shots due to firing and impact with soil may increase the dissolution of muniton metals. Increased metal dissolution could potentially increase metal transport and leaching, affecting metal concentrations in surface and groundwater. This research describes the relationship between the surface changes on fired tungsten-nickel-iron (94% W:2% Ni:4% Fe) composite shots and metals leaching from those shots. Tungsten composite shot was fired into, and aged in, three soil types (Silty Sand, Sandy Clay, and Silt) in mesoscale rainfall lysimeters to simulate live-fire conditions and subsequent interactions between the metals of the composite and soil. Leachate, runoff, and soil samples were collected from the lysimeters and analyzed for metal content. The shots were analyzed using scanning electron microscopy (SEM) to evaluate surface changes. SEM results indicated that a soil’s particle size distribution initially affected the amount of metal that was sheared from the surface of the fired W-composite shots. Shearing was greatest in soils with larger soil particles (sand and gravel); shearing was least in soils composed of small soil particles (fines). Increased metallic shearing from the shot’s surface was associated with increased W dissolution, compared to controls, following a simulated 1 year soil aging.     

Heavy metal displacement in salt-water-irrigated soil during phytoremediation

In regions where phytoremediation is carried out, brackish water must often be used. However, no information exists concerning the consequences of saline-water irrigation on the mobility of heavy metals in sludge applied to soil during phytoremediation. The purpose of this experiment was to determine the effect of NaCl irrigation on displacement of seven heavy metals in sludge (Cd, Cu, Fe, Mn, Ni, Pb, Zn) applied to the surface of soil columns containing barley plants. Half the columns received NaCl irrigation (10,000mg L(-1)) and half the columns received tap-water irrigation. Half the columns were treated with the chelating agent EDTA. With no EDTA, irrigation with the NaCl solution increased the concentrations of Cd, Fe, Mn, and Pb in the drainage water above drinking-water standards. Irrigation of sludge farms with brackish water is not recommended, because saline water increased the mobility of the heavy metals and they polluted the drainage water.     

Dynamic chemical characteristics of soil solution after pig manure application: A column study

When manures from intensive livestock operations are applied to agricultural or vegetable fields at a high rate, large amounts of salts and metals will be introduced into soils. Using a column leaching experiment, this study assessed the leaching potential of the downward movement of Cu and Zn as well as some salt ions after an intensive farm pig manure at rates of 0%, 5% and 10% (w/w) were applied to the top 20 cm of two different textured soils (G soil -sandy loam soil; H soil-silty clay loam soil), and investigated the growth of amaranth and Cu and Zn transfer from soil to amaranth (Amaranthus tricolor). Soil solutions were obtained at 20, 40 and 60 cm depth of the packed column and analyzed for pH, electrical conductivity (EC), dissolved organic matter (DOC) and Cu and Zn concentrations. The results indicated that application of pig manure containing Cu and Zn to sandy loam soil might cause higher leaching and uptake risk than silty clay loam soil, especially at high application rates. And manure amendment at 5% and 10% significantly decreased the biomass of amaranth, in which the salt impact rather than Cu and Zn toxicity from manures played more important role in amaranth growth. Thus the farmer should avoid application the high rate of pig manure containing metal and salt to soil at a time, especially in sandy soil.