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1.
Field trials with inorganic fertilizer (nitrogen, phosphorus, and potassium) nutrients were simulated in the greenhouse to remediate hydrocarbon‐polluted soils from a spill site in the Niger Delta, Nigeria. Samples of the polluted soils taken from two depths were displayed in a randomized complete block (RCB) design and treated with 10–100 g of (NH4)2SO4, KH2PO4, and KCl. The agronomic addition of the chemical nutrients was found to enhance the concentrations of nitrate‐nitrogen, phosphate‐phosphorus, and potassium in the soils. Pretreated nitrate‐nitrogen content ranged from 432 to 590 mg/kg in the polluted samples (with a control at 522 mg/kg), while posttreatment concentrations were 3,285 ± 154 mg/kg and 3,254 ± 159 mg/kg for surface and subsurface soils, respectively. © 2007 Wiley Periodicals, Inc.  相似文献   

2.
Animal manure is waste that contains large amounts of fertilizer resources. Incineration technology is effective in decreasing the volume of animal manure and concentrating the nutrients. In this study, the nutrient concentration and chemical compounds of several types of animal manure ash were examined to promote their recycling for agriculture. The nutrient concentration of manure ash was dependent on the reduction rate of solid materials by incineration. The phosphorus (P) and potassium (K) of cattle and layer manure were not concentrated greatly because of high silicon (Si) and calcium (Ca) concentrations, respectively. On the other hand, the P concentration of swine manure and broiler litter was increased to 10.1–12.0 % (3.6–4.6 times compared with original materials), equivalent to that of phosphate rock used as fertilizer material. The K concentration of broiler litter ash (16.1 %) was highest of all. The phosphate compounds of cattle and swine manure ashes were determined as Ca9Fe(PO4)7 or Ca9MgK(PO4)7. Hydroxyapatite (Ca5(PO4)3(OH)) was detected in layer manure and broiler litter ashes. By acid treatment of ash, P and K availability of the fertilizer made from layer manure ash (33 % of materials) was equivalent to that of conventional chemical fertilizer.  相似文献   

3.
The use of soluble PO43− as a heavy metal chemical stabilization agent was evaluated for a dust generated from melting or vitrification of municipal solid waste combustion residues. Vitrification dusts contain high concentrations of volatile elements such as Cl, Na, K, S, Pb, and Zn. These elements are present in the dusts largely as simple salts (e.g. PbCl2, ZnSO4) which are highly leachable. At an experimental dose of 0.4 moles of soluble PO43− per kg of residue, the pH-dependent leaching (pH 5,7,9) showed that the treatment was able to reduce equilibrium concentrations by factors of 3 to 100 for many metals; particularly Cd, Cu, Pb and Zn. Bulk and surface spectroscopies showed that the insoluble reaction products are tertiary metal phosphate [e.g. Zn3(PO4)2] and apatite [e.g. Pb5(PO4)3Cl] family minerals. Geochemical thermodynamic equilibrium modeling showed that apatite family and tertiary metal phosphate phases act as controlling solids for the equilibrium concentrations of Ca2+, Zn2+, Pb2+, Cu2+, and Cd2+ in the leachates during pH-dependent leaching. Both end members and ideal solid solutions were seen to be controlling solids. Soluble phosphate effectively converted soluble metal salts into insoluble metal phosphate phases despite the relatively low doses and dry mixing conditions that were used. Soluble phosphate is an effective stabilization agent for divalent heavy metals in melting dusts where leachable metals are present in high concentrations.  相似文献   

4.
This study presents the chemical composition of bulk deposition during the period of February 1996–May 1997 and the chemical composition of sub-event wet deposition on 13 August 1997 in Gebze. Samples were analyzed for SO4 2-, NO3 -, Cl-,Ca2+, Mg2+, K+, Na+, and NH4 + in addition to pH. The source of some ionic components in the bulk deposition such as K+ and Ca2+ were found to be the terrestrial regions, as expected. The (non-sea Cl-)/Cl- ratio of 0.05 suggests that the very large portion of Cl- in the bulkdeposition was of marine origin. The ratio of (non-sea SO4 2-)/SO4 2- varied between 0.86 and 0.99,indicating that the main source of sulfate was not the sea. It is found that the sulfate and calcium concentrations were highest in summer and lowest in fall. The analysis of bulk deposition also indicated that nearly 24% of the events were acidic (pH < 5.6). During sub-event wet deposition collectedon the same site pH decreased continually, and during the passageof cold front concentrations of Cl-, SO4 2- and NO3 - increased.  相似文献   

5.
This article attempts to put the light on the air quality of the Black Sea region of Turkey. In addition to that, it endeavors to locate the possible sources of the different pollutants at local, regional and long range transported scales. About 196 rainwater samples were collected over the Black Sea region of Amasra between 1995 and 1999, and analyzed for major ions and trace elements using spectrophotometric techniques. Andersen wet only rain samples were used to collect rain events, where the rain sample was filtered inline using 0.45 m cellulose acetate filters. Major anions (SO4 2-, NO3 - and Cl-) were determined using ion chromatography, whereas metals (Ca, Mg, Al, Fe, Na, K), werequantified using ICP-AES. This study shows that, the Black Sea region receives different amounts and types of anthropogenic pollutants via long-range transport according to trajectory models. Although the pH of rain water is not considered acidic (pH = 5.21) yet the neutralizing species are lower than other sites around Europe.  相似文献   

6.
The purpose of the present work was to investigate the chemistry of rain in the Gulf of Iskenderun, North East Mediterranean, Turkey. The Gulf region has a large number of industries. Main industries existing in the region are iron and steel works, fertilizer plants, a cement plant, and several medium and mini size steel mills in addition to the international pipe line terminals. This study aims to apportion the local sources contributing to the overall pollution of the region. To this end a precipitation sampling program was started in January 2000, and over 48 precipitation samples were collected from each of 5 stations located at Iskenderun city center, Iskenderun industrial zone, Payas city center, the campus of Iskenderun Technical College and the campus of Mustafa Kemal University. Samples were analysed for pH, NO3 +, Cl-. Ca, Al, Ba, Na, Cd, Co, Cr, Cu, Pb, Li, Mg, Mn, Ni, Zn, Fe, K. Concentrations of metal ions were determined by ICP-AES. NO3 - ions and pH were determined by using NO3 - selective electrode and pH meter, respectively.pH values of the collected samples at the industrial zone and at Payas city center, ranged between 5.02 and 7.38, respectively. NO3 - and metal ions concentrations were highly variable. Concentrations of Ca and Fe ions were higher in the industrial zone and Payas city center. In the other three stations, concentrations of metal ions and NO3 - ion were lower than that of industrial zone and the values of pH ranged between 6 and 7.4. The average pH values at Iskenderun Gulf showed that the precipitation was not acidic, because of the high concentration of Ca. The highest concentrations of Na and Cl ions were recorded in the University campus because the campus is located by the Mediterranean Sea.  相似文献   

7.
Anaerobic co-digestion of dairy manure (DM) and concentrated food processing wastes (FPW) under thermophilic (55 °C) and mesophilic (35 °C) temperatures, and fertilizer value of the effluent were investigated in this study. Two types of influent feedstock were utilized: 100 % DM and a 7:3 mixture (wet weight basis) of DM and FPW. The contents of the FPW, as feedstock were 3:3:3:1 mixture of cheese whey, animal blood, used cooking oil and residue of fried potato. Four continuous digestion experiments were carried out in 10 L digesters. Co-digestion under thermophilic temperature increased methane production per digester volume. However, co-digestion at 35 °C was inhibited. Total Kjeldahl nitrogen (N) recovered after digestion ranged from 73.1 to 91.9 %, while recoveries of ammonium nitrogen (NH4-N) exceeded 100 %. The high recovery of NH4-N was attributed to mineralization of influent organic N. The mixture of DM and FPW showed greater recoveries of NH4-N after digestion compared to DM only, reflecting its greater organic N degradability. The ratios of extractable to total calcium, phosphorus and magnesium were slightly reduced after digestion. These results indicate that co-digestion of DM and FPW under thermophilic temperature enhances methane production and offers additional benefit of organic fertilizer creation.  相似文献   

8.
Spent coagulant in water supply plant sludge was extracted with H2SO4 and the efficiency of the reused coagulant was studied. The optimum pH values for coagulant extraction and clarification with the reused coagulant were 3.0–4.0 and about 6, respectively. In treating raw influent obtained from a sewage treatment plant and wastewater from a coastal landfill site, the removal of chemical oxygen demand (COD), total nitrogen, and total phosphorous with the recovered coagulant was higher than that with commercial aluminum sulfate or polyaluminum chloride. In addition, the sludge settling properties, the extra sludge mass formation, the supernatant quality, and the cost of reagents were also studied. The coagulant recovered from water supply plant sludge by H2SO4 extraction could be successfully reused for the clarification of domestic and food industry wastewaters.  相似文献   

9.
Resurrection of the iron and phosphorus resource in steel-making slag   总被引:4,自引:0,他引:4  
 This research focused on the treatment of steel-making slags to recycle and recover iron and phosphorus. The carbothermal reduction behavior of both synthesized and factory steel-making slag in microwave irradiation was investigated. The slags were mixed with graphite powder and heated to a temperature higher than 1873 K to precipitate a lump of Fe–C alloy with a diameter of 2–8 mm. The larger the carbon equivalent (Ceq, defined in the text), the higher the fractional reduction of iron and phosphorus. An increase in the SiO2 content of slag led to a considerable improvement in the reduction for both iron and phosphorus because of the improvement in the fluidity of the slags and an increase in the activity coefficient of P2O5 in the slags. The extraction behavior of phosphorus from Fe–P–Csatd alloy was also investigated at 1473 K by carbonate flux treatment. For all the experiments with a processing time longer than 10 min, the phosphorus in the fluxes could be concentrated to more than 9% (w/w) showing that it could be used as a phosphorus resource. Compared with K2CO3 flux treatment, that using Na2CO3 was more effective for the extraction of phosphorus, and this was attributed to the lower evaporation of Na2CO3. Finally, a recycling scheme for steel-making slag is proposed. Received: March 16, 2001 / Accepted: November 12, 2001  相似文献   

10.
The purpose of this study was to investigate NOx and SO2-inducednitrogen and sulfur levels accumulated over vegetation and soil in the surrounds of the fertilizer plant in Kütahya, Turkey. Therefore, leaf samples collected from the seven locations adjacent to the plant were morphologically observed (pollution-related injuries and color deformation) and chemically analyzed. Besides, nitrogen and sulfur contents were determined in the soil samples collected from each location. A significant correlation was achieved between locations and different vegetation samples and soil samples. The highest nitrogen level present in the trees was 3.07 ± 0.105% (3rd location, Robinia pseudoacacia), with the highest sulfur level being 5.79 ± 0.085% (3rd location, Salix alba). The highest nitrogen and sulfur levels in soils were 0.31 ± 0.045 and 0.57 ± 0.052% (3rd location), respectively. Furthermore, the highest nitrogen and sulfur levels were 4.69 and 2.20%, respectively,in agricultural plants in the surrounds of the fertilizer plant. A higher level of pollutants was observed in the samples collectedfrom the locations in the direction of the prevailing wind. Also, differences between locations as well as between plant specimens were statistically evaluated.  相似文献   

11.
The fertilizer properties of anaerobic digestate depend on the feedstock and operating conditions of digestion. In this study, the comparative fertilizer properties of mesophilic and thermophilic digestates from dairy manure were evaluated for plant nutrient contents, and special attention was paid to plant growth promoting bacteria (PGPB). Two digestates contained similar plant nutrient contents, while the thermophilic digestate contained higher contents of NH4+–N. The quantity of Bacillus and Pseudomonas in the mesophilic digestate was significantly higher than in the thermophilic digestate. Furthermore, Bacillus showed siderophore production and antifungal activity (43.5–75.3%), and Pseudomonas showed siderophore and phytohormone production (4.2–75.2 µg ml?1). One phosphate solubilizing isolate was also detected in the mesophilic digestate. These results indicated that two digestates showed different fertilizer properties with respect to nutrient contents and PGPB, and digestates had the potential to increase the availability of phosphorus and iron in the soil, both to provide phytohormones to plant roots and protect plants from fungal phytopathogens. The contents of indicator bacteria and heavy metals were analyzed to determine their environmental risk, and the results showed a high reduction in indicator bacteria and lower levels of heavy metals than in other feedstocks.  相似文献   

12.
Soil solution samples were taken from two sites (Horröd and Hasslöv) in the south part of Sweden to evaluate how soil solution chemistry responded to different treatmentswith dolomite and wood ash. At Horröd, samples were taken four years after application of wood ash, 4.28 ton ha-1 and dolomite, 3.25 ton ha-1. At Hasslöv dolomite, 3.45 ton ha-1 and 8.75 ton ha-1 was applied and samples were taken 15 yr later. It was found that treatment with dolomite at one site (Hasslöv) resulted in higher pH values (<2 pH units) and higher nitrification. It was also found at this site that the total Al and the inorganic Al concentrations decreased with dolomite treatment. The Ca, Mg, DOC, Fe, SO4 2- and Cl- concentrations, mainly in the topsoil, were found to be higher at both sites, following dolomite treatment; Ca and Mg concentrations were 2–8 times higher (<820 M) than in controls (<70 M). Wood ash was found to have less impact. The PO4 concentration in the O2 horizon at Hasslöv decreased due to dolomite-treatment. ANOVA (Analyse of Variance) and PLS (Partial Least Square) were used to evaluate the data from the two sites.  相似文献   

13.
Year-to-year variation in SO4 2-,NO3 -, Ca2+, K+, and Mg2+concentrations in forest floor and mineral soil percolatefrom a forested, podzolic soil at the Turkey Lakes Watershedon the Precambrian Shield was assessed for monotonic trendsbetween 1986 and 1995. Our objective was to examine howrapidly ion concentrations in soil percolate equilibratedafter stabilization of SO4 2- concentrations inprecipitation. Significant negative trends were detected inmonthly Ca2+, and Mg2+ concentrations in forestfloor and SO4 2-, Ca2+, and Mg2+ inmineral soil percolate during the 10-year-period. Thedecline in Ca2+ and Mg2+ was greater than annualdecreases in SO4 2- and NO3 - in forestfloor percolate and proportional to the reduction inSO4 2- in mineral soil percolate. Response ofmineral soil percolate to a 15 molc L-1SO4 2- decrease in wet-only precipitation between1985 and 1986 was a gradual decline in SO4 2-concentration through 1995. The five-year meanSO4 2- concentration in bulk precipitation, forestfloor percolate, and mineral soil percolate decreased 8, 9and 18 molc L-1 from 1986–90 to 1991–95.Microbial (mineralization of organic S) and sorption(release from and/or retention in the pool of insolubleSO4 2-) processes in the soil were logicalexplanations for the observed changes in SO4 2- inmineral soil percolate.  相似文献   

14.
The recovery of phosphorus from sewage sludge ash samples obtained from 7 operating sludge incinerators in the UK using a sulfuric acid washing procedure to produce a technical grade phosphoric acid product has been investigated. The influences of reaction time, sulfuric acid concentration, liquid to solid ratio and source of ISSA on P recovery have been examined. The optimised conditions were the minimum stoichiometric acid requirement, a reaction time of 120 min and a liquid to solid ratio of 20. Under these conditions, average recoveries of between 72% and 91% of total phosphorus were obtained. Product filtrate was purified by passing through a cation exchange column, concentrated to 80% H3PO4 and compared with technical grade H3PO4 specifications. The economics of phosphate recovery by this method are briefly discussed.  相似文献   

15.
As an alternative or in addition to direct seeding, container-grown transplants provide a means of economically and rapidly revegetating waste fly ash lagoons through the expeditious establishment of vegetation islands. Survival and growth ofEnchylaena tomentosaandNitraria billardiereitransplants were largely dependent on the size of the root volume at transplanting. Growth response of both species in fly ash increased significantly as transplant container size increased from 110 ml to 800 ml. Fly ash incorporated into the potting mix during the containerised stage of growth generally reduced plant growth and survival following eventual transplantation. Gradual hardening ofEnchylaena tomentosaseedlings to increasing concentrations of fly ash in the potting mix (25 to 50 to 75% fly ash), however, improved immediate survival following transplantation, into pure ash. Nitrogen deficiency in Port Augusta fly ash was a major nutritional limitation to growth of these two species. Growth and dry matter production responded optimally to application of N fertiliser (NH4NO3) at 100–150 kg N ha−1. Although bicarbonate-extractable P levels in fly ash were high (over 250 mg kg−1), a response ofEnchylaena tomentosato supplementary P application [Ca(H2PO4)2.H2O] at 100–200 kg P ha−1was observed.N. billardiereidid not respond to supplementary P, and it was suggested that fly ash P may be selectively available to plants on a species dependent basis. No growth responses to K application (KCl) at rates of up to 400 kg K ha−1were found.  相似文献   

16.
The recovery of phosphorus from waste is very important for Japan because Japan has no natural phosphorus resources. In order to recover phosphorus from incineration ash of chicken manure, an acid dissolution–alkali precipitation method was investigated. Phosphorus content in the ash was 8%. The ash was treated with hydrochloric acid to obtain phosphorus-rich solution. Phosphorus could then be recovered as a precipitant by adding sodium hydroxide solution into the phosphorus-rich solution and gradually changing the pH in the solution to 3, 4, and 8. At pH 3, a small amount of phosphorus was precipitated to remove iron, which would cause coloring of subsequent precipitants. At pH 4, 84% of the phosphorus in the original solution could be recovered as CaHPO4 · 2H2O with a purity of 92%. At pH 8, 8% of the phosphorus in the phosphorus-rich solution could be recovered as identified hydroxyapatite. A recovery rate of 92% phosphorus as CaHPO4 · 2H2O and identified as hydroxyapatite was achieved.  相似文献   

17.
In this present paper, statistical screening and optimization of jackfruit seed powder based medium components were investigated for pullulan production from Aureobasidium pullulans. Seven medium variables jackfruit seed powder, K2HPO4, yeast extract, (NH4)2SO4, NaCl, MgSO4·7H2O and ZnSO4·7H2O were screened by employing Plackett–Burman (PB) method. PB method showed jackfruit seed powder, ZnSO4·7H2O, K2HPO4 and yeast extract were significant. Central composite design of response surface method applied to optimize the significant variables identified from the PB experiment. Statistical analysis of the experimental results showed optimal values were found to be jackfruit seed powder 2 % (w/v), K2HPO4 0.55 % (w/v), yeast extract 0.30 % (w/v) and ZnSO4·7H2O 0.006 % (w/v) with maximum pullulan concentration of 18.76 (g/L). Maximum pullulan concentration of 17.95 (g/L) was observed in the validation experiment. This experimental result explained the model was fitted 96 % as compare with the result predicted by response surface method.  相似文献   

18.
A solution containing 35SO4 2- and 3H2O was applied to four plots (5 × 5 m) in a boreal coniferous forest in the Laflamme Lake watershed, Québec, under two contrasting conditions: in summer (plots 1 and 2), and on the snowpack before snowmelt (plots 3 and 4). The transit of both these tracers in the soil solution was then followed through a network of soil lysimeters located at different depths. Four months after the summer application, 3H2O had infiltrated the whole soil profile at plot 1, while 35SO4 2- was only observed in the LFH and Bhf horizons. A 35SO4 2- budget calculated from mid-August to November indicated that 89 and 10.6% of the added 35SO4 2- was retained within the LFH and the Bhf layers, respectively. Fifteen months later, the added 35SO4 2- was distributed in the following proportions within the soil horizons: LFH (73.7%), Bhf (11.8%) and Bf (12.8%), for a total retention rate of 98.3%. The superficial penetration of 3H2O at plot 2 was indicative of a major lateral water movement that prevented the calculation of a 35SO4 2- budget. This situation also was observed at plot 4 during snowmelt. At plot 3, 3H2O moved freely through the soil profile and a significant fraction of the added 35SO4 2- reached the B horizons, where it was presumably adsorbed on aluminum (Al) and ferric (Fe) oxides. The 35SO4 2- budget for plot 3 from March to November indicated that 87% of the added 35SO4 2- was retained within the soil profile, with most being retained in the B horizons (LFH = 33.1%, Bhf = 33.1%, Bf = 20.8%). The contrasting retention patterns of 35SO4 2- within the soil profile following the summer addition and snowmelt likely was caused by the contrastingsoil temperatures and soil solution residence times within the differentsoil layers. The persistence of 35SO4 2- in the soil solution of the entire profile long after the initial tracer infiltration, and the relative temporal stability of specific activity of SO4 2-, point to the establishment of an isotopic equilibrium between the added 35SO4 and the active S-containing reservoirs within a given soil horizon. Overall, the results clearly illustrate the very strong potential for 35SO4 2- retention and recycling in forest soils.  相似文献   

19.
The present study was conducted to evaluate the impact of lead toxicity on the growth parameters of spinach and the performance of lead-resistant bacterial isolates under lead stress conditions. Out of four bacterial isolates selected for this study, only two isolates AMB-CD-2 and AMB-CD-4 were selected based on their lead tolerance ability. A polybag experiment was conducted with six treatments and four replications in spinach. The treatments included T1 (RDF + control), T2 (lead acetate), T3 (AMB-CD-2 + lead), T4 (AMB-CD-4 + lead), T5 (AMB-CD-2), and T6 (AMB-CD-4). Results showed that lead contamination significantly decreased plant growth parameters, particularly in the treatment T2 (lead acetate) when compared with other treatments. Similarly, reduced uptake of nitrogen, phosphorus, and potassium (NPK) was recorded in T2. Inoculation with lead-resistant bacteria, AMB-CD-2, significantly improved plant growth parameters (plant height, root fresh weight, shoot fresh weight, root dry weight, shoot dry weight, and root length). The uptake of NPK was higher in T5 (AMB-CD-2) in the absence of lead by approximately 0.81%, 0.37%, and 0.42% than in the control, respectively. Through atomic absorption spectrophotometer analysis, the lead concentration in treatment T2 (control) was about 3.20 mg/g while in treatment T3 (AMB-CD-2 + lead) it was about 1.32 ppm. The 16S rRNA gene sequencing revealed that AMB-CD-2 resembles Brevibacillus parabrevis. The results demonstrate that the lead-resistant bacteria B. parabrevis AMB-CD-2 showed a significant lead reduction of approximately 58.75% compared to the control.  相似文献   

20.
In the present work, a shaft-type furnace model in which the furnace column is divided into multiple cells was proposed and equilibrium reaction calculation software was used to describe the model. The model was used to study the effects of gasification and melting conditions such as temperature, oxygen partial pressure, and chlorine content on the volatilization behaviors of the low-boiling-point metals Na, K, Pb, and Zn during the gasification and melting process of municipal solid waste in a shaft-type furnace. Consequently, the volatilization ratios of Na, K, Pb, and Zn compounds in the exhaust gas from a pilot plant shaft-type furnace were found to be in good agreement with the calculation results, and the Na, K, Pb, and Zn compounds were volatilized mainly as metal chlorides in the temperature range up to approximately 1173 K. With a further rise in temperature, these low-boiling point metals were volatilized as metallic forms. It was found that almost 100% of Pb and Zn compounds were volatilized regardless of the chlorine content in municipal solid waste; in contrast, the volatilization rates of Na and K increased when the chlorine content increased. Finally, Na, K, Pb, and Zn compounds were converted from reduced metals to metal chlorides such as NaCl, KCl, PbCl2, and ZnCl2 with an increase in the ratio of chlorine to each metal.  相似文献   

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