Decontaminating Biological Sludge for Agricultural Use

1985 ◽  
Vol 17 (4-5) ◽  
pp. 575-586 ◽  
Author(s):  
L. Wong ◽  
J. G. Henry
Keyword(s):  
Heavy Metals ◽  
Agricultural Land ◽  
Oxidation Process ◽  
Metal Removal ◽  
Aeration Rate ◽  
Agricultural Lands ◽  
Bacterial Leaching ◽  
Biological Sludge ◽  
Agricultural Use ◽  
Digested Sewage Sludge

A biological oxidation process called bacterial leaching was used to remove heavy metals from anaerobically digested sewage sludge. The purpose was to decontaminate the sludge so that it could be utilized on agricultural land. The leaching process was found to be affected by pH, aeration and temperature. At α pH of 4, an aeration rate of 100 cm3 of air per litre of sludge per minute and a temperature of 25°C, the following metal removal efficiencies were observed: cadmium, 80 - 85% ; copper, 66 - 80% ; nickel, 70 - 78% and zinc, 84 - 90%. No significant removal was observed for lead. In addition to removing heavy metals, bacterial leaching preserves the soil conditioning and fertilizing properties of the sludge. According to Ontario guidelines, the sludge used in this study was initially not acceptable for use on agricultural lands. However, after bacterial leaching, all criteria for the application of sludge to agricultural lands were easily met.

Bacterial Leaching of Heavy Metals From Anaerobically Digested Sewage Sludge

1983 ◽  
Vol 18 (1) ◽  
pp. 151-162 ◽  
Author(s):  
L. Wong ◽  
J.G. Henry
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Agricultural Land ◽  
Metal Removal ◽  
Health Hazard ◽  
Dry Weight ◽  
Low Grade ◽  
Bacterial Leaching ◽  
Beneficial Reuse ◽  
Digested Sewage Sludge

Abstract Spreading of sewage sludges on agricultural land is an attractive sludge management option because it combines beneficial reuse and disposal at the same time. However, it is important to reduce the metal content in the sludge in order to minimize the health hazard associated with metal uptake by plants and its subsequent accumulation in the food chain. Treatment of sludge with acid for metal removal is not practical because a large amount of acid is required. Typically 0.5 to 0.8 g of H2SO4/g dry weight of sludge will be required to achieve over 70% removal of cadmium (Cd), zinc (Zn) and nickel (Ni). Lead (Pb) and copper (Cu) are not significantly removed. A biological process called bacterial leaching, which has been used commercially for extracting copper and uranium from low grade ores, was reviewed and its potential for removing heavy metals from anaerobically digested sewage sludge was investigated. Leaching experiments were conducted and the results showed that about 80 to 90% removal of cadmium, zinc and nickel, and 60 to 70% removal of copper were possible. The acid requirement was significantly reduced because only 0.15 g of H2SO4/g dry weight of sludge was needed.

Fate of indicator organisms in sludge during bacterial leaching of metals

1991 ◽  
Vol 18 (2) ◽  
pp. 237-243 ◽  
Author(s):  
J. G. Henry ◽  
D. Prasad ◽  
W. B. Lohaza
Keyword(s):  
Sewage Sludge ◽  
Suspended Solids ◽  
Agricultural Land ◽  
Thiobacillus Ferrooxidans ◽  
Metal Removal ◽  
Bacterial Pathogens ◽  
Indicator Bacteria ◽  
Bacterial Leaching ◽  
Solids Concentration ◽  
Pathogenic Organisms

Biological extraction (bacterial leaching) of heavy metals from digested sewage sludge has been shown to be a practical means for decontaminating sludge for use on agricultural land. However, it was not known whether pathogenic organisms would survive or be destroyed in the acidic environment necessary for the bacterial leaching process. The purpose of the research reported herein was to assess the effect of bacterial leaching on various bacteria commonly used to indicate the possible presence of pathogenic organisms. Although pathogenic viruses, bacteria, protozoa, and helminths may be present in sludge, this study is concerned only with bacterial pathogens. The concentrations of the four indicator bacteria selected to represent the bacterial pathogens were determined in a series of laboratory bacterial leaching units. Results showed that, although about 80–90% metal removal efficiencies were achieved (at a pH of 4.0, an aeration rate of 100 mL of air per minute per litre of sludge) at a temperature of 20–25 °C, the indicator bacteria were not reduced during bacterial leaching at high suspended solids concentrations. The survival of indicator bacteria was found to be a function of the suspended solids concentration in the leaching units, regardless of the source or type of indicator bacteria. At suspended solids concentrations greater than 10 g/L, the indicator bacteria were able to survive, apparently unaffected by the unfavourable environmental conditions (10 days retention at pH 4.0). Below this suspended solids concentration of 10 g/L, significant reductions of total coliforms, faecal coliforms, and faecal streptococci were achieved. Total heterotrophs did not follow the same trends as the other indicator bacteria. Key words: bacterial leaching, Thiobacillus ferrooxidans, indicator bacteria, enteric pathogens removal, sewage sludge, sludge disposal.

scholarly journals DISTRIBUTION OF RESTORATION SUCCESSIONS IN TAIGA AND FOREST-STEPPE LANDSCAPES OF THE PERMSKY PRIKAMYE (ON THE EXAMPLE OF AGRICULTURAL LANDS)

2021 ◽  
Vol 31 (4) ◽  
pp. 416-424
Author(s):  
A.P. Belousova ◽  
N.N. Nazarov
Keyword(s):  
Remote Sensing ◽  
Soil Fertility ◽  
Forest Cover ◽  
Agricultural Land ◽  
Remote Sensing Data ◽  
Forest Steppe ◽  
Landscape Changes ◽  
Agricultural Lands ◽  
Natural Factors ◽  
Agricultural Use

The research of forest cover development on agricultural lands in the Perm Prikamye was carried the example of taiga and forest-steppe types of landscapes. The Babkinsko-Yugovskoy and Irensko-Kungursky landscapes were select for research. Received information about the geosystem condition in different years using remote sensing data. All landscape changes were record during the formed stable snow cover. As a result, was divide into two classes - forested and treeless areas. Established, the main natural factors of land differentiation by an areas and a pace of withdrawal from agricultural use are the small contours of agricultural land and differences in soil fertility. The growth pace of forest geosystems within the forest-steppe landscape was 2.5 times higher than of the taiga. The research of the dynamics of forest cover showed that in the Perm Prikamye in the forest-steppe landscape substitution of anthropogenic geosystems with natural-anthropogenic ("wild") accompanied by the development of forest biogeocenosis, not steppe.

scholarly journals Pyrolysis of Municipal Sewage Sludge to Investigate Char and Phosphorous Yield together with Heavy-Metal Removal—Experimental and by Thermodynamic Calculations

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1477
Author(s):  
Naeimeh Vali ◽  
Lars-Erik Åmand ◽  
Aurélie Combres ◽  
Tobias Richards ◽  
Anita Pettersson
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Agricultural Land ◽  
Microwave Plasma ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Chemical Fractionation ◽  
Different Temperatures

Sewage sludge is regarded as a potential source for soil fertilizer However, the direct utilization of sewage sludge in agricultural land is restricted since it also contains heavy metals, pathogens, and toxic compounds. Pyrolysis of the sewage sludge destroys the organic pollutants and partly volatilizes the heavy metals. In this study, pyrolysis of sewage sludge was carried out in order to determine the optimum residence time and temperature to recover the phosphorous and remove heavy metals from the resultant sewage sludge char (SSC). Pyrolysis was conducted on dried sewage sludge (DSS) by means of thermogravimetric analysis (TGA) and high-temperature oven with an N2-atmosphere. Microwave Plasma-Atomic Emission Spectroscopy (MP-AES) was used to determine the concentration of P and trace elements in the resulting solid char fraction. A combination of chemical fractionation (step-by-step leaching) of the DSS and thermodynamic equilibrium calculations were utilized to estimate the availability of phosphorous and removal of heavy metals in the SSC fraction at different temperatures. The results from the thermodynamics calculation were in line with the measured chemical composition of the SSC. Furthermore, the energy contents of the SSC obtained at different temperatures were measured. The pyrolysis evaluation results indicate that phosphorous was enriched in the char, while lead, zinc, and cadmium were significantly removed.

Evaluation of agricultural utilisation of the sludge produced at Psyttalia WWTP

2000 ◽  
Vol 42 (9) ◽  
pp. 21-28 ◽  
Author(s):  
D. Mamais ◽  
A. Kouzeli ◽  
D. G. Christoulas ◽  
A. Andreadakis ◽  
E. Aftias
Keyword(s):  
Heavy Metals ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Biological Sludge ◽  
Scale Unit ◽  
High Zinc ◽  
Zinc Concentrations ◽  
Agricultural Use ◽  
High Concentrations ◽  
Year 2000

A six-month experimental study was conducted to evaluate the agricultural use of the sludge produced at Psyttalia after completion of secondary biological treatment. Based on the results obtained from a bench scale activated sludge system the average biological sludge production for the year 2000, is estimated to be approximately 111 tn DS/day. Using the values of heavy metals measured in Psyttalia primary dewatered sludge and in the biological sludge obtained from the laboratory scale unit, the approximate heavy metal concentrations of the sludge produced in Psyttalia after the construction of the Biological Treatment Plant were determined: 327 mgCu/kg DS, 4140 mgZn/kg DS, 981 mgCr/kg DS, 264 mgPb/kg DS, 228 mgNi/kg DS, 1.6 mgCd/kg DS and 7 mgHg/kg DS. According to the above results the use of sludge in agriculture is unfeasible at present given the high zinc concentrations that exceed EC Regulations, but also considering the high concentrations of other heavy metals that exceed the more stringent regulations of several European countries.

The effects of silt fields of Bortnytska aeration station on ecological state of land and water in the adjacent areas

2021 ◽  
pp. 114-128
Author(s):  
M. V. Yatsiuk ◽  
A. M. Shevchenko ◽  
R. P. Bozhenko ◽  
S. M. Lyutnitsky
Keyword(s):  
Heavy Metals ◽  
Agricultural Land ◽  
Ecological State ◽  
Crop Failure ◽  
Maximum Permissible Concentrations ◽  
Mobile Forms ◽  
Exchangeable Magnesium ◽  
Agricultural Use ◽  
Almost All ◽  
The Impact

The article highlights the results of research on assessing the ecological state of the land near the silt fields №1 and №3 of Bortnytska aeration station in the Zolochiv village community of Boryspil district in Kyiv region. The presence of previously recorded increased content of heavy metals in soils compared to the background content, both in terms of their gross content and the content of mobile forms was confirmed within the certain areas near the silt fields. For the elements-pollutants (Zn, Cu, Cr, Pb) at some points within the agricultural land, exceeding the values ​​of their gross content and the content of mobile forms (Zn, Cu) of the maximum permissible concentrations was recorded at 1.1-6.2 and 1.1 -2.6 times, respectively. The average values ​​of heavy metals content for floodplains (settlement) and agricultural land near silt fields indicate their prevailing values ​​for the latter in almost all elements, as well as exceeding the background values ​​and maximum permissible concentrations for the land where silt deposits were previously applied as fertilizers. Within the surveyed areas, soils are classified as unsalted, but the increased content of exchangeable magnesium may adversely affect soil fertility. Increased mineralization and content of ammonium and nitrates in groundwater are observed near silt fields, which is obviously related to the impact of silt water and can lead to deterioration of groundwater quality in the area of ​​their transit and discharge, in particular within the village Gnidyn. The area of ​​land with an extremely dangerous pollution rate in terms of total heavy metal is about 300 hectares, with a dangerous pollution rate is 260 hectares, and the estimated damage from crop failure may be 1.65 million UAH/year and 0.3 million UAH/year respectively. Within the areas adjacent to the silt fields, the condition of soils, water resources, cultivated products and the health of the population should be constantly monitored, especially when using the polluted land for agricultural use or housing.

Conflicts caused by afforestations of agricultural land in densely populated areas

1991 ◽  
Vol 56 ◽  
Author(s):  
N. Lust ◽  
B. Muys
Keyword(s):  
Nature Conservation ◽  
Agricultural Land ◽  
Agricultural Lands ◽  
Biological Value ◽  
Ecological Problems ◽  
The Subject ◽  
Points Of View

In  densely populated areas, such as Flanders, serious conflicts arise due to the  afforestation of agricultural lands. Roughly speaking, three sectors are  involved: agriculture, forestry and nature conservation. These groups do not  always share the same points of view. But even within the different sectors  there are several subgroups with their own interests and approaches.  Generally speaking, agriculture is strongly opposed, forestry has a  relatively diversified meaning, whereas nature conservation is either opposed  or in favour, depending on the region's biological value.     The policy in this matter is not forest friendly. Legislation strongly  hampers the afforestation of agricultural lands. Moreover the subject leads  to a series of ecological problems, which have not really been considered up  to now.

scholarly journals Synthesis, characterization and heavy metal removal efficiency of nickel ferrite nanoparticles (NFN’s)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Waheed Ali Khoso ◽  
Noor Haleem ◽  
Muhammad Anwar Baig ◽  
Yousuf Jamal
Keyword(s):  
Heavy Metals ◽  
Nickel Ferrite ◽  
Contact Time ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Ferrite Nanoparticles ◽  
Batch Adsorption ◽  
Aqueous Environment ◽  
Human Beings ◽  
Nickel Ferrite Nanoparticles

AbstractThe heavy metals, such as Cr(VI), Pb(II) and Cd(II), in aqueous solutions are toxic even at trace levels and have caused adverse health impacts on human beings. Hence the removal of these heavy metals from the aqueous environment is important to protect biodiversity, hydrosphere ecosystems, and human beings. In this study, magnetic Nickel-Ferrite Nanoparticles (NFNs) were synthesized by co-precipitation method and characterized using X-Ray Diffraction (XRD), Energy Dispersive Spectroscopy (EDS) and Field Emission Scanning Electronic Microscopy (FE-SEM) techniques in order to confirm the crystalline structure, composition and morphology of the NFN’s, these were then used as adsorbent for the removal of Cr(VI), Pb(II) and Cd(II) from wastewater. The adsorption parameters under study were pH, dose and contact time. The values for optimum removal through batch-adsorption were investigated at different parameters (pH 3–7, dose: 10, 20, 30, 40 and 50 mg and contact time: 30, 60, 90, and 120 min). Removal efficiencies of Cr(VI), Pb(II) and Cd(II) were obtained 89%, 79% and 87% respectively under optimal conditions. It was found that the kinetics followed the pseudo second order model for the removal of heavy metals using Nickel ferrite nanoparticles.

Divergent response of heavy metal bioavailability in soil rhizosphere to agricultural land use change from paddy field to various drylands

2021 ◽  
Author(s):  
Yujuan Gao ◽  
Jianli Jia ◽  
Beidou Xi ◽  
Dongyu Cui ◽  
Wenbing Tan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Land Use ◽  
Land Use Change ◽  
Agricultural Land ◽  
Rhizosphere Soil ◽  
Agricultural Land Use ◽  
Metal Bioavailability ◽  
Soil Rhizosphere ◽  
Divergent Response

The heavy metal pollution induced by agricultural land use change has attracted great attention. In this study, the divergent response of bioavailability of heavy metals in rhizosphere soil to different...

scholarly journals Optimal Solutions for the Use of Sewage Sludge on Agricultural Lands

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 585
Author(s):  
Catalina Iticescu ◽  
Puiu-Lucian Georgescu ◽  
Maxim Arseni ◽  
Adrian Rosu ◽  
Mihaela Timofti ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Agricultural Production ◽  
Agricultural Land ◽  
Chemical Characteristics ◽  
Optimal Solutions ◽  
Physico Chemical ◽  
Agricultural Areas ◽  
The Impact ◽  
Made In

The use of sewage sludge in agriculture decreases the pressure on landfills. In Romania, massive investments have been made in wastewater treatment stations, which have resulted in the accumulation of important quantities of sewage sludge. The presence of these sewage sludges coincides with large areas of degraded agricultural land. The aim of the present article is to identify the best technological combinations meant to solve these problems simultaneously. Adapting the quality and parameters of the sludge to the specificity of the land solves the possible compatibility problems, thus reducing the impact on the environment. The physico-chemical characteristics of the fermented sludge were monitored and optimal solutions for their treatment were suggested so as to allow that the sludge could be used in agriculture according to the characteristics of the soils. The content of heavy metals in the sewage sludge was closely monitored because the use of sewage sludge as a fertilizer does not allow for any increases in the concentrations of these in soils. The article identifies those agricultural areas which are suitable for the use of sludge, as well as ways of correcting some parameters (e.g., pH), which allow the improvement of soil quality and obtained higher agricultural production.

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