scholarly journals Heavy metals partition between leachate and solids in the course of municipal sewage treatment

2019 ◽  
pp. 367-377
Author(s):  
Hanna Obarska-Pempkowiak ◽  
Wieslaw Butajlo ◽  
Janusz Pempkowiak
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Agricultural Land ◽  
Sewage Treatment ◽  
Municipal Sewage ◽  
Soil Fertilization ◽  
Second Stage ◽  
Secondary Sludge ◽  
Treated Sewage ◽  
Two Stages

Measurements of heavy metals contents (Cu, Zn, Pb, Cd) were carried out in liquid and solid fractions of sewage and sewage sludge after stabilization as well as dewatering. Investigation was carried out in municipal WWTP ,,Wschod" in Gdansk. The flow of sewage was equal to 88 000 m3 /d. The treatment consists of two stages: the first stage - mechanical (4screens, 2 sandtraps, 4 primary sedimentation tanks) and the second stage - advanced biological MUCT system (6 reactors - each incorporating the following chambers: dephosphatation, pre-denitrification, denitrification and nitrification followed by 2 secondary sedimentation tanks) modified by introduction of an additional chamber which secures dioxidation of sewage recirculated between nitrification and denitrification chambers. Sewage sludge (primary and secondary) is stabilized by fermentation. The last step of sludge utilization is mechanical dewatering. Samples of sewage were collected at the following points of the WWTP: at the beginning - raw sewage, mechanically treated sewage and biologically treated sewage. Samples of reject waters after thickening and after mechanical dewatering of sludge were collected too. The following types of sewage sludge were investigated: primary, secondary, thickened (on the Klein press), digested and mechanically dewatered (Noxon centrifuges). In the sampling points samples were collected twice per month during the 6 months period in the years 2000-2001. Inflowing sewage carried the following loads of heavy metals: Zn - 27.2 kg/d, Cu - 5.4 kg/d, Pb - 1.3 kg/d and Cd - 0.4 kg/d.  Basing on balances of heavy metals loads it was proved that 87.0% Zn and 83.0% Cu were kept in sludge. Among analysed sewage sludge samples, the highest contents of heavy metals was found in sludge after mechanical dewatering and in the mixture of primary and secondary sludge (Zn - 780.4 mg/kg d.m., Cu - 144.6 mg/kg d.m., Pb - 5.4 mg/kg d.m. and Cd - 2.4 mg/kg d.m. The contents of heavy metals in examined sludge were compared with Polish admissible loads of metals applied with sludge to soil fertilization. Basing on the findings, admissible loads of sewage sludge to agricultural land were not exceeded.

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.

scholarly journals Impact of Alkalization of Surplus Activated Sludge on Biogas Production

2013 ◽  
Vol 20 (2) ◽  
pp. 343-351 ◽  
Author(s):  
Klaudiusz Grűbel ◽  
Alicja Machnicka ◽  
Stanisław Wacławek
Keyword(s):  
Sewage Sludge ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Municipal Sewage ◽  
Rate Limiting Step ◽  
Secondary Sludge ◽  
Environmentally Safe ◽  
Biological Decomposition

Abstract Large amounts of sludge are produced in biological wastewater treatment plants. Since the sludge is highly contaminated, it has to undergo proper stabilization before it is disposed or utilized in an environmentally safe way. On the whole, the aim of bacterial cell disintegration is the release of cell contents in the form of an aqueous extract. Chemical disintegration of surplus activated sludge by alkalization results in destruction and disruption of the flocs and microorganisms as well as increase concentration of organic matter in supernatant. The mesophilic anaerobic sewage sludge digestion is an established process, most often applied at medium and large municipal sewage treatment plants. Four major steps of anaerobic digestion are distinguished. The first hydrolysis step leads to solubilization of insoluble particulate matter and biological decomposition of organic polymers to monomers or dimers. The hydrolysis step is recognized as the rate-limiting step of the following second and third steps, the processes of acidogenesis and acetogenesis. Chemical disintegration activates biological hydrolysis and, therefore, it can significantly increase the stabilization rate of the secondary sludge. It has been shown that when the activated sludge was subjected to alkalization to pH 9.0 value, the COD concentration increased from 101 to 530 mg/dm3 in sludge supernatant. The paper presents a potential application of chemical disintegration for sewage sludge (mainly activated sludge) to upgrading biogas production.

scholarly journals USE PF URBAN SLUDGE COMPOST AS FERTILIZANT ON APPLE ORCHARDS

2021 ◽  
Vol 37 (37) ◽  
pp. 103-114
Author(s):  
Claudia Nicola ◽  
◽  
Mihaela Paraschiv ◽  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Sewage Sludge ◽  
Apple Orchard ◽  
Growth And Yield ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Soil Fertilization ◽  
Sludge Compost ◽  
Sewage Sludge Compost

This study shows the influence of compost fertilization derived from sludge obtained from wastewater treatment on the nutrition of an eight-year-old apple orchard, ʹJonathanʹ cv. A field experiment was conducted to demonstrate the beneficial and negative aspects of (urban) sludge compost fertilization in apples and to assess the risk of soil contamination with heavy metals from municipal sewage sludge compost. The experimental factor was the compost with the following gradations: V1 = 0 t/ha, V2 = 20 t/ha, V3 = 40 t/ha, V4 = 60 t/ha, V5 = 80 t/ha. After two years (2019-2021) from soil fertilization with compost, the nitrogen content of the leaves increased in the treatment with the maximum fertilization dose (80 t/ha) by 30% compared to the unfertilized control, while the phosphorus content of leaves increased by 80% compared to non-fertilization control. The potassium content of the leaves increased by 36% in the 80 t/ha treatment compared to the unfertilized control, but still remained at a deficit level. The results showed that growth and yield were improved by using sewage sludge compost. However, sewage sludge compost applications have not significantly altered the heavy metal content of plant tissues. The concentration of heavy metals in the soil did not exceed the maximum permissible thresholds according to standards established in other EU countries, where compost from sewage sludge is considered product, not waste. However, the calculation of the Igeo index (geoaccumulation index of heavy metal in soil) showed certain levels of soil pollution already installed with Cd Zn, Pb in all variants fertilized with compost.

scholarly journals Immobilization of selected heavy metals from fly ash from thermal treatment of municipal sewage sludge in hardening slurries

2018 ◽  
Vol 64 (3) ◽  
pp. 131-144 ◽  
Author(s):  
Łukasz Szarek ◽  
Paweł Falaciński ◽  
Małgorzata Wojtkowska
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Fly Ash ◽  
Sewage Sludge ◽  
Thermal Treatment ◽  
Sewage Treatment ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Heavy Metal Immobilization ◽  
Key Issues

AbstractThe growing number of municipal sewage treatment plants in Poland raises the problem of managing more and more sludge. The thermal treatment of municipal sewage sludge (TTMSS), which significantly reduces the volume of waste, results in an increase in the concentration of heavy metals in the fly ashes – the final products of the process. The search for methods of utilization of fly ash from TTMSS resulted in attempts to use it in hardening slurries widely used in hydro-engineering. Due to the nature of the application of this material in the cut-off walls (exposure to groundwater flow) one of the key issues is the degree of heavy metal immobilization. The paper attempted to determine the degree of leaching of selected heavy metals from the hardened hardening slurry, composed of fly ash from TTMSS. For this purpose, the eluates were prepared from samples, after various periods of curing, using a dynamic short-term method called “Batch test”. The liquid used for leaching was: distilled water and 0.1 molar EDTA solution – to determine the amount of potentially mobile heavy metal forms. The results show the possibility of the safe usage of fly ash from TTMSS as an additive for hardening slurries.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

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.

Assessment of Environmental Quality of Soil Fertilized Grapefruit Trees with Municipal Sewage Sludge

2013 ◽  
Vol 671-674 ◽  
pp. 2736-2741
Author(s):  
Yin An Ming ◽  
Tao Tao
Keyword(s):  
Sewage Sludge ◽  
Environmental Quality ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Land Application ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Limiting Factor

To reuse municipal sewage sludge safely, experiment was carried out on grapefruit trees fertilized with composted sludge from Shiweitou Sewage Treatment Plant in Xiamen City of China, and a method was introduced of how to assess the environmental quality of grapefruit trees soil fertilized with sludge by Set Pair Analysis (SPA) model. The results showed that the soil in the surface layer (0-15cm) and the deeper layer (15-30cm) was less clean, and the environment of soil was not polluted. Thus it was feasible to use sludge as fruit fertilizer. The maximum service life of sludge for continuous land application was estimated by taking Cd as the limiting factor, which would provide scientific guide and technical support for safe land application of sludge.

scholarly journals Bioavailability of heavy metals in soils amended with sewage sludge

2002 ◽  
Vol 82 (4) ◽  
pp. 433-438 ◽  
Author(s):  
M T Morera ◽  
J. Echeverría ◽  
J. Garrido
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Dry Weight ◽  
Matter Content ◽  
Alkaline Soils ◽  
Toxic Heavy Metals ◽  
Heavy Metals Bioavailability ◽  
Heavy Metals In Soils

The recycling of sewage sludge to agricultural land results in the slow accumulation of potentially toxic heavy metals in soils. A greenhouse experiment was conducted to determine the bioavailability of Cu, Ni, Pb and Zn applied to soils in urban anaerobically stabilized sewage sludge. The soils were Lithic Haplumbrept (Lh), Calcixerollic Xerochrept (Cx1 and Cx2) and Paralithic Xerorthent (Px). Sunflower plants (Helianthus annuus L) were grown in the soils following amendment with the sludge. The addition of sewage sludge markedly increased the average dry weight of the plants in the soils that had lower yields without sludge addition (Lh, Cx2, and Px). The acid pH of the Lh soil favoured the bioavailability of Zn from sewage sludge. The bioavailability of Cu was greater in the alkaline soils than in the acidic soil (Lh), which can be attributed to the high organic matter content of the Lh soil which complexes Cu and impairs its uptake by the plants. The concentration of metals in the plants increased with the sewage sludge dose. The effect of the soil type on the metal concentration in plants was greater that the effect of the dose. Key words: Soils, sewage sludge, heavy metals, bioavailability, sunflower

scholarly journals Regulatory and technological prerequisites of the use of sewage sludge for the production of organic fertilizers

2020 ◽  
pp. 162-170
Author(s):  
R. Edgecock ◽  
V. V. Bratishko ◽  
I. V. Zinchenko ◽  
S. H. Karpus ◽  
D. O. Milko ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Municipal Wastewater ◽  
Raw Materials ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Raw Material ◽  
Organic Fertilizers ◽  
Mineral Fertilizers

Annotation Purpose. Summarize the regulatory and technological requirements for the production of organic (organo-mineral) fertilizers on the base of sewage sludge. Methods. Analysis and generalization of the requirements of regulatory documents on the management of organic waste and their use as raw materials for the production of organic fertilizers and soil improvers. Results. The current legislative, departmental and regulatory documentary base in Ukraine concerning the treatment of sediment resulting from biological sewage treatment at municipal wastewater treatment plants for its further use in agriculture as fertilizers is analysed. Indicators are identified and analysed to determine the possibility, feasibility, efficiency and scope of organic fertilizers produced using sewage sludge. The analysis of changes in the content of organic matter and total nitrogen in the sewage sludge during its storage at the sewage treatment plant sites is presented. The technological feasibility of using sludge of different shelf life in composting production has been determined. Conclusions 1. The regulatory framework of Ukraine contains a sufficiently complete list of indicators that should be met by organic raw materials (sewage sludge) for further use as organic fertilizers. Some of these indicators – bio security and heavy metals content – can be improved in the composting process of fertilizers. 2. Fresh sediment, as well as sediment accumulated in the last late autumn and winter periods, is of main value for use as a raw material in the production of organic fertilizers. 3. The use in the production of compost sludge stored on sludge sites for a period of half a year or more requires special control of the process of decontamination. In this case, it is advisable to use additional means of wastewater decontamination. Keywords: heavy metals, manure, humus, decontamination, composting, organic fertilizers, sewage sludge.

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