Spatial Patterns of Heavy Metals in the Sediments of a Municipal Wastewater Treatment Pond System and Receiving Waterbody, Cha am, Thailand

The contamination of the sewage sludge fields of municipal wastewater treatment plants (WWTPs) by heavy metals, hydrocarbons or other pollutants is a major environmental problem. Sludge can retain up to 96% of all the metals entering the WWTPs in sewage, therefore, when it is disposed to land, heavy metals will be accumulated in the soil. Effects of heavy metal accumulation are long lasting and even permanent. Phytotoxicity is the main problem, although metals can be transferred directly to man via vegetables and other crops or indirectly via animals, primarily cattle, eating herbage (zootoxic). The common metals in sludge are Zn, Cu, Ni, Pb, Cr, and Cd which are generally the most toxic metal found in high concentration.Conventional treatment techniques of contaminated territory suffer from serious shortcomings which limit their applicability and efficiency. These include high cost and maintenance requirements, the need to transfer the contamination from one medium to another, and the extended duration of the operation. Alternatives to these treatments lie in insitu phytoremediation. Plants are among the most tolerant organisms to pollution, which emphasizes their utility for the detoxification or degradation of pollutants. The concept of phytoremediation was inspired by the discovery of hyper-accumulators, most of which belong to the botanical families Brassicaceae, Poaceae, Papilionaceae, Caryophyllaceae, and Asteraceae, which provide most of the candidates for heavy metal phytoremediation. Two other families are important - the Salicaceae with the genera Salix and Populus, which are effective against a range of pollutants; and the Betaceae which contribute species effective against salt ions and small (few rings) polycyclic aromatic hydrocarbons (PAHs). Some Asteraceae species have been shown to be good phytoremediants of radionuclide pollution [ I ].This paper summarizes the results obtained from laboratory, as well as from in-situ experiments (sludge fields at Kharkiv's WWTP, total area is approx. 126 ha) which focused on phytoremediation methodologies for the removal of heavy metals from sewage sludge.

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Occurrence and Fate of Selected Heavy Metals in a Conventional Municipal Wastewater Treatment Plant in Kisumu City, Kenya

Advanced Treatment Techniques for Industrial Wastewater - Advances in Environmental Engineering and Green Technologies ◽

10.4018/978-1-5225-5754-8.ch012 ◽

2019 ◽

pp. 211-224

Author(s):

Victor Odhiambo Shikuku ◽

George O. Achieng'

Keyword(s):

Heavy Metals ◽

Wastewater Treatment ◽

Municipal Wastewater ◽

Treatment Plant ◽

Potential Effect ◽

Quality Parameters ◽

Municipal Wastewater Treatment ◽

Effluent Quality ◽

Kisumu City ◽

National Environmental

The objective of this work was to investigate the occurrence and fate of five heavy metals in water, sludge, and sediments from a conventional municipal wastewater treatment facility in Kisumu City, Kenya. The effluent quality was compared with the effluent quality parameters stipulated by the National Environmental Management Authority (NEMA) to assess the efficiency of the plant and potential effect of the discharged effluent on the recipient river. The levels of the heavy metals recorded in the sludge samples were significantly higher than those in the corresponding water samples. The order of the metal percentage removal efficiency (%R) from the treatment plant was Mg>Cu>Mn>Fe>Zn. It is concluded that the plant is a point source for Zn loading into the recipient waters which poses potential risk to end users downstream. The heavy metal-laden sludge was within permissible limits for utilization in agricultural lands.

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Heavy metal contents and mobility of artificially inundated grasslands along River Weser, Germany

Water Science & Technology ◽

10.2166/wst.2001.0873 ◽

2001 ◽

Vol 44 (11-12) ◽

pp. 507-514

Author(s):

C. Erber ◽

P. Felix-Henningsen

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Wastewater Treatment ◽

Atmospheric Deposition ◽

Municipal Wastewater ◽

Total Content ◽

Municipal Wastewater Treatment ◽

Metal Enrichment ◽

Metal Contents ◽

The One

At the beginning of the 20th century municipal wastewater was used to fertilize grassland in the freshwater marsh of the river Weser. In 1987, 150 ha of the marsh became part of a mitigation area with artificial inundation during winter and spring. Heavy metal input may be expected from former wastewater treatment and artificial flooding nowadays. In addition, inundation may increase the availability of heavy metals that were accumulated during municipal wastewater treatment. In order to get an idea of heavy metal content and availability, the content of Cd, Cr, Cu, Ni, Pb, and Zn of the soil, the vegetation, and the input due to inundation were determined. Metal enrichment in the epipedon is evident for Cr, Cu, Pb, and Zn. Total content of Pb and Zn exceed the precaution limit. Soils treated with wastewater seems to contain more heavy metals than the ones without. Inundation causes an input of metals, but it is very low and varies in a broad range. Metal input is higher by atmospheric deposition than the one due to inundation. Degree of enrichment can be arranged in the order: atmospheric deposition > municipal wastewater >> inundation. In shallow ditch soils heavy metals are becoming more available.

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Variations of heavy metals in the city of Windsor municipal wastewater treatment plants

International Journal of Environmental Studies ◽

10.1080/00207238708710390 ◽

1987 ◽

Vol 30 (2-3) ◽

pp. 157-175 ◽

Cited By ~ 1

Author(s):

R. G. Zytner ◽

N. Biswas ◽

J. K. Bewtra

Keyword(s):

Heavy Metals ◽

Wastewater Treatment ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Municipal Wastewater Treatment ◽

Municipal Wastewater Treatment Plants ◽

The City

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Treatment of Excess Sludge Containing Heavy Metal by Chemical Ways

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.178-181.507 ◽

2012 ◽

Vol 178-181 ◽

pp. 507-511

Author(s):

Zhi Min Zhang

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Wastewater Treatment ◽

Municipal Wastewater ◽

Metal Removal ◽

Wastewater Treatment Plants ◽

Heavy Metal Removal ◽

Municipal Wastewater Treatment ◽

Excess Sludge ◽

Municipal Wastewater Treatment Plants

The concentration of heavy metals in excess sludge from municipal wastewater treatment plants has restricted its convertion to soil fertilizer, so it is necessary to remove the heavy metals from sludge. In this article, the effects of heavy metal removal by some mineral acids such as HCl, H2SO4, H3PO4, HNO3 were analysed, when treating excess sludge from a second sediment tank in municipal wastewater treatment plants. To improve the treatment, a combination of H2O2 and acid was also investigated. Consequently, the difference of heavy metal removal among those acids was showed. Its removal of Hg by HNO3 was better than by other acids. Lower pH enhanced the dissolving of heavy metal, yet the removal of Cr was insensitive to the pH. Aided by H2O2, the removal by the acid was enhanced. The suitable dosage of H2O2 was specially related to the solid content of sludge, pH and the acid kind.

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Conversion of Sewage Sludge and Other Biodegradable Waste into High-Value Soil Amendment within a Circular Bioeconomy Perspective

Energies ◽

10.3390/en14216953 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6953

Author(s):

Ewa Neczaj ◽

Anna Grosser ◽

Anna Grobelak ◽

Piotr Celary ◽

Bal Ram Singh

Keyword(s):

Heavy Metals ◽

Wastewater Treatment ◽

Sewage Sludge ◽

Wastewater Treatment Plant ◽

Municipal Wastewater ◽

Treatment Plant ◽

Organic Fertilizers ◽

Municipal Wastewater Treatment ◽

Biodegradable Waste ◽

Digestion Process

Resource recovery from biodegradable waste is essential in order to reach the goals of zero circular economy waste generation and zero greenhouse gas emissions from the waste sector. Waste whose management is a real challenge is sewage sludge, mainly because of high concentrations of heavy metals. The aim of this study was to compare the effectiveness of material stabilization during aerobic stabilization of two feedstocks with sewage sludge obtained from different sources, namely, digestate from a municipal wastewater treatment plant and digestate from a co-digestion process. Moreover, the goal of the experiment was to assess the quality of compost in terms of remediation potential. The composting process was carried out for four different mixtures consisting of the mentioned digestates, municipal solid waste, and grass. A better composting efficiency with digestate from the co-digestion process was observed. In that case, a higher temperature in the thermophilic phase (>55 °C) and a higher organic matter loss ratio (60%) were obtained as compared to the process with digestate from wastewater treatment plant. Taking into account the fertilizing properties and the concentration of heavy metals, all obtained composts met the requirements set out in the Polish Regulation for organic fertilizers. Only the content of Helminth eggs in the composts produced with the digestate from the wastewater treatment plant was above the acceptable level. The research also proved that the produced composts can be used in the phytoremediation process of the degraded area. It was found that all composts caused a significant increase in fescue biomass. The highest yield was achieved for compost produced from a mixture with the addition of 30% sewage sludge from the co-digestion process.

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Upgrading of decentralized ponds for municipal wastewater treatment and restricted reuse

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2011.022 ◽

2011 ◽

Vol 1 (3) ◽

pp. 141-151 ◽

Cited By ~ 2

Author(s):

Hussein I. Abdel-Shafy ◽

Inka Hobus ◽

Werner Hegemann

Keyword(s):

Wastewater Treatment ◽

Water Reuse ◽

Municipal Wastewater ◽

Removal Rate ◽

Municipal Wastewater Treatment ◽

Land Area ◽

Pond System ◽

Treated Effluent ◽

Wastewater Quality ◽

Construction Operation

Upgrading of a pond system for municipal wastewater treatment in a decentralized area is evaluated. The pond was constructed for the treatment of 63 m3/d. Currently it receives 83 m3/d, therefore poor treatment efficiency was recorded. An expansion of 1.6 times the present land area was required. In addition to construction, operation and maintenance were required to meet the permissible limits. The other option was to introduce aeration system to the ponds without any additional requirements. The efficiency of the successive treatment steps on the wastewater quality, including metals in the treated effluent/sludge and bacterial counts, was evaluated for agricultural reuse. The physical, chemical and bacterial parameters as well as the input aeration load (h) during the study period were investigated extensively. The results indicated that remarkable improvement in the treated effluent was achieved after upgrading the pond system via aeration. The removal rate of the pollution parameters ranged from 75 to 85%. The level of heavy metals in the produced sludge was below the permissible concentration and does not represent any risk. Meanwhile, it was possible to avoid any requirements for addition land area or construction of treatment and proved that the treated effluents can be reused for restricted water reuse.

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The Fate of Heavy Metals in Wastewater Treatment Plants

Water Science & Technology ◽

10.2166/wst.1992.0524 ◽

1992 ◽

Vol 25 (4-5) ◽

pp. 413-419

Author(s):

A. V. Ghirardini ◽

F. Avezzù ◽

P. Cescon

Keyword(s):

Heavy Metals ◽

Mathematical Model ◽

Wastewater Treatment ◽

Activated Sludge ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Municipal Wastewater Treatment ◽

North East ◽

The North

In a previous paper the A.A. used a mathematical model to describe the complex mechanisms affecting heavy metals distribution between liquid and solid phases in order to predict the quality of effluents of an activated sludge biological treatment system. In the present work the mathematical model is employed to depict the behaviour of particulate and soluble zinc in large municipal wastewater treatment plants for which operating data were available in the existing literature. The results obtained by this model, compared with experimental data, describe zinc behaviour in activated sludge systems satisfactorily. The behaviour of some other metals (zinc, nickel, copper, chromium), studied in solid and liquid3 flows of a municipal wastewater treatment plant in the north-east of Italy (5000 m3/day), is satisfactorily simulated.

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Factors affecting the distribution of heavy metals in wastewater treatment processes: role of sludge particulate

Water Science & Technology ◽

10.2166/wst.2001.0577 ◽

2001 ◽

Vol 44 (10) ◽

pp. 47-52 ◽

Cited By ~ 5

Author(s):

C. P. Huang ◽

J. M. Wang

Keyword(s):

Heavy Metals ◽

Wastewater Treatment ◽

Ionic Strength ◽

Municipal Wastewater ◽

Treatment Process ◽

Metal Removal ◽

Primary Treatment ◽

Metal Distribution ◽

Municipal Wastewater Treatment ◽

Wastewater Samples

The distribution of heavy metals, namely, Ag(I), Cd(II), Co(II), Cr(III,VI), Cu(II), Hg(II), Ni(II), Pb(II), and Zn(II) in 4 municipal wastewater treatment plants was evaluated as a function of several parameters including pH, COD, ionic strength and SS. Although there are variations in pH, alkalinity, COD and ionic strength, the results show that wastewater samples containing less than 5 g/L suspended solids concentration have similar characteristics. Correlations among heavy metal distribution (as the ratio between dissolved to total metals) and wastewater characteristics were attempted. Correlation between the parameters monitored and metal distribution is poor. In the case of pH, no apparent relationship could be seen. In general, increasing COD and ionic strength decreases the metal distribution. Metal distribution relies almost entirely on the concentration of solids in wastewater samples. Total metal removal in primary treatment process is lower than that reported in the literature. This could be attributed to the low average solids removal observed in the treatment plants investigated. Solids reduction at the effluent were larger than 80% and total metals removal was identical to that of the primary treatment process.

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