Modern approaches to treatment and recovery of secondary sludge of domestic sewage

For today, pollution of the environment, in particular of surface waters, has led to an environmental crisis in many countries of the world. One of the reasons for this is the use of outdated approaches to the treatment and recovery of sewage sludge. The article presents the results of the study of literary sources in order to analyze the proposals for the treatment of secondary sludge of domestic sewage in different countries. To neutralize sewage sludge, scientists consider the possibility of obtaining fertilizes under conditions of biosulfidogenesis during the dissimilation recovery of poorly soluble sulfates or the use of enhanced oxidation technology. A new concept of domestic sewage treatment has also been proposed, which can solve the issue of sewage sludge control at the place of its forming. The main areas of sustainable sludge control are its use in agriculture as fertilizer and for the reclamation of devastated or degraded lands, as well as energy recovery by burning and alternative thermal methods such as pyrolysis, quasi-pyrolysis and gasification. It was established that the applicability of this or that technology of sewage sludge recovery depends on many local factors, in particular: productivity of sewage station; composition and methods of sewage treatment and its sediments; efficiency of sewage treatment plants; climatic zone of the sewage system location; availability of energy and material resources, etc. Today, it is relevant to monitor the qualitative composition of sewage sludge, as well as soils and natural waters regarding pollutants that can be detected in the sewage of the corresponding settlement, in order to make operational decisions to control environmental risks, as well as conduct scientific research to improve recycling and recovery technologies for sewage sludge of various composition in agricultural systems, which will help to protect the environment against pollution and rational use of land.

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Agricultural and non-agricultural directions of bio-based sewage sludge valorization by chemical conditioning

Environmental Science and Pollution Research ◽

10.1007/s11356-021-15293-4 ◽

2021 ◽

Author(s):

Grzegorz Izydorczyk ◽

Katarzyna Mikula ◽

Dawid Skrzypczak ◽

Krzystof Trzaska ◽

Konstantinos Moustakas ◽

...

Keyword(s):

Sewage Sludge ◽

Sewage Treatment ◽

Thermal Methods ◽

Industrial Practice ◽

Ultrasonic Methods ◽

Sewage Sludge Management ◽

Neutralizing Agent ◽

Cadmium Lead ◽

Lead Nickel ◽

Chemical Sludge

AbstractThis literature review outlines the most important—agricultural and non-agricultural—types of sewage sludge management. The potential of waste sludge protein hydrolysates obtained by chemical sludge conditioning was reported. The discussed areas include acidic and alkaline hydrolysis, lime conditioning, polyelectrolyte dewatering and other supporting techniques such as ultrasounds, microwave or thermal methods. The legislative aspects related to the indication of the development method and admission to various applications based on specified criteria were discussed. Particular attention was devoted to the legally regulated content of toxic elements: cadmium, lead, nickel, mercury, chromium and microelements that may be toxic: copper and zinc. Various methods of extracting valuable proteins from sewage sludge have been proposed: chemical, physical and enzymatic. While developing the process concept, you need to consider extraction efficiency (time, temperature, humidity, pH), drainage efficiency of post-extraction residues and directions of their management. The final process optimization is crucial. Despite the development of assumptions for various technologies, excess sewage sludge remains a big problem for sewage treatment plants. The high costs of enzymatic hydrolysis, thermal hydrolysis and ultrasonic methods and the need for a neutralizing agent in acid solubilization limit the rapid implementation of these processes in industrial practice. Graphical abstract

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Proposed treatment applicable scenario for the treatment of domestic sewage sludge which is produced from a sewage treatment plant under warm climates conditions

Desalination and Water Treatment ◽

10.1080/19443994.2012.748464 ◽

2013 ◽

Vol 51 (13-15) ◽

pp. 3081-3089 ◽

Cited By ~ 2

Author(s):

Antonis A. Zorpas ◽

Irene Voukkali ◽

Pantelitsa Loizia

Keyword(s):

Sewage Sludge ◽

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Domestic Sewage ◽

Warm Climates

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Impact of Alkalization of Surplus Activated Sludge on Biogas Production

Ecological Chemistry and Engineering S ◽

10.2478/eces-2013-0025 ◽

2013 ◽

Vol 20 (2) ◽

pp. 343-351 ◽

Cited By ~ 2

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.

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

Linnaeus Eco-Tech ◽

10.15626/eco-tech.2003.044 ◽

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.

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Operational Results of Melting System for Sewage Sludge

Water Science & Technology ◽

10.2166/wst.1991.0632 ◽

1991 ◽

Vol 23 (10-12) ◽

pp. 1773-1781 ◽

Cited By ~ 6

Author(s):

Daisaku Yashiki ◽

Tadahiro Murakami

Keyword(s):

Sewage Sludge ◽

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Melting Furnace ◽

Effective Utilization ◽

History Of ◽

Sludge Properties ◽

Operation Results

Sludge melting furnaces have been applied recently to the treatment of a great deal of sludge generated from the sewage treatment plant. In this report, an explanation is provided of the history of system introduction, outline of treatment flow, sludge properties, operation results and effective utilization of slag generated at the reflector melting furnace, which began operation in July 1988 at the Futakami Sewage Treatment Plant in Toyama Prefecture. The melting furnace almost totally satisfies the needs of its design, and the properties of the generated melted slag exhibit the features that fully enable its effective utilization.

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Sludge Treatment and Disposal Systems for Rural Areas in Germany

Water Science & Technology ◽

10.2166/wst.1993.0190 ◽

1993 ◽

Vol 27 (9) ◽

pp. 159-171 ◽

Cited By ~ 3

Author(s):

Eberhard Steinle

Keyword(s):

Sewage Sludge ◽

Rural Areas ◽

Public Awareness ◽

Sewage Treatment ◽

Treatment Needs ◽

Sludge Treatment ◽

Sewage Treatment Plants ◽

Sewage Purification ◽

Treatment And Disposal ◽

Nitrogen Phosphorus

First an overview of the systems currently in use and being discussed for sludge treatment is presented will) particular emphasis on distinguishing between the object of the system (conditioning objective of the various phases in the system) and a system concept (concept of various phases of the system in sequence to attain the disposal objective). More detailed information is given as to the salient systems as used with smaller sewage treatment plants in rural areas, such as digestion, dewatering, hygienization, composting and thermal drying. A further item of discussion is how sludge treatment influences the sewage treatment process. For the critical emissions (nitrogen, phosphorus) demanded in Germany, and thus for the degree of sewage treatment required, the load of the sewage treatment system resulting from sludge treatment needs to be taken into account. Accordingly, operation of sludge treatment and sewage purification must always be harmonized. The extent of these return loads also limits the spatial centralization of the system phases; this applies in particular to smaller sewage treatment plants in rural areas. In conclusion, an attempt is made to present a perspective for the agricultural utilization of such sludge in Germany. Since the critical values for emissions have been further tightened by new regulations, thus considerably elevating the associated sophistication of monitoring techniques, it is to be expected that the use of sewage sludge in agriculture will also be further reduced in rural areas, especially since public awareness of emission control has considerably reduced the acceptance of sewage sludge as fertilizer.

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Treatment of Rural Domestic Sewage by Solar Ozonic Ecological Sewage Treatment Plant

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.3393 ◽

2014 ◽

Vol 955-959 ◽

pp. 3393-3399 ◽

Cited By ~ 1

Author(s):

Wei Zheng ◽

Yan Ming Yang ◽

Yun Long Li ◽

Jian Qiu Zheng

Keyword(s):

Municipal Wastewater ◽

Operating Cost ◽

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Domestic Sewage ◽

Design Parameters ◽

Small Scale ◽

Municipal Wastewater Treatment ◽

Average Percentage

The process technique and design parameters of project of Solar Ozonic Ecological Sewage Treatment Plant (short for SOESTP) which consists of anaerobic reactor, horizontal subsurface flow (HSSF) constructed wetlands(CWs) and the combination of solar power and ozone disinfection are described, the paper further examines the removal efficiency for treating rural domestic sewage, running expense and recycling ability of product water. The results show that the average percentage removal values of CODcr，BOD5，SS，TN，NH3-N，TP range from 95.6% to 98.0%, 96.0% to 98.7%, 93.1% to 96.1%, 97.0% to 98.9%, 96.9% to 99.5%, 98.2% to 99.6%, respectively, the reduction of fecal coliform (FC) reaches 99.9%, the effluent quality meets the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant（GB18918-2002）. The running cost of SOESTP is 0.063yuan/ m3, saves much more than traditional sewage treatment, and the ozone water obtained from the reservoir will be an ideal choice for disinfection .The system has characteristics of easy manipulation, low operating cost, achieving advanced water, energy conservation and environment protection, is thought to be very suitable for use as the promotion of rural small - scale sewage treatment.

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