From municipal/industrial wastewater sludge and FOG to fertilizer: A proposal for economic sustainable sludge management.
After a ban on the depositing of untreated sludge in landfills, the sludge from municipal and industrial water-treatment plants can be regarded as a problem. Waste products of the water treatment process can be a problem or an opportunity - a source for obtaining raw materials. In the European Union...
| Published in: | Journal of Environmental Management Vol. 183; pp. 1009 - 1026 |
|---|---|
| Main Authors: | , , , , , , |
| Format: | Article |
| Published: |
Academic Press Inc.
Dec2016 Part 3
|
| Subjects: | |
| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ssf&AN=118569054&site=ehost-live header: @attributes: shortDbName: ssf uiTerm: 118569054 longDbName: Social Sciences Full Text (H.W. Wilson) uiTag: AN controlInfo: bkinfo: jinfo: jid: 03014797 EMJ jtl: Journal of Environmental Management issn: 03014797 maglogo: N pubinfo: dt: Dec2016 Part 3 vid: 183 pid: 735 pub: Academic Press Inc. artinfo: ui: 118569054 10.1016/j.jenvman.2016.09.063 ppf: 1009 ppct: 17 formats: tig: atl: From municipal/industrial wastewater sludge and FOG to fertilizer: A proposal for economic sustainable sludge management. aug: au: Bratina, Božidar Šorgo, Andrej Kramberger, Janez Ajdnik, Urban Zemljič, Lidija Fras Ekart, Janez Šafarič, Riko affil: Faculty of Electrical Engineering and Computer Science, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia Faculty of Natural Sciences and Mathematics, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia Gorenje Surovina d.o.o., Ulica Vita Kraigherja 5, 2000 Maribor, Slovenia su: Wastewater treatment Raw materials Fats & oils & the environment Sewage disposal plants Sustainability Sludge management sug: subj: Other Farm Product Raw Material Merchant Wholesalers Water and Sewer Line and Related Structures Construction Waste treatment and disposal Sewage Treatment Facilities Solid Waste Landfill Rendering and Meat Byproduct Processing Rendering and meat processing from carcasses Medicinal and Botanical Manufacturing Wastewater treatment Raw materials Fats & oils & the environment Sewage disposal plants Sustainability Sludge management keyword: Digestate Fertilizer Heavy metals' reduction Sludge treatment Wastewater sludge Digestate Fertilizer Heavy metals' reduction Sludge treatment Wastewater sludge ab: After a ban on the depositing of untreated sludge in landfills, the sludge from municipal and industrial water-treatment plants can be regarded as a problem. Waste products of the water treatment process can be a problem or an opportunity - a source for obtaining raw materials. In the European Union, raw sludge and fats, oil and grease (FOG) from municipal and industrial wastewater treatment plants (WWTP) cannot be deposited in any natural or controlled environment. For this reason, it must be processed (stabilized, dried) to be used later as a fertilizer, building material, or alternative fuel source suitable for co-incineration in high temperature furnaces (power plants or concrete plants). The processes of drying sludge, where heat and electricity are used, are energy consuming and economically unattractive. Beside energy efficiency, the main problem of sludge drying is in its variability of quality as a raw material. In addition to this, sludge can be contaminated by a number of organic and inorganic pollutants and organisms. Due to the presence or absence of pollutants, different end products can be economically interesting. For example, if the dried sludge contains coliform bacteria, viruses, helminths eggs or smaller quantities of heavy metals, it cannot be used as a fertilizer but can still be used as a fuel. The objectives of the current article is to present a batch-processing pilot device of sludge or digestate that allows the following: (1) low pressure and low temperature energy effective drying of from 10 to 40% remaining water content, (2) disinfection of pathogen (micro)organisms, (3) heavy metal reduction, (4) production of products of predetermined quality (e.g. containing different quantities of water; it can be used as a fertilizer, or if the percentage of water in the dry sludge is decreased to 10%, then the dried sludge can be used as a fuel with a calorific value similar to coal). An important feature is also the utilization of low-pressure technology to prevent odorous gasses from spreading into the environment. There are presented two new technologies: a) Sewage sludge or digestate drying in the vacuum chamber consumes approx. 1 kWh/dm 3 of evaporated water and, therefore, reaches a price of 180–240 Euros/t Dry Matter (DM), and b) Heavy metals' reduction using adsorbing reaction with magnetite nanostructures can decrease the level of heavy metals in the sewage sludge or digestate up to 20% in one cycle, which can be repeated several times on the same sludge. The aim of the paper is to present a newly developed technology which can provide economic and safe use of moderate heavy metals polluted sewage sludge on agricultural lands as organic fertilizer and, therefore, returning the nutrients (nitrogen, phosphorous, potassium) back to the human food chain, instead of being incinerated or landfilled. The proposed drying technology is economically sustainable due to the low vacuum and temperature (35 °C–40 °C), that increases the efficiency of the heat pump (coefficient of performance 5–7,2) of the energy produced by the anaerobic digestion. Hence, the main emphasis is given to the development of: an efficient method for heavy metals' reduction in the sludge treatment chain by using chitosan covered magnetite nanoparticles, an efficient drying method in a vacuum with low temperature energy which can be exploited from sludge digestion to reduce organic matter, and an energy sustainable concept of sludge treatment, with the addition of fats, oil and grease (FOG) to produce enough biogas for sludge drying to produce fertilizer. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: N holdings: @attributes: islocal: N |
|---|