ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Sludge, a natural, uncalled for byproduct of aerobic/ anaerobic biological digestion oforganic matter present in wastewaters, also known as biosolids, is a thick, black and viscoussubstance comprising of dead and degraded microbial cells that digested the influents. Thisdead microbial material, accumulates on the bottom of anaerobic lagoons/ reactors, is organic innature and rich in plant nutrients such as nitrogen, phosphorus and essential trace elements. Itmust be removed periodically. Therefore, the objective is to use the sludge as a fertilizer onagricultural land. It is an environmentally acceptable and economical method of sludge disposal.The application of organic wastes to farmland has increased over the years as it contributes tothe preservation of the environment and results in an improvement of chemical, biochemical andphysical properties of soil, although there is an increased risk of soil and ground water beingcontaminated by pollutants. Sewage sludge may contain heavy metals whose presence in soilmay reduce enzyme activities and affect microbial communities in soil. They accumulate in soiland are taken up by crop plants thus posing health hazard. The study was conducted tocharacterize anaerobic sludge and quantify the concentration of heavy metals in it, to determinethe suitability of the sludge as fertilizer for crops. Physicochemical and biochemical analysesshowed that anaerobic sludge produced at Upflow Anaerobic Sludge Blanket (UASB) sewagetreatment plant at Faridabad (an industrial town), Haryana, India, contained total organic C15.714 percent, total Kjeldahl N 0.795 percent, available P 8 3g g-1and heavy metals Zn 15003g g-1, Ni 226 3g g-1, Fe 3000 3g g-1 and high activity of enzymes like alkaline phosphatase anddehydrogenase in the sludge. These enzymes are important for soil fertility and nutrient cycling.The toxic heavy metals have been accumulated by bacteria from sewage waters. The ideal C/Nratio, P and enzyme activities show its suitability as fertilizer but presence of heavy metals is amatter of concern. Therefore its application as crop fertilizer or onto land has to be carefullymanaged
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.20-21.213.pdf
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