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Combustion Characteristics of Sewage Sludge and Algae  [PDF]
Yaman Kumar Sahu, Pravin Kumar Sahu, Suryakant Chakradhari, Khageshwar Singh Patel
Natural Resources (NR) , 2016, DOI: 10.4236/nr.2016.74019
Abstract: Sewage sludge is a good source of energetically desirable compounds and green algae in developing country like India. In this work, the combustion characteristics of sewage sludge and green algae are described. The calorific value (CV) of dried sewage sludge (n = 7) and green algae (n = 11) was ranged from 1800 to 6250 and 3700 to 6280 kcal/kg with mean value of 3999 ± 1347 and 4428 ± 547 kcal/kg, respectively. The effect of proximate variables and water quality parameters in the CV of sludge and algae are discussed.
Characteristics of sewage sludge and distribution of heavy metal in plants with amendment of sewage sludge
DAI Jia-yin,CHEN Ling,ZHAO Jian-fu,MA Na,
DAI Jia-yin
,CHEN Ling,ZHAO Jian-fu,MA Na

环境科学学报(英文版) , 2006,
Abstract: In order to better understand land application of sewage sludge, the characterization of heavy metals and organic pollutants were investigated in three different sewage sludges in Shanghai City, China. It was found that the total concentrations of Cd in all of sewage sludge and total concentrations of Zn in Jinshan sewage sludge, as well as those of Zn, Cu, and Ni in Taopu sludge are higher than Chinese regulation limit of pollutants for sludge to be used in agriculture. Leachability of Hg in all of studied samples and that of Cd in Taopu sewage sludge exceed the limit values of waste solid extraction standard in China legislation. Based on the characteristics for three kinds of sewage sludge, a pot experiment was conducted to investigate the effect of soil amended with Quyang sewage sludge on the accumulation of heavy metal by Begonia semperflorens-hybr; Ophiopogon japonicus (L.F.) Ker-Gaw; Loropetalum chindense-var. rubrum; Dendranthema morifolium; Viola tricolor; Antirrhinum majus; Buxus radicans Sieb; Viburnum macrocephalum; Osmanthus fragrans Lour; Cinnamomum camphora siebold and Ligustrum lucidum ait. Results showed that 8 species of plant survived in the amended soil, and moreover they flourished as well as those cultivated in the control soil. The heavy metal concentration in plants varied with species, As, Pb, Cd and Cr concentration being the highest in the four herbaceous species studied, particularly in the roots of D. morifolium. These plants, however, did not show accumulator of As, Pb, Cd and Cr. The highest concentration of Ni and Hg was found in the roots of D. morifolium, followed by the leaves of B. semperflorens-hybr. Levels of Zn and Cu were much higher in D. morifolium than in the other plant species. D. morifolium accumulated Ni, Hg, Cu and Zn, which may contribute to the decrease of heavy metal contents in the amended soil. Treatment with sewage sludge did not significantly affect the uptake of heavy metals by the L. chindense-var. rubrum, however, it significantly affected the uptake of heavy metals by D. morifolium.
Effect of Sewage Sludge on Soil Physical Properties  [cached]
M. R. Bahremand,M. Afyuni,M. A. Hajabbassi,Y. Rezaeinejad
Journal of Science and Technology of Agriculture and Natural Resources , 2003,
Abstract: A field experiment was conducted to investigate the effects of sewage sludge and of time lapse after sludge application on soil physical properties. Four sewage sludge treatments (0, 25, 50, and 100 ton/ha) in a complete randomized block design with three replications were applied and mixed to a depth of 20 cm. Wheat was planted and soil physical properties were measured 23, 85, 148, and 221 days after sewage sludge application. Sewage sludge application significantly increased MWD, hydraulic conductivity, final infiltration rate, moisture percentage at 1/3 and 15 bars, and plant available soil moisture, while it significantly decreased soil bulk density. In general, the best results obtained with the 100 ton/ha sewage sludge treatment. Time lapse after sewage sludge application caused soil physical properties to approach the values of the control. However, even 221 days after sludge application, the 50 and 100 ton/ha treatments had significantly different values compared with the control treatment. The results in this research show that sewage sludge can help to improve soil physical conditions and this effect persists over long periods. This effect is specially important with plant available soil moisture and infiltration.
Evaluation of the Pozzolanic Activity of Sewage Sludge Ash  [PDF]
M. A. Tantawy,A. M. El-Roudi,Elham M. Abdalla,M. A. Abdelzaher
ISRN Chemical Engineering , 2012, DOI: 10.5402/2012/487037
Abstract: Raw sewage sludge was characterized by XRD, FTIR, SEM, and TGA techniques and incinerated in temperature range 650–950°C for 2?h. The effect of incineration temperature on the microstructure and pozzolanic activity of the resultant ash was investigated by techniques mentioned above as well as Chapelle test. It was concluded that incineration of sewage sludge affects the microstructure and pozzolanic activity of the resultant ash. During incineration at temperatures lower than 800°C, amorphous silica captures fixed carbon resulting from incomplete combustion conditions whereas at higher temperatures crystallization of amorphous silica was enhanced. Hydration products formed from hydrothermal treatment of silica fume with lime is amorphous whereas that of sewage sludge ash is fibrous. Hence, incineration of sewage sludge ash must be optimized at 800°C to preserve the pozzolanic activity of the resultant ash. 1. Introduction Sewage is the collection of wastewater effluents from domestic, hospital, commercial, industrial establishments, and rain water. The objective of sewage treatment is to produce treated sewage water and sewage sludge suitable for safe discharge into the environment or reuse [1]. The most common treatment options for sewage sludge include anaerobic digestion, aerobic digestion, and composting. Choice of the treatment method depends on the amount of sludge and other site-specific conditions [2]. Sewage sludge tends to accumulate heavy metals existing in the wastewater. The composition of sewage sludge and its content of heavy metals vary widely depending on the sludge origins and treatment options [3]. In past decades, sewage sludge was primarily disposed to landfills and seawaters [4]. Space limitations on existing landfills and increasing environmental concerns such as groundwater pollution from landfill leachate, odor emission and soil contamination have prompted the investigation of alternative disposal routes [5]. Sewage sludge has been used in agriculture as fertilizer and soil amendment [6]. However heavy metals such as Zn, Cu, Ni, Cd, Pb, Hg, and Cr are principal elements restricting the use of sludge for agricultural purposes [3]. The solidification/stabilization of sewage sludge in cementitious matrix has been evaluated [7]. Sewage sludge adversely affects durability of concrete, mainly due to the organic material which retards setting and heavy metals which interfere with the hardening reactions [8]. Hence, sewage sludge addition in concrete was limited to 10?wt.% and the solidified concrete was recommended for use in certain
The drying of sewage sludge by immersion frying
Silva, D. P.;Rudolph, V.;Taranto, O. P.;
Brazilian Journal of Chemical Engineering , 2005, DOI: 10.1590/S0104-66322005000200015
Abstract: the objective of this work was to dry sewage sludge using a fry-drying process. the frying experiments were carried out in commercial fryers modified by adding thermocouples to the setup. during frying, typical drying curves were obtained and it was verified that, in relation to the parameters: oil temperature, oil type and shape of the sample, the shape factor the most effect on the drying rate, at least within the range chosen for the variables studied. oil uptake and calorific value were also analyzed. the calorific value of the samples increased with frying time, reaching values around 24mj/kg after 600s of frying (comparable to biocombustibles such as wood and sugarcane bagasse). the process of immersion frying showed great potential for drying materials, especially sewage sludge, obtaining a product with a high energy content, thereby increasing its value as a combustible.
Effect of Sewage Sludge on the Growth of Maize Crop
M. Qasim,Naheeda Javed,Himayatullah,M. Subhan
Journal of Biological Sciences , 2001,
Abstract: Sewage sludge application had significantly effected all parameters of maize crop except germination percentage. Maximum Shoot length, Number of leaves per plant, Leaf area, Plant height, Root length, Shoot dry weight and Root dry weight of maize crop were obtained where sewage sludge was applied @ 10-30 ton ha-1. It was recommended that application of sewage sludge at the rate of 20 or 30 ton ha -1 will have favorable effect on the maize crop under the agro-climatic conditions of D.I.Khan.
Study of heavy metal in sewage sludge and in Chinese cabbage grown in soil amended with sewage sludge
P Wang, S Zhang, C Wang, J Hou, P Guo, Z Lin
African Journal of Biotechnology , 2008,
Abstract: The study was performed to investigate the heavy metal content and availability for crops in sewage sludge and its accumulation in Chinese cabbage grown in sewage sludge amended soil. We determined the total and chemical fraction of As, Cr, Cd, Pb, Ni, Cu, Zn, Fe, Mg and Mn in sewage sludge and the total content of these metals in Chinese cabbage grown in soil amended with sewage sludge. Total content of all metals (except for As) was below the top limits for land application of sewage sludge in China. The majority of As, Cd, Pb, Zn and Fe was present in the residual fraction (70 – 95%) of the total concentration, and 21% of Cd, 59% of Cr and 56% of Cu were present in oxidizable fraction in sewage sludge. Most of the content of metals increased in Chinese cabbage with the increase in sludge amendments ratio, and the content of heavy metal As, Cd, Cr and Zn exceeded the top limits of metals content in China. Our results suggested that application of sewage sludge could enhance the output of vegetable while the risk of heavy metal should be of concern.
Sewage Sludge as Nitrogen Source for Irrigated Silage Sorghum
Bilal Keskin,Ibrahim Hakki Yilmaz,Mehmet Ali Bozkurt,Hakki Akdeniz
Journal of Animal and Veterinary Advances , 2012,
Abstract: Field experiment was conducted in clay loam soil in Van, located in the eastern part of Turkey, to study sewage sludge and ammonium sulphate as nitrogen sources for sorghum. Silage and dry matter yield, plant height, stem, leaf and panicle ratio, plant nitrogen content, total N uptake, leaf nutrient and heavy metal content, soil DTPA-extractable nutrient and heavy metal content were quantified. The experimental design was a randomized complete block with four replications. Two rates of ammonium sulphate (50, 100 kg ha-1) and three rates of sewage sludge (5.95, 11.90 and 23.80 Mg ha-1) were applied to plots. Sorghum plant was irrigated once a week until soil water content reached to field capacity. Silage and dry matter yield, plant height and total N uptake increased with application of chemical N fertilizer and sewage sludge as compared to control. The yield results revealed that, 100 kg ha-1 nitrogen rate and 23.80 Mg ha-1 sewage sludge rate caused to produce almost the same amount of silage and dry matter yield. Leaf N, P, Ca, Mg, Fe and Mn content of sorghum increased with application of N fertilizer and sewage sludge. Mentioned nutrients in leaf were found pretty similar with application of 100 kg ha-1 N rate and 23.80 Mg ha-1 sludge rate. Besides, Potassium content of sorghum leaf was not affected by either treatment. Leaf Zn content increased with application of N fertilizer and sewage sludge and it reached the highest level at 23.80 Mg ha-1 sludge rate. Leaf Cu content increased only with application of sewage sludge. Also, Fe, Zn, Cu and Ni contents in experiment soil increased with application of sewage sludge and their levels reached to the highest at 23.80 Mg ha-1 sludge rate. None of heavy metal reached toxic level either in plant or in soil. Results indicated that sewage sludge, produced in Van region, could be used as a fertilizer nitrogen source for sorghum, without risks associated with toxic heavy metals.
The Importance of Sludge Microorganisms in Nitrogen Transformations in Podzolic Soil Amended with Sewage Sludge
Jolanta Joniec , Jadwiga Furczak , Stanis aw Baran
Archives of Environmental Protection , 2012, DOI: 10.2478/v10265-012-0003-y
Abstract: The laboratory experiment was set up on a podzolic soil in two variants. In one of them non-sterile sewage sludge was introduced into the soil, and in the second - the same sludge but subjected previously to the process of sterilisation. In both variants the same doses of the sludge were applied: 30 (1%), 75 (2.5%), 150 (5%), 300 (10%) and 600 Mg·ha-1 (20%). Then, after 0.5, 1, 2, 3, 4 and 5 months, the soil of both experimental variants was analysed for the numbers of bacteria and fungi decomposing proteins, the rate of the process of ammonification, the rate of the process of nitrification, and for proteolytic activity. The results obtained revealed a stimulating effect of the sludge, both sterile and non-sterile, on the numbers of the microbial groups under study and on the rate of nitrification and protease activity. Only the process of ammonification was subject to inhibition. The observed effects of the sludge were the most pronounced in the case of the higher sludge doses. Significantly greater numbers of protein-decomposing fungi and higher activity of almost all (except for ammonifcation) analysed biochemical parameters in the soil with non-sterile sludge compared to that with sterile sludge indicate an effect of microorganisms from the sludge on the microbiological transformations of nitrogen in soil amended with sewage sludge.
Utilization of Sewage Sludge as Organic Fertiliser in Sustainable Agriculture  [PDF]
M. Jamil,M. Qasim,M. Umar
Journal of Applied Sciences , 2006,
Abstract: A field experiment was conducted to study the effect of addition of different levels of domestic sewage sludge on the soil properties and yield of wheat crop. Addition of sewage sludge raised soil pH, increased organic matter, ECe, NPK, Ca+Mg and trace metals (Fe, Cu, Mn and Zn) with its increasing levels. Different treatments of sludge also increased the yield and yield attributing components as compared to untreated (control) treatments. Significantly maximum plant height (107 cm), number of tillers (433 m-2) and straw yield (9.82 t ha-1) were obtained where 80 t ha-1 sewage sludge was applied while spike length, number of productive tillers m-2, number of grains spike-1, 1000-grain weight and grain yield were maximum in the treatments amended with 40 t ha-1 of sewage sludge. The study indicates that sludge application at the rate of 40 t ha-1 can enhance economic yield of wheat and also improve soil productivity.
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