Showing 32 results for Sewage
Majid Hejazi Mehrizi, Hossein Shariatmadari, Majid ََafyuni,
Volume 17, Issue 64 (9-2013)
Abstract
Application of sewage sludge has been considered as an organic fertilizer in arid and semi-arid regions of Iran. This study was conducted to investigate cumulative and residual effects of sewage sludge on soil inorganic fractions and their relation to phosphorus (P) availability. Two levels of application (50 and 100 Mg ha-1) and three consecutive times of sewage sludge application (1, 3 and 5 years) with a control treatment were studied in a randomized complete block split plot design with three replications. Composite soil samples were collected from 0-30 depth at the end of 5th year of application. Increasing the rate and application year of sewage sludge enhanced dicalcium phosphate (Ca2-P), octacalcium phosphate (Ca8-P), apatite (Ca10-P), aluminum phosphate (Al-P), iron phosphate (Fe-P) and available P but decreased occluded P (OC-P). Residual effect of sewage sludge application resulted in increased inorganic fractions in blocks treated for 1 year compared to control. Positive correlations were observed between inorganic P fractions and Olsen P, wheat yield and P uptake (except OC-P). We concluded that inorganic P fractions and P availability increased in sewage sludge amended soil.
K. Hashemimajd, Sh. Jamaati-E-Somarin,
Volume 17, Issue 65 (12-2013)
Abstract
Improper properties of sewage sludge include odors, trace elements concentration, and presence of pathogens limit its use in agriculture. Composting and using of earthworms in this process is one of the most suitable methods for stabilization and removal of unsuitable properties of sewage sludge. To investigate the effects of kind and mixing proportion of bulking material and sewage sludge decomposition stage on vermicompost quality, an experiment was carried out in a split plot design with three replications. In this experiment, the stage of sewage decomposition (raw sewage, digested sludge in digester, dewatered sludge in lagoons, and final dried sludge in lagoons) was main factor and kind of bulking materials (woodchips, three leaves, and wheat straw) and mixing proportion of bulking materials to swage sludge (0, 15, 30, and 45 %, V/V) were as subordinate factors. Chemical properties of sewage in different decomposition stages and bulking materials were determined. After 5 months of incubation in the controlled moisture and temperature condition, and in the presence of earthworms, the pot's contents were harvested, and nutrients and heavy metal concentration of vermicomposts were measured. Vermicomposts had relatively low pH and EC. Their nutrients content especially N, P, Fe, and Zn were high. These properties showed vermicompost suitability for use as a soil amendment and organic fertilizer. Heavy metals concentrations of vermicomposts, except for Zn, were lower than recommended values by EPA. Despite no significant difference between the kinds of bulking materials, mixing of these materials with sewage sludge decreased pH, N, and Pb content of produced vermicompost. According to the results, 30% (v/v) mixing of bulking material and sewage sludge is recommended
H. Motaghian, A. Hosseinpur, F. Raiesi, J. Mohammadi,
Volume 17, Issue 65 (12-2013)
Abstract
Studying the distribution of Zn in the soils allows investigating their mobility and bioavailability. In this research, 10 calcareous soil samples were selected, and sewage sludge-amended (1% w/w) and -unamended (control) soils were incubated for 1 month. Before planting, fractions of Zn were determined, three seeds of wheat were planted in each pot and after 8 weeks, they were harvested. Results showed that all Zn fractions were increased by sewage sludge addition. Results of pot experiment indicated a significant correlation between Zn concentration in wheat with exchangeable (r=0.92**) and Zn associated with Fe and Mn oxides (r=0.76*) in control soils. In addition, significant correlation coefficient was found between Zn associated with Fe and Mn oxides and Zn uptake index (r=0.86**). Moreover, wheat responses were significantly correlated with Zn exchangeable (r=0.71*- 0.84**) in amended soils. Yield was correlated with Zn associated with carbonates and Zn associated with Fe and Mn 0.69 and 0.75, respectively. Zn uptake index was correlated with Zn associated carbonates (r=0.64*). Therefore, the exchangeable and Zn associated with Fe and Mn oxides in control soils and the exchangeable and Zn associated carbonates and Zn associated with Fe and Mn oxides in amended soils could be used as available fractions of wheat.
H. Taheri Sodejani, S.h. Tabatabaei, M. Ghobadinia, H. Kazemian,
Volume 18, Issue 67 (6-2014)
Abstract
Zeolites are substances that have been renowned for their remarkable nitrogen adsorption capacity resulting of decrease
in leaching rate of soil nitrogen. This research was conducted to study the effect of the zeolite dosage, zeolite particle
size and the method of application on the nitrate leaching of the soil irrigated by treated wastewater (TWW). All of the
adsorption tests were carried out in a 27 PVC columns with 11 cm diameter and 60 cm length. The experiments were
consisted of 9 treatments and 3 replications including 2 zeolite application method (mixed and layered), 2 zeolite’s
grain size (63-125 and <63 micrometer) and 2 zeolite dosage (2 and 4 percent). Zeolite powders were added to the soil
in mixed or layered fashion. The soil columns were irrigated 13 times with TWW in a weekly period. In the 4th, 9th and
13th irrigation event, three samples were taken from input and output TWW introduced to columns to measure the
change in nitrate concentration. The results were shown that nitrate absorption rate was increased by average of 164.3%
and 350.7% in mixed and layered treatments, respectively compared to the control. The result showed that zeolite
application method, irrigation event, zeolite’s grain size and dosage were statistically significant on nitrate absorption
efficiency (P<0.01). It shows that as the zeolite size decrease the soil nitrate adsorption increases significantly. It
increases when the zeolite percentage increases. The result show that the soil nitrate adsorption decreases as the
irrigation event increase and soil adsorption potential degraded with irrigation events.
S. Rahimi, M. Afyuni, A. H. Khoshgoftarmanesh, M. Noruzi,
Volume 19, Issue 71 (6-2015)
Abstract
Management of organic and inorganic treatments may have positive or negative effects on soil quality, plant growth and human nutrition. The objectives of this study were to determine the effects of organic and inorganic zinc fertilizer application on soil quality indicators and wheat yield. This research was conducted at Agricultural Research Station Roudasht, Isfahan, Iran. Sewage sludge and cow manure (5 and 10 t/ha), ash rubber (1 t/ha), powder rubber (200 kg/ha), ZnSO4 (40 kg/ha) were applied and wheat was cultivated. Soil samples were collected at tilling and harvest stages. After taking samples and measurements of the soil parameters, we determined the critical limits for each category and class rating for the each soil parameters, and the soil quality index was calculated. The results showed sewage sludge and rubber ash were significantly effective in increasing soil bioavailable Zn compared to other treatments. Application of sewage sludge and cow manure at 10 ton/ha improved soil quality. The expanded soil quality index can help better understand the effect of fertilizers on soil. A positive and significant relationship between soil quality indicators and Zn uptake and wheat yields was also observed. Our results indicate that addition of 10 t/ha sewage sludge as fertilizer can significantly improve soil quality, supplying the necessary amount of Zn for wheat growth.
A. Abdolahi Arjenaki, A. A. Fadaei Tehrani,
Volume 19, Issue 71 (6-2015)
Abstract
Plant parasitic nematodes, especially root knot nematodes, cause damage to most of agricultural products, and many efforts have been done to control them. In recent years, application of industrial waste and wastewater sludge as organic fertilizers in agriculture has been increased. To investigate the effects of sewage sludge on root knot nematode pathogenicity in tomato, different weights of sewage sludge (0, 4, 8, 15 and 25% of sludge in the soil) in soil were added as a completely randomized design with six replications. Analysis variance and mean comparison of growth indices of plants showed significant effects of treatments. For example, means of stem length of plants increased in soil with more amount of sewage sludge. This relationship was also observed in other indices and nutrients elements. So using sewage increased nitrogen, phosphorous, calcium and magnesium in tomato shoots inoculated with nematodes while the change of potassium was very small. Application of sewage sludge decreased the number of galls, egg-masses and eggs in egg-mass of root knot nematode.
T. Raiesi, A. Hosseinpur,
Volume 19, Issue 71 (6-2015)
Abstract
The ability of different soil tests in predicting soil phosphorus (P) is important in soils amended with municipal sewage sludge. The objective of the present study was to evaluate several chemical extractants to estimate available P for bean growing in 10 calcareous soils amended with municipal sewage sludge from Chaharmahal-Va-Bakhtiari province under the greenhouse conditions. For this purpose, the soil samples were incubated with sludge at a rate of 39-ton sludge ha–1. The amount of available P of the soil samples was determined by Olsen, Colwell, ammonium bicarbonate-DTPA, 0.01 M calcium chloride, BrayІ, ІІ, Mehlich І and ІІ methods. A pot experiment in a completely randomized design was conducted to evaluate the bean plant indices. The results showed that the amount of extractable P with the above methods decreased in the following order: Colwell> Bray ІІ> Mehlich ІІ> Olsen> Ammonium bicarbonate DTPA> Mehlich І> Bray І> 0.01M chloride calcium. The extractable P with 0.01M chloride calcium, Mehlich І, ІІ Colwell and Olsen methods correlated significantly with plant indices (P concentration and P uptake). Thus, mentioned methods could be used to estimate plant-available P in the soils amended with sewage sludge.
H. R. Motaghian, A. R. Hosseinpur, J. Mohammadi, F. Raiesi,
Volume 20, Issue 75 (5-2016)
Abstract
Zinc (Zn) is one of the essential micronutrients for plant growth and its deficiency frequently occurs in calcareous soils. But, a suitable extractant for estimation of plant-available Zn in calcareous soils, amended with sewage sludge, has not been presented yet. The aim of this research was to assess several chemical extractants (7 extractants) for estimation of available Zn in calcareous soils amended (1% w/w) and unamended with sewage sludge. Results showed that Mehlich 3 and Mehlich 1 extractants extracted the highest and the lowest concentrations of Zn in both amended and unamended soils, respectively. All wheat indices (wheat yield, Zn concentration and Zn uptake) increased by sewage sludge addition. Besides, the results indicated that in unamended soils, significant correlations were found (r=0.65*- 0.91**) between extracted Zn using AB-DTPA, DTPA-TEA and Mehlich 3 extractants and different wheat indices. On the contrary, in sewage sludge-amended soils, only the correlation between extracted Zn using Mehlich 2 and Zn concentration was significant (r=0.83**). According to this study findings, the suitable extractant for extracting wheat-available Zn is thoroughly different in calcareous soils amended and unamended with sewage sludge.
Sh. Ghorbani Dashtaki, N. Karimian, F. Raeisi,
Volume 21, Issue 1 (6-2017)
Abstract
The use of organic matter such as urban sewage sludge may help sustainable soil fertility via improving the physical, chemical and biological soil characteristics. The main purpose of this study was to determine the effect of urban sewage sludge on chemical properties, soil basal respiration and microbial biomass carbon in a calcareous soil with silty clay loam texture. Therefore, three levels of water repellency (zero, weak and strong) were artificially created in a silty clay loam soil by adding urban sewage sludge (S0=0:100; S50=50:50 and S80=80:20 sludge weight: soil ratio). Water repellency was determined by water drop penetration time (WDPT) method. Also some chemical properties such as soil acidity (pH) and Electrical Conductivity (EC), Soil Organic Carbon (OC), soluble sodium (Na+) and soluble potassium (K+) were measured. The samples were incubated at 23-25 ºC for 30 days and their moisture was maintained at 70-80 % under field capacity and soil basal respiration and microbial biomass carbon of incubation period were evaluated. The results showed that the effect of urban sewage sludge on chemical properties was significant (P ≤0.0001). The application of urban sewage sludge led to significant increase in basal respiration (16 and 27 times) and microbial biomass carbon (15.2 and 26.5 times) in the water repellency soils (S50 and S80) compared to control soil. The observed positive effect of sewage sludge might be due to a high content of organic carbon and nutrients in urban sewage sludge and decrease in the labile organic matter and nutrients during incubation period.
H. Hasheminejada, M. Sayedbarzin, K. Jeirany, A. Taebi,
Volume 23, Issue 1 (6-2019)
Abstract
Detergents are the main organic pollutants in the industrial and domestic wastewater. Electro-chemistry methods are advanced purification methods developed with high efficiency features. The goal of this study was to investigate the possibility of using electrocoagulation and the complementary flocculation process to achieve the highest removal efficiency of the detergent COD. So, with iron electrode, synthetic samples at the concentrations of 500, 750 and 1000 mg/l (with COD of 217, 268 and 370 mg/l, respectively) and with the initial pH levels of 5, 7.3 and 9 were tested. Variable parameters during the electrocoagulation process included the current duration at 3, 5 and 10 minutes, and the current density was at 4, 10, 16 and 22 mA/cm2. The primary results showed that in the optimum conditions, the coagulation process and complementary flocculation could reduce the sample’s COD with an initial concentration of detergent (500 mg/l) from 217 mgO2/l to 81.30 mgO2/l. The electrocoagulation method could reduce the chemical oxygen demand to below the standard limit of environmental discharge (200 mgO2/l) and compensate for the possibility of the irrigation of green spaces due to water shortages.
F. Afzalinejad, S. Ghasemi, S. E. Seyfati, Sh. Shahbazi,
Volume 24, Issue 4 (2-2021)
Abstract
Today, the use of organic wastes as fertilizers to improve the physical, chemical and biological properties of soil is common. In this study, to investigate the effect of the sewage sludge on the growth and concentration of chlorophyll, nitrogen, phosphorus and potassium in quinoa plant, a factorial experiment was conducted based on a completely randomized design with three replications in a calcareous soil with electrical conductivity of 13.1 dS m-1. Treatments included three genotypes of quinoa (Red carina, Titicaca, Q29) and three levels of sewage sludge (0, 20 and 40 t ha-1). The results showed that the effects of the quinoa genotype, different levels of sewage sludge and the interaction of treatments on the root dry weight, shoot P concentration and chlorophyll concentration were significant. Also, the sewage sludge had a significant effect on the shoot length, shoot dry weight and shoot nitrogen concentration. By increasing the level of the sewage sludge, root length, shoot length, shoot dry weight and shoot N concentration were increased, on average, by 44.7 %, 48.8%, 42.0% and 46.6%, respectively. Also, application of 40 t ha-1 sewage sludge significantly increased the chlorophyll concentration and shoot P concentration in Q29 and Titicaca genotypes. According to the results of this study, application of sewage sludge can increase the growth of quinoa by improving its nutrition.
F. Khafi, A.r. Hossienpour, H. Motaghian,
Volume 26, Issue 2 (9-2022)
Abstract
One of the significant factors affecting biochar properties is the pyrolysis temperature. This study aimed to investigate the effect of pyrolysis temperature on the properties and fractionation of Zn and Pb in biochars produced by sewage sludge. Biochars were prepared at temperatures of 300 to 700 °C and the physicochemical properties, availability, and fractionation of Zn and Pb were investigated. The results showed that pH, pHzpc, percentage of calcium carbonate, cation exchange capacity, specific surface area, and porosity in biochars were higher than in the feedstock. By increasing biochar production temperature, the mentioned properties increased. FT-IR revealed that the OH functional group is present in free form, either in the structure of C-OH and -COOH and aliphatic-CH2 groups in the sewage sludge. By converting sewage sludge to biochar, the intensity of these peaks decreased. In contrast, peaks representing complex aromatic structures appeared. The availability of Zn and Pb in biochar was reduced as compared to sewage sludge. The results of fractionation indicated that sewage sludge has bio-availability and toxicity of Pb and Zn. the amount of oxide and residual fractions of these two metals increased by converting sewage sludge to biochar at different temperatures. Therefore, it seems that biochar production from sewage sludge reduces the toxicity and bio-availability of Zn and Pb. Also, by incrementing the temperature of production, the bio-availability potential (bonding with organic matter), and non-toxicity (residual) of these metals increased.
