Nutrient balancing for phytoremediation enhancement of urea manufacturing raw wastewater

2017 ◽  
Vol 202 ◽  
pp. 225-231 ◽  
Author(s):  
Sara Yavari ◽  
Amirhossein Malakahmad ◽  
Nasiman B. Sapari ◽  
Saba Yavari ◽  
Eakalak Khan
1995 ◽  
Vol 31 (12) ◽  
pp. 171-183 ◽  
Author(s):  
M. M. Saqqar ◽  
M. B. Pescod

The performance of the primary anaerobic pond at the Alsamra Wastewater Treatment Plant in Jordan was monitored over 48 months. Overall averages for the removal efficiencies of BOD5, COD and suspended solids were 53%, 53% and 74%, respectively. An improvement in removal efficiency with increase in pond water temperature was demonstrated. A model, which takes into account the variability of raw wastewater at different locations, has been developed to describe the performance of a primary anaerobic pond in terms of a settleability ratio for the raw wastewater. The model has been verified by illustrating the high correlation between actual and predicted pond performance.


1996 ◽  
Vol 34 (11) ◽  
pp. 51-58 ◽  
Author(s):  
K. Chigusa ◽  
T. Hasegawa ◽  
N. Yamamoto ◽  
Y. Watanabe

Nine strains of yeasts capable of decomposing oil were isolated in order to directly treat wastewater from oil manufacturing plants with no pretreatment. The oil decomposing ability of these yeast strains was evaluated in terms of lipase activity and β-oxidation activity. Since the mixture of the isolated yeasts was superior to any single strain in the oil removal rate, a pilot plant utilizing the mixed strains was operated at the soybean oil factory. Following a one year pilot plant operation, it was found that 10,000 mgℓ−1 of hexane extracts in the raw wastewater could be reduced by yeast treatment to a concentration of about 100 mgℓ−1. This concentration was further treated by the activated sludge process to 2 mgℓ−1. The dominant yeasts in the pilot plant were found to form mycelial or pseudomycelial pellets and have low fermenting ability.


2020 ◽  
Vol 42 (8) ◽  
pp. 1449-1455 ◽  
Author(s):  
Yongmei Zuo ◽  
Tassnapa Wongsnansilp ◽  
Xiaodong Zhang ◽  
Guiping Chen ◽  
Zhe Wu

2011 ◽  
Vol 415-417 ◽  
pp. 1675-1678
Author(s):  
Kai Ning Yu ◽  
Cheng Wang ◽  
Yang Yu ◽  
Yan Li

The decolorization of coking wastewater is an urgent issue for coking wastewater treatment. Using mineral adsorbents to deal with the coking wastewater is an effective way to solve the above problem. In this paper, fluidized bed combustion (FBC) ashes, diatomite and clinoptiolite were used to decolorize the coking wastewater. UV-Vis was used to estimate the decolorization efficiency of the FBC ashes. The materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the sequence rule for the decolorization effect of three mineral adsorbents is FBC ashes > diatomite > clinoptiolite. In addition, the chroma of treated coking wastewater reduced from 320 times to less than 5 times in the comparison of raw wastewater. It is much lower than the chroma of GB8978-1996 1A discharge standard. The excellent decolorization effect of FBC ashes might be due to large contains of CaO and f-CaO.


Author(s):  
Е.В. Алексеев

Широкое распространение реагентного коагулирования в технологии очистки природных и промышленных сточных вод обусловлено, с одной стороны, сложностью химического состава и фазово-дисперсного состояния их аквасистем, с другой – многофакторностью действия на них коагулянтов. Рассмотрены основные механизмы взаимодействия коагулянтов и загрязняющих веществ на примере очистки промышленных сточных вод, содержащих органические вещества (поверхностно-активные вещества и синтетические красители). Физико-химическое понятие «коагуляция» отражает только один из механизмов действия коагулянтов на загрязнители. Принятые в настоящее время технологические показатели «доза коагулянта» и «удельная доза коагулянта» также не отражают многообразие взаимодействий загрязняющих веществ с солями коагулянтов и не привязаны к результату коагулирования. Это обусловливает трудность описания совокупного действия физико-химических процессов при добавлении коагулянтов в очищаемые воды и его количественной оценки. Решение проблемы возможно введением понятия «коасорбция», определяющего многофакторность взаимодействия коагулянтов с загрязняющими веществами в процессах очистки сточных вод коагулированием, и технологического показателя «удельная коасорбция», устанавливающего количественную взаимосвязь между величинами загрязняющих веществ в исходной и очищенной воде с дозой коагулянта. Графически представлены функции удельной коасорбции в форме изотерм коасорбции для двух типов поверхностно-активных веществ и синтетических красителей. На основании результатов анализа особенностей изотерм показано, что они отражают разные механизмы взаимодействия коагулянтов и загрязняющих веществ. Использование коасорбции как технологического понятия способствует выявлению механизмов взаимодействия загрязняющих веществ с коагулянтом и созданию наилучших условий для осуществления процесса коагулирования. Функциональное описание изотерм коасорбции позволяет экстраполировать результаты пробного коагулирования в широком интервале концентраций загрязняющих веществ. Практическое значение изотерм удельной коасорбции состоит в возможности определения доз реагентов при коагулировании воды по начальному содержанию загрязняющих веществ и требуемому в очищенных водах. The widespread use of chemical coagulation in purification of natural water and industrial wastewater is due, on the one hand, to the complex chemical composition and phase-disperse state of their aqua systems, and on the other hand, to the multifactorial effect of coagulants on them. The main mechanisms of interaction between coagulants and pollutants are considered through the example of industrial wastewater treatment containing organic substances (surfactants and synthetic dyes). The physicochemical term «coagulation» reflects only one of the mechanisms of the effect of coagulants on pollutants. The currently accepted process parameters «dose of coagulant» and «specific dose of coagulant» do not reflect the variety of interactions of pollutants with coagulant salts either, and are not linked to the result of coagulation. This makes it difficult to describe the collective effect of physicochemical processes while adding coagulants to the treated water and to quantify it. The solution to the problem is possible introducing the concept of «coasorption» that determines the multifactorial origin of the interaction of coagulants and pollutants in the processes of wastewater treatment by coagulation; and the process parameter «specific coasorption» that establishes a quantitative relationship between the concentrations of pollutants in raw wastewater and effluent with a dose of coagulant. The specific coasorption functions are graphically presented in the form of coasorption isotherms for two types of surfactants and synthetic dyes. Based on the results of the analysis of the features of the isotherms, it is shown that they reflect different mechanisms of interaction between coagulants and pollutants. The use of coasorption as a technological concept provides for identifying the mechanisms of interaction of pollutants with a coagulant and establishing the best conditions for the coagulation process. The functional description of the coasorption isotherms allows extrapolating the results of trial coagulation in a wide range of pollutant concentrations. The practical importance of specific coasorption isotherms provides for determining the dosages of chemicals during coagulation of water based on the initial concentration of pollutants and effluent standard.


2016 ◽  
Vol 14 (1) ◽  
pp. 01-14 ◽  
Author(s):  
M A Mojid ◽  
G C L Wyseure ◽  
S K Biswas

Due to increasing scarcity of fresh water, use of unconventional water source (e.g., wastewater) in irrigation has now become important. However, inclusive information on the effects of wastewater on crop production and soil health is necessary for such intervention. This study was designed to evaluate these effects by demonstrating the contribution of municipal wastewater (hereafter called wastewater) on yield and nutrient requirement of wheat (<i>Triticum aestivum</i> L.) cv Shatabdi. Five irrigation treatments - I1, I2, I3, I4 and I5  were tested in a Randomized Complete Block Design (RCBD) with three replications during November-March of 2007-2008, 2008-2009, 2009-2010 at the experimental field of the Bangladesh Agricultural University,  Mymensingh. The treatments I2-I5 consisted of blended wastewater and I1 of fresh water (control). The ratio of wastewater to total irrigation water was 0.25, 0.50, 0.75 and 1.0 in I2, I3, I4 and I5, respectively. Wheat was cultivated with three irrigations and recommended doses of fertilizer in three consecutive years. Wastewater contained nitrogen (N), phosphorus (P) and potassium (K) @ 17.5, 3.7 and 10.3 mg/L, respectively, and irrigation by raw wastewater (I5) contributed 19.1, 15.1 and 21.7% of the recommended N, P and K, respectively. Biomass yield increased with increasing fraction of wastewater in irrigation. Grain yield increased for the wastewater fraction of 0.50 - 0.75 in irrigation but decreased when irrigation was applied by raw wastewater. Excess fertilizer (under I5) boosted up growth of wheat, but did not contribute to the grain yield. Number of grains per spike; and grain, straw and biological yields significantly (p = 0.05) increased due to the contribution of wastewater. Wastewater significantly improved grain and biomass production, with the largest value obtained in I4 (4.61 t/ha grain yield and 11.36 t/ha biomass yield).  Raw wastewater in combination with recommended fertilizer doses caused over-fertilization that contributed only in biomass production but not in grain production of wheat and irrigation by wastewater substantially reduced fertilizer requirement of wheat.The Agriculturists 2016; 14(1) 01-14


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