Single Sludge Anoxic–Aerobic Systems for Biological Treatment of Coke Plant Wastewaters

1985 ◽  
Vol 17 (2-3) ◽  
pp. 421-432 ◽  
Author(s):  
M. Beccari ◽  
A. C. Di Pinto ◽  
R. Passino ◽  
R. Ramadori ◽  
V. Tandoi

A study on the biological treatment of coke plant liquid wastes, with high concentration of ammonium nitrogen and phenols, is presented. The anoxic-aerobic single sludge process is used, with the phenols as electron donors in the denitrification process; the inhibiting effect of toxic substances present in the wastewater is prevented by means of dilution. Tests were conducted in a laboratory scale plant to determine the minimum dilution ratio necessary to avoid inhibition and the parameters required for the designing of a full scale plant. Finally the basic design considerations of a wastewater treatment plant for a 1000 t/d coke plant are reported and capital and running costs are evaluated.

Author(s):  
М.Г. Зубов ◽  
Е.В. Вильсон ◽  
В.А. Литвиненко ◽  
А.А. Кадревич

Целью прикладного научного исследования является определение удельной скорости окисления токсичных органических соединений – этиленгликоля, формальдегида и метанола – сообществом микроорганизмов иммобилизованного биоценоза на носителе ЁРШ®, установленном в пилотной установке. Для достижения поставленной цели реализован многоэтапный эксперимент, позволивший определить возможность глубокой биодеградации токсичных веществ и установить необходимую концентрацию азота аммонийного в исходной сточной воде для реализации процесса биодеградации. В ходе исследования были выполнены следующие работы: определение времени выхода на режим пилотной установки после плановой остановки в подаче сточных вод на 31-й день; оценка удельной скорости окисления прикрепленным биоценозом по показателям этиленгликоль, формальдегид, ХПК, БПК; оценка ассимиляции и трансформации соединений азота; формулирование выводов на основе проведенного анализа результатов исследований, необходимых для оценки целесообразности применения биологической очистки сточных вод прикрепленным биоценозом исследуемых загрязнителей и определения расчетных параметров очистного сооружения. The objective of the applied scientific research is to determine the specific rate of oxidation of toxic organic compounds – ethylene glycol, formaldehyde and methanol – by the community of microorganisms of the immobilized biocenosis on the IORSh carrier installed in a pilot plant. To achieve this goal, a multi-stage experiment was carried out that provided for determining possible enhanced biodegradation of toxic substances and specifying the required concentration of ammonium nitrogen in raw wastewater for the implementation of the biodegradation process. In the course of the study, the following works were carried out: determining the process stabilization time in the pilot plant after the scheduled shutdown in the wastewater supply on the 31stday; assessing the specific rate of oxidation by the attached biocenosis in terms of ethylene glycol, formaldehyde, COD, BOD; assessing the assimilation and transformation of nitrogen compounds; drawing conclusions based on the analysis of the research results required for estimating the feasibility of using biological wastewater treatment with the attached biocenosis of the pollutants under study and determining the design parameters of the treatment plant.


2014 ◽  
Vol 522-524 ◽  
pp. 854-860
Author(s):  
Qing Tao Zhang ◽  
Zhi Jian Zhang ◽  
Jiong Ma ◽  
Jiao Xiang

The growth performance of duckweed (Spirodela polyrrhiza) and its removal rate of nitrate and phosphorus in sewages taken from sewage treatment plant with different processes were studied. The experiments were conducted in an environmentally controlled growth chamber. Three kinds of sewages were taken from a grit chamber, a sedimentation tank, and the anoxic pond in a sewage treatment plant, respectively. The fourth kind of sewage was mixed using the sedimentation tank sewage and the anoxic pond sewage in a volumetric ratio 1:1. The weight of duckweed biomass were determined with a balance. Wastewater samples taken from the media were analyzed for total nitrogen (TN), ammonium nitrogen (NH4N), total phosphorus (TP), phosphatephosphorus (PO4P) using AA3 Continous Flow Analyzer. The results showed that Spirodela polyrrhiza grew well in sewages taken from grit chamber and sedimentation tank of a sewage treatment plant, whereas a lot of duckweed fronds were dead in the sewage taken from the anoxic pond due to the high TP (higher than 7.9 mg/L) and TN (higher than 51.6 mg/L). The suitable TN concentration for Spirodela polyrrhiza growth should not be higher than 45 mg/L. Compared with the treatments without duckweed, the NH4N concentrations were reduced more than 60% in ST and GC sewages with duckweed due to the NH4N uptake by duckweed. Spirodela polyrrhiza could remove TN efficiently in sewages with relative low concentration TN (less than 20 mg/L), while duckweed could not remove TN effectively in sewages with high concentration TN (higher than 20 mg/L). The TN concentration in GC sewage decreased greatly in the first four days, which probably brought about anaerobic condition, thus P uptake switched to net release of P, which caused the increase of the TP concentration in the GC sewage without duckweed in the last six days. O2 or oxidant should be provided for sewage treatment system using duckweed to ensure that efficient removal of TN and TP meanwhile. The TP and PO4P concentrations in the mixed sewage with duckweed increased far more than those for no-duckweed treatments, which could be related that the dead duckweed released P into the sewage.


2012 ◽  
Vol 38 (4) ◽  
pp. 49-58 ◽  
Author(s):  
Marzena Smol ◽  
Maria Włodarczyk-Makuła

Abstract The paper presents the results of studies on the changes in the PAHs concentration during pre-filtration and ultrafiltration (UF) processes. In the study, biologically treated wastewater (after denitrification and nitrification processes), discharged from the biological treatment plant and used in coke plant, was used. A gas chromatography-mass spectrometry (GC-MS) was used in order to qualify and quantify the PAHs. Sixteen PAHs listed by EPA were determined. The wastewater samples were collected three fold and initially characterized for the concentration of nitrate nitrogen, ammonium nitrogen, COD, TOC and pH. In the first step, wastewater was filtrated on the sand bed. Total concentration of 16 PAHs in the treated wastewater before initial filtration was in the range of 44.8‒53.5 mg/L. During the process the decrease in the concentration of the most studied hydrocarbons was observed. Concentration of PAHs after initial filtration ranged from 21.9 to 38.3 μg/L. After the initial filtration process the wastewater flew to the ultrafiltration module and then was separated on the membrane (type ZW-10). The total concentration of 16 PAHs in the process of ultrafiltration was in the range of 8.9‒19.3 mg/L. The efficiency of removal of PAHs from coke wastewater in the process of ultrafiltration equaled 66.6%. Taking into account the initial filtration, the total degree of removal of PAHs reached 85%. The obtained results indicate the possibility of using the ultrafiltration process with the initial filtration as additional process in the coke wastewater treatment.


2011 ◽  
Vol 63 (10) ◽  
pp. 2340-2345 ◽  
Author(s):  
M. V. Kevbrina ◽  
Y. A. Nikolaev ◽  
D. A. Danilovich ◽  
A. Ya. Vanyushina

Aerobic biological treatment of digested sludge was studied in a continuously operated laboratory set-up. An aerated reactor was filled with thermophilically digested sludge from the Moscow wastewater treatment plant and inoculated with special activated sludge. It was then operated at the chemostat mode at different flow rates. Processes of nitrification and denitrification, as well as dephosphatation, occurred simultaneously during biological aerobic treatment of thermophilically digested sludge. Under optimal conditions, organic matter degradation was 9.6%, the concentrations of ammonium nitrogen and phosphate decreased by 89 and 83%, respectively, while COD decreased by 12%. Dewaterability of digested sludge improved significantly. The processes were found to depend on hydraulic retention time, oxygen regime, and temperature. The optimal conditions were as follows: hydraulic retention time 3–4 days, temperature 30–35 °C, dissolved oxygen levels 0.2–0.5 mg/L at continuous aeration or 0.7–1 mg/L at intermittent aeration. Based on these findings, we propose a new combined technology of wastewater sludge treatment. The technology combines two stages: anaerobic digestion followed by aerobic biological treatment of digested sludge. The proposed technology makes it possible to degrade the sludge with conversion of ∼45% volatile suspended solids to biogas, to improve nitrogen and phosphorus removal in reject water from sludge treatment units, and to achieve removal of malodorous substances after 8–9 days of anaerobic–aerobic sludge treatment.


2006 ◽  
Vol 53 (12) ◽  
pp. 11-20 ◽  
Author(s):  
M.C.M. van Loosdrecht ◽  
S. Salem

Nitrogen removal in side stream processes offers a good potential for upgrading wastewater treatment plants (WWTPs) that need to meet stricter effluent standards. Removing nutrients from these internal process flows significantly reduces the N-load to the main treatment plant. These internal flows mainly result from the sludge processing and have a high temperature and a high concentration of ammonia. Therefore, the required reactor volumes as well as the required aerobic SRT are small. Generally, biological treatment processes are more economical and preferred over physical–chemical processes. Recently, several biological treatment processes have been introduced for sludge water treatment. These processes are available now on the activated sludge market (e.g. SHARON®, ANAMMOX® and BABE® processes). The technologies differ in concept and in the limitations guiding the application of these processes for upgrading WWTPs. This paper reviews and compares different biological alternatives for nitrogen removal in side streams. The limitations for selecting a technology from the available ones in the activated sludge market are noted and analysed. It is stressed that the choice for a certain process is based on more aspects than pure process engineering arguments.


2016 ◽  
pp. 51-56
Author(s):  
Thi Le Thuy Nguyen ◽  
Thanh Sinh Do ◽  
Thi Hoa Tran

Backgroud: Gac is a fruit containing many antioxidants, especially lycopene, with high concentration. However the variety and value of products from gac are limited. We introduce a modified method to produce lycopene and others carotenoids from gac oil towards available and safe applications in nutraceutical and cosmetics. Materials and method: We study the extraction with different parameters and limit at the saponification of gac oil using less toxic substances such as ethanol, propylene glycol, postasium hydroxide and sodium chlorid. Results: Concentrations of lycopene and β-carotene determined silmutaneously by UVVis spectrophotometer present that the efficiency reaches 65.07% as 20 g of gac oil is saponified with 8 g KOH 12 mol/L in 120 mins. The purity of product is 89.02%. Conclusions: This process could minimize toxic residue in the powder after the precipitation, filtration and washing. Besides, the method is stable and applicable to the mass production. Key words: Carotenoids, Lycopene, safe extraction, UV Vis silmutaneous concentration determination


2001 ◽  
Vol 1 (2) ◽  
pp. 9-17
Author(s):  
Y.-H. Lee ◽  
H.-K. Lee ◽  
C.-H. Chang ◽  
W.-H. Kim

A bio-monitoring system for toxicants in water has been developed and verified for actual applications. This system is based on the motionality of five Acheilognathus lanceolata, a fish known to be very sensitive to toxic substances, moving around in an aquarium. Their movements are continuously monitored with a charge coupled device (CCD) camera and analyzed to find and quantify any abnormal behavior in their motional characteristics in comparison with the pre-acquired data. That is, the images of fish captured by a CCD camera are digitalized to identify the location of fish in a constant time interval and the locations of each fish were then analyzed mathematically with a personal computer using the equations proposed to determine the motional characteristics such as floatness, fledness and mobility(agility). These data are then converted by means of fuzzy estimation to an index value, defined as the contamination index (CI), by which the system provides the information about the overall toxic strength of the toxicant in the water flowing into the aquarium. If the fish are exposed to toxicant(s), the CI value will be proportional to the strength of its toxicity. The pilot test was performed in a water treatment plant for six months in order to verify the reproducibility of the system over the unstable conditions such as highly turbid water after rainfall as well as in normal conditions. The test results revealed that this monitoring system has good reproducibility and sensitivity, proving our approach, described in this paper, is reliable. As a result, this approach seems to enable us to make a quick and easy detection of toxic substances contained in water, therefore, this system can be applied to a source of water supply as a toxicant watching system.


1994 ◽  
Vol 30 (6) ◽  
pp. 31-40 ◽  
Author(s):  
Hiroyshi Emori ◽  
Hiroki Nakamura ◽  
Tatsuo Sumino ◽  
Tadashi Takeshima ◽  
Katsuzo Motegi ◽  
...  

For the sewage treatment plants near rivers and closed water bodies in urbanized areas in Japan and European countries, there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus from the viewpoints of water quality conservation and environmental protection. In order to remove nitrogen by the conventional biological treatment techniques, it is necessary to make a substantial expansion of the facility as compared with the conventional activated sludge process. In such urbanized districts, it is difficult to secure a site and much capital is required to expand the existing treatment plant. To solve these problems, a compact single sludge pre-denitrification process using immobilized nitrifiers was developed. Dosing the pellets, which are suitable for nitrifiers growth and physically durable, into the nitrification tank of single sludge pre-denitrification process made it possible to perform simultaneous removal of BOD and nitrogen in a retention time equal to that in the conventional activated sludge process even at the low water temperature of about 10 °C. The 3,000 m3/d full-scale conventional activated sludge plant was retrofitted and has been successfully operated.


1994 ◽  
Vol 30 (5) ◽  
pp. 87-95 ◽  
Author(s):  
Susan E. Murcott ◽  
Donald R. F. Harleman

In the past decade, the development of polymers and new chemical technologies has opened the way to using low doses of chemicals in wastewater treatment. “Chemical upgrading” (CU) is defined in this paper as an application of these chemical technologies to upgrade overloaded treatment systems (typically consisting of conventional primary plus biological treatment) in Central and Eastern European (CEE) countries. Although some of the chemical treatment technologies are proven ones in North America, Scandinavia, and Germany, a host of factors, for example, the variations in composition and degree of pollution, the type of technologies in use, the type and mix of industrial and domestic sewage, and the amount of surface water, had meant that the viability of using CU in CEE countries was unknown. This report describes the first jar tests of CU conducted during the summer of 1993. The experiments show CU's ability to improve wastewater treatment plant performance and to potentially assist in the significant problem of overloaded treatment plants. Increased removal of BOD, TSS, and P in the primary stage of treatment is obtained at overflow rates above 1.5 m/h, using reasonably priced, local sources of metal salts in concentrations of 25 to 50 mg/l without polymers.


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