Dewatering and Mineralization of Sludge from Secondary Sedimentation Tank in a Constructed Sludge Drying Reed Bed

2012 ◽  
Vol 209-211 ◽  
pp. 1111-1115
Author(s):  
Chun Zhang ◽  
Jie Deng ◽  
Wei Zhang

The dewatering and mineralization of sludge in the constructed reed bed was investigated in this study.The sludge from the secondary sedimentation tank is from in the wastewater treatment plant in Yiyang city,Hunan province.Anaerobic pond and oxidation ditch biological treatment processes is accepted there.The performance of the system was monitored for one year. Total Solids (TS), Volatile Solids(VS), Chemical Oxygen Demand, nutrients (TKN) and Total Phosphorus(TP), heavy metals in the sludge were analysed.The removal rate of COD,NH4-N,and TP of the percolated fluid for the first cycle was also monitored. TS content reached 36.5% for the surface layer and 37.8% for the bottom layer at the end of the examination period.Sludge stabilization in the bed was also observed(VS content decreased to 31.3% and 13.4% respectively for the surface and bottom layer).Concentration of nutrients of the sludge accumulated in the bed also decreased. The heavy metal concentration meets the European Union standards for heavy metals in case of agricultural disposal of the treated sludge.

2019 ◽  
Vol 6 (1) ◽  
pp. 16-20
Author(s):  
Ali Akbar Rahmani Sarmazdeh ◽  
Mostafa Leili

This research mainly aimed to investigate phosphorus removal from stabilization pond effluent by using anionic resins in the continuous flow mode of operation due to high amounts of phosphorus in the wastewater treatment plant effluent of Kaboodrahang, western Iran, as well as the violation from a prescribed effluent standard to discharge receiving the surface waters. For this purpose, the pilot was made of a plexiglass cylinder and other equipment such as pump and other accessories, as well as Purolite A-100 resin. The reactor effects on the desired study parameters were assessed in two warm and cold seasons. The results showed that the phosphorus concentrations reduced from 7-10 mg/L to 4-7 mg/L and the rate of phosphorus removal was higher in the hot season compared to the cold season. Moreover, the optimum temperature and pH were obtained 21ºC and 8.5, respectively. The mean inlet biological oxygen demand (BOD) was 150 mg/L for both warm and cold seasons, where the highest removal rate of 17% was obtained in the cold season. The mean chemical oxygen demand concentration of the pilot was 250 mg/L for both seasons, and the highest removal rate was observed in the cold season with an efficiency of 18%. Regarding the total suspended solids with the mean inlet of 230 mg/L, the highest removal efficiency was obtained 6% in the warm season.


2005 ◽  
Vol 51 (9) ◽  
pp. 251-258 ◽  
Author(s):  
M. Scholz ◽  
P. Anderson ◽  
B.I. Forman

The aim of this investigation was to assess the treatment efficiencies for gully pot liquor of 12 experimental vertical-flow constructed wetland filters containing Phragmites australis (Cav.) Trin. ex Steud. (Common Reed) and filter media of different adsorption capacities in a cold climate. Seven of the twelve filters received inflow water spiked with heavy metals. For one year, hydrated copper nitrate and hydrated nickel nitrate were added to sieved gully pot liquor to simulate contaminated primary treated storm water runoff. The inflow concentrations for dissolved copper, nickel and nitrate-nitrogen were approximately 1.0, 1.0 and 1.45 mg/l, respectively, which represent mean loading rates of 0.063 g/m2/d for Filters 2 and 7 to 11, and 0.115 g/m2/d for Filter 12. For these filters receiving metals, an obvious breakthrough of dissolved nickel was recorded after road gritting and salting during winter. Sodium chloride was responsible for nickel leaching. Reductions of copper, nickel, biochemical oxygen demand and suspended solids were frequently insufficient compared to international secondary wastewater treatment standards. Moreover, the overall filtration performance for all filters was similar.


2001 ◽  
Vol 44 (11-12) ◽  
pp. 149-155 ◽  
Author(s):  
H. Rustige ◽  
Chr. Platzer

One of the most interesting sites for research on CWs in Germany has been established in Wiedersberg (Saxonia). The multi-stage concept with primary settling, vertical and horizontal flow reed bed followed by UV-disinfection and a special phosphorus filter bed, allows numerous ways of operation and investigations. Denitrification can be improved by recirculation through VF bed and sedimentation tank or by means of adding carbonaceous water from the primary stage to a second level within the VFB or directly to the following HF bed. In order to investigate the efficiency of P-elimination four kinds of natural sands containing different amounts of iron have been used. To maintain a long-term capacity for P-reduction an additional filter bed is filled with gravelly sand which had been used for the precipitation of iron from drinking water before. After saturating with P this filter medium can be exchanged easily. A result of more than one year of operation is the high performance rate for adsorption of phosphorus by enriched iron on drinking water filter sand. At a total loading rate of 350 g P/m3 filter medium 250 g P/m3 have been adsorbed. Design considerations can not be given yet. The median denitrification rate at VFB is 1.3 g N m-2d-1 and at HFB is 0.25 g Nm-2d-1. The low denitrifcation rate of HFB might be due to a very high quota of wastewater dilution by storm- and ground-water of 100 to 200 percent. The investigations on this wastewater treatment plant will be continued until June 2001 and experiments with filter columns will be added.


2004 ◽  
Vol 49 (5-6) ◽  
pp. 273-279
Author(s):  
B.S. Lim ◽  
J.U. Kim ◽  
H.D. Park

This study was performed to increase the treatment efficiency and to reduce operation and maintenance costs of the existing nightsoil treatment plant. The existing nightsoil plant was not established by the nitrogen removal process, and was operated ineffectively with deterioration of treatment efficiency rate, and according to the demand of many operators, the expenses of operation and maintenance have become excessive. Modified plant has been changed through two steps. The first step, liquid decayed tank using closed oxidation ditch is operated to increase retention time only for nitrification. The second step, modified liquid decayed tank including anoxic tank is operated, it has an excellent nitrogen removal rate. In first step, when HRT was increased from 10 days to 13 days in liquid decayed tank including aeration tank using closed oxidation ditch, TN concentration of effluent appeared below 51 mg/l less than discharge limit, 60 mg/L. In second step, when anoxic tank and oxic tank were installed, HRT has been increased to 13 days and 26 days, respectively. Then average TN concentration of effluent was detected less than 13 mg/L for over one year. The simple process modified the existing two processes resulted in the reduction of costs for operation and maintenance in the personnel, chemical, and filter change sphere.


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.


2020 ◽  
Vol 145 ◽  
pp. 02052
Author(s):  
Weijian Zhou ◽  
Wenzhong Liang ◽  
Yining Ding ◽  
Yutao Lei ◽  
Zhihua Pang ◽  
...  

Considering the land shortage features of a given district in Hangzhou city, the High-sludge sedimentation tank + denitrification filtering tank + nitrification filtering tank + cloth media filtering tank process is adopted for purification treatment. When the system (with the treatment scale of 15,000m3/d) runs for 60 days, the average removal rate of COD and ammoniacal nitrogen are 86% and 96% respectively and the effluent quality reach the quasi grade IV standard.


2018 ◽  
Vol 9 (2) ◽  
pp. 240-248 ◽  
Author(s):  
Zhilin Ran ◽  
Jia Zhu ◽  
Ke Li ◽  
Li Zhou ◽  
Pei Xiao ◽  
...  

Abstract The main component of surfactant is linear alkylbenzene sulfonate (LAS), which is toxic to the ecological environment and can cause serious harm. In this study, some activated sludge was taken from the aerobic and anaerobic tank of a sewage treatment plant in Shenzhen, then cultivated and domesticated in a membrane bioreactor with artificial surfactant wastewater. The start-up phase of the reactor adapted the constant-flux filtration, and the HRT was 12 h. The pH was below 5.5, which needed the addition of NaHCO3 after 6 days to adjust to the more optimal level (pH 6.5–7.5). After operation for 20 days, the start-up of the system was considered successful. At the early stage, the removal rates of chemical oxygen demand (COD) and LAS were relatively stable, reaching as high as 85.49%–93.31% and 80%, respectively. When the LAS concentration reached over 175 mg/L and the COD declined to about 83%, the removal rate of LAS also significantly decreased. LAS removal rate further decreased to about 60% when the dosage reached 200 mg/L, indicating that the resistance of microorganisms against LAS toxicity was also limited. LAS degradation could have been mainly driven by Dechloromonas, Gemmata, Pseudomonas and Zoogloea in the system.


2020 ◽  
Vol 322 ◽  
pp. 01026
Author(s):  
Mateusz Sitarz ◽  
Tomasz Zdeb ◽  
João Castro Gomes ◽  
Erick Grünhäuser Soares ◽  
Izabela Hager

Sewage sludge is a semi-solid waste material created as a result of the sewage treatment of industrial or municipal wastewater. Because the laws and regulations of the European Union require not only a reduction in waste generation but also the preparation of waste for reuse and disposal, it is necessary to look for new methods of the application of sewage sludge as part of sustainable waste management. In this study, ash formed as a result of the combustion of sewage sludge from the sewage treatment plant in Płaszów, Krakow in a fluidised bed furnace at a temperature of around 800°C was used. Sewage sludge ash (SSA) contains over 30% SiO2 and approx. 10% Al2O3, which indicates potential applications in geopolymer materials. In this study, samples of geopolymer mortars with a binder containing sewage sludge ash as well as fly ash (FA) and ground granulated blast furnace slag (GGBFS) were prepared. The mechanical parameters were determined after 2, 7, 14, and 28 days. The results show that the sewage sludge ash-based geopolymer shows binding properties at ambient temperature and, depending on the presence of FA and/or GGBFS, the compressive strength varies from 5 to 45 MPa after 28 days. The aim of the research was also to determine the total content of heavy metals (Sb, As, Cr, Cd, Cu, Ni, Pb, Hg, Zn) in the raw materials used and their leachability from the structure of the hardened materials. Immobilisation of heavy metals is very promising. Based on the results of tests, it seems possible to use SSA in geopolymer materials, but not as the main component of the binder.


Author(s):  
Hiba Tlili ◽  
Mahmoud Bali ◽  
Rachid Boukchina

Abstract Intermittent planted filters are extensive biological purification techniques aimed at oxidizing and decontaminating urban wastewater at a low cost and with minimum environmental impacts. The main purpose of this study was to evaluate the performances of intermittent planted filters in treating urban wastewater under arid conditions of southern Tunisia. The experimental study was carried out on a pilot scale plant comprising five constructed gravel-sand basins. Screened urban wastewater effluent was intermittently applied with a daily hydraulic load of 400 L/m2. Several water quality parameters were monitored at the inlet and outlet of this treatment plant. The average removal rate were 94.8%, 92.3%, 99.3%, 89.9% and 93.3% for chemical and biological oxygen demand, total suspended solids, ammonium nitrogen and orthophosphate, respectively. Additionally, results demonstrated that this treatment system is capable to remove 3.67, 3.22 and 2.44 log units of total and faecal coliforms, and faecal streptococci, respectively. Results showed that Phragmites australis allowed the development of biofilm in the sand filter beds, improving their purification efficiency. Furthermore, no bio-sludge production, no mechanical aeration, low energy requirement (0.02 kW/m2) and green aesthetic ambience are the additional particular strengths of the proposed pilot-plant.


1997 ◽  
Vol 35 (5) ◽  
pp. 223-230 ◽  
Author(s):  
Monika Schönerklee ◽  
Ferdinand Koch ◽  
Reinhard Perfler ◽  
Raimund Haberl ◽  
Johannes Laber

In Strengberg, Lower Austria, a vertical flow reed bed system (gravel/sand) was chosen as a new type of tertiary treatment which was designed as a full scale pilot plant with various possibilities of operational use. The surface of the vertical flow pilot plant amounts to about 600 m2 and is divided into four beds whereby two different depths of substrate are used. The application of the conventional plant effluent is carried out in intermittent flushes and at changeable time intervals. Final nitrification and partial denitrification and elimination of phosphorus are the main goals to be achieved. In the framework of the present research project the load limits will be determined by gradually raising the influent load. The efficiency and operational reliability within the whole year period (summer/winter) are considered to be an important factor for establishing general dimensioning approaches. The pilot plant has been in operation for more than one year now. Different operational stages up to a hydraulic load of 1.3 m2.p.e.−1 (i.e. 0.75 m2.p.e.−1) were carried out. The average chemical oxygen demand (COD) of the reed bed effluents varied from 1 to 20 mg.1−1. Not surprisingly the ammonium (NH4-N) results showed more variation. Results, thus far, indicate NH4-N removal efficiencies between 40% and 90%.


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