2008 ◽  
Vol 3 (1) ◽  
Author(s):  
K. Klinksieg ◽  
T. Dockhorn ◽  
N. Dichtl

Full-scale and lab-scale research experiments were conducted to determine the phosphorous precipitation efficiency of iron hydroxide sludge from drinking water treatment. During full-scale investigations at a wastewater treatment plant, ferric sludge was added to the inflow of the primary settling tank in a first experimental phase and to the inflow of the aeration tank in a second phase. In the outflow of the mechanical stage and in the outflow of the biological stage, a reduction of the PO4-P concentrations could be observed. The concentration of COD, the SVI and the filament abundance were not changed significantly by adding the ferric sludge to the wastewater treatment plant. In lab tests, improved precipitation efficiency of the ferric sludge could be achieved by using anaerobic conditions and acid pulping. The research showed that the wastewater treatment process can benefit from the reuse of ferric sludge from drinking waterworks and that this also presents an inexpensive recycling option for these sludges.


Author(s):  
R. Babko ◽  
V. Pliashechnyk ◽  
T. Kuzmina ◽  
Y. Danko ◽  
J. Szulżyk-Cieplak ◽  
...  

Abstract The work is devoted to the task of simplifying the assessment of the effect of effluents from treatment facilities on the river hydrobiocenosis. The studies were carried out on the mountain river Uzh (Uzhgorod, Ukraine). Our approach to assessing the impact of waste treatment facilities on the river receiver is based on the estimate of the similarity of species composition and quantitative characteristics of populations of organisms from the aerotank and from the river. It is shown that the quantitative development of populations of species of ciliates from the aeration tank is a good indicator for assessing the degradation of organic matter coming with wastewater. The use of qualitative and quantitative characteristics of the protozoa from the wastewater treatment plant as a criterion for assessing the quality of the environment in the area of wastewater discharge showed their representativeness and effectiveness. The use of a limited number of species makes it possible to conduct an express assessment of the effect of effluents on receiving reservoirs for specialists working with activated sludge in the laboratories of treatment facilities.


2011 ◽  
Vol 8 (4) ◽  
pp. 363 ◽  
Author(s):  
Lena Vierke ◽  
Lutz Ahrens ◽  
Mahiba Shoeib ◽  
Eric J. Reiner ◽  
Rui Guo ◽  
...  

Environmental contextPolyfluoroalkyl compounds, widely used chemicals in consumer and industrial products, are global pollutants in the environment. Transport mechanisms and environmental pathways of these compounds, however, are not yet fully understood. We show that a wastewater treatment plant can be an important source for polyfluoroalkyl compounds to the atmosphere where they have the potential to be transported long distances. AbstractAn air sampling campaign was conducted at a wastewater treatment plant (WWTP) to investigate air concentrations and particle–gas partitioning of polyfluoroalkyl compounds (PFCs). Samples were collected at an aeration tank and a secondary clarifier using both active high volume samplers and passive samplers comprising sorbent-impregnated polyurethane foam (SIP) disks. Water to air transport of PFCs was believed to be enhanced at the aeration tank owing to aerosol-mediated transport caused by surface turbulence induced by aeration. Mean air concentrations of target PFCs at the aeration tank were enriched relative to the secondary clarifier by factors of ~19, ~4 and ~3 for ∑fluorotelomer alcohols (FTOHs) (11 000 v. 590 pg m–3), ∑perfluorooctane sulfonamides & perfluorooctane sulfonamidoethanols (FOSAs & FOSEs) (120 v. 30 pg m–3) and ∑perfluoroalkyl carboxylates & perfluoroalkyl sulfonates (PFCAs & PFSAs) (4000 v. 1300 pg m–3) respectively. The particle associated fraction in the atmosphere increased with increasing chain length for PFCAs (from 60 to 100%) and PFSAs were predominantly bound to particles (~98%). Lower fractions on particles were found for FTOHs (~3%), FOSAs (~30%) and FOSEs (~40%). The comparison of the active and passive air sampling showed good agreement.


2013 ◽  
Vol 8 (1) ◽  
pp. 1-8

Successful start-up of a full-scale wastewater treatment plant (WWTP) is a key issue for the succeeding operation of WWTP on the one hand and the nutritious phosphorus removal is of great concern on the other. After the construction of Mudanjiang WWTP with a flow rate of 100,000 m3 d-1 in Heilongjiang Province of China, a novel way of start-up through feeding wastewater continuously into the system was attempted against the conventional start-up method of inoculating activated sludge in the aeration tank by feeding wastewater intermittently. Activated sludge was cultivated and proliferated in the aeration tanks instead of dosing acclimated sludge from other source. After one-month’s start-up operation, MLSS, SV and SVI increased to 2.5 kg m-3, 30% and nearly 80% respectively, which indicated that quick and simple start-up had been achieved. After successful start-up, an investigation into phosphorus removal was conducted with the emphasis on influencing factors such as ORP and NOx-N concentration etc. When the aeration tank was switched from aerobic to anaerobic mode, phosphorus removal efficiency of 80% could be realized within the whole treatment system. Experimental results revealed that an ORP of -140 mV and NOX-N of 2 mg l-1 were critical for the anaerobic phosphorus release, and DO in the range of 1.7-2.5 mg l-1, BOD5/TP of 20-30 and SVI of 70~80 as well as SRT of 5 days were the optimal phosphorus removal conditions for the aeration tanks.


2019 ◽  
Vol 8 (4) ◽  
pp. 6761-6768

Several methods of wastewater treatment systems are implemented but among these methods activated sludge process is demonstrating process in Malaysia. Fortunately, numbers of studies have been conducted to treat and remove either nitrogen or combined phosphorus and nitrogen resulted in enhancement removal of nutrients worldwide. This research aims to study the current operation in Mawar wastewater treatment plant and monitor the reduction of several parameters. The research also examines the new standard limits of effluents. From the result obtained, the monitoring of Mawar wastewater treatment plant indicates that influent concentration of majority of the parameters were in small. Despite that, the removal efficiency of several parameters was not high. That was basically because to the need of proper maintenance activities. Besides, the concentration of measured parameters in the aeration tank inlet were small. Comparison of Mawar wastewater to the typical composition of untreated domestic sewage indicated that the wastewater in Mawar wastewater treatment plant is classified as weak wastewater. The enhancement of nitrogen removal resulted in Mawar wastewater treatment plant led to decrease the removal efficiency of several parameters.


2011 ◽  
Vol 1 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Mehdi Ahmadi ◽  
Hassan Izanloo ◽  
Aliakbar Mehr alian ◽  
Hoda Amiri ◽  
Mohammad Noori Sepehr

The potential of a moving bed biofilm reactor (MBBR) in full scale has been investigated as an alternative for upgrading of the Kish Island Markazi wastewater treatment plant. In this regard, the activated sludge process (ASP) upgraded to an MBBR process and different operating parameters results in this change compared with ASP. Results show that with increasing the average flow influent from 1,049 ± 88 to 1,944 ± 275 m3 d−1 and reducing the aeration tank volume from 300 to 150 m3, organic loading rate (OLR), mixed liquor suspended solids (MLSS), sludge retention time (SRT), sludge volume index (SVI), hydraulic loading rate (HLR) and hydraulic retention time (HRT) were changed to 0.32 ± 0.04–1.8 ± 0.36 kg COD/m3d, 2,641.19 ± 284.99–7,354.2 ± 778.35 mg L−1, 5.28 ± 0.64–22.1 ± 1.53 d, 135 ± 37.3–29.2 ± 3.81, 23.14 ± 1.94–43.37 ± 5.04 m d−1 and 2.76 ± 0.22–1.48 ± 0.18 h, respectively. Effluent concentrations under this operation condition were well below the discharge limits for irrigation water. Therefore, the MBBR process is a good alternative for upgrading wastewater plants especially when there is inadequate space or modifications are needed that will require large investment.


2013 ◽  
Vol 8 (1) ◽  
pp. 61-67 ◽  

The methylation of mercury has been investigated and documented mainly in sediments, fish and microorganisms, while limited number of relevant studies is available for wastewater. The procedure of mercury methylation can occur via biological pathway (by microorganisms) and via chemical or photochemical reactions. Methylation of mercury occurs mainly under anaerobic conditions, but some studies have shown its existence also under aerobic conditions. The resulting concentration of methyl mercury, which is a highly toxic compound, depends on the specific rates of methylation/demethylation of mercury. The factors affecting these procedures are the availability of inorganic mercury, pH, organic matter concentration, microbial activity, redox potential and temperature. Bacteria which can methylate mercury are often present in wastewater, and, therefore, the formation of methyl mercury during wastewater treatment is possible. The objective of the present investigation was the determination of methyl mercury in a pilotscale activated sludge wastewater treatment plant supplied with synthetic wastewater enriched with mercury. For this purpose, a Liquid-Liquid Extraction / Simultaneous Derivatization - GC/MS method was developed and applied for the analysis of samples from the aeration tank, from the treatment plant effluent and from the sludge. Methyl mercury was not detected in the samples (detection limit 0.07 μg l-1), leading to the conclusion that mercury is not methylated under the particular experimental conditions of the pilot-scale water treatment plant.


1994 ◽  
Vol 30 (3) ◽  
pp. 11-19 ◽  
Author(s):  
Chang-Won Kim ◽  
Byung-Goon Kim ◽  
Tae-Ho Lee ◽  
Tae-Joo Park

An on-line toxic detection system is introduced for early and continuous observation of toxicity in an industrial wastewater treatment plant. The system consists of a contact chamber and an on-line respiration meter. If a raw wastewater sample is taken at the head of the wastewater treatment plant, one can detect toxicity of the wastewater before it reaches the aeration tank. For proper usage of this system a maximum respiration rate should be measured in the contact chamber. To apply this system on the petrochemical wastewater the Qe/Qs, ratio should be maintained higher than 0.6 among other operating conditions required When this system was tested under high and low pH, Co2+ inhibition, and recovered catalyst wastes addition, the system responded very sensitively.


Engevista ◽  
2015 ◽  
Vol 17 (3) ◽  
pp. 375 ◽  
Author(s):  
Renato Pereira Ribeiro ◽  
Jaime Lopes da Mota Oliveira ◽  
Débora Cynamon Kligerman ◽  
Renata Barbosa Alvim ◽  
Samara Almeida Andrade ◽  
...  

Nitrous oxide emissions were determined in three campaigns in the aeration tank of a full scale conventional activated sludge wastewater treatment plant. During these experiments, the carbonaceous organic matter (BOD and COD) removal was high and rather constant (97-98% and 93-96%). The results indicate that the concentration of total nitrogen in the influent wastewater, especially NH4+, and the aeration flow rate are key controlling factor of N2O emissions from the aeration tank. Nitrification was the major source of N2O, suggested by the behavior of DO concentrations, NO3-/NH4+ ratio and pH values along the six interlinked zones of the aeration tank. Excessive air flow intensified N2O transfer from the liquor to the atmosphere by air stripping.


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