scholarly journals Endogenous respiration process analysis between aMBR and UV/O3-aMBR for polluted surface water treatment

2019 ◽  
Vol 68 (8) ◽  
pp. 793-802 ◽  
Author(s):  
Lu Li ◽  
Kang Song ◽  
Chettiyappan Visvanathan

Abstract The microbial endogenous respiration process is very important in biological water treatment processes. This study analyzed and compared the endogenous respiration process in an attached growth membrane bioreactor (aMBR) system and a UV/O3 integrated aMBR system (UV/O3-aMBR) in treating polluted surface water with CODMn around 10 mg/L. The endogenous respiration activity of heterotrophic microbes and autotrophic nitrifiers activity in both systems was analyzed and compared. Results show that heterotrophic bacteria and autotrophic nitrifiers enter endogenous respiration at 6 h aeration in an aMBR and 0 h in a UV/O3-aMBR system. Biomass amount on PVA-gel in aMBR was higher than in UV/O3-aMBR in terms of specific respiration rates SOURt, SOURH, and SOURA. Substrate remained on PVA-gel in the aMBR system, but no substrate remained on PVA-gel in the UV/O3-aMBR system. Higher species of microbes, including recoverable and irrecoverable components, existed in the aMBR system as compared to the UV/O3-aMBR system. The UV/O3-aMBR system could make full use of the advanced oxidation process (AOP) and biological process, leading to a higher treatment performance, and has the potential to mitigate total energy demand. Thus, the UV/O3-aMBR system can be used as a new technology for treating polluted surface water with the co-contribution of biological process and AOP treatment.

2006 ◽  
Vol 54 (3) ◽  
pp. 23-28 ◽  
Author(s):  
J. Rapala ◽  
M. Niemelä ◽  
K.A. Berg ◽  
L. Lepistö ◽  
K. Lahti

The removal of cyanobacteria, hepatotoxins produced by them (microcystins), phytoplankton, heterotrophic bacteria and endotoxins were monitored at a surface water treatment plant with coagulation, clarification, sand filtration, ozonation, slow sand filtration and chlorination as the treatment process. Coagulation–sand filtration reduced microcystins by 1.2–2.4, and endotoxins by 0.72–2.0 log10 units. Ozonation effectively removed the residual microcystins. The treatment process reduced phytoplankton biomass by 2.2–4.6 and heterotrophic bacteria by 2.0–5.0 log10 units. In treated water, the concentration of microcystins never exceeded the WHO guide value (1 μg/L), but picoplankton and monad cells were often detected in high numbers. The heterotrophic bacterial isolates from the treated waters belonged to genera Sphingomonas, Pseudomonas, Bacillus, Herbaspirillum and Bosea.


2016 ◽  
Vol 17 (2) ◽  
pp. 526-536 ◽  
Author(s):  
Charles E. Schaefer ◽  
Graig M. Lavorgna ◽  
Todd S. Webster ◽  
Marc A. Deshusses ◽  
Christina Andaya ◽  
...  

Electrochemical disinfection of surface water using mixed metal oxide anodes was evaluated in a pilot-scale demonstration. Disinfection rates, chlorine generation, energy demand, and generation of disinfection by-products were monitored over the 190-day study. Particular attention was given to the generation of trihalomethanes (THMs) and haloacetic acids (HAAs) during the electrochemical treatment cycle. In addition, the potential for generation of THMs and HAAs during post-treatment storage of the water was assessed. The electrochemical treatment system resulted in a 2- to 3-log removal of total heterotrophic bacteria, with values below detection (<1 CFU/mL) often observed. Disinfection occurred with only very low levels of observed chlorine generation (<0.1 mg/L), suggesting that alternate disinfection mechanisms likely played a significant role in the observed removal of bacteria. THM and HAA concentrations after treatment were consistently well below regulatory levels. Results also showed that electrochemical treatment significantly reduced the formation of bromoform when the water received subsequent exposure to hypochlorite. Removal of naturally occurring bromide in the water by the electrochemical system may have been the cause (in part) for this observed mitigation of bromoform formation. The formation of calcium scale on the cathode surface over time was the primary operational challenge.


2009 ◽  
Vol 8 (4) ◽  
pp. 859-863 ◽  
Author(s):  
Daniela Simina Stefan ◽  
Cristina Costache ◽  
Viorica Ruxandu ◽  
Monica Balas ◽  
Mircea Stefan

1988 ◽  
Vol 20 (3) ◽  
pp. 149-163 ◽  
Author(s):  
Carol Braester ◽  
Rudolf Martinell

Nearly one fifth of all water used in the world is obtained from groundwater. The protection of water has become a high priority goal. During the last decades pollution of water has become more and more severe. Today groundwater is more and more used in comparison with surface water. Recently we have seen accidents, which can pollute nearly all surface water very quickly. Generally the groundwater is easier to protect, as well as cheaper to purify, and above all it is of better quality than the surface water. During the past two decades, alternatives to the traditional method of treating the water in filters have been developed, that is in situ water treatment i.e. the VYREDOX and NITREDOX methods. The most common problem regarding groundwater is too high content of iron and manganese, which can be reduced with the VYREDOX method. In some areas today there are severe problems with pollution by hydrocarbons and nitrate as well, and with modification of the VYREDOX treatment method it is used for hydrocarbon and nitrate treatment as well. The method to reduce the nitrate and nitrite is known as the NITREDOX method.


Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 285 ◽  
Author(s):  
Wanda Czyżewska ◽  
Marlena Piontek

The research presented in this manuscript concerns the evaluation of the effectiveness of microstrainers, which are designed to reduce the amount of plankton in treated surface water. The efficiency of microstrainer filtration analysis is very important for the proper course of the water-treatment process not only in the Water-Treatment Plant (WTP) in Zielona Góra (central western Poland) but also in other WTPs around the world. The qualitative and quantitative monitoring of the abundance of plankton including cyanobacteria during the particle-filtration process allows not only for the assessment of the potential cyanotoxic risk in surface water providing a source of drinking water, but also allows the evaluation of the action and the prevention of adverse impacts of microstrainers. Over four years of research, it was observed that the largest amount of cyanobacteria before microstrainer filtration took place in May. The dominant species was Limnothrix redeckei. The microstrainer removal of plankton and cyanobacteria was statistically significant. The quantity of removed plankton increased with its increasing content in raw water. The particle-filtration process, by reducing the amount of cyanobacteria, contributes to a decrease in intracellular microcystins.


2019 ◽  
Vol 5 (11) ◽  
pp. 1985-1992 ◽  
Author(s):  
Nor Elhouda Chadi ◽  
Slimane Merouani ◽  
Oualid Hamdaoui ◽  
Mohammed Bouhelassa ◽  
Muthupandian Ashokkumar

We have recently reported that the reaction of H2O2/IO4− could be a new advanced oxidation process for water treatment [N. E. Chadi, S. Merouani, O. Hamdaoui, M. Bouhelassa and M. Ashokkumar, Environ. Sci.: Water Res. Technol., 2019, 5, 1113–1123].


1998 ◽  
Vol 37 (9) ◽  
pp. 121-126 ◽  
Author(s):  
T. Hedberg ◽  
T. A. Wahlberg

The paper describes how waterworks can be upgraded by the use of microbiologically unit operations to make it possible to remove manganese from groundwater and surface water. Pilot plant studies and full-scale plant studies show that conventional oxidants as permanganate may be replaced by biooxidation thus reducing the use of chemicals in water treatment. Water containing high amounts of Fe and/or Mn and organic matter may be difficult to treat and pilot plant studies are therefore recommended. This study shows that one ground waterworks and one surface waterworks succed in removing manganese where previous treatment with permangante had failed.


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