scholarly journals Effects of Ferric Salt of Different Forms on Phosphorus Removal

2020 ◽  

<p>This paper has studied phosphorus removal effects of ferric chloride (ionic state), polyferric chloride (polymer state) and ferric hydroxide (gel state) on the effluent of a municipal sewage treatment plant. The total phosphorus (TP) in the effluent was 1.74 mg·L-1. Results showed that ferric chloride was the best phosphorus remover among the three forms of ferric salt coagulants. With a dosage of 40 mg·L-1, its phosphorus removal rate could reach 90% and TP in the treated wastewater was reduced to less than 0.17 mg·L-1. After the treatment, the effluent quality met the first level A criteria in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002). At the same doage of 40 mg·L-1, the phosphorus removal rates of polyferric chloride and ferric hydroxide were 62% and 59%, respectively, lower than the rate of ferric chloride.</p>

2001 ◽  
Vol 43 (11) ◽  
pp. 109-117 ◽  
Author(s):  
D. Bixio ◽  
P. van Hauwermeiren ◽  
C. Thoeye ◽  
P. Ockier

The municipal sewage treatment plant (STP) of the city of Ghent (Belgium) has to be retrofitted to a 43%-increase in the nitrogen treatment capacity and to phosphorus removal. Cold weather, dilute sewage and a critical COD over N ratio make the retrofit a challenge for full biological nutrient removal. The potential for fermentation of primary sludge to alter those critical feed sewage characteristics was experimentally evaluated. The idea was that the pinpoint introduction of fermentate could optimise the available reactors by achieving high-rate denitrification and enhanced biological phosphorus removal. The fermentation process was evaluated with a bench scale apparatus. At 20°C (heated process), the hydrolysis yield - expressed in terms of soluble COD - varied from 11% to 24% of the total sludge COD. The fermentation yield expressed in VFA COD varied from 8% to 13% of the total sludge COD. The efficiency of heated fermentation of primary sludge was lower during cold and wet weather, due to the different sewage characteristics, as a result of extended dilution periods and low temperature. The raw sewage, the primary effluent and the fermentate were fractionated according to the requirements for the IAWQ Activated Sludge Model No. 2d. The results clearly show that fermentation in the sewer played an important role and temperature was the driving parameter for the characteristics of the dissolved COD. Instead, the weather flow conditions were the driving parameter for the characteristics of the suspended COD. The results of the detailed fractionation were used as background for process evaluation. The final scenario choice for the retrofit depends on a cost-efficiency calculation.


2018 ◽  
Vol 45 ◽  
pp. 00036
Author(s):  
Zbigniew Kowalewski

The process of designing and exploiting municipal sewage treatment plants has become much simpler and more efficient thanks to mathematical modeling. The ASM model family is able to simulate the operation of existing or designed objects in a satisfactory manner. The basic problem in Poland is the insufficient amount of data for simulations coming from plant monitoring. It is provided to create unstable model results with difficulties in calibration and validation. The aim of this article is to confirm how the amount of data and its completeness will affect the quality of the simulation performed in the ASM model. The study object is a sewage treatment plant located in Chicago in the USA. It is a sewage treatment plant operating with activated sludge technology, with regular monitoring of the quality of raw and treated wastewater. For modeling, a variant of the ASM model built into the BioWin 5.2 software was used.


2008 ◽  
Vol 58 (4) ◽  
pp. 953-956 ◽  
Author(s):  
L. Balest ◽  
G. Mascolo ◽  
C. Di Iaconi ◽  
A. Lopez

The removal of selected endocrine disrupter compounds (EDCs), namely estrone(E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), bisphenol A (BPA) and 4-tert-octylphenol (4t-OP) from municipal wastewater was investigated using a sequencing batch biofilter granular reactor (SBBGR), a new system for biological treatment based on aerobic granular biomass. This new biological treatment is characterized by high biomass concentration (up to 40 g/L), high sludge retention times (up to 6 months) and low sludge production (i.e., an order of magnitude lower than commonly reported for conventional biological technologies). The investigation was carried out comparing a demonstration SBBGR system with a conventional full-scale activated sludge process. Results showed that the SBBGR performed better than a conventional activated sludge process in removing E1, E2, BPA and 4t-OP. In fact, the average removal percentages of the above mentioned EDCs, obtained during a four month operating period, were 62.2, 68, 91.8, 77.9% and 56.4, 36.3, 71.3, 64.6% for the demonstrative SBBGR system and the conventional activated sludge process of the municipal sewage treatment plant, respectively


Proceedings ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 18
Author(s):  
Magdalena Łój-Pilch ◽  
Anita Zakrzewska ◽  
Ewa Zielewicz

Risk management, an aspect of which is risk assessment, is a process supporting the proper function of municipal sewage treatment plants. Many factors affect the quality of treated wastewater. Risk assessment, its analysis, and hierarchization permit the elimination of events with the most destructive impacts on the purification process.


Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 827 ◽  
Author(s):  
Yong Li ◽  
Siyuan Zhao ◽  
Jiejie Zhang ◽  
Yang He ◽  
Jianqiang Zhang ◽  
...  

The aerobic denitrifying phosphate accumulating bacteria (ADPB) use NO3− as an electron acceptor and remove nitrate by denitrification and concomitant uptake of excessive phosphorus in aerobic conditions. Activated sludge was collected from the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town, Chengdu City. The candidate ADPB strains were obtained by cultivation in the enriched denitrification media, followed by repeated isolation and purification on bromothymol blue (BTB) solid plates. The obtained candidates were further screened for ADPB strains by phosphorus uptake experiment, nitrate reduction test, metachromatic granules staining, and poly-β-hydroxybutyrate (PHB) staining. The 16 sedimentation ribosome deoxyribonucleic acid (16 S rDNA) molecular technique was used to determine their taxonomy. Further, the denitrification and dephosphorization capacities of ADPB strains were ascertained through their growth characteristics in nitrogen-phosphorus-rich liquid media. The results revealed a total of 25 ADPB strains screened from the activated sludge of the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town. These strains belonged to two classes, four orders, and five genera. Among them, the strain SW18NP2 was a potentially new species in the Acinetobacter genus, while the strain SW18NP24 was a potential new species in the Pseudomonas genus at the time of their characterization. The Acinetobacter was the dominant genus. The obtained ADPB strains demonstrated a rich diversity. The ADPB strains had significant variations in denitrification and dephosphorization capacities. Twenty-three strains exhibited a total phosphorus removal rate of above 50%, and 19 strains exhibited a total nitrogen removal rate of above 50%. The strain SW18NP2 showed the best denitrifying phosphorus removal (DPR) capacity, with a dephosphorization rate of 82.32% and a denitrification rate of 73.73%. The ADPB in the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town demonstrated a rich diversity and a strong DPR capacity.


1976 ◽  
Vol 33 (4) ◽  
pp. 776-782 ◽  
Author(s):  
James A. Buckley ◽  
Cecil M. Whitmore ◽  
Robert I. Matsuda

Yearling coho salmon (Oncorhynchus kisutch) were exposed for 12 wk to either 0.3, 1.1, or 3.6% chlorinated municipal sewage treatment plant effluent with seawater diluent (average salinity 28‰)under continuous flow conditions. The maximum safe concentration of effluent lies between 0.3 and 1.1% (average total residual chlorine (TRCl2) content 0.003 and 0.009 mg/liter, respectively). Effluent concentrations of 0.3% produced no discernible effects on the fish. Concentrations of 1.1 and 3.6% (average content of TRCl2 0.030 mg/liter) resulted in reductions of hemoglobin and hematocrit to levels indicative of anemia. Observations of the erythrocytes revealed lysed and degenerating cells, increased numbers of circulating immature cells, and abnormal cells. These hematological effects are attributed to the oxidative nature of TRCl2.


2011 ◽  
Vol 383-390 ◽  
pp. 3422-3427
Author(s):  
Yan Li ◽  
Yan Qiu Zhang

For engineering research, ECOSUNIDE technique was applied in a sewage treatment plant under low temperature and low carbon resource. The whole experimental system has being running steadily after reasonable adjustments of influent distribution, returned sludge ratio and DO. The effluent qualities meet the Class I-B Criteria Specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002).Effluent BOD5 and NH3-N meet the Class I-A Criteria. The results indicates that the treatment capacity could fluctuate within a range of ±3000 m3/d with DO properly controlled. In aerobic sections, the best DO was 2-3 mg/L. The optimal sludge emission amount could be attained through settlement ratio and sludge concentration with the present emission amount of sludge of 680 m3/d. It might be the restrictive factor that BOD/TN was less than 3 on TN removal which could not steadily achieve the Class I-A Criteria.


2016 ◽  
Vol 23 (4) ◽  
pp. 665-675 ◽  
Author(s):  
Grzegorz Wielgosiński ◽  
Robert Cichowicz ◽  
Jacek Wiśniewski

Abstract In quantitative terms, sludge produced in the process of municipal wastewater treatment represents a small part of the total waste generated in municipal sources - its quantity represents only a few percent of the generated mass of municipal waste. However, the threats it brings, do not allow it to be neglected while designing the wastewater treatment process. At the same time, with increasing requirements regarding the quality of sewage discharged into the environment, there is an increase in the amount of sludge produced in wastewater treatment processes. In recent years, the share of thermal treatment of municipal sewage sludge has risen sharply - about 12 modern sludge incineration plants have been built and construction of new ones is considered. During more than a four-year operation of the sewage sludge incineration plant in the Combined Sewage Treatment Plant in Lodz (GOS) a large ammonia emission from the combustion process was observed. So, a decision was taken to examine this process. The paper presents results of ammonia emission from the combustion of sewage sludge from GOS as a function of temperature.


2011 ◽  
Vol 374-377 ◽  
pp. 1013-1016
Author(s):  
Hui Yang ◽  
Yu Zhang ◽  
Yue Xu

Abstract. The paper aims to study the fast start-up of anaerobic-aerobic-anoxic-aerobic sequencing batch reactor, with domestic sewage as treating object, to solve the problem of SBR that can be used for denitrification or dephosphorization independently and to realize simultaneous nitrogen and phosphorus removal in a single SBR system. Phosphorus accumulating organisms were enriched at the anaerobic condition for 2h/aerobic for 3h after activated sludge were inoculated. Then denitrifying polyphosphate-accumulating organisms were enriched by inserting an anoxic phase into the aerobic phase. The lengths of anaerobic time, anoxic time and aerobic time were adjusted and the nitrogen and phosphorus removal effect of (AO)2SBR system were observed. The (AO)2SBR system was started successfully with 80d of training and domesticating. The nitrogen and phosphorus removal effect was performed preferably at the condition of anaerobic(2h)-aerobic(1.5h)-anoxic(1.5h)-aerobic(0.5h). The removal rate of COD, NH4+-N, TN and TP reached 90%, 97%, 88% and 92% respectively. And 33% of energy was saved when aerobic time was shortened from 3h to 2h, while the treating effect dropped off rarely. The results show that (AO)2SBR is applicable for simultaneous nitrogen and phosphorus removal, and the effluent water quality meets the first level B criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002). The system can also reach the aim of saving energy and providing theoretical basis for the nitrogen and phosphorus removal in single SBR systems.


1999 ◽  
Vol 39 (6) ◽  
pp. 119-125
Author(s):  
Edward Cusack ◽  
Graham Gloag ◽  
Gerry Stevens

This paper describes the design and optimisation of the Nambour Sewage Treatment Plant. The plant utilises a 4 Stage Westbank Biological Excess Phosphorus Removal process (3 stage Bardenpho with pre-anoxic zone) and a static primary sludge fermenter (the first of its kind in Australia) to achieve better than a 50 percentile Total Nitrogen 10 mg/l and Total Phosphorus 2 mg/l treated wastewater standard. The plant also uses anaerobic digesters to produce a Grade B stabilised biosolids and lime treatment to remove phosphorus from the sidestream liquors. Commissioning and operational experiences are also discussed.


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