scholarly journals Upgrading of decentralized ponds for municipal wastewater treatment and restricted reuse

2011 ◽  
Vol 1 (3) ◽  
pp. 141-151 ◽  
Author(s):  
Hussein I. Abdel-Shafy ◽  
Inka Hobus ◽  
Werner Hegemann

Upgrading of a pond system for municipal wastewater treatment in a decentralized area is evaluated. The pond was constructed for the treatment of 63 m3/d. Currently it receives 83 m3/d, therefore poor treatment efficiency was recorded. An expansion of 1.6 times the present land area was required. In addition to construction, operation and maintenance were required to meet the permissible limits. The other option was to introduce aeration system to the ponds without any additional requirements. The efficiency of the successive treatment steps on the wastewater quality, including metals in the treated effluent/sludge and bacterial counts, was evaluated for agricultural reuse. The physical, chemical and bacterial parameters as well as the input aeration load (h) during the study period were investigated extensively. The results indicated that remarkable improvement in the treated effluent was achieved after upgrading the pond system via aeration. The removal rate of the pollution parameters ranged from 75 to 85%. The level of heavy metals in the produced sludge was below the permissible concentration and does not represent any risk. Meanwhile, it was possible to avoid any requirements for addition land area or construction of treatment and proved that the treated effluents can be reused for restricted water reuse.

2016 ◽  
Vol 11 (1) ◽  
pp. 104-117 ◽  
Author(s):  
C. Zaffaroni ◽  
G. Daigger ◽  
P. Nicol ◽  
T. W. Lee

Industrial wastewater differs from municipal wastewater. The limits for treated effluent discharge and targets for re-use are typically the same, and derived from the best available technology for municipal wastewater treatment. The main treatment unitary processes are also the same; although proper adaptation to specific, different, industrial wastewater streams is needed. This paper provides some examples of the challenges presented by specific wastewater sources (high total dissolved solids, high temperature, spent caustic, etc.), lack of previous similar experience – e.g., using membrane bioreactors for refinery wastewaters, and/or absorption chillers, and plate and frame heat exchangers) or to legislation protecting sensitive environments (limits on total nitrogen or soluble metals). The methods by which these were faced and overcome to achieve treatment and/or re-use standards are described. General water cycle optimization issues around industrial facilities with appropriate use of existing wastewater treatment units are also discussed, as well as selecting between treated municipal and industrial effluents as sources for water re-use.


Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1339
Author(s):  
Javier Bayo ◽  
Sonia Olmos ◽  
Joaquín López-Castellanos

This study investigates the removal of microplastics from wastewater in an urban wastewater treatment plant located in Southeast Spain, including an oxidation ditch, rapid sand filtration, and ultraviolet disinfection. A total of 146.73 L of wastewater samples from influent and effluent were processed, following a density separation methodology, visual classification under a stereomicroscope, and FTIR analysis for polymer identification. Microplastics proved to be 72.41% of total microparticles collected, with a global removal rate of 64.26% after the tertiary treatment and within the average retention for European WWTPs. Three different shapes were identified: i.e., microfiber (79.65%), film (11.26%), and fragment (9.09%), without the identification of microbeads despite the proximity to a plastic compounding factory. Fibers were less efficiently removed (56.16%) than particulate microplastics (90.03%), suggesting that tertiary treatments clearly discriminate between forms, and reporting a daily emission of 1.6 × 107 microplastics to the environment. Year variability in microplastic burden was cushioned at the effluent, reporting a stable performance of the sewage plant. Eight different polymer families were identified, LDPE film being the most abundant form, with 10 different colors and sizes mainly between 1–2 mm. Future efforts should be dedicated to source control, plastic waste management, improvement of legislation, and specific microplastic-targeted treatment units, especially for microfiber removal.


2013 ◽  
Vol 68 (3) ◽  
pp. 575-583 ◽  
Author(s):  
R. Mosteo ◽  
M. P. Ormad ◽  
P. Goñi ◽  
J. Rodríguez-Chueca ◽  
A. García ◽  
...  

The aim of this research work is to identify the presence of pathogens, bacteria and protozoa, in different treated urban wastewaters and to relate biological pollution with the processes used in wastewater treatment plants. A study of the possibilities for water reuse is carried out taking into account bacterial and parasite composition. The analysed bacteria and protozoa are: Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium perfringens (spore), Salmonella spp., Legionella spp., helminths eggs, Giardia, Cryptosporidium spp. and free-living amoebae (FLA). The selected municipal wastewater treatment plants (MWTPs) are located in Navarra (Spain) and the main difference between them is the use of natural lagoons as tertiary treatment in some plants. The results concerning bacteriological identification showed contamination of mainly faecal origin, and the use of natural lagoons as tertiary treatment in some MWTPs produced an important disinfection effect. Moreover, pathogen parasites such as Giardia and Cryptosporidium were not detected in the samples studied although FLA were identified in all cases.


2016 ◽  
Vol 74 (7) ◽  
pp. 1602-1609 ◽  
Author(s):  
Long Pang ◽  
Peijie Yang ◽  
Jihong Zhao ◽  
Hongzhong Zhang

Organophosphate esters (OPs), widely used as flame retardants and plasticizers, are regarded as a class of emerging pollutants. The effluent of municipal wastewater treatment plants is generally considered to be the main contributor of OP pollution to the surface water. In this study, anoxic–oxic (AO) and University of Capetown (UCT) processes were selected to investigate the removal efficiency of OPs. The results indicated that the UCT process showed better removal efficiency than that of the AO process. For the chlorinated OPs, approximately 12.3% of tri(2-chloroethyl)phosphate and 11.8% of tri(chloropropyl)phosphate can be removed in the UCT process, which was 12% and 7.8% higher than that of the AO process. In contrast, non-chlorinated OPs, including tris(2-butoxyethyal)phosphate, triphenyl phosphate, and tributyl phosphate, were able to be removed in both processes, with the removal rate of 85.1%, 74.9%, and 29.1% in the AO process, and 88.4%, 63.6%, and 25.2% in the UCT process. Furthermore, linear correlation between the removal rate and logKow of OPs (r2 = 0.539) was observed in the AO process, indicating that OPs with high Kow value (e.g. tri(dichloropropyl)phosphate and triphenyl phosphate) are prone to be removed by adsorption on the residual activated sludge.


2011 ◽  
Vol 356-360 ◽  
pp. 1248-1252
Author(s):  
Ai Bin Kang ◽  
Ying Qiang Yao ◽  
Yu Long Dong

The removal and mechanism of ammonia nitrogen and total nitrogen were studie through three-step series of constructed rapid infiltration system by using high ammonia nitrogen domestic sewage of students' living area in a university. The result shows that the removal rate of ammonia nitrogen is 94.47% by using this system, which is 3% higher than conventional rapid infiltration system.The effluent can meet the standard Ⅰ—A of “Discharge standard of pollutants for municipal wastewater treatment plant(GB 18918-2002)”. The amount of ammonium oxidizing bacteria, nitrate oxidizing bacteria, nitrite oxidizing bacteria in this system is higher than that in conventional rapid infiltration system. The correlation between the removal of ammonia nitrogen and ammonium oxidizing bacteria, nitrate oxidizing bacteria, nitrite oxidizing bacteria is significant. The removal rate of total nitrogen is 47.38% by using this system, which is 20.72% higher than that in conventional rapid infiltration system. However, the effluent still can not meet the standard Ⅰ—A of “Discharge standard of pollutants for municipal wastewater treatment plant (GB 18918-2002)”. The amount of denitrifying bacteria in the three-step subsystem increased significantly, which improves the removal of total nitrogen. The correlation between the removal of TN and denitrification bacteria is significant.


2005 ◽  
Vol 5 (1) ◽  
pp. 87-94 ◽  
Author(s):  
J.H.J.M. van der Graaf ◽  
J. de Koning ◽  
A. Ravazzini ◽  
V. Miska

In 2003 the Aquarec project sponsored by the European Commission under the 5th Framework Programme was started, aiming at “integrated concepts for reuse of upgraded wastewater with special focus on the European countries”. One of the key elements is the development of a treatment matrix, in which wastewater treatment processes are categorised as a function of the raw wastewater quality and the reuse application and are further characterised with respect to costs, operational critical control points and environmental aspects. The construction of the treatment matrix is based on the reuse options (industrial, domestic, natural and agricultural applications), the water quality requirements, the treatment requirements and the extensive description of the various treatment processes and schemes. In the process of constructing the matrix it can be concluded that the actual knowledge on municipal wastewater treatment is definitely well consolidated until the so-called secondary treatment including biological or physical/chemical nutrients removal; the treatment of this effluent should be accomplished by more advanced techniques. As a consequence of the actual EU rules on water discharges, it makes sense to focus the Aquarec project on the possible refinements of secondary effluent. Great attention must be given to the advanced or tertiary wastewater treatment processes, as a mean to upgrade the effluent to water suitable for reuse.


2020 ◽  
Vol 194 ◽  
pp. 04009
Author(s):  
Qiaoquan Wei ◽  
Guanwen Cheng ◽  
Bangzhou Sun ◽  
Liao Zhang ◽  
Yuling Zhang ◽  
...  

Operation efficiency, effect and operation energy consumption are the main basis for the evaluation of the operation and management level of wastewater treatment plant. The statistics of the operation data of the small municipal wastewater treatment plant in Luocheng County show that the operation rate of the facility is high, and the treated effluent reaches the Level A standard of the “Discharge standard of pollutants for municipal wastewater treatment plant” (GB18918-2002), and the various evaluation indicators of the urban wastewater treatment plant basically normal. However, the average operating load of some municipal wastewater treatment plant has not reached the index requirement for the operation period of production, and the load rates of CODCr and NH4+-N are mostly below 60%, and wastewater treatment plant unit wastewater volume, unit CODCr and NH4+-N load energy consumption is high. The reason is that the water quality of the design of the micro-municipal wastewater treatment plant is not reasonable, the construction scale is too large, and the operation fails to adopt effective management and control technology measures.


Author(s):  
Robert Kreuzig ◽  
Jaqueline Haller-Jans ◽  
Cornelia Bischoff ◽  
Johannes Leppin ◽  
Jörn Germer ◽  
...  

AbstractFor a novel approach of resource-efficient water reuse, a municipal wastewater treatment plant was extended at pilot scale for advanced wastewater treatment, i.e., ozonation and biological activated carbon filtration, and a hydroponic system for reclaimed water driven lettuce cultivation. The treatment specific wastewater lines with the corresponding lettuce plants, differentiated into roots and shoots, were monitored for priority wastewater micropollutants, i.e., acesulfame (sweetener), caffeine (stimulant), carbamazepine, diclofenac, ibuprofen, sulfamethoxazole with acetyl-sulfamethoxazole (human pharmaceuticals), 1H-benzotriazole, and 4/5-methylbenzotriazole (industrial chemicals). As clearly demonstrated, conventional tertiary treatment could not efficiently clean up wastewater. Removal efficiencies ranged from 3% for carbamazepine to 100% for ibuprofen. The resulting pollution of the hydroponic water lines led to the accumulation of acesulfame, carbamazepine, and diclofenac in lettuce root systems at 32.0, 69.5, and 135 μg kg−1 and in the uptake of acesulfame and carbamazepine into lettuce shoots at 23.4 and 120 μg kg−1 dry weight, respectively. In contrast, both advanced treatment technologies when operating under optimized conditions achieved removal efficiencies of > 90% also for persistent micropollutants. Minimizing the pollution of reclaimed water thus met one relevant need for hydroponic lettuce cultivation. Graphical abstract


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