The performance of the waste stabilisation pond system at Boujaad, Morocco

2000 ◽  
Vol 42 (10-11) ◽  
pp. 9-16 ◽  
Author(s):  
M. Yagoubi ◽  
L. Echihabi ◽  
A. Foutlane ◽  
L. Bourchich ◽  
J. Jellal ◽  
...  

The wastewater stabilisation ponds system of the city of Boujaâd was constructed and put into operation in 1992. The two main objectives of this plant are the prevention of pollution of water resources and the environment by means of wastewater discharges as well as the saving of fresh water by means of reuse of treated wastewater for irrigation purposes. Within the period of March 1997 to March 1998 a comprehensive analysis campaign of both the raw and the treated wastewater at a number of different sampling points has been carried out in order to evaluate the treatment efficiency of this wastewater treatment plant.The results of these investigations showed an average raw wastewater flow of 1600 m3/d, which is well below the design flow of 2500 m3/d. With respect to the physico-chemical treated wastewater quality and in comparison with the French treated wastewater standards (1980) these results indicated that 90 % of the wastewater samples showed BOD5-figures below the quoted French standard, whereas 83 % of the samples showed COD-figures above the corresponding French treated wastewater standard. With average treated wastewater suspended solids contents of 56 mg/l the suspended solids removal rate has been determined as being in the range of 65 %. If compared to the anticipated Moroccan wastewater standards for direct wastewater discharge into receiving water bodies as stipulated in the Moroccan Standards Project the obtained wastewater analysis results showed COD- and BOD5 values below these foreseen Moroccan wastewater discharge standards. The analysis results of SS, TKN and total phosphorus (Ptot) showed figures slightly above these Moroccan standards. In view of the microbiological wastewater characteristics the treated effluents of the Boujaâd WSP respond to the WHO directive with respect to wastewater to be used for restricted irrigation (category B). Taking into consideration the CEC directive for wastewater generated by wastewater treatment plants and discharged to the environment, the efficiency of the Boujaâd WSP is relatively low with respect to the SS-removal, the removal of organic matter (expressed by BOD5 and COD) as well as the removal of nutrients (expressed by TKN and Ptot). This relatively low efficiency might basically be caused by the already highly diluted incoming raw wastewater, which again is caused by the effect of significant infiltration of groundwater into the sewerage network. Besides the evaluation of the overall treatment efficiency, detailed investigations of the performance of individual ponds have been carried out as well.

2006 ◽  
Vol 54 (10) ◽  
pp. 87-93 ◽  
Author(s):  
T. Hashimoto ◽  
K. Takahashi ◽  
T. Murakami

Since the natural estrogens 17 β-estradiol (E2) and estron (E1), and the synthetic estrogen 17 α-ethynyl estradiol (EE2) have strong endocrine disrupting effects and the tendency to persist in effluent from wastewater treatment plants, effective measures are needed to remove them from wastewater. In this research, to gain an understanding of the characteristics of estrogen decomposition by ozonation, experiments were conducted using effluent from an actual wastewater treatment plant. In this experiment, estrogen was added to effluent at a concentration of 200 ng/l and 20 ng/l before the ozonation experiments. The results showed 90% or more of estrogen concentration and estrogenic activity of E2, E1 and EE2 to be removed at an ozone dose of 1 mg/l. At an ozone dose of 3 mg/l, the estrogen concentration and estrogenic activity of E2, E1 and EE2 in the treated water fell below the detection limit. The removal rate was not influenced by the kind of estrogen. No generation of byproducts with estrogenic activity was observed. The authors conclude that estrogen in secondary treated wastewater can be almost entirely removed at the practical ozone dose rate applied for the purpose of disinfection, which is up to about 5 mg/l.


DYNA ◽  
2015 ◽  
Vol 82 (192) ◽  
pp. 230-238 ◽  
Author(s):  
Juan Pablo Rodríguez Miranda ◽  
César Augusto García-Ubaque ◽  
Juan Carlos Penagos Londoño

Some of the most significant aspects in the selection of wastewater treatment plants are the investment costs, since they cross-linkthe treatment level, the quality of the raw wastewater, the design flow and the purpose of the treated wastewater. Through a multivariable exponential regression analysis, data from 51 projects of new treatment plants was analyzed, and from that process, data of cost scale elasticity was obtained, in slow growth, in comparison to the design flow for each of the treatment technologies analyzed.


Author(s):  
Mirela Alina Constantin ◽  
Lucian Alexandru Constantin ◽  
Ion Viorel Patroescu ◽  
Gheorghe Batrinescu

Collagen production is generating wastewater with high organic loading. This type of wastewater is still containing valuable compounds that can be reused in other applications. In order to investigate the possibility to recover and reuse these compounds the membrane based processes were investigated. Four types of commercial available membranes were characterised and then used to recover the proteins. The results proved that membrane based processes represent a viable alternative to treatment of wastewater generated by collagen production facilities when recovery of valuable compounds is envisaged. It has to be stressed that on the other hand only membrane processes do not assure too reach the quality norms imposed by the legislation for treated wastewater discharge into sewerage systems or natural receivers. Therefore, when proteins recovery and reuse is wanted, the membrane processes represent only the first step of wastewater treatment and should be followed by biological processes in order to obtain the organic loading quality indicators required for wastewater treatment plants discharges.


Separations ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 20 ◽  
Author(s):  
Anastasios Zouboulis ◽  
Efrosyni Peleka ◽  
Anastasia Ntolia

The performance of a vibratory shear-enhanced process (VSEP) combined with an appropriate membrane unit for the treatment of simulated or industrial tannery wastewaters was investigated. The fundamental operational and pollution parameters were evaluated, i.e., the membrane type, the applied vibration amplitude, as well as the removal rates (%) of tannins, chemical oxygen demand (COD), Ntotal, turbidity and color. Regarding the system’s treatment efficiency, specific emphasis was given towards the removal of organics (expressed as COD values), suspended solids (SS), conductivity (as an index of dissolved solids’ presence) and total nitrogen. The removal of organic matter in terms of COD exceeded 75% for all the examined cases. The quality of treated wastewater was affected not only by the membrane specific type (i.e., the respective pore diameters), but also by the applied vibration amplitude. Furthermore, an average 50% removal rate, regarding the aforementioned parameters, was observed both for the simulated and the industrial tannery wastewaters during the microfiltration (MF) experiments. That removal rate was further increased up to 85%, when ultrafiltration (UF) was applied, and up to 99% during the Reverse Osmosis (RO) experiments, considering the maximum applied vibration amplitude (31.75 mm).


2020 ◽  
Vol 74 (3) ◽  
pp. 156-160 ◽  
Author(s):  
Thomas Poiger ◽  
Martina Keller ◽  
Ignaz J. Buerge ◽  
Marianne E. Balmer

The herbicide glyphosate is frequently detected in surface waters and its occurrence is linked to agricultural as well as urban uses. Elevated concentrations downstream of wastewater treatment plants (WWTPs) suggest that municipal wastewater is an important source of glyphosate in surface waters. We therefore conducted a study at a typical municipal WWTP in Switzerland to characterize the seasonality of glyphosate occurrence, the removal efficiency, and the processes involved in glyphosate removal. Glyphosate was present in raw (mechanically treated) wastewater during the whole study period (April to November). A lab incubation experiment with activated sludge indicated negligible degradation of glyphosate. Lack of degradation combined with strong adsorption lead to substantial enrichment of the compound in the sludge. Due to this enrichment and the long residence time of activated sludge (several days, compared to hours for wastewater itself), concentrations in treated wastewater show comparatively little variation, whereas concentrations in raw wastewater may fluctuate considerably. Overall removal efficiencies were in the range of 71–96%. This behavior could be described qualitatively using a numerical model that included input of glyphosate via raw wastewater, adsorption to activated sludge, and export via treated wastewater and excess sludge, but excluded degradation processes.


2017 ◽  
Vol 77 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Shaoxiong Si ◽  
Zhong Yan ◽  
Zhaobo Gong ◽  
Pengfei Liu ◽  
Yumin Zhang ◽  
...  

Abstract In order to meet the latest Environmental Protection Law of China on wastewater discharge standards, this paper studied a pilot-scale micro-flocculation filtration pretreatment process for the treatment of oilfield wastewater. The experiment showed that the removal rate of oil and suspended solids (SS) respectively increased from 91.52% to 95.38% and from 66.42% to 97.19%. After the treatment by the micro-flocculation filtration device, the relevant characteristics of the discharge wastewater satisfied the latest standards continuously. Moreover, the polyaluminum chloride (PAC) dosage was reduced from 200 mg/L to 100 mg/L (50 mg/L in micro-flocculation device and 50 mg/L in the cyclone reactor) at the same time. In order to decrease the degree of scaling in the filter, ceramsite was chosen as the filter material instead of quartz sand that is widely applied in the oilfields. The scaling experiment showed that the HCO3−, Ca2+ and Mg2+ contents in the extract from quartz sand after the scaling study were increased by 38.05, 35.91 and 0.28 mg/L, respectively. Meanwhile, the HCO3−, Ca2+ and Mg2+ contents in the extract from ceramsite were only increased by 13.14, 6.26 and 0.27 mg/L, respectively. Therefore, the ceramsite is not so prone to scaling as compared to quartz sand under identical test conditions, which avoided a hardened and impervious filter after operating for some time. These results suggest that the micro-flocculation filtration with the ceramsite as filter media is a suitable pretreatment process for the oilfield wastewater treatment.


2021 ◽  
Author(s):  
Peng Liu ◽  
Zihan Li ◽  
Zifan Che ◽  
Hu Xinran ◽  
Ming Ying ◽  
...  

Abstract Enteric viruses are known to be prevalent in municipal wastewater, but information on the health risks arising from wastewater reuse is limited. This study quantified six common enteric viruses in raw wastewater and determined the effectiveness of different secondary and tertiary treatment processes at reducing their abundances in three full-scale wastewater treatment plants in China. In the raw wastewater, polyomavirus BK and norovirus GII (Nov GII) exhibited the highest abundance among the detected DNA and RNA viruses, respectively, with concentrations >5 log10 copies/L. Viruses in the raw wastewater were mainly removed by the secondary treatment processes, with log reduction values ranging from 1 to 2. The tertiary treatment processes of both chlorination and ultraviolet irradiation facilitated the additional reduction of viruses. The quantitative microbial risk assessment was applied to estimate the health risks of adenovirus (Adv) and Nov GII when reusing the treated wastewater for irrigation of public green spaces and crops. Estimated disabled-adjusted life-years of Adv and Nov GII for both reuses were higher than the risk threshold (10−6) required by the WHO in the actual scenarios. More effective treatment technologies should be implemented to remove viruses for safe reuse of the treated wastewater.


1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.


1993 ◽  
Vol 28 (10) ◽  
pp. 33-41
Author(s):  
Jes la Cour Jansen ◽  
Bodil Mose Pedersen ◽  
Erik Moldt

Influent and effluent data from about 120 small wastewater treatment plants (100 - 2000 PE) have been collected and processed. Seven different types of plants are represented. The effluent quality and the treatment efficiency have been evaluated. The most common type of plant is mechanical/biological treatment plants. Some of them are nitrifying and some are also extended for chemical precipitation of phosphorus. Constructed wetlands and biological sandfilters are also represented among the small wastewater treatment plants.


1995 ◽  
Vol 31 (12) ◽  
pp. 171-183 ◽  
Author(s):  
M. M. Saqqar ◽  
M. B. Pescod

The performance of the primary anaerobic pond at the Alsamra Wastewater Treatment Plant in Jordan was monitored over 48 months. Overall averages for the removal efficiencies of BOD5, COD and suspended solids were 53%, 53% and 74%, respectively. An improvement in removal efficiency with increase in pond water temperature was demonstrated. A model, which takes into account the variability of raw wastewater at different locations, has been developed to describe the performance of a primary anaerobic pond in terms of a settleability ratio for the raw wastewater. The model has been verified by illustrating the high correlation between actual and predicted pond performance.


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