Occurrence and removal of protozoan cysts and helminth eggs in waste stabilisation ponds in Marrakech

2000 ◽  
Vol 42 (10-11) ◽  
pp. 159-164 ◽  
Author(s):  
K. Bouhoum ◽  
O. Amahmid ◽  
S. Asmama
Keyword(s):  
Wastewater Treatment ◽  
Entamoeba Histolytica ◽  
Municipal Wastewater ◽  
Arid Climate ◽  
Waste Stabilisation Ponds ◽  
Helminth Eggs ◽  
Mean Concentration ◽  
Raw Wastewater ◽  
Main Factor

The present study aimed to determine the occurrence and removal of protozoan cysts and helminth eggs from municipal wastewater by pilot waste stabilisation ponds in the arid climate of Marrakech (Morocco). Protozoan cysts detected in raw wastewater at the entrance of the system were identified as Entamoeba histolytica, Giardia sp. and Entamoeba coli at a mean concentration of 1.5×104 cysts/l. Helminth eggs identified were Ascaris, Trichuris, Hymenolepis, Enterobius and Taenia with an average of 7.6 eggs/l. The effluent at the system outlet did not contain detectable cysts or eggs. Sludge samples collected in the pond basins resulted in detection of protozoan cysts and helminth eggs. Sedimentation therefore seems to be the main factor for cyst and egg elimination during wastewater treatment by waste stabilisation ponds. This phenomenon leads however to parasite accumulation in the sediment.

Parasite removal by natural wastewater treatment systems: performance of waste stabilisation ponds and constructed wetlands

2003 ◽  
Vol 48 (2) ◽  
pp. 97-104 ◽  
Author(s):  
R. Stott ◽  
E. May ◽  
D.D. Mara
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Intestinal Parasites ◽  
Low Cost ◽  
Domestic Wastewater ◽  
Treated Wastewater ◽  
Waste Stabilisation Ponds ◽  
Helminth Eggs ◽  
Wetland System ◽  
Raw Wastewater

Parasite removal and low cost systems for wastewater treatment have become increasingly important requirements in developed and developing countries to safeguard public health from wastewater-associated intestinal diseases. Pilot and field-scale ponds and wetlands in Brazil and Egypt have been investigated for the fate and removal of eggs of human intestinal parasites from domestic wastewater. In northeast Brazil, parasite removal was investigated for a series of five waste stabilisation ponds treating raw wastewater. In Egypt, parasite removal was studied for Gravel Bed Hydroponic constructed wetlands treating partially treated wastewater. Influents to ponds and wetlands contained a variety of parasite helminth eggs (e.g. Ascaris, hookworm, Trichuris, and Hymenolepis spp.). The ponds consistently removed parasite eggs though rate of removal by individual ponds may have been related to influent egg numbers and extent of short-circuiting. Parasite eggs were reduced on average by 94% and 99.9% in the anaerobic and facultative ponds respectively. No eggs were found in effluent from the second maturation pond. In the wetland system, parasite removal varied with reedbed length. The majority of parasite eggs were retained within the first 25 m. Parasite eggs were reduced on average by 98% after treatment in 50 m beds and completely removed after treatment in 100 m beds.

Application of Biotechnology to Municipal Wastewater Treatment

1991 ◽  
Vol 23 (10-12) ◽  
pp. 1723-1732 ◽  
Author(s):  
T. Matsui ◽  
S. Kyosai ◽  
M. Takahashi
Keyword(s):  
Wastewater Treatment ◽  
Genetic Engineering ◽  
Municipal Wastewater ◽  
Engineering Application ◽  
Municipal Wastewater Treatment ◽  
Sludge Treatment ◽  
National Project ◽  
Wastewater Treatment Systems ◽  
Raw Wastewater

Application of biotechnology to wastewater treatment for its improvement and greater understanding was investigated in the Japanese national project named Biofocus WT as to a microorganism bank, genetic engineering application, immobilization of microorganisms, bioreactors for wastewater treatment, bioreactors for sludge treatment, SS separators for raw wastewater, biosensors and new wastewater treatment systems.

scholarly journals Epidemiological risks of endoparasitoses spread by municipal waste water

2015 ◽  
Vol 52 (3) ◽  
pp. 188-194 ◽  
Author(s):  
A. Dudlová ◽  
P. Juriš ◽  
P. Jarčuška ◽  
L. Čisláková ◽  
I. Papajová ◽  
...  
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Developmental Stages ◽  
Wastewater Sludge ◽  
Indirect Detection ◽  
Treated Wastewater ◽  
High Concentration ◽  
Epidemiological Aspect ◽  
Helminth Eggs

AbstractThe occurrence of developmental stages of endoparasite germs (cysts, oocysts, protozoa, and helminth eggs) as an indirect detection factor of endoparasitoses circulation in the environment, was examined in raw municipal wastewater, sludge and biologically cleaned waste water. Examination of municipal wastewater and sludge from five monitored wastewater treatment plants (WWTPs) in east Slovakia, from various fractions of municipal wastewater, confirmed 35.87 % positivity of samples for the endoparasitic germs. Among of all analysed samples 11.09 % were protozoan oo(cysts) and 20.87 % were helminth eggs. 3.91 % of samples showed positivity to both the helminth eggs and protozoan oo(cysts). In the raw wastewater the protozoa comprised of Giardia spp. (1.08 %) and Entamoeba spp. (1.08 %). The helminth eggs primarily consisted of Ascaris spp. (4.35 %) and strongyle-type eggs (3.26 %). No germs of protozoa or helminths were found in the treated wastewater. However, the highest presence of the germs was found in drained stabilised sludge. The average number of oo(cysts)/kg was 2.86±0.24 and the average number of helminth eggs/kg was 5.77±0.09. In all kinds of sludge, obtained during the process of wastewater treatment, there were protozoan (Giardia spp., Cryptosporidium spp., Entamoeba spp.) and helminths eggs (Ascaris spp., Trichuris spp., Taenia spp., Hymenolepis spp., or strongyle-type eggs) presented. In drained (condensed) stabilised sludge the eggs of Capillaria spp. and Toxocara spp. were also detected. From the epidemiological aspect the sewage sludge, due to high concentration of protozoal oo(cysts) or helminth eggs, represents a significant epidemiological risk for the endoparasitoses dissemination.

Small municipal wastewater treatment plants in Greece

2000 ◽  
Vol 41 (1) ◽  
pp. 41-48 ◽  
Author(s):  
K.P. Tsagarakis ◽  
D.D. Mara ◽  
N.J. Horan ◽  
A.N. Angelakis
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Poor Performance ◽  
Municipal Wastewater Treatment ◽  
Natural Systems ◽  
Waste Stabilisation Ponds ◽  
Good For ◽  
Municipal Wastewater Treatment Plants

Data from 147 small municipal wastewater treatment plants (MWTP), with a population equivalent (p.e.) less than 10,000, have been collected and analysed. Extended aeration plants are the most common (75%), followed by natural systems - waste stabilisation ponds (9%) and hydroponic silviculture (6%). Only 71 MWTP (out of the 147) were operational in 1997; the performance of only 15 of these was good, for 36 was moderate and for 20 it was poor. It was found that the reasons for poor performance, for the plant failure and for delays in commissioning were managerial and institutional, rather than purely technical.

scholarly journals Improving the performance of waste stabilization ponds in an arid climate

2021 ◽  
Author(s):  
Badre Achag ◽  
Hind Mouhanni ◽  
Abdelaziz Bendou
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Municipal Wastewater ◽  
Poor Performance ◽  
Treatment Method ◽  
Fecal Coliforms ◽  
Arid Climate ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
Waste Stabilization

Abstract In many parts of the world, waste stabilization ponds (WSPs) are currently the preferred wastewater treatment method for municipal wastewater. The objective of this research is to examine the performance of a WSP in an arid climate region and to identify ways to improve its purification efficiency so that it can meet the criteria for reuse. The results attributed the poor performance to both improper process and physical design after 12 months of physicochemical and bacteriological analyses, as well as monitoring of operation, maintenance and loading rates. In tertiary treatment, maturation ponds are added, an increase in the capacity of the station, and management of the flow rate and retention time for each pond. By simulating the new WSP with GPS-X, the best pond area ratio obtained is 2.5 m2/capita, with a retention time of 4 days for anaerobic ponds, 20 days for facultative ponds and 3 days for two maturation ponds in series, which is suitable and provides reduction rates of BOD and fecal coliforms of 95 and 99%, respectively, with an average effluent concentration of 20 mg/L and 195 CFU. According to the results, well-maintained WSPs provide a viable, self-sufficient and environmentally friendly wastewater treatment solution for irrigation water supply in dry areas.

scholarly journals Behavior of Glyphosate in Wastewater Treatment Plants

2020 ◽  
Vol 74 (3) ◽  
pp. 156-160 ◽  
Author(s):  
Thomas Poiger ◽  
Martina Keller ◽  
Ignaz J. Buerge ◽  
Marianne E. Balmer
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Surface Waters ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treated Wastewater ◽  
Excess Sludge ◽  
Strong Adsorption ◽  
Raw Wastewater ◽  
Herbicide Glyphosate

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.

Occurrence and removal of Ascaris sp. ova by waste stabilisation ponds in Kenya

1996 ◽  
Vol 33 (7) ◽  
pp. 75-82 ◽  
Author(s):  
A. M. Grimason ◽  
H. V. Smith ◽  
G. Young ◽  
W. N. Thitai
Keyword(s):  
Laboratory Experiments ◽  
Municipal Wastewater ◽  
Waste Stabilisation Ponds ◽  
Physico Chemical ◽  
Microbiological Parameters ◽  
The Republic ◽  
Wastewater Samples ◽  
Raw Wastewater ◽  
Settling Rates

A study was conducted to determine the occurrence of Ascaris sp. ova in municipal wastewater and their removal by a variety of waste stabilisation pond systems in the republic of Kenya. A total of 52 wastewater samples were examined for the presence of ova, comprising 10 raw wastewater and 42 pond effluent samples over a two month period during 1990. Ascaris sp. ova were detected in 6 out of 10 designated pond systems examined. In raw wastewater, ova concentrations ranged from 17.5 to 133.3 ova/l and in pond effluents from 0.7 to 88.9 ova/l. Although the majority of ova were removed in primary ponds that received raw wastewater, ova were detected in pond effluents with estimated hydraulic retention times far in excess of estimated settling rates for Ascaris. The occurrence of ova in pond effluent samples suggested that in these multi-pond systems, estimated cumulative retention periods of 12.4 (Eldoret), 26.2 (Dandora) and 17.8 (Nakuru) days, respectively, were required to achieve an effluent free of Ascaris sp. ova. Laboratory experiments were performed to assess physico-chemical and microbiological parameters to provide an indication of pond performance.

scholarly journals Prevalence of common enteric viruses in municipal wastewater treatment plants and their health risks arising from wastewater reuse

2021 ◽  
Author(s):  
Peng Liu ◽  
Zihan Li ◽  
Zifan Che ◽  
Hu Xinran ◽  
Ming Ying ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Health Risks ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Wastewater Reuse ◽  
Enteric Viruses ◽  
Treated Wastewater ◽  
Tertiary Treatment ◽  
Treatment Processes ◽  
Raw Wastewater

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.

STUDIES REGARDING THE PERFORMANCES OF MUNICIPAL WASTEWATER TREATMENT PROCESSES

2006 ◽  
Vol 5 (4) ◽  
pp. 685-692
Author(s):  
Elisabeta Chirila ◽  
Ionela Carazeanu Popovici ◽  
Techin Ibadula ◽  
Alice Iordache
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Municipal Wastewater Treatment ◽  
Treatment Processes
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