Evaluation of the WHO nematode egg guidelines for restricted and unrestricted irrigation

1996 ◽  
Vol 33 (10-11) ◽  
pp. 277-283 ◽  
Author(s):  
Ursula J. Blumenthal ◽  
D. Duncan Mara ◽  
Rachel M. Ayres ◽  
Enrique Cifuentes ◽  
Anne Peasey ◽  
...  

Epidemiological studies were conducted in Mexico to assess the health risks associated with restricted crop irrigation using raw and treated wastewaters. Experimental studies were done in northeast Brazil and Leeds, in which Ascaris lumbricoides contamination of lettuces spray-irrigated with raw wastewater and waste stabilization pond effluents containing different helminthological qualities was determined (Brazil); and Ascaridia galli infection was monitored in immunosuppressed chickens fed lettuces spray-irrigated with water containing different A. galli egg numbers (Leeds). The results indicate that the WHO guideline quality of ≤ 1 egg per litre protects crop consumers, but not necessarily fieldworkers and their families especially children. This is particularly the case when wastewater treatment systems are not stable, when recontamination of the partially treated wastewater with small quantities of raw wastewater may occur, and when wild vegetables are harvested and consumed. In such cases a stricter guideline quality of ≤ 0.5 egg per litre may be required.

1996 ◽  
Vol 33 (10-11) ◽  
pp. 401-408
Author(s):  
Naïla Ouazzani ◽  
Khadija Bousselhaj ◽  
Younes Abbas

The aim of this work was to determine the depuration efficiencies of an infiltration percolation plant to remove organic matter and nutrients (N and P) and to test the effect of treatment by such system on the fertilizer value of wastewater compared to untreated influent and a control (groundwater). Results of investigations carried out over a month of each season showed the high capacity of this depuration system to remove both particulate and dissolved organic matter (TSS 91%, COD 93% and dCOD 89 to 95%) at all season. Nitrogen and phosphorus were more eliminated at winter and summer. At spring they presented a low percent removal efficiency due probably to overloaded influent. Tests consisting in the reuse a raw wastewater (RW), settled wastewater (SW) or completely treated wastewater (FW) for irrigation of (Lolium perenne) plots showed that biomass yield, nutrients (N,P) exported by plants and protein amount in the plants tissue decreased from plots irrigated by (RW) to completely treated wastewater. But all of them were more important than in the control plants (irrigated by groundwater) and exceeded the mean values reported in literature for meadows plants. The amount of nitrogen and P2O5) applied during the irrigation by wastewater, was equivalent or superior to recommanded dose of fertilizer for meadows. The expected meat or milk production showed a promising potentiality to promove the nutritional quality of farm animals food by using treated wastewater.


Author(s):  
L.A. Fesik ◽  
◽  
N.V. Sorokina ◽  
E.А. Geraskina ◽  
T.S. Airapetian ◽  
...  

Abstract. The urgency of the problem of local biological treatment of domestic wastewater from housing in non-canalized areas with improving the quality of treated wastewater to the level of requirements for discharge into fishery bodies of water is considered. The analysis of the state of local wastewater treatment is given. Existing technological schemes and methods of local sewage, which are used for sewage treatment, are considered. The results of theoretical and experimental studies of a complex of a local anaerobic-aerobic biological treatment of domestic wastewater from housing in non-canalized areas at the low-productivity plants are presented. The results of theoretical and experimental researches of complex of local anaerobic-aerobic biological purification of domestic wastewater of habitation in non-canalized areas at the low-productivity plants are given. On the basis of the analysis of work and embodiment of low-productivity plants, used in home and foreign practice of local treatment of domestic wastewater the expediency of application flowing multistage anaerobic-aerobic biological purification of domestic wastewater with use of communities of attached and free-swimming microorganisms is shown. The proposed low-productivity plant, which includes a three-stage aerobic biological treatment of anaerobically treated wastewater is described. The use of ruff fillers for the retention of hydrobionts gives the opportunity to clear salvo discharge, rapid restoration of the activity of the ruff fillers (for example, in power outages). The ruff fillers make it possible to organize an appropriate trophic chain of hydrobionts, which dramatically reduces the amount of excess biomass and the removal of suspensions in treated wastewater. Using the experiments in laboratory conditions and at real industrial treatment plant of a new design there were received parameters of work of stages of anaerobic and aerobic biological purification, the law of nitrification and denitrification processes, the law of specific speed of oxidation of organic pollution in specific conditions of anaerobic-aerobic technology; the opportunity of reception of quality of treated wastewater at the level of the requirements of the specifications for dump of drains in fishing reservoirs is proved.


1996 ◽  
Vol 33 (10-11) ◽  
pp. 327-334 ◽  
Author(s):  
Bouchaïb El Hamouri ◽  
Abderrahim Handouf ◽  
Mohamed Mekrane ◽  
Mohamed Touzani ◽  
Addi Khana ◽  
...  

Raw (RW) and Waste Stabilization Ponds treated wastewater (TW) were used in comparison with groundwater (Control) for crop production under arid and saline conditions without any chemical fertilization. Four irrigation methods namely, surface, drip (with 2 systems “Bas Rhône” and “Rain bird”) and sprinkler irrigation were compared on each water type. The results of the 3-year-experimentation period were: a) TW applications instead of groundwater attenuated the detrimental effect of water salinity on the crop; b) Drip irrigation, “Bas Rhône” system, showed the highest irrigation performances and crop yields; c) the morphology and the way the crop was conducted were found to play an important role in determining its final bacteriological quality; d) TW irrigated crops and soils did not show any helminth eggs contaminations and e) Faecal coliforms were not isolated from the TW irrigated soil beyond the limit of 0.25 m.


2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.


Author(s):  
T. N. Antipova ◽  
D. S. Shiroyan

The system of indicators of quality of carbon-carbon composite material and technological operations of its production is proved in the work. As a result of the experimental studies, with respect to the existing laboratory equipment, the optimal number of cycles of saturation of the reinforcing frame with a carbon matrix is determined. It was found that to obtain a carbon-carbon composite material with a low cost and the required quality indicators, it is necessary to introduce additional parameters of the pitch melt at the impregnation stage.


1995 ◽  
Vol 31 (12) ◽  
pp. 91-101 ◽  
Author(s):  
Y. Racault ◽  
C. Boutin ◽  
A. Seguin

In 1992, a survey was conducted on the performance of waste stabilization ponds in France. The data selected come from a sample of 178 ponds, with an average capacity of 600 p.e., throughout France. For each plant, one or several input--output load measurements over a 24-h period are available. The average organic load level received is approximately 25 kg BOD/ha.d, representing 50% of the nominal load. The quality of the treated water is presented based on the type of sewerage system feeding the ponds. The results appear dispersed, however; in 70% of the cases the concentrations in COD and BOD on filtered samples are under 120 mg/l and 40 mg/l, respectively, and the concentration in TSS under 120 mg/l (discharge standards in France for waste stabilization ponds). The reductions in nitrogen and phosphorus nutrients are on average from 60% to 70%. The influence of different parameters (sewerage system type, organic load, season, age of plant, etc.) was studied. The results appear noticeably worse when the ponds receive wastewater from a strictly separate sewerage system.


2018 ◽  
Vol 24 (3) ◽  
pp. 341-358 ◽  
Author(s):  
Xiaotong Ji ◽  
Yingying Zhang ◽  
Guangke Li ◽  
Nan Sang

Recently, numerous studies have found that particulate matter (PM) exposure is correlated with increased hospitalization and mortality from heart failure (HF). In addition to problems with circulation, HF patients often display high expression of cytokines in the failing heart. Thus, as a recurring heart problem, HF is thought to be a disorder characterized in part by the inflammatory response. In this review, we intend to discuss the relationship between PM exposure and HF that is based on inflammatory mechanism and to provide a comprehensive, updated evaluation of the related studies. Epidemiological studies on PM-induced heart diseases are focused on high concentrations of PM, high pollutant load exposure in winter, or susceptible groups with heart diseases, etc. Furthermore, it appears that the relationship between fine or ultrafine PM and HF is stronger than that between HF and coarse PM. However, fewer studies paid attention to PM components. As for experimental studies, it is worth noting that coarse PM may indirectly promote the inflammatory response in the heart through systematic circulation of cytokines produced primarily in the lungs, while ultrafine PM and its components can enter circulation and further induce inflammation directly in the heart. In terms of PM exposure and enhanced inflammation during the pathogenesis of HF, this article reviews the following mechanisms: hemodynamics, oxidative stress, Toll-like receptors (TLRs) and epigenetic regulation. However, many problems are still unsolved, and future work will be needed to clarify the complex biologic mechanisms and to identify the specific components of PM responsible for adverse effects on heart health.


Author(s):  
Judit Biosca-Brull ◽  
Cristian Pérez-Fernández ◽  
Santiago Mora ◽  
Beatriz Carrillo ◽  
Helena Pinos ◽  
...  

Autism spectrum disorder (ASD) is a complex set of neurodevelopmental pathologies characterized by impoverished social and communicative abilities and stereotyped behaviors. Although its genetic basis is unquestionable, the involvement of environmental factors such as exposure to pesticides has also been proposed. Despite the systematic analyses of this relationship in humans, there are no specific reviews including both human and preclinical models. The present systematic review summarizes, analyzes, and discusses recent advances in preclinical and epidemiological studies. We included 45 human and 16 preclinical studies. These studies focused on Organophosphates (OP), Organochlorine (OC), Pyrethroid (PT), Neonicotinoid (NN), Carbamate (CM), and mixed exposures. Preclinical studies, where the OP Chlorpyrifos (CPF) compound is the one most studied, pointed to an association between gestational exposure and increased ASD-like behaviors, although the data are inconclusive with regard to other ages or pesticides. Studies in humans focused on prenatal exposure to OP and OC agents, and report cognitive and behavioral alterations related to ASD symptomatology. The results of both suggest that gestational exposure to certain OP agents could be linked to the clinical signs of ASD. Future experimental studies should focus on extending the analysis of ASD-like behaviors in preclinical models and include exposure patterns similar to those observed in human studies.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Fabrizio Luppi ◽  
Meena Kalluri ◽  
Paola Faverio ◽  
Michael Kreuter ◽  
Giovanni Ferrara

AbstractIdiopathic pulmonary fibrosis (IPF) is a chronic and progressive disorder with an estimated median survival time of 3–5 years after diagnosis. This condition occurs primarily in elderly subjects, and epidemiological studies suggest that the main risk factors, ageing and exposure to cigarette smoke, are associated with both pulmonary and extrapulmonary comorbidities (defined as the occurrence of two or more disorders in a single individual). Ageing and senescence, through interactions with environmental factors, may contribute to the pathogenesis of IPF by various mechanisms, causing lung epithelium damage and increasing the resistance of myofibroblasts to apoptosis, eventually resulting in extracellular matrix accumulation and pulmonary fibrosis. As a paradigm, syndromes featuring short telomeres represent archetypal premature ageing syndromes and are often associated with pulmonary fibrosis. The pathophysiological features induced by ageing and senescence in patients with IPF may translate to pulmonary and extrapulmonary features, including emphysema, pulmonary hypertension, lung cancer, coronary artery disease, gastro-oesophageal reflux, diabetes mellitus and many other chronic diseases, which may lead to substantial negative consequences in terms of various outcome parameters in IPF. Therefore, the careful diagnosis and treatment of comorbidities may represent an outstanding chance to improve quality of life and survival, and it is necessary to contemplate all possible management options for IPF, including early identification and treatment of comorbidities.


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