scholarly journals Use of faecal pollution indicators to estimate pathogen die off conditions in source separated faeces in Kathmandu Valley, Nepal

2008 ◽  
Vol 7 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Anjali Manandhar Sherpa ◽  
Denis Byamukama ◽  
Roshan R. Shrestha ◽  
Raimund Haberl ◽  
Robert L. Mach ◽  
...  

As the introduction and promotion of dehydrating toilets progresses, the safety of handling and reuse of their biosolids remains a question. A detailed study to understand the storage conditions and the fate of selected faecal indicators was conducted on four urine diverting dehydrating toilet units, using ash as a major additive, in Kathmandu Valley, Nepal. Presumptive Escherichia coli, total coliforms, enterococci and different fractions of Clostridium perfringens were investigated under field storage conditions. In addition, chemo-physical and chemical (carbon, nitrogen, phosphorous content) parameters were investigated. Observed temperature was low in all the four toilets with a median of 24.0°C, which was in the same range as the ambient temperature. pH was below the desired range of >9 and moisture level was very high (>60%). No single factor of the studied chemo-physical and chemical parameters could be found by statistical analysis to have accounted for the reduction of the indicators in any of the toilets. By time series analysis of the investigated strata in the faecal heaps (n=96), the determined reduction rate showed increasing persistence characteristics for E. coli, coliforms and enterococci with respective average log10 reduction of −0.4, −0.3 and −0.2 per month (p<0.001). No significant reduction was observed for the different fractions of C. perfringens determined for the non-pasteurised and pasteurised fraction at 60°C and 85°C. 72% of randomly selected and analysed samples (n=36) were found to contain helminthes eggs. The used 6 months storage time did not prove sufficient to reach appropriate safety levels for handling and reuse of the biosolids.

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 221
Author(s):  
Rafał Tytus Bray ◽  
Katarzyna Jankowska ◽  
Eliza Kulbat ◽  
Aneta Łuczkiewicz ◽  
Aleksandra Sokołowska

The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation).


2021 ◽  
Vol 2 (1) ◽  
pp. 23-26
Author(s):  
Herna Febrianty Sianipar ◽  
Theresia Monika Siahaan ◽  
Apriani Sijabat

This service aims to provide information about the value of good water quality and demonstrate directly the tools used to measure it which aim to cultivate Batak fish based on biological, physical and chemical parameters such as temperature, dissolved oxygen, carbon dioxide, pH, and provide information on the names of measuring devices. . This service has been carried out in Gorat Village, Toba Samosir Regency with the method of counseling and material discussion (exposure and question and answer), as well as the practice of measuring water quality externally and analyzing the results of its value. The results of the counseling show that many fish farmers do not understand the value of good water quality for batak fish cultivation and not many know the equipment that can be used to check water quality. From this counseling, it can be seen that the interest of fish farmers and the community is very high, and they become more aware of the value of good water quality for fish farming and know the equipment. Abstrak Pengabdian ini bertujuan untuk memberikan penyuluhan tentang nilai kualitas air yang baik dan mendemonstrasikan langsung alat yang digunakan mengukurnya yang bertujuan untuk membudidayakan ikan batak berdasarkan parameter biologi, fisika dan kimia seperti suhu, oksigen terlarut, karbondioksida, pH, serta memberikan informasi nama alat-alat pengukurnya. Pengabdian ini telah dilakukan di Desa Gorat, Kabupaten Toba Samosir dengan metode penyuluhan dan diskusi materi (paparan dan tanya jawab), serta praktek pengukuran kualitas air secara eksitu dan menganalisis hasil nilainya. Hasil penyuluhan menunjukan bahwa banyaknya petani ikan yang belum paham tentang nilai kualitas air yang baik untuk budidaya ikan batak serta belum banyak yang mengetahui peralatan yang dapat digunakan untuk memeriksa kualitas air. Dari penyuluhan ini terlihat animo petani ikan dan masyarakat sangat tinggi, dan mereka menjadi lebih paham tentang nilai kualitas air yang baik untuk budidaya ikan serta mengetahui peralatannya.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1200
Author(s):  
Cecilia Barba Guevara ◽  
Luis Montaluisa ◽  
María Elena Maldonado Rodriguez

Background: This research was carried out in order to study the antimicrobial effectiveness of crude latex of two varieties of "Sangre de Drago": Croton lechleri Muller Arg. and Croton urucurana Baill and compare that effectiveness to the antimicrobial activity of the alcoholic extracts of its leaves and bark.  Methods: The activity of the alcoholic extracts and latex were evaluated against bacterial strains of Staphylococcus epidermidis, Bacillus subtilis and Escherichia coli. The extraction of the alcoholic extracts (20% Tincture) of the leaves, bark and latex from the two Croton species was carried out by maceration using 70% alcohol as a menstruum, at room temperature, for 2 to 7 days, with shaking at least twice a day.  A 20% tincture was obtained, from which the physical and chemical parameters were determined as indicated by the Ecuadorian Quality Control Standard for natural medicinal products. Results: It was found that both the alcoholic extracts of the plant material and the crude latex indicate antimicrobial activity for S. epidermidis, moderate antimicrobial activity for B. subtilis and no antimicrobial activity for E. coli. The moderate antimicrobial activity against B. subtilis, at doses of 125 p.p.m., is in line with the findings of previous studies by other authors.  Conclusions: he antimicrobial activity of the latex of the two species against S. epidermidis is not registered in literature and, the negative antimicrobial activity for E. coli does not agree with what has been reported by previous studies.


2020 ◽  
Vol 32 (11) ◽  
pp. 2743-2747
Author(s):  
Thi Kim Ngan Tran ◽  
Tan Phat Dao ◽  
Thi Cam Quyen Ngo ◽  
Thien Hien Tran ◽  
Ung Thanh Dat ◽  
...  

Essential oils are known to be susceptible to changes and degradation that can lead to loss of quality and pharmacological properties. In this work, lemongrass essential oil is stored under different storage conditions under the influence of light and temperature, assessing the physical and chemical properties as well as the chemical composition of the citronella essential oil respectively. The change in the chemical composition of citronella oil is determined based on the storage time of 4 months under different conditions i.e. light (45 ºC) and in dark (4 ºC). To determine the change in the composition of the essential oil, based on the results of GC-MS analysis methods to monitor the chemical changes of the essential oil. The content of main components of citral and β-myrcene increases significantly after storage time under the influence of light and temperature. Some low content components (β-citronello, β-caryophyllen, p-cymen-8-ol, etc.) are likely to be oxidized and lost under light conditions, even in the dark. Therefore, the importance of external storage factors for the chemical and physical stability of essential oils is a matter of concern to control the quality of scientific evaluation.


2010 ◽  
Vol 79 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Eva Standarová ◽  
Lenka Vorlová ◽  
Pavlína Kordiovská ◽  
Bohumíra Janštová ◽  
Michaela Dračková ◽  
...  

The aim of this study was to evaluate the effects of temperature and storage time on the formation of biogenic amines (BAs) in the traditional Czech curd cheese (Olomoucké tvarůžky). Samples were stored for 7 weeks at 5 °C and 20 °C. BAs were studied as dansyl derivatives by the RP-HPLC method with fluorescence detection, histamine was determined using a photodiode array detector. Physical and chemical properties were analyzed as specified by the Czech National Standard, as were the sensory characteristics (colour, odour, texture and flavour). The major amines found were cadaverine (124–2413 mg kg-1) and tyramine (117–1058 mg kg-1), followed by putrescine (75–767 mg kg-1) and histamine (74–411 mg kg-1). Low concentrations of tryptamine, spermine and spermidine were present. Total concentrations of BAs significantly increased with storage time (P < 0.01), depending significantly on temperature (P < 0.01). Total BAs in cheese stored at 20 °C compared to 5 °C were more than three times higher, reaching 4600 mg kg-1 at the end of storage. The toxicologically critical value of 900 mg kg-1 for the sum of histamine + tyramine + putrescine + cadaverine was reached 17 days later in the cheese stored at 5 °C compared to 20 °C. When stored at 5 °C, the samples retained adequate sensory characteristics for the entire safe storage time. The effects of storage conditions on BAs formation are relevant to reducing the risk associated with consumption of cheese high in BAs.


Author(s):  
Mulia Winirsya Apriliyani ◽  
Abdul Manab ◽  
Premy Puspitawati Rahayu ◽  
Miftahul Jannah ◽  
Puput Nurul Hidayah ◽  
...  

Microbial contamination and fat oxidation may cause physical and chemical changes that can reduce the quality of broiler meat. The objective of this study was to determine the ability of casein chitosan edible coatings in maintaining the quality of broiler meat stored in certain storage time under refrigeration (8 oC), in terms of water activity (Aw), cooking loss, organoleptic properties (i.e. color, aroma and possible deviations), physicochemical properties (i.e. moisture content, water holding capacity/WHC, pH, lipid content, color), Total Plate Count (TPC), and microbial properties (i.e. Staphylococcus aureus, Escherichia coli, and Salmonella sp.). The materials used were broiler breast fillets and casein chitosan edible coating. The research was conducted using a Completely Randomized Design (CRD) based on 5 variations in storage time treatments i.e. at 0 h; 24 h; 72 h; 120 h; and 168 h in 4 replications. Edible coating casein chitosan on broiler meat under storage showed significant on Aw, WHC, pH, lightness, TPC, S. aureus, and E. coli. The application of casein-chitosan as an edible coating could be suitable to assure the safety of food products such as chicken meat at the range of storage time studied.


Author(s):  
M. Haider ◽  
B. Bohrmann

The technique of Z-contrast in STEM offers the possibility to determine the local concentration of macromolecules like lipids, proteins or DNA. Contrast formation depends on the atomic composition of the particular structure. In the case of DNA, its phosphorous content discriminates it from other biological macromolecules. In our studies, sections of E. coli, the dinoflagellate Amphidinium carterae and Euglena spec. cells were used which were obtained by cryofixation followed by freeze-substitution into acetone with 3% glutaraldehyde. The samples were then embedded either in Lowicryl HM20 at low temperature or in Epon at high temperature. Sections were coated on both sides with 30Å carbon.The DF- and the inelastic image have been recorded simultaneously with a Cryo-STEM. This Cryo-STEM is equipped with a highly dispersive Electron Energy Loss Spectrometer. With this instrument pure Z-contrast can be achieved either with a Filtered DF-image divided by the inelastic image or, as is used in this paper, by dividing the conventional DF-image by an inelastic image which has been recorded with an inelastic detector whose response is dependent on the total energy loss of the inelastically scattered electrons.


2018 ◽  
Vol 6 (10) ◽  
pp. 123-130
Author(s):  
Yaroslava Zhukova ◽  
◽  
Pylyp Petrov ◽  
Olena Boloba ◽  
Tetiana Ohrimenko ◽  
...  

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 520e-520
Author(s):  
Juan E Manzano ◽  
Oswaldo Valor

Mango fruits `Criollo de Bocado' harvested at the mature-green stage were treated with a hydrothermic treatment of 55 °C for 3 min and stored for 20 days at temperatures of 10 ± 2, 15 ± 2 and 28 ± 2 °C. A randomized design 2 × 3 × 4 with three replications was used. Some chemical parameters were analyzed, such as total soluble solids content (% TSS), pH, tritatable acidity, and TSS/tritatable acidity ratio. TSS content increased with storage time at low temperature. The pH increased measurably with storage temperature, while tritatable acidity values results had inconsistent data.


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