scholarly journals Disappearance of Residual Chlorine and Formation of Chloroform in Vegetables Treated with Sodium Hypochlorite

1992 ◽  
Vol 33 (3) ◽  
pp. 267-273_1 ◽  
Author(s):  
Toshio HIDAKA ◽  
Tadashi KIRIGAYA ◽  
Masaya KAMIJO ◽  
Hiroshi KIKAWA ◽  
Taro KAWAMURA ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Residual Chlorine

scholarly journals Study of the performance of disinfection with sodium hypochlorite on a full-scale sewage treatment plant

2020 ◽  
Vol 15 (6) ◽  
pp. 1
Author(s):  
Maria Rosaria Boni ◽  
Sabrina Copelli ◽  
Massimo Raboni
Keyword(s):  
Sodium Hypochlorite ◽  
Retention Time ◽  
Contact Time ◽  
Regression Line ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Process Efficiency ◽  
Residual Chlorine

A full-scale sewage treatment plant was investigated to assess the performance of the disinfection stage. Sodium hypochlorite was used as a disinfectant agent and the process efficiency was evaluated by E.coli removal. The research took place over a period of two years in order to evaluate the effect of retention time (t) and residual chlorine (Cr) under different seasonal conditions. The effectiveness of E.coli removal with sodium hypochlorite proved to be strictly dependent on the factor CR  t (product of residual chlorine with the contact time). The regression line of the experimental points was, on the whole, well comparable with the model proposed by Collins, especially in the field of CRt lower than 30 mg L-1 min.

scholarly journals Potential Use of Water Guard as a Disinfectant for Domestic Water Use

2008 ◽  
Vol 31 (2) ◽  
pp. 62-69
Author(s):  
L. Yohana ◽  
D.A. Mashauri
Keyword(s):  
Drinking Water ◽  
Sodium Hypochlorite ◽  
Dar Es Salaam ◽  
Residual Chlorine ◽  
Urban Water ◽  
Treatment Results ◽  
Domestic Water ◽  
Disinfectant Solution ◽  
Different Sources ◽  
Potential Use

Water Guard which consists of 0.75% sodium hypochlorite (chlorine-based water disinfectant solution) has been identified as an alternative method for treatment of domestic drinking water. The aim of this study was to investigate the effectiveness of Water Guard in disinfecting drinking water from different sources drawn from Kinondoni district, Dar es Salaam as well as to establish appropriate dosage that can be used during the treatment. Results showed that, a dose of 4.0mL per 20 litrer of water guard is sufficient for disinfectionof urban water sources. The above prescribed doses provide 100% disinfection efficiency with residue chlorine of less than 0.3mg/l. Water with turbidity values of 30-35 NTU, chlorine dosage of 8mL/20 litres is recommended and this gives residue chlorine of 0.3 – 0.5 mg/L. From this study, it can be concluded that, Water guard is effective against pathogen and that there is an increase of residue chlorine as the dosage increases irrespective of from which source the water was drawn. Also the safety of water is obtained even where the residual chlorine is less that 0.1mg/l. However, there are health implications associated with theuse of Water Guard which need further research

Sporicidal Action of Hypochlorite on Conidia of Aspergillus parasiticus

1980 ◽  
Vol 43 (10) ◽  
pp. 784-788 ◽  
Author(s):  
STEPHEN D. VER KUILEN ◽  
E. B. MARTH
Keyword(s):  
Sodium Hypochlorite ◽  
Phosphate Buffer ◽  
Aspergillus Parasiticus ◽  
Residual Chlorine ◽  
Buffer Solutions ◽  
Ph Values ◽  
Free Residual Chlorine

The sporicidal action of sodium hypochlorite was determined using conidiospores of Aspergillus parasiticus NRRL 2999 and NRRL 3315. Conidia were harvested after the mold grew 10 days on Moyer's or mycological agar. The conidia were suspended in phosphate buffer solutions at pH 5, 6, 7 and 8, and heated to 30 or 40 C. Initial trials were made with 3 ppm of free residual chlorine. Other experiments were done with 50 ppm of chlorine added to solutions containing 0.10 or 0.25% tryptone or 1% sucrose or glucose. Surviving conidia were enumerated with mycological agar. When tryptone was absent, chlorine at 3 ppm was more lethal to conidia than was 50 ppm when tryptone was present. Generally, survival of conidia was substantially greater at pH 8 and 30 C than at pH 5, 6 and 7 where survival was similar. When tryptone was present, substantial numbers of conidia survived at pH 7 and 8. Chlorine was markedly more lethal at 40 than 30 C at all pH values. No conidia survived in the presence of 1% sucrose and 50 ppm of chlorine.

The effect of bisphenol A and chlorinated derivatives of bisphenol A on the level of serum vitellogenin in Japanese medaka (Oryzias latipes)

2004 ◽  
Vol 50 (5) ◽  
pp. 125-132 ◽  
Author(s):  
A. Tabata ◽  
N. Watanabe ◽  
I. Yamamoto ◽  
Y. Ohnishi ◽  
M. Itoh ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Sodium Hypochlorite ◽  
Estrogenic Activity ◽  
Water Environment ◽  
Aquatic Organisms ◽  
Mature Male ◽  
Japanese Medaka ◽  
Residual Chlorine ◽  
Effect Concentration ◽  
Derivatives Of

2,2-bis (4-hydroxyphenyl) propane or Bisphenol A (BPA), has been reported to behave as an endocrine disrupter below acute toxic levels, and is widely present in the water environment. Although BPA is easily chlorinated, very little is reported on the effect of chlorinated BPA to the aquatic organisms. In this study, the estrogenic activities of BPA and its chlorinated derivatives were evaluated by the induction of vitellogenin (VTG) in the serum of mature male Japanese medaka. In addition, the effect of sodium hypochlorite on the decomposition of BPA was tested. The relative potencies of estrogenic activities of chlorinated BPA descended in the order 3,3′-diClBPA>BPA≥3-ClBPA>3,3′,5-triClBPA, and no estrogenic activity was observed in 3,3′,5,5′-tetraClBPA. Lowest Observed Effect Concentration (LOEC) and No Observed Effect Concentration (NOEC) for both 3-ClBPA and 3,3′-diClBPA were 500 μg/L and 200 μg/L, respectively. LOEC for 3,3′,5-triClBPA was >500 μg/L. When BPA was reacted with sodium hypochlorite (24 hours; residual chlorine at 1 ppm), however, complete decomposition of BPA and its chlorinated derivatives was observed. The decrease in BPA and its chlorinated derivatives paralleled the decrease in estrogenic potency evaluated by the induction of vitellogenin (VTG) in the serum of mature male Japanese medaka.

Performance of chlorination process during nanofiltration of sulfonamide antibiotic

2015 ◽  
Vol 72 (9) ◽  
pp. 1611-1620 ◽  
Author(s):  
Mohd Redzuan Ramli ◽  
Nik Meriam Nik Sulaiman ◽  
Mustafa Ali Mohd ◽  
Mohamad Fairus Rabuni
Keyword(s):  
Removal Efficiency ◽  
Sodium Hypochlorite ◽  
Laboratory Scale ◽  
Active Chlorine ◽  
Residual Chlorine ◽  
Feed System ◽  
Chlorination Process

The effectiveness of combined nanofiltration and disinfection processes was studied by comparing the pre-disinfection and post-disinfection when in combination with nanofiltration. Four types of sulfonamide (sulfanilamide, sulfadiazine, sulfamethoxazole, and sulfadimethoxine) were chosen as substrates, with sodium hypochlorite as a disinfectant. A laboratory-scale nanofiltration system was used to conduct the following sets of experiment: (1) a pre-chlorination system, where the free active chlorine (FAC) was added to the membrane influent; and (2), a post-chlorination system, where the FAC was added to the membrane effluent. Overall, the pre-disinfection nanofiltration system showed higher sulfonamide removal efficiency compared to the post-chlorination nanofiltration system (>99.5% versus >89.5%). In the case of limited FAC ([FAC]0: [sulfonamide]0 ≤ 1), the removal efficiency for the post-chlorination nanofiltration system was higher, due to the prior nanofiltration process that could remove 12.5% to 80% of sulfonamide. The flux of the treated feed system was considerably higher than in the untreated feed system; however, the membrane was observed to be slightly damaged due to residual chlorine attack.

scholarly journals Application of sodium hypochlorite (NaOCl) for ammonia removal in wastewater effluent of PT. HS

2020 ◽  
Vol 5 (2) ◽  
pp. 156
Author(s):  
Hiqmatus Sholichah
Keyword(s):  
Sodium Hypochlorite ◽  
Ammonia Concentration ◽  
Ammonia Removal ◽  
Wastewater Effluent ◽  
Primary Data ◽  
Optimum Dose ◽  
Residual Chlorine ◽  
Chlorination Process ◽  
Industrial Estate ◽  
Standard Limit

<table width="508" border="1" cellspacing="0" cellpadding="0"><tbody><tr><td valign="top" width="380"><p><strong>Abstract.</strong> PT HS is a world’s leading toy manufacturing company with more than 6,000 workers. Due to the high number of workers in PT. HS, it will impact to domestic activities (toilet discharge). Based on the annual report for wastewater effluent, noted that parameter ammonia from PT HS’s wastewater effluent was exceeding the industrial estate limit which the average of ammonia concentration is 50 mg/L. Whereas, In the industrial estate regulation contain of several standard parameters that must be comply by the company such as ammonia standard which has maximum 10 mg/L for the wastewater effluent. <strong>Objectives:</strong> The objectives of this experiment are to know the optimum dose of NaOCl 9% on ammonia removal and to know the concentration of residual chlorine after the treatment process. <strong>Method and results</strong>: This research use the experimental method to get the primary data. After the experiment in the laboratory, the results proved that the sodium hypochlorite exposure reduces ammonia concentration in water samples with 82,2% removal efficiency from 50 mg/L to 8,9 mg/L ammonia concentration reduced with 110 mg/L of NaOCl 9% solution within 30 minutes contact time and it resulted the residual chlorine 0.72 mg/L. <strong>Conclusion:</strong> The chlorination process was effective to reduce the ammonia concentration. Also, the residual chlorine was still in the standard limit which not exceeds from 1 mg/L. The result also shows that the dose variations of sodium hypochlorite influence ammonia removal efficiencies. Also, mostly the total residual chlorine forecast will increase with the increasing sodium chlorine dose.</p></td></tr></tbody></table>

scholarly journals Effect of sodium hypochlorite on typical biofilms formed in drinking water distribution systems

2017 ◽  
Vol 15 (2) ◽  
pp. 218-227 ◽  
Author(s):  
Huirong Lin ◽  
Xuan Zhu ◽  
Yuxin Wang ◽  
Xin Yu
Keyword(s):  
Drinking Water ◽  
Sodium Hypochlorite ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Drinking Water Treatment ◽  
Cellular Damage ◽  
Residual Chlorine ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Human health and biological safety problems resulting from urban drinking water pipe network biofilms pollution have attracted wide concern. Despite the inclusion of residual chlorine in drinking water distribution systems supplies, the bacterium is a recalcitrant human pathogen capable of forming biofilms on pipe walls and causing health risks. Typical drinking water bacterial biofilms and their response to different concentrations of chlorination was monitored. The results showed that the four bacteria all formed single biofilms susceptible to sodium hypochlorite. After 30 min disinfection, biomass and cultivability decreased with increasing concentration of disinfectant but then increased in high disinfectant doses. PMA-qPCR results indicated that it resulted in little cellular damage. Flow cytometry analysis showed that with increasing doses of disinfectant, the numbers of clusters increased and the sizes of clusters decreased. Under high disinfectant treatment, EPS was depleted by disinfectant and about 0.5–1 mg/L of residual chlorine seemed to be appropriate for drinking water treatment. This research provides an insight into the EPS protection to biofilms. Resistance of biofilms against high levels of chlorine has implications for the delivery of drinking water.

Comparison of Acrylamide and Agar Gels by Freeze-Etching

1977 ◽  
Vol 35 ◽  
pp. 606-607
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Electron Microscope ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Chromic Acid ◽  
Distilled Water ◽  
Thin Sheets ◽  
Acid Cleaning ◽  
Agar Gels ◽  
Freeze Etching ◽  
Water Cut

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.

Freeze-Etch Crystal-Like Structures in Membranous Glomerulosclerosis

1969 ◽  
Vol 27 ◽  
pp. 394-395
Author(s):  
Burton B. Silver
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Sodium Hypochlorite ◽  
Kidney Tissue ◽  
Extraction Process ◽  
Donor Kidney ◽  
Unknown Substance ◽  
Etched Surface ◽  
Standard Fixation ◽  
Diseased Kidney

Tissue from a non-functional kidney affected with chronic membranous glomerulosclerosis was removed at time of trnasplantation. Recipient kidney tissue and donor kidney tissue were simultaneously fixed for electron microscopy. Primary fixation was in phosphate buffered gluteraldehyde followed by infiltration in 20 and then 40% glycerol. The tissues were frozen in liquid Freon and finally in liquid nitrogen. Fracturing and replication of the etched surface was carried out in a Denton freeze-etch device. The etched surface was coated with platinum followed by carbon. These replicas were cleaned in a 50% solution of sodium hypochlorite and mounted on 400 mesh copper grids. They were examined in an Siemens Elmiskop IA. The pictures suggested that the diseased kidney had heavy deposits of an unknown substance which might account for its inoperative state at the time of surgery. Such deposits were not as apparent in light microscopy or in the standard fixation methods used for EM. This might have been due to some extraction process which removed such granular material in the dehydration steps.

Isolation of Asbestos from Lung Tissue and Sputum

1982 ◽  
Vol 40 ◽  
pp. 330-331
Author(s):  
M. G. Williams ◽  
C. Corn ◽  
R. F. Dodson ◽  
G. A. Hurst
Keyword(s):  
Sodium Hypochlorite ◽  
Lung Tissue ◽  
Body Fluids ◽  
Unknown Etiology ◽  
The Past

During this century, interest in the particulate content of the organs and body fluids of those individuals affected by pneumoconiosis, cancer, or other diseases of unknown etiology developed and concern was further prompted with the increasing realization that various foreign particles were associated with or caused disease. Concurrently particularly in the past two decades, a number of methods were devised for isolating particulates from tissue. These methods were recently reviewed by Vallyathan et al. who concluded sodium hypochlorite digestion was both simple and superior to other digestion procedures.

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