1.An investigation of the chemical and physical aspects of water pollution at 6 provincial general hospitals caused by medical wastes
Journal of Medical Research 2003;24(4):75-81
Waste waters were collected from 6 provincial hospitals (Yen Bai, Viet Tri, Quang Nam, Quang Ngai, Can Tho, Dong Thap) and resident areas near by them. Basic chemical and physical enviromental parameters were analysed. Findings were as follows: In the hospitals without waste water treatment system: water was polluted severely, even in surrounding residential areas. In the hospital with waste water treatment system: after treatment, the water met B limit value, both for basic physical and chemical parameter. 58% of samples of living water collected at the hospitals without treatment does not met the hygiene standard. Further researches will have to be done to conclude firmly. 25.3% of samples of living water collected at the hospital sites having treatment system also do not meet the hygien standard.
Water Pollution
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Water
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Medical Waste
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Hospitals
2.Advances in denitrification microorganisms and processes.
Xiaoqian NIU ; Shenghu ZHOU ; Yu DENG
Chinese Journal of Biotechnology 2021;37(10):3505-3519
Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to the advantages such as cost-effectiveness, process simplicity, and absence of secondary pollution. This review summarized the advances on biological denitrification processes in recent years according to the different physiological characteristics and denitrification mechanisms of denitrification microorganisms. The pros and cons of different biological denitrification processes developed based on nitrifying bacteria, denitrifying bacteria, and anaerobic ammonia-oxidizing bacteria were compared with the aim to identify the best strategy for denitrification in a complex wastewater environment. The rapid development of synthetic biology provides possibilities to develop highly-efficient denitrifying strains based on mechanistic understandings. Combined with the applications of automatic simulation to obtain the optimal denitrification conditions, cost-effective and highly-efficient denitrification processed can be envisioned in the foreseeable future.
Aerobiosis
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Denitrification
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Nitrification
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Nitrogen
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Waste Water
3.Aeromonas immobilized on chitosan for treating high-oil wastewater from kitchens.
Jin QU ; Yinyan CHEN ; Ruojin ZHAO ; Yiyi LI ; Peng JIN ; Zhanwang ZHENG
Chinese Journal of Biotechnology 2021;37(2):615-624
To effectively solve the serious impact of high oil in the kitchen wastewater on the downstream treatment process, an excellent oil-degrading strain Aeromonas allosaccarophila CY-01 was immobilized to prepare Chitosan-Aeromonas pellets (CH-CY01) by using chitosan as a carrier. Oil degradation condition and efficiency of CH-CY01 pellets were assessed. The growth of immobilized CH-CY01 was almost unaffected, and the maximum degradation rate of soybean oil was 89.7%. Especially at 0.5% NaCl concentration, oil degradation efficiency of CH-CY01 was increased by 20% compared with free cells. In the presence of a surfactant (sodium dodecylbenzene sulfonate) at 1 mg/L, the degradation efficiency of oil by CH-CY01 was increased by 40%. Moreover, using the high-oil catering wastewater as the substrate, more than 80% of the solid oil was degraded with 1% (V/V) CH-CY01 pellets treatment for 7 days, significantly higher than that of free cells. In summary, immobilized CH-CY01 significantly improved the efficiency of oil degradation.
Aeromonas
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Chitosan
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Surface-Active Agents
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Waste Water
4.Nanowastes treatment in environmental media.
Environmental Health and Toxicology 2014;29(1):e2014015-
OBJECTIVES: This paper tried to review a recent research trend for the environmental exposure of engineered nanomaterials (ENMs) and its removal efficiency in the nanowaste treatment plants. METHODS: The studies on the predicted environmental concentrations (PEC) of ENMs obtained by exposure modeling and treatment (or removal) efficiency in nanowaste treatment facilities, such as wastewater treatment plant (WTP) and waste incineration plant (WIP) were investigated. The studies on the landfill of nanowastes also were investigated. RESULTS: The Swiss Federal Laboratories for Materials Science and Technology group has led the way in developing methods for estimating ENM production and emissions. The PEC values are available for surface water, wastewater treatment plant effluents, biosolids, sediments, soils, and air. Based on the PEC modeling, the major routes for the environmental exposure of the ENMs were found as WTP effluents/sludge. The ENMs entered in the WTP were 90-99% removed and accumulated in the activated sludge and sludge cake. Additionally, the waste ash released from the WIP contain ENMs. Ultimately, landfills are the likely final destination of the disposed sludge or discarded ENMs products. CONCLUSIONS: Although the removal efficiency of the ENMs using nanowaste treatment facilities is acceptable, the ENMs were accumulated on the sludge and then finally moved to the landfill. Therefore, the monitoring for the ENMs in the environment where the WTP effluent is discharged or biomass disposed is required to increase our knowledge on the fate and transport of the ENMs and to prevent the unintentional exposure (release) in the environment.
Biomass
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Environmental Exposure
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Incineration
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Nanostructures
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Plants
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Sewage
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Soil
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Waste Disposal Facilities
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Waste Water
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Water pollution
5.Zoosporic Fungi Isolated From Four Egyptian Lakes and the Uptake of Radioactive Waste.
Yehia A G MAHMOUD ; Alaa M ABOU ZEID
Mycobiology 2002;30(2):76-81
Aquatic fungi from four brackish water lakes; Edku, Burullus and Manzala lakes which are located at the northern region of Egypt and Qarun lake that located in El-Fayoum city are reported in this manuscript. Twenty-nine fungal species which belong to 19 genera of aquatic fungi were recovered from water samples collected from the studied lakes. The most frequently isolated fungal species were Chytridium conferrop, Allomyces throughout and Rhizoclosmatium globosum. Thraustochytrium amoeboidum and Leptolegniella exoosporus have a moderately occurrence frequency. The maximum fungal count of recovered aquatic fungi was recorded in Burrullus lake followed by EdKu, Manzala and Qarun lakes. This study was extended to test the ability of six selected aquatic fungi (Brevilegniella keratinophila, Blastocladiella cystogena, Chytridium conferrop, Entophlyctis variabilis, Schizochytrium mangrovei and Thraustochytrium rosii), to uptake the radionuclide from their culture medium as a step to biologically treat the waste water or solution with radio-cesium and radio-cobalt. Fifty seven % of Cs-137 and 35% of Co-60 could be removed from liquid waste by the selected aquatic fungi.
Allomyces
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Blastocladiella
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Colony Count, Microbial
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Egypt
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Fungi*
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Lakes*
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Radioactive Waste*
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Waste Water
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Water
6.Inactivation and regrowth of antibiotic-resistant bacteria by PAA disinfection in the secondary effluent of a municipal wastewater treatment plant.
Jing Jing HUANG ; Jing Ying XI ; Hong Ying HU ; Fang TANG ; Yu Chen PANG
Biomedical and Environmental Sciences 2013;26(10):865-868
Inactivation and microbial regrowth of penicillin-, ampicillin-, cefalexin-, tetracycline-, chloramphenicol-, and rifampicin-resistant bacteria were studied to explore risks associated with selection and regrowth of antibiotic-resistant bacteria after PAA disinfection. The results showed that after exposure to 20 mg/L PAA for 10 min, inactivation of ampicillin-resistant bacteria reached 2.3-log, which was significantly higher than that of total heterotrophic bacteria with a decrease of 2.0-log. In contrast, inactivation of tetracycline- resistant bacteria was significantly less efficient, reaching only 1.1-log. Chloramphenicol-and tetracycline-resistant bacteria, as well as total heterotrophic bacteria regrew more than 10 fold compared to those in the untreated wastewater sample with 22 h stilling culture after exposure to 2 or 5 mg/L PAA as for 10 min. Selection and potential regrowth of tetracycline-and chloramphenicol-resistant bacteria are potential risks when utilizing PAA disinfection, which may induce the spread of specific antibiotic-resistant bacteria in reclaimed water.
Anti-Bacterial Agents
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pharmacology
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Bacteria
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drug effects
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Disinfection
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Waste Disposal, Fluid
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Waste Water
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Water Microbiology
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Water Purification
7.Optimization of Inpatient Management of Radioiodine Treatment in Korea.
Min Jae PARK ; Jung Hyun KIM ; Jung Chan JANG ; Chang Ho KIM ; Jae Min JEONG ; Dong Soo LEE
Nuclear Medicine and Molecular Imaging 2008;42(4):261-266
We established a model to calculate radioactive waste from sewage disposal tank of hospitals to optimize the number of patients receiving inpatient radioiodine therapy within the safety guideline in our country. According to this model and calculation of radioactivity concentration using the number of patients per week, the treatment dose of radioiodine, the capacity and the number of sewage tanks and the daily amount of water waste per patient, estimated concentration of radioactivity in sewage waste upon disposal from disposal tanks after longterm retention were within the safety guideline (30 Bq/L) in all the hospitals examined. In addition to the fact that we could increase the number of patients in two thirds of hospitals, we found that the daily amount of waste water was the most important variable to allow the increase of the number of patients within the safety margin of disposed radioactivity. We propose that saving the water amount be led to increase the number of patients and they allow two patients in an already furnished hospital inpatient room to meet the increasing need of inpatient radioiodine treatment for thyroid cancer.
Humans
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Inpatients
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Korea
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Radioactive Waste
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Radioactivity
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Retention (Psychology)
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Sewage
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Thyroid Gland
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Waste Water
9.Physicochemical and ecological characteristics of the granular sludge during start-up of Anammox reactor.
Yuxia SONG ; Lei XIONG ; Liyuan CHAI ; Qi LIAO ; Chongjian TANG ; Xiaobo MIN ; Zhihui YANG
Chinese Journal of Biotechnology 2014;30(12):1854-1864
The anaerobic granular sludge from an Internal Circulation (IC) reactor of a paper mill wastewater treatment plant were seeded in an Anammox upflow anaerobic sludge blanket reactor. After 185 days operation, the reactor was finally started up by increasing the influent ammonium and nitrite concentrations to 224 mg/L and 255 mg/L, respectively, with volumetric nitrogen removal rate increasing to 3.76 kg/(m3·d). The physicochemical characteristics of the cultivated Anammox granules were observed by scanning electron microscope, transmission electron microscope and Fourier Transform infrared spectroscopy (FTIR). Results suggested that during the start-up course, the granular sludge initially disintegrated and then re-aggregated. FTIR spectra results revealed that the Anammox granular sludge contained abundant functional groups, indicating that it may also possess good adsorption properties. The ecological structure of the granular sludge, analyzed by the metagenomic sequencing methods, suggested that the relative abundance of the dominant bacterial community in the seeding sludge, i.e., Proteobacteria, Firmicutes, Bacteroidetes, significantly reduced, while Planctomycetes which contains anaerobic ammonium oxidation bacteria remarkably increased from 1.59% to 23.24% in the Anammox granules.
Ammonia
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chemistry
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Bacteria
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Bioreactors
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Nitrogen
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chemistry
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Sewage
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microbiology
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Waste Disposal, Fluid
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methods
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Waste Water
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chemistry
10.Distribution and influence factors of Anammox bacteria in sewage treatment systems.
Bingyu ZHENG ; Yongzhen PENG ; Liang ZHANG ; Anming YANG ; Shujun ZHANG
Chinese Journal of Biotechnology 2014;30(12):1817-1827
Nitrogen removal techniques based on Anammox process are developing rapidly these years. The distribution and diversity of Anammox have become important research directions. A variety of Anammox have been detected till now, of which only Kuenenia and Brocadia are often detected in wastewater treatment systems. In addition, in a single niche there is only one type of Anammox bacteria. However, the distribution mechanism and transformation of Anammox bacteria in different niches are still ambiguous. Therefore, the distribution of Anammox in various conditions was summarized and analyzed in this article. And the key factors influencing the distribution of Anammox were concluded, including substrate concentration and the specific growth rate, sludge properties and microbial niche, the joint action and influence of multiple factors. The engineering significance research on the distribution and influencing factors of Anammox bacteria in the sewage system and proposed research prospects were expounded.
Ammonia
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chemistry
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Anaerobiosis
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Bacteria
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Nitrogen
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chemistry
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RNA, Ribosomal, 16S
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Sewage
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microbiology
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Waste Disposal, Fluid
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Waste Water