OBJECTIVETo investigate the reduction of chlorination by-products (CBPs) precursors using the fluidized-bed biofilm reactor (FBBR).

METHODSReduction of total organic carbon (TOC), ultraviolet absorbance (UV254), trihalomethane (THM) formation potential (THMFP), haloacetic acid (HAA) formation potential (HAAFP), and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3 degrees C, however, it could quickly rise to over 50% above 3degrees C. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.

Biofilms ; Chlorine ; Water Purification

Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth's surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save.
Filtration ; Fresh Water ; analysis ; Water Purification ; instrumentation ; methods ; Water Supply

PURPOSE: The purpose of this study was to develop nursing practice guidelines for water treatment system used in hemodialysis and to evaluate the guidelines by applying them in practice. METHOD: The first draft for the guidelines was developed based on advice and recommendations obtained from procedure review of critical literature. The draft was modified through evaluation by an expert group and pilot application to practice. The final draft was evaluated by the expert group using the AGREE instrument (Appraisal of Guidelines for Research and Evaluation). RESULTS: For the pilot test using the draft guidelines, 144 samples were collected from the water treatment system and hemodialysis machines. Results showed no bacteria. Endotoxin tests and chemical tests passed the criteria. After revision of the draft guidelines and additions to the draft guidelines, the final draft was confirmed. The quality of the final draft was evaluated by 4 experts using the AGREE instrument. The mean standard score was 76.9% for the 19 items. CONCLUSION: The clinical guidelines developed in this research can be utilized as systematic and scientific guidelines for water treatment systems used in hemodialysis. In addition, the results of the research can contribute to improving care services.
Bacteria ; Hemodiafiltration ; Renal Dialysis ; Water ; Water Purification ; Water Supply

For drinking water security the German waterworks proceed on a comprehensive concept, i.e., the protection of all the regions from the recharge area to the client. It includes the protection of the recharge area by a precautionary management, a safe water treatment, a strict maintenance of the water distribution network, continuous control and an intensive training of staff. Groundwater protection zones together with effective regulations and control play a very important role. Three protection zones with different restrictions in land-use are distinguished. Water in reservoirs and lakes is also protected by Surface Water Protection Zones. Within the surrounding area the land-use is controlled, too. Special treatment is necessary if acidification happens caused by acid rain, or eutrophication caused by the inflow of sewage. Very important is the collaboration between waterworks and the farmers cultivating land in the recharge area in order to execute water-protecting ecological farming with the aim to reduce the application of fertilizers and plant protection agents. Probable financial losses have to be compensated by the waterworks.
Ecology ; Germany ; Water Pollutants ; isolation & purification ; Water Pollution ; prevention & control ; Water Purification ; methods ; Water Supply ; analysis

The present drinking water purification system in Egypt uses surface water as a raw water supply without a preliminary filtration process. On the other hand, chlorine gas is added as a disinfectant agent in two steps, pre- and post-chlorination. Due to these reasons most of water treatment plants suffer low filtering effectiveness and produce the trihalomethane (THM) species as a chlorination by-product. The Ismailia Canal represents the most distal downstream of the main Nile River. Thus its water contains all the proceeded pollutants discharged into the Nile. In addition, the downstream reaches of the canal act as an agricultural drain during the closing period of the High Dam gates in January and February every year. Moreover, the wide industrial zone along the upstream course of the canal enriches the canal water with high concentrations of heavy metals. The obtained results indicate that the canal gains up to 24.06x10(6) m3 of water from the surrounding shallow aquifer during the closing period of the High Dam gates, while during the rest of the year, the canal acts as an influent stream losing about 99.6x10(6) m3 of its water budget. The reduction of total organic carbon (TOC) and suspended particulate matters (SPMs) should be one of the central goals of any treatment plan to avoid the disinfectants by-products. The combination of sedimentation basins, gravel pre-filtration and slow sand filtration, and underground passage with microbiological oxidation-reduction and adsorption criteria showed good removal of parasites and bacteria and complete elimination of TOC, SPM and heavy metals. Moreover, it reduces the use of disinfectants chemicals and lowers the treatment costs. However, this purification system under the arid climate prevailing in Egypt should be tested and modified prior to application.
Egypt ; Industry ; Seasons ; Water Microbiology ; Water Movements ; Water Pollutants ; Water Purification ; methods ; Water Supply ; analysis

The performance of the Dongying multi-stage ponds-wetlands ecosystem was investigated in this work. Study of the removal of different pollutants (BOD(5), COD, SS, TP, TN, NH(3)-N, etc.) in different temperature seasons and different units in this system indicated that effluent BOD(5) and SS were constant to less than 11 mg/L and 14 mg/L throughout the experimental processes; but that the removal efficiencies of pollutants such as TP, TN, NH(3)-N, COD varied greatly with season. The higher the temperature was, the higher was the observed removal in this system. Additionally, each unit of the system functioned differently in removing pollutants. BOD(5) and SS were mainly removed in the first three units (hybrid facultative ponds, aeration ponds and aerated fish ponds), whereas nitrogen and phosphates were mainly removed in hydrophyte ponds and constructed reed wetlands. The multi-stage ponds-wetlands ecosystem exhibits good potential of removing different pollutants, and the effluent quality meet several standards for wastewater reuse.
Ecosystem ; Fresh Water ; chemistry ; Nitrogen ; isolation & purification ; Phosphates ; isolation & purification ; Temperature ; Waste Disposal, Fluid ; Water ; chemistry ; Water Purification ; methods

This paper introduces the technical features of hydrosurgery system and evaluates it from three aspects:safety and effectiveness, economy and technology maturity. The evaluation results show that the safety and effectiveness are high, and the safety mainly involves the misuse of the system, which cause the adverse events. A large number of literatures have proved that the system is more suitable for the debridement of fine parts. It is estimated that hydrosurgery system has better economic performance, but the cost and patients' cost is also increased correspondingly. In the aspect of technology maturity assessment, this technology is a patented technology, and the number of published papers both at home and abroad is on the rise, indicating that the initial application of the technology is better and the technology is in infancy stage. Therefore, hydrosurgery system has certain advantages in all aspects. Hospitals need to allocate the equipment according to their own needs and clinical application, while a wider range of clinical trials is needed to provide evidence-based evidence for clinical applications and promotion.
Debridement ; instrumentation ; Equipment and Supplies ; Humans ; Water Purification

The effective inactivation of microorganisms in drinking water by Ultraviolet (UV) irradiation is regarded as a new low-cost water treatment method shoeing high removal rate of relatively stable infectious virus particles including poliovirus. In the present study, we examined virus inactivation by UV in various water environments. Samples were collected from finished water and surface water, and tested for turbidity. UV dose of 18, 22, 30, 36 and 40 milli-Joule (mJ)/cm2 were used by combination of 2 mW/cm2 UV intensity and time of 9, 11, 15, 18 and 20 second. Depths of water were fixed at 0.37 cm and 8 cm, and virus titers were shown by plaque forming unit (PFU). Poliovirus was inactivated to 99.0% by 18 mJ/cm2 of UV dose in the condition of 0.08 Nephelometry Turbidity Unit (NTU) and 8 cm depth of water. Poliovirus at 30 mJ/cm2 of UV dose under the same condition was inactivated to 99.7%. Furthermore, Poliovirus at 56.60 NTU and 8 cm depth of water was inactivated to 92.0% and 98.5% by 18 mJ/cm2 and 30 mJ/cm2 of UV dose, respectively. The degrees of virus inactivation were dependent upon the UV dose, the turbidit, y and the depth of water. In conclusion, introduction of UV disinfections can be considered in drinking water purification systems in case reasonable engineering support is possible.
Drinking Water ; Nephelometry and Turbidimetry ; Poliovirus ; Shoes ; Virion ; Virus Inactivation ; Water Purification ; Water*

The effective inactivation of microorganisms in drinking water by Ultraviolet (UV) irradiation is regarded as a new low-cost water treatment method shoeing high removal rate of relatively stable infectious virus particles including poliovirus. In the present study, we examined virus inactivation by UV in various water environments. Samples were collected from finished water and surface water, and tested for turbidity. UV dose of 18, 22, 30, 36 and 40 milli-Joule (mJ)/cm2 were used by combination of 2 mW/cm2 UV intensity and time of 9, 11, 15, 18 and 20 second. Depths of water were fixed at 0.37 cm and 8 cm, and virus titers were shown by plaque forming unit (PFU). Poliovirus was inactivated to 99.0% by 18 mJ/cm2 of UV dose in the condition of 0.08 Nephelometry Turbidity Unit (NTU) and 8 cm depth of water. Poliovirus at 30 mJ/cm2 of UV dose under the same condition was inactivated to 99.7%. Furthermore, Poliovirus at 56.60 NTU and 8 cm depth of water was inactivated to 92.0% and 98.5% by 18 mJ/cm2 and 30 mJ/cm2 of UV dose, respectively. The degrees of virus inactivation were dependent upon the UV dose, the turbidit, y and the depth of water. In conclusion, introduction of UV disinfections can be considered in drinking water purification systems in case reasonable engineering support is possible.
Drinking Water ; Nephelometry and Turbidimetry ; Poliovirus ; Shoes ; Virion ; Virus Inactivation ; Water Purification ; Water*

OBJECTIVETo introduce synergetic inactivation of microorganisms in drinking water by short-term free chlorination for less than 15 minutes followed by monochloramination.

METHODSIndicator microorganisms such as Escherichia coli, Staphylococcus aureus, Candida albicans, and spores of Bacillus subtilis were used to assess the efficiency of sequential chlorination and free chlorination.

RESULTSThe sequential chlorination was more efficient in inactivating these microorganisms than free chlorination, indicating that synergy was provided by free chlorine and monochloramine. Ammonia addition time, temperature and pH had influences on this synergy.

CONCLUSIONSThe possible mechanism of this synergy might involve three aspects: free chlorine causing sublethal injury to microorganisms and monochloramine further inactivating them; different ability of free chlorine and monochloramine to penetrate and inactivate microorganism congeries; and higher concentration of residual chlorine in sequential chlorination than in free chlorination.

Chloramines ; chemistry ; pharmacology ; Chlorine ; chemistry ; Disinfection ; methods ; Halogenation ; Water ; chemistry ; Water Microbiology ; Water Purification ; methods