Design of Water Disinfection Scheme for Rural Drinking Water Safety Project

As further promotion of the rural drinking water safety project in whole country, small villages in vast countryside have been or will be equipped with safety drinking water project. We analyzed necessity of the rural drinking water disinfection, discussed disinfection method suitable for rural drinking water characteristics, and put forward disinfection schemes for different water supply sources.

Drinking water safety and the development of purification technology

This paper briefly introduced the evolution of purification technology for drinking water over time. After description of the 1st generation processes in the beginning of the 20th century - conventional processes and the 2nd generation processes in 1970s - advanced treatment processes, a tertiary processes - UF (ultrafiltration) based on integrated processes was proposed. Moreover, reaction measures (dosing variety of regents for different contaminants) for urban source water emergencies were illustrated in brief. A new technology of KMnO4 and potassium permanganate composite (PPC) for drinking water purification which was developed by Harbin Institute of Technology (HIT) was concisely introduced.

Integrated Control of Agricultural Non-point Source Pollution to Provide Safe and Healthy Drinking Water for Rural Areas

Agricultural non-point source pollution has become the main part of water pollution prevention and control in China. This paper made a brief introduction to the causes and hazards of agricultural non-point source pollution and the current situation of agricultural non-point source pollution prevention and control in China. In view of the serious agricultural non-point source pollution in water environment of Guangxi and the difference in quality of drinking water between urban and rural areas,it came up with recommendations for strengthening agricultural non-point source pollution prevention and control from scientific distribution,linked operation and maintenance,popular science education,and legal system construction,to guarantee safe and healthy drinking water in rural areas.

Comprehensive Control of Ecological Environment in Water Sources

To scientifically and effectively conduct comprehensive control of water sources to achieve water safety,the importance,main steps and plan of comprehensive control of ecological environment in water sources were analyzed on the basis of analyzing the development and protection process of foreign water sources.The results show that for the comprehensive control of water sources,it is needed to pay attention to the accurate grasp of the current environmental quality of water sources and carefully analyze the problems in the ecological environment of water sources.Besides,it is necessary to ensure the water quality and quantity of sources,focus on the implementation of environmental remediation and ecological restoration,implement regional protection of water sources,and combine engineering and non-engineering measures to take comprehensive control of environmental problems.

Importance and vulnerability of lakes and reservoirs supporting drinking water in China

Drinking water is closely related to human health,disease and mortality,and contaminated drinking water causes 485,000 deaths from diarrhea each year worldwide.China has been facing increasingly severe water scarcity due to both water shortages and poor water quality.Ensuring safe and clean drinking water is a great challenge and top priority,especially for China with 1.4 billion people.In China,more than 4000 centralized drinking water sources including rivers,lakes and reservoirs,and groundwater have been established to serve urban residents.However,there is little knowledge on the percentage,serving population and water quality of three centralized drinking water source types.We collected nationwide centralized drinking water sources data and serving population data covering 395 prefecture-level and county-level cities and water quality data in the two most populous provinces(Guangdong and Shandong)to examine their contribution and importance.Geographically,the drinking water source types can be classified into three clear regions exhibiting apparent differences in the respective contributions of rivers,lakes and reservoirs,and groundwater.We further found that overall,lakes and reservoirs account for 40.6%of the centralized drinking water sources vs.river(30.8%)and groundwater(28.6%)in China.Lakes and reservoirs are particularly important in the densely populated eastern region,where they are used as drinking water sources by 51.0%of the population(318 million).Moreover,the contribution to the drinking water supply from lakes and reservoirs is increasing due to their better water quality and many cross-regional water transfer projects.These results will be useful for the government to improve and optimize the establishment of centralized drinking water sources,which provide safe and clean drinking water in China to safeguard people's lives and health and realize sustainable development goals.

Characterizing the photodegradation-induced release of volatile organic compounds from bottled water containers

While plastic water bottles are known to potentially release various volatile organic compounds(VOCs)when exposed to light,existing knowledge in this field remains limited.In this study,we systematically examined the composition,yield,and toxicity of VOCs released from six plastic containers obtained from different continents under UV-A and solar irradiation.After light exposure,all containers released VOCs,including alkanes,alkenes,alcohols,aldehydes,carboxylic acids,aromatics,etc.The 1#,3#,4#,5#,and 6#containers exhibited 35,32,19,24 and 37 species of VOCs,respectively.Specifically,the 2#container released 28 and 32 series of VOCs after 1-day(short-term)and 7-day(long-term)UV-A irradiation,respectively,compared to 30 and 32 species under solar irradiation.Over half of the VOCs identified were oxidized compounds alongside various short-chain hydrocarbons.Significant differences in VOC compositions among the containers were observed,potentially originating from light-induced aging and degradation of the polyethylene terephthalate structure in the containers.Toxicological predictions unveiled distinctive toxic characteristics of VOCs from each container.For example,among the various VOCs produced by the 2#container,straight-chain alkanes like n-hexadecane(544-76-3)were identified as the most toxic compounds.After long-term irradiation,the yield of these toxic VOCs from the 2#container ranged from 0.11 ng/g to 0.79 ng/g.Considering the small mass of a single bottle,the volatilization of VOCs from an individual container would be insignificant.Even after prolonged exposure to light,the potential health risks associated with inhaling VOCs when opening and drinking bottled water appear manageable.

Investigation of drinking water bacterial community through high-throughput sequencing

Delivery of safe and pathogen-free drinking water is crucial to public health.However,there exist challenges to the maintenance of the sterility of drinking water throughout the drinking water distribution systems（DWDS）.Microbial growth in DWDS,such as growth of opportunistic pathogenic microorganisms,can lead to severe health problems in consumers（Berry et al.,2006;Brettar and Hofle,2006;Lu et al.,2014;Zhang et al.,2015）.

Evaluation of different primers of the 18S rRNA gene to profile amoeba communities in environmental samples

Amoeboid protists,an assemblage of organisms belonging to different phylogenetic lineages,have drawn increasing attention due to their crucial ecological roles in various environments and their potential health risks.Currently,18S rRNA gene sequencing is widely applied for the detection of amoebae.However,it is not clear which is the best primer pair for 18S rRNA gene amplification in amoebae.This study compared the four most commonly used primer pairs for revealing the diversity,composition,core species,and community assembly processes of amoebae in water and sediments.We found that the choice of primers artificially influences the detection of community composition of amoebae.We also found that short-read fragments may lead to mismatches in taxonomy and were not suitable for phylogenetic analyses.In contrast,full-length primers could detect the highest number of amoeba lineages and annotate 80%of reads belonging to amoebae to known species.However,full-length primers did not detect as many amoeba species as V4 primers.Moreover,we showed that beta diversity and community assembly determination were largely unaffected by primer choice,but different primers could influence our interpretations of the ecological process underlying stochasticity and determinism.This study indicates that full-length read sequencing and V4 region Illumina sequencing are suitable for profiling amoeba diversity in the environment.