2015—2019年辽宁省农村饮用水硝酸盐污染状况及分布特征

Nitrate pollution and distribution characteristics of rural drinking water in Liaoning Province from 2015-2019

目的了解辽宁省农村地区饮用水硝酸盐污染状况及分布特征,为进一步有针对性地采取治理措施、提高饮水质量提供一定依据。方法2015—2019年按照供水方式和水源类型构成在全省农村地区选取5496个供水单位进行基本信息调查,按照GB/T 5750—2006《生活饮用水标准检验方法》进行22761份水样采集、保存和检测。检测结果按照GB 5749—2006《生活饮用水卫生标准》进行评价。结果共调查供水单位5496个,水源类型主要为地下水(94.83%),仅有22.62%供水单位有不同的水处理措施。共采集检测水样22761份,硝酸盐达标率为94.20%。2015—2019年每年硝酸盐达标率(94.66%、94.99%、93.32%、94.19%、93.94%)差异有统计学意义(P<0.01)。枯水期(94.68%)硝酸盐达标率高于丰水期(93.72%),地表水(97.91%)水源达标率高于地下水(93.99%),且差异均有统计学意义(均P<0.01)。采取水处理措施(96.67%)水样达标率高于无处理措施(93.49%)水样,差异有统计学意义(P<0.01)。硝酸盐达标率较低的地区在西部地区。结论辽宁省农村地区饮用水存在硝酸盐污染状况,且与水源、水期、水处理措施、地区均有一定关系。减少污染,需从水源选址、水处理、卫生防护、居民卫生意识等多方面采取措施。

Objective To understand the nitrate pollution and distribution characteristics of rural drinking water in Liaoning Province,provides a basis for further taking targeted measures to improve the quality of drinking water.Methods According to water supply mode and water source type,5496 water supply projects were collected from the rural areas of the province to conduct the basic information survey from 2015-2019.Totally 22761 water samples were collected,preserved and tested according to the Standard Examination Methods for Drinking Water(GB/T 5750-2006).The test results were evaluated according to the Standard for Drinking Water Quality(GB 5749-2006).Results A total of 5496 water supply projects were investigated.The main water source type was groundwater(94.83%).Only 22.62%of water supply projects had different water treatment measures.Totally 22761 water samples were collected and examined,and the qualified rate of nitrate was 94.20%.There was statistically significant difference in the annual qualified rate from 2015-2019(94.66%,94.99%,93.32%,94.19%,93.94%)(P<0.01).The qualified rate of nitrate in dry season(94.68%)was higher than that in wet season(93.72%),the qualified rate of drinking water from surface(97.91%)was higher than that of drinking water from groundwater(93.99%),and the differences were statistically significant(both P<0.01).The qualified rate of treated drinking water(96.67%)was higher than that of untreated drinking water(93.49%),and the difference was statistically significant(P<0.01).The area with low qualified rate of nitrate was in the west.Conclusion There is nitrate pollution of drinking water in rural areas of Liaoning Province,and it is related to the water source,the season,the treatment measures and the location.To reduce the pollution,measures should be taken in the aspects of water source,water treatment,and protection of the project and the health awareness of residents.