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1、哈尔滨工业大学工学硕士学位论文摘要将回用水用于农田灌溉是解决水资源短缺的有效途径，但回用过程中对作物、土壤环境和人体健康产生的影响还不太清楚，这极大的限制了回用水的安全应用。本研究通过现场种植瓜果类(黄瓜)、茎叶类(白菜)以及粮食作物(玉米)这三种常规农作物，以清水作为对照，分别考察了污水、二级出水和三级出水作为灌溉用水对农作物及土壤的影响，并对再生水回用于农业的安全性进行了初步评价，得到以下一些结论。用三级水和二级水浇灌作物，对作物品质无显著影响，污水浇灌时作物中蛋白质、糖类含量略有升高；不同处理程度水浇灌时作物中的非金属无机盐含量是逐渐升高的，清水浇灌最低，污水浇灌最高。污水浇灌时白菜中硝
2、酸盐含量为 554.4mg/kg，亚硝酸盐含量为 5.213mg/kg，均已达到污染水平(其它指标均符合国家无公害蔬菜标准)，因此污水不适合做灌溉水源；与清水浇灌相比，三级水浇灌对作物中重金属残留影响不大，二级水浇灌会使重金属略有提高，污水浇灌则使农作物发生明显的重金属积累；由于灌溉期较短，所以不同水浇灌条件下，土壤中重金属含量变化不大。对三种回用水回用农业进行健康风险评价，结果表明：三级水、二级水和污水灌溉时，重金属所导致的个人年患癌总风险分别为 4.3110 -7/a、5.6910-7/a和 3.3310 -6/a，均低于国际辐射防护委员会(ICRP)推荐的最大可接受风险水平 5.010-
3、5/a；化学躯体毒物质对人体健康造成的终身风险分别为 5.3610 -10、8.2310-10和 4.6110-9，均低于国际公认的终身最大可接受风险水平 710-5；回用水灌溉时病毒引起的健康风险分别以轮状病毒、甲肝病毒和柯萨奇病毒计算，污水浇灌对工作人员的健康风险分别为 0.998/a、0.920/a和 2.84110-2/a，均超过USEPA认可的最大可接受风险阈值(10-4/a)。对于二级水浇灌，只有按柯萨奇病毒计算时其年患病风险(2.66010-6/a)小于可接受水平 (10-4/a)，考虑到水中还有很多传染性更强的病毒，实际风险会高于此值，所以二级水浇灌属于不安全范围。三级水浇灌时
4、，即便全部按照感染性最强的轮状病毒计算，其年患病风险也低于可接受水平。综合以上结果，初步建议采用三级水进行农田灌溉。关键词回用水灌溉；作物；土壤；风险评价I-哈尔滨工业大学工学硕士学位论文AbstractWastewater reuse for agriculture is one of efficient paths to meet theshortage of water resource. However, there are little studies about its effects oncrops, soil environments and human health was
5、found, largely limits its safeapplications for reclaimed water. This study was is mainly focusing on (i) theinfluence of irrigating with reclaimed water treated into different extends forcrops(cucumber, celery cabbage, maize) and soil; (ii) the primaryassessmentsfor health risk of irrigation with re
6、claimed water.The quality of crops was slightly affected when irrigating with tertiaryeffluent or second effluent. In comparison, irrigation with sewage led to a littleincrease of proteins and sugar in crops. The contents of non-metallic inorganicmatters in crops after irrigation with different wate
7、r followed the order: tap water tertiary effluent secondary effluent sewage. When sewage was directlyused for irrigation, the content of NO3 -and NO2 - in celery cabbage was554.4mg/kg and 5.213mg/kg, respectively, which both overran the standardlevels. So sewage was not considered to be suitable eno
8、ugh for irrigation.Irrigating with tertiary effluent did not have great influence for the heavy metalcontent compare with rinsing irrigation; irrigation with second effluent resultedin slight increase of heavy metals and sewage could lead to apparentaccumulation of heavy metals. Due to the short per
9、iod irrigation, there was notbig change for the content of heavy metals in soils when diffluent water sourceswere used.Risk assessments of applying reclaimed water in agriculture suggested thatwhen using tertiary effluent, secondary effluent and sewage, the total risk ofpersonal cancer annually caus
10、ed by heavy metals was 4.3110-7/a, 5.6910-7/a,3.3310-6/a, respectively, which were lower than maximum acceptable level of5.010 -5/a, recommended by International Commission on RadiologicalProtection (ICRP). Lifelong risk to humanbody health caused by chemical hazardmatters reached 5.3610-10/a, 8.231
11、0-10/a and 4.6110-9/a, without excess of themaximum acceptable risk level(710-5/a). The health risk of reclaimed waterII -哈尔滨工业大学工学硕士学位论文reuse in irrigation was calculated on the basis of Rotavirus, Hepatitis A virus andCoxsackie, as a result, the health risk to workers using sewage for irrigation w
12、as0.998/a, 0.920/a and 2.84110-2/a, respectively, which all exceeded the range ofacceptable value to intestinal virus (10-4/a, USEPA). For secondary-treated water,only the value that was computed based on Coxsackie(2.66010-6/a)was less thanthe acceptable value(10-4/a), however, the possible presence
13、 of virus withstronger ability of infection can make such value overstep the acceptable range.Therefore, secondary effluent belongs to unsafe irrigation-used water. In contrast,the risk was much lower than acceptable values when tertiary effluent is used,even the result was obtained depending on Rotavirus with the strongest infectionability.In total, we preliminarily proposed that tertiary effluent can be used foragricultural irrigation safely.Keywordsreclaimed water irrigation; crop; soil; risk assessmentIII -哈尔滨工业大学工学硕士学位论文目录摘要 .IAbstract . II第 1章绪论 . 11.1水资源短缺及水体污染现状 .
