Malkawi Hanan I, Mohammad Munir J
Yarmouk University, Faculty of Science, Dept of Biological Sciences, Irbid, Jordan.
J Basic Microbiol. 2003;43(1):47-55. doi: 10.1002/jobm.200390004.
Secondary-treated wastewater was used to irrigate forage crops during two years (1994 and 1995). The bacteriological quality of the soil irrigated with both secondary treated wastewater (without chlorination) and with potable water was evaluated. The following three treatments were investigated in this study: i) irrigation with potable water in amount equivalent to 100% of the class A Pan evaporation reading (as taken from the nearest Meteorological Weather Station); ii) irrigation with treated wastewater in amount equivalent to 100% of the A Pan reading and iii) irrigation with treated wastewater in amount equivalent to 125% of the A Pan reading. At the end of the last growing season, soil samples were collected at two soil depths and subjected to microbiological analysis. The bacteriological analysis showed that the total aerobic bacterial counts of surface soil were similar in all irrigated plots, suggesting that the use of this wastewater did not stimulate or inhibit these microflora. Surface soil was found to have higher bacterial counts than deeper soil suggesting bacterial removal from irrigation water by the first few centimeters of soil due to natural infiltration of soil. The total coliforms ranged from 2.1 x 10(3) CFU/g to 4.2 x 10(3) CFU/g while fecal coliforms were less, ranging from 1.2 x 10(2) CFU/g to 4.2 x 10(2) CFU/g. No detectable helminth eggs were recorded in the treated wastewater used for irrigation. The results strongly suggest the necessity to treat wastewater effluents to an extent to which no or very few residual bacterial contaminants will be detected.
在1994年和1995年这两年间，使用二级处理后的废水灌溉饲料作物。对用二级处理后的废水（未加氯）和饮用水灌溉的土壤的细菌学质量进行了评估。本研究调查了以下三种处理方式：i）以相当于A类蒸发皿蒸发量读数100%的量（取自最近的气象站）用饮用水灌溉；ii）以相当于A类蒸发皿蒸发量读数100%的量用处理后的废水灌溉；iii）以相当于A类蒸发皿蒸发量读数125%的量用处理后的废水灌溉。在最后一个生长季节结束时，在两个土壤深度采集土壤样本并进行微生物分析。细菌学分析表明，所有灌溉地块表层土壤的需氧细菌总数相似，这表明使用这种废水不会刺激或抑制这些微生物群落。发现表层土壤的细菌数量高于深层土壤，这表明由于土壤的自然渗透，灌溉水中的细菌在前几厘米土壤中被去除。总大肠菌群数量在2.1×10³CFU/g至4.2×10³CFU/g之间，而粪大肠菌群数量较少，在1.2×10²CFU/g至4.2×10²CFU/g之间。用于灌溉的处理后废水中未检测到蛔虫卵。结果强烈表明有必要对废水进行处理，使其达到检测不到或仅能检测到极少残留细菌污染物的程度。
