امکان سنجی کاهش اثرات منفی یونهای پساب تصفیه خانه فاضلاب شهری گرگان با کمک گیاه پالایی و مغناطیس کردن برای استفاده در آبیاری کم فشار

One of the main solutions to deal with the water shortage is the proper use of unconventional water. Unconventional types of water include saline water, drainage water, agricultural wastewater, effluent (domestic, industrial, agricultural, fisheries) and rainwater. But the direct use of unconventional water in some condition can cause irreparable damage to agricultural products, soil, humans and the environment. In particular, the use of unconventional water in the drip irrigation method (which is expensive) can cause clogging of the drippers and make this method economically and technically difficult. For this reason, it is necessary to use purification methods to use unconventional water. Unconventional water treatment methods include phytoremediation, chemical methods and also the method of magnetizing water. Each of these methods has its own advantages and disadvantages



Materials and Methods

In this research, with the help of phytoremediation method and magnetization technique, the possibility of using the effluent of Gorgan urban treatment plant (as an unconventional permanent water source) in drip irrigation was investigated.

For this purpose In this research, a factorial experiment was conducted in the form of a randomized complete design with three factors and three repetitions to investigate the possibility of using the wastewater of the Gorgan urban treatment plant (as a permanent non-conventional water source). The first factor of water quality (including two types of control water and wastewater from the urban treatment plant), the second factor of magnetization (control water and wastewater) and the third factor of plant treatment in three levels without plants, treatment with Phragmites australis and treatment with Bambuseae were considered. Four time remainds: 3, 5, 7 and 10 days in phytoremediation were considered



Results and Discussion

The results of analysis of variance on hardness parameter showed that the effect of water quality after 5 and 7 days on total water hardness at 5% level was significant. Also, the hardness of water under the influence of magnetizing was not significant after 5 days, but it became significant at the level of 1% in 7 days. Also, the effect of phytoremediation at the time of 5 days, at the level of 5% probability and at the time of 7 days at the level of 1% probability was significant. The interaction effect of water quality and phytoremediation has been significant at the level of 5% on total hardness in just 7 days. The interaction effect of water quality and magnetization of water after 5 days at the level of 1% on the total hardness has been significant. Also, phytoremediation with Phragmites australis has caused a significant increase in hardness. But the hardness of water and effluent with Bambuseae and without plant was not significantly different. The interaction of water quality and phytoremediation also showed that Phragmites australis plant has increased the total hardness compared to other treatments. The values of analysis of variance of the effect of different treatments during the retention time on the amount of calcium indicate that the amount of calcium in the water samples, except for the phytoremediation treatment at the time of 10 days, did not change significantly. Comparison of the average effect of different phytoremediation treatments with a remind time of 10 days shows that the calcium content of water samples in phytoremediation treatment with Phragmites australis is higher than Bambuseae and non-phytoremediation treatments. Analysis of variance of the effects of different treatments at different times on the amount of carbonate indicates that during the stay of 3 and 5 days, these treatments had no effect on the amount of carbonate. Also, after 7 days, only phytoremediation had a significant effect on the carbonate content of the samples at the level of 1%. But with a remind time of 10 days, the simple effects of water quality treatments, magnetic modification and phytoremediation were significant and their interactions were not significant. Due to the fact that the simple effect of phytoremediation on water carbonate in different treatments was significant only after 7 days remind time, the amount of carbonate in Phragmites australis phytoremediation treatment was higher than the amount of Bambuseae phytoremediation without phytoremediation. carbonate has increased significantly in the presence of Phragmites australis roots compared to Bambuseae and without plants. Also, the effect of magnetization has caused a significant increase in carbonate after ten days. After ten days, phytoremediation with Phragmites australis and Bambuseae has significantly increased the amount of carbonate in water samples

Different quality treatments, magnetic modification and phytoremediation did not have a significant effect on bicarbonate ions at different remind times. Therefore, modification or reduction of this ion by the methods mentioned in this study will not be effective.





Conclusions

In general, it can be said that the minimum retention time of 7 days seems necessary for the effect of Phragmites australis and Bambuseae treatment on reducing the effects of waste water. There is a possibility of increasing water hardness in the conditions of plant treatment with Phragmites australis. However, this result was not obtained in the case of the Bambuseae. Also, magnetization of water has not shown any special effect on other ions, except the effect on the increase of carbonate in long retention times.