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To overcome the global water shortage, the treated wastewater is increasingly utilized in agricultural irrigation, and thus reducing freshwater consumption and increasing the water sustainability. Drip irrigation technology is the most appropriate irrigation method to utilize these water sources. However, its operating performance is negatively affected by calcium carbonate (CaCO 3 ) scaling, which is one of the most dominant precipitations and also closely related to dissolved ions and the hydraulic characteristics inside irrigation systems. Thus, the effects of eight common dissolved ions (K + , Mg 2+ , Mn 2+ , Zn 2+ , Fe 3+ , NO 3 - , SO 4 2- , and PO 4 3- ) in these water sources and four hydraulic shear stresses (0, 0.2, 0.4, and 0.6 Pa) on CaCO 3 scaling formation were assessed in this study. Results showed that CaCO 3 scaling was primarily formed of calcite and aragonite. Fe 3+ would significantly accelerate the CaCO 3 scaling accumulation, as it reduced the unit cell volume and chemical bonds of calcite, enhancing calcite adhesion and stability. On the other hand, Mg 2+ , Mn 2+ , NO 3 - , SO 4 2- , and PO 4 3- significantly inhibited CaCO 3 scaling. Among them, Mg 2+ , Mn 2+ , and PO 4 3- followed the typical water chemical precipitation rule, while NO 3 - increased water molecule diffusion rate and thus decreased the possibility that Ca 2+ and CO 3 2- to precipitate. SO 4 2- grabbed the binding point belonging to CO 3 2- and was adsorbed on the calcite crystal, which inhibited crystal growth. However, those treatments under K + and Zn 2+ did not reach a significant level due to their solubleness. During the precipitation of CaCO 3 , there were significant (p < 0.01) interactions between dissolved ions and hydraulic shear stresses. When hydraulic shear stresses varied, the effects of Fe 3+ and SO 4 2- on the CaCO 3 scaling were relatively weakened, while that of Mg 2+ was relatively strengthened. In return, dissolved ions affected the effect of hydraulic shear stresses on CaCO 3 scaling. Overall, the results obtained could provide theoretical reference for high-efficiency utilization of treated wastewater for agricultural irrigation through the management of CaCO 3 scaling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aims to investigate the performance of disc, conventional screen, and automatic screen filters when rainbow trout fish effluent is used for irrigation. The experiments were performed in a fish farm, located in the north-west of Iran. The disc and conventional screen filters were tested at pressures of 150 and 300 kPa, and the automatic screen filter at 200 and 300 kPa. The filtration experiments continued until the backwashing was reached. The results showed that (1) the initial head loss of disc and conventional screen filters was 40 kPa, while for the automatic screen filter was 5 kPa. (2) In the disc filter, with increasing working pressure, the filtered volume significantly (P < 0.05) increased from 9.7 to 14.5 m 3  m -2 (10 kPa) -1 , but for conventional and automatic screen filters, it was constant at 5.5 and 7.0 m 3  m -2 (10 kPa) -1 , respectively, and all of them had significant (P < 0.05) differences. (3) In the disc filter, with increasing the working pressure, the filtered volume to reach backwashing significantly (P < 0.01) increased from 80.9 to 104.4 m 3  m -2 , while in the conventional screen filter increased from 14.1 to 16.4 m 3  m -2 . This volume at two working pressures was 29.5 m 3  m -2 for the automatic screen filter. These volumes were significantly different (P < 0.01) between filters. (4) The mass retention for the disc, conventional, and automatic screen filters were 28.88, 9.11, and 7.72 g min -1  m -2 , respectively, and tended to increase at lower working pressures. Based on this index, the difference in the performance of the filters was significant (P < 0.01). (5) Overall, the best performance was for the disc filter, and after that was the automatic screen filters, but the period of time to operate for the filters until backwashing time was less than half an hour, which is not applicable under farm conditions., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Fouling growth in brackish water distribution systems (BWDS), especially calcium-silica fouling, is inevitable issue in brackish water desalination, chemical and agricultural industry, eventually threaten the cleaner production process and environment. Magnetic Field (MF) has been a greener and effective technology to control calcium carbonate fouling. However, the effects of MF on composite calcium-silica fouling are still elusive. Therefore, this paper assessed the effect of MF on calcium and silica fouling. We found that MF not only significantly reduce the calcium carbonate fouling, but also obviously decreased the silica fouling. The MF reduced the calcite fouling reached 38.2%-64.3% by changing water quality parameters to trigger the transformation rate of CaCO 3 crystal from compact calcite to looser aragonite, as well as increase the unit-cell parameters and chemical bond lengths of calcite and aragonite. The MF also decreased the content of silica fouling (silica and silicate) reached 22.4-46.3% by reducing the concentration of soluble silica and accelerating the flocculation settlement to form large size solid particles in BW. Furthermore, MF broke the synergistic interactions among calcium and silica fouling. In addition, the anti-fouling ability of permanent MF was higher by 12.3-35.1% than electric MF. Overall, these findings demonstrate that MF is an effective and chemical-free technology to control calcium-silica fouling in BWDS, and provide a new perspective for sustainable application of brackish water., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier B.V.)