Modern Water (United Kingdom)

IntroductionSoil salinization poses an urgent challenge by constraining cotton yields and exacerbating freshwater scarcity.MethodsA two-year field experiment was carried out from 2023 to 2024. This study systematically assessed the effects of combining Deep Vertical Rotary Tillage (DVRT) with Saline Water Drip Irrigation (SWDI) on the soil salinity profile in the 0–100 cm layer, as well as on agronomic traits, fiber quality, yield, and water use efficiency (WUE) of cotton.ResultsResults indicate that the DVRT-SWDI treatment significantly improved soil water storage capacity, among which the D3M2 treatment achieved the highest increment (12.06% higher than the control). Soil water storage exhibited a “decrease-increase-decrease” dynamic pattern throughout the growing season. Treatments with deep vertical rotary tillage (D2/ D3) effectively alleviated salt accumulation in the 0–60 cm root zone, with D3M1 showing the optimal salt-blocking effect, whereas shallow plowing combined with high-salinity water irrigation (D1M3) led to the most severe salt accumulation. Deep vertical rotary tillage integrated with low/medium-salinity water (M1/M2) significantly promoted cotton growth and yield formation. In 2023, the seed cotton yields under D2M2 and D3M2 treatments increased by 35.24% and 31.84%, respectively, compared with the control (CK). Comprehensive evaluation via the entropy weight method revealed that the D3M2 treatment delivered the highest overall benefit. Based on a multi-objective optimization model, the optimal combination of agronomic and tillage parameters was determined as a deep vertical rotary tillage depth of 40–45 cm and a saline water drip irrigation salinity of 2.82–3.29 g·L-1, which yielded seed cotton at 5767.38–6052.86 kg·ha-1.DiscussionThis study clarifies the mechanisms of salt suppression and growth promotion by deep vertical rotary tillage under brackish water irrigation conditions, providing theoretical basis and technical support for the efficient utilization of water and soil resources and the suitable cultivation of cotton in saline-alkali lands of southern Xinjiang.

Abstract The centre of the vortex within the drip irrigation emitter easily forms a low‐speed or zero‐velocity zone, which easily causes sediment deposition and blocks the narrow channel of the emitter. To solve this problem, a funnel‐shaped drip irrigation emitter was designed and optimized. Numerical simulations and field tests were conducted to compare and analyse the flow index, energy dissipation coefficient and relative energy dissipation ratio of the emitter. The results showed: (1) When the incident angle (θ) of the diversion channel increased from 0 to 37.4°, the energy dissipation increased from 20% to 64%. The main way of energy dissipation in the emitter changed from impingement of water to viscous drag in the vortex. (2) Under normal pressure, the energy dissipation coefficient of the vortex energy dissipation scheme (F5) was 60% higher than that of the impingement energy dissipation scheme (F1). The flow index of F5 was lower than that of F1 in both the high‐pressure and low‐pressure regions, which was in the range of 0.433–0.466. (3) Due to the spiral flow, there was a vortex with a large axial velocity inside the conical cavity, which can effectively avoid sediment deposition in the vortex centre.

A two-step forward osmosis (FO) desalination process combining both FO and reverse osmosis (RO) systems has been developed by the Centre for Osmosis Research and Applications at the University of Surrey and commercialised by Modern Water plc. In the FO + RO process seawater was used as feed water (FW) and a concentrated aqueous solution was used as a draw solution (DS). By taking advantage of natural osmosis, pure water is transferred from the FW to the DS and then recovered from the DS by the RO process utilising low resistance membranes, and hence lower specific energy consumption (SEC). This paper presents results of FO experiments conducted on flat sheet membrane using a bench-scale rig. The osmotic agent investigated in this study was magnesium sulphate, which is non-toxic, and highly soluble in water. Furthermore experiments were carried out on the RO pilot in order to regenerate the DS for reuse in the FO process and produce clean water. This paper also presents some pilot plant results and data from commercial plants in Oman and Gibraltar. The data demonstrates the efficiency of the FO + RO compared with the conventional RO process in terms of SEC and membrane fouling performance.