Phosphate recovery from the P-enriched brine of AnMBR-RO-IE treating municipal wastewater via an innovated phosphorus recovery batch reactor with nano-sorbents.

Municipal wastewater is a very unique pool full of energy and useful substances. Though the innovative integrated anaerobic membrane bioreactor and reverse osmosis-ion exchange (AnMBR-RO-IE) process can produce high-grade reclaimed water with high energy efficiency, phosphorus resources recovery in the WWTPs has been rarely reported thus far. This study evaluated the feasibility of a phosphorus recovery batch reactor (PRBR) as an approach for the phosphate production from the P-enriched brine from AnMBR-RO-IE. With operating PRBR for 162 cycles, high to 85% of P recovery rate was obtained for 145 cycles, leading to a P production rate of 6.17 g/m3 domestic wastewater with nano-sorbents (NSs) consumption rate of 10.2 g/m3. Acidification pretreatment efficiently improved the adsorption capacity and reduced the NSs renewing frequency. High adsorption selectivity of NSs contributed to low impurities (<0.3%) in the P-enriched reclaimed solution. Moreover, the integrated AnMBR-RO-IE-PRBR process saved 47% of energy consumption compared to the present NEWater production process in Singapore. The innovative PRBR reactor was competitive compared to the commonly-used chemical precipitation methods in conventional WWTPs in terms of phosphorus recovery/loss and energy balance. It is expected that the proposed integrated process can offer new insights into the direction of phosphorus reclamation in the future WWTPs.

Application of a Zwitterionic Hydrophobic Associating Polymer with High Salt and Heat Tolerance in Brine-Based Fracturing Fluid.

ZID16PM, a zwitterionic hydrophobic associating polymer, has equivalent positive and negative charges and some hydrophobic monomers with twin-tailed long hydrophobic chains. It exhibits a great heat resistance and salt tolerance to the common salt in formation brine (MgCl2, CaCl2, NaCl, and KCl), which is attributed to its anti-polyelectrolyte effect and strong association force. High-salinity water (seawater or formation water) can be prepared as a fracturing fluid directly. In this paper, the formation water of the West Sichuan Gas Field is directly prepared into fracturing fluid with a concentration of 0.3% ZID16PM (Fluid-1), and the seawater of the Gulf of Mexico is directly prepared into fracturing fluid with a concentration of 0.3% ZID16PM (Fluid-2). Finally, rheological measurements, proppant suspension tests, and core matrix permeability damage rate tests for the Fluid-1 and Fluid-2 are conducted. Results show that after 120 min of shearing at 140 and 160 °C, respectively, the viscosity of Fluid-1 remains in the range of 50-85 mPa‧s, and the viscosity of Fluid-2 remains in the range of 60-95 mPa‧s. And the wastewater produced by an oilfield in Shaanxi, Xinjiang, and Jiangsu are also prepared into fracturing fluids with a concentration of 0.3% ZID16PM, the viscosity of these fracturing fluids can remain 32, 42, and 45 mPa‧s, respectively, after 120 min of shearing at 160 °C. All results demonstrate that the polymer ZID16PM displays prominent performance in fracturing fluids.