Recovery of Fluoride-Rich and Silica-Rich Wastewaters as Valuable Resources: A Resource Capture Ultrafiltration-Bipolar Membrane Electrodialysis-Based Closed-Loop Process.

Traditional technologies such as precipitation and coagulation have been adopted for fluoride-rich and silica-rich wastewater treatment, respectively, but waste solid generation and low wastewater processing efficiency are still the looming concern. Efficient resource recovery technologies for different wastewater treatments are scarce for environment and industry sustainability. Herein, a resource capture ultrafiltration-bipolar membrane electrodialysis (RCUF-BMED) system was designed into a closed-loop process for simultaneous capture and recovery of fluoride and silica as sodium silicofluoride (Na2SiF6) from mixed fluoride-rich and silica-rich wastewaters, as well as achieving zero liquid discharge. This RCUF-BMED system comprised two key parts: (1) capture of fluoride and silica from two wastewaters using acid, and recovery of the Na2SiF6 using base by UF and (2) UF permeate conversion for acid/base and freshwater generation by BMED. With the optimized RCUF-BMED system, fluoride and silica can be selectively captured from wastewater with removal efficiencies higher than 99%. The Na2SiF6 recovery was around 72% with a high purity of 99.1%. The aging and cyclic experiments demonstrated the high stability and recyclability of the RCUF-BMED system. This RCUF-BMED system has successfully achieved the conversion of toxic fluoride and silica into valuable Na2SiF6 from mixed wastewaters, which shows great application potential in the industry-resource-environment nexus.

Novel electrocatalytic capacitive deionization with catalytic electrodes for selective phosphonate degradation: Performance and mechanism.

Phosphonate is becoming a global interest and concern owing to its environment risk and potential value. Degradation of phosphonate into phosphate followed by the recovery is regarded as a promising strategy to control phosphonate pollution, relieve phosphorus crisis, and promote phosphorus cycle. Given these objectives, an anion-membrane-coated-electrode (A-MCE) doped with Fe-Co based carbon catalyst and cation-membrane-coated-electrode (C-MCE) doped with carbon-based catalyst were prepared as catalytic electrodes, and a novel electrocatalytic capacitive deionization (E-CDI) was developed. During charging process, phosphonate was enriched around A-MCE surface based on electrostatic attraction, ligand exchange, and hydrogen bond. Meanwhile, Fe2+ and Co2+ were self-oxidized into Fe3+ and Co3+, forming a complex with enriched phosphonate and enabling an intramolecular electron transfer process for phosphonate degradation. Additionally, benefiting from the stable dissolved oxygen and high oxygen reduction reaction activity of C-MCE, hydrogen peroxide accumulated in E-CDI (158 µM) and thus hydroxyl radicals (·OH) were generated by activation. E-CDI provided an ideal platform for the effective reaction between ·OH and phosphonate, avoiding the loss of ·OH and triggering selective degradation of most phosphonate. After charging for 70 min, approximately 89.9% of phosphonate was degraded into phosphate, and phosphate was subsequently adsorbed by A-MCE. Results also showed that phosphonate degradation was highly dependent on solution pH and voltage, and was insignificantly affected by electrolyte concentration. Compared to traditional advanced oxidation processes, E-CDI exhibited a higher degradation efficiency, lower cost, and less sensitive to co-existed ions in treating simulated wastewaters. Self-enhanced and selective degradation of phosphonate, and in-situ phosphate adsorption were simultaneously achieved for the first time by a E-CDI system, showing high promise in treating organic-containing saline wastewaters.

Anti-Wetting Performance of an Electrospun PVDF/PVP Membrane Modified by Solvothermal Treatment in Membrane Distillation.

Membrane distillation (MD) is attractive for water reclamation due to the fact of its unique characteristics. However, membrane wetting becomes an obstacle to its further application. In this paper, a novel hydrophobic polyvinylidene fluoride/poly(vinyl pyrrolidone) (PVDF/PVP) membrane was fabricated by electrospinning and solvothermal treatment. The electrospun membranes prepared by electrospinning showed a multilevel interconnected nanofibrous structure. Then, a solvothermal treatment introduced the micro/nanostructure to the membrane with high roughness (Ra = 598 nm), thereby the water contact angle of the membrane increased to 158.3 ± 2.2°. Owing to the superior hydrophobicity, the membrane presented high resistance to wetting in both NaCl and SDS solutions. Compared to the pristine PVDF membrane, which showed wetting with a flux decline (120 min for 0.05 mM surfactant solution treatment), the prepared membrane showed outstanding stability over 600 min, even in 0.2 mM surfactant solutions. These results confirm a simple method for anti-wetting hydrophobic membrane preparation, which presented universal significance to direct contact membrane distillation (DCMD) for industrial application.

Patterned dense Janus membranes with simultaneously robust fouling, wetting and scaling resistance for membrane distillation.

Membrane fouling, wetting and scaling are three prominent challenges that severely hinder the practical applications of membrane distillation (MD). Herein, polyamide/polyvinylidene fluoride (PA/PVDF) Janus membrane comprising a hydrophobic PVDF substrate and a patterned dense PA layer by reverse interfacial polymerization (R-IP) was developed. Direct contact MD experiments demonstrated that PA/PVDF Janus membrane could exhibit simultaneously superior resistance towards surfactant-induced wetting, oil-induced fouling and gypsum-induced scaling without compromising flux. Importantly, the size-sieving effect, rather than the breakthrough pressure of the membrane, was revealed as the critical factor that probably endowed its resistance to wetting. Furthermore, a unique possible anti-scaling mechanism was unveiled. The superhydrophilic patterned dense PA layer with strong salt rejection capability not only prevented scale-precursor ions from intruding the substrate but also resulted in the high surface interfacial energy that inhibited the adhesion and growth of gypsum on the membrane surface, while its relatively low surface -COOH density benefited from R-IP process further ensured the membrane with a low scaling propensity. This study shall provide new insights and novel strategies in designing high-performance MD membranes and enable robust applications of MD facing the challenges of membrane fouling, wetting and scaling.

Ionic resource recovery for carbon neutral papermaking wastewater reclamation by a chemical self-sufficiency zero liquid discharge system.

Papermaking industry discharges large quantities of wastewater and waste gas, whose treatment is limited by extra chemicals requirements, insufficient resource recovery and high energy consumption. Herein, a chemical self-sufficiency zero liquid discharge (ZLD) system, which integrates nanofiltration, bipolar membrane electrodialysis and membrane contactor (NF-BMED-MC), is designed for the resource recovery from wastewater and waste gas. The key features of this system include: 1) recovery of NaCl from pretreated papermaking wastewater by NF, 2) HCl/NaOH generation and fresh water recovery by BMED, and 3) CO2 capture and NaOH/Na2CO3 generation by MC. This integrated system shows great synergy. By precipitating hardness ions in papermaking wastewater and NF concentrate with NaOH/Na2CO3, the inorganic scaling on NF membrane is mitigated. Moreover, the NF-BMED-MC system with high stability can simultaneously achieve efficient CO2 removal and sustainable recovery of fresh water and high-purity resources (NaCl, Na2SO4, NaOH and HCl) from wastewater and waste gas without introducing any extra chemicals. The environmental evaluation indicates the carbon-neutral papermaking wastewater reclamation can be achieved through the application of NF-BMED-MC system. This study establishes the promising of NF-BMED-MC as a sustainable alternative to current membrane methods for ZLD of papermaking industry discharges treatment.

Ionic Control of Functional Zeolitic Imidazolate Framework-Based Membrane for Tailoring Selectivity toward Target Ions.

Ion exchange membranes with strong ionic separation performance have strategic importance for resource recovery and water purification, but the current state-of-the-art membranes suffer from inadequate ion selective transport for the target ions. This work proposes a new class of zeolitic imidazolate framework (ZIF)-based anion exchange membranes (named as S@ZIF-AMX) with suppressed multivalent anion mobility and enhanced target ion transport via an ionic control strategy under alternating current driven assembly. In electrodialysis with an initial concentration of 50 mM of NaBr, NaCl, Na2SO4, and Na3PO4 (mixed feed) and a current density of 10 mA cm-2, the S@ZIF-AMX membrane demonstrated an excellent transport of the target ion (Cl-) based on the synergy between the Cl- regulated ZIF cavity and the electrostatic interaction with sulfonic groups. The separation efficiency and permselectivity of PO43-/Cl- through S@ZIF-AMX largely increased to 83% and 32, respectively, compared to 42% and 4.0 of the pristine AMX membrane (a commercial anion exchange membrane), respectively. Furthermore, the separation between SO42- and Cl- was also enhanced, the separation efficiency and permselectivity of SO42-/Cl- increased from 11% and 1.4 to 45% and 4.3, respectively. In addition, the combined strategy developed in the S@ZIF-AMX membrane was proven effective in promoting Cl- transport by shifting the separation equilibrium of the ion pair Br-/Cl-, which is known to be extremely challenging. This work provides a new design strategy toward pushing the limits of current ion exchange membranes for target ion separation in water, resource, and energy applications.

Membrane bioreactors for hospital wastewater treatment: recent advancements in membranes and processes.

Discharged hospital wastewater contains various pathogenic microorganisms, antibiotic groups, toxic organic compounds, radioactive elements, and ionic pollutants. These contaminants harm the environment and human health causing the spread of disease. Thus, effective treatment of hospital wastewater is an urgent task for sustainable development. Membranes, with controllable porous and nonporous structures, have been rapidly developed for molecular separations. In particular, membrane bioreactor (MBR) technology demonstrated high removal efficiency toward organic compounds and low waste sludge production. To further enhance the separation efficiency and achieve material recovery from hospital waste streams, novel concepts of MBRs and their applications are rapidly evolved through hybridizing novel membranes (non hydrophilic ultrafiltration/microfiltration) into the MBR units (hybrid MBRs) or the MBR as a pretreatment step and integrating other membrane processes as subsequent secondary purification step (integrated MBR-membrane systems). However, there is a lack of reviews on the latest advancement in MBR technologies for hospital wastewater treatment, and analysis on its major challenges and future trends. This review started with an overview of main pollutants in common hospital waste-water, followed by an understanding on the key performance indicators/criteria in MBR membranes (i.e., solute selectivity) and processes (e.g., fouling). Then, an in-depth analysis was provided into the recent development of hybrid MBR and integrated MBR-membrane system concepts, and applications correlated with wastewater sources, with a particular focus on hospital wastewaters. It is anticipated that this review will shed light on the knowledge gaps in the field, highlighting the potential contribution of hybrid MBRs and integrated MBR-membrane systems toward global epidemic prevention.

Integration of Bipolar Membrane Electrodialysis with Ion-Exchange Absorption for High-Quality H3PO2 Recovery from NaH2PO2.

H3PO2 has emerged as an indispensable reducing agent for electroless nickel plating. Commercial preparation of H3PO2, with high purity and low cost, is a great challenge. In this work, a novel technique by the integration of bipolar membrane electrodialysis (BMED) with ion-exchange absorption was designed to prepare high-quality H3PO2 aqueous solution. The critical parameters, such as voltage drop, NaH2PO2 concentration, and different types of anion-exchange membranes, were systematically investigated. Continuous experiments indicated that a high yield of up to 80.06% with a low energy consumption of 4.99 kW h/kg was achieved under optimal operation conditions (voltage drop of 20 V, feed concentration of 15 wt % NaH2PO2, and anion-exchange membrane of AHA). Moreover, leakage of Na+ ions through the bipolar membrane was observed. By using T-52H cation-exchange resin, the final concentration of Na+ ions in H3PO2 aqueous solution was reduced to 20.91 mg/L. Subsequently, a long-term experiment was performed to evaluate the stability of the BMED stack, and the concentration of H3PO2 in the acid compartment reached 4.15 mol/L. Under optimal conditions, the H3PO2 production cost was estimated at $0.937 kg-1, which was competitive and economically friendly for industrial application.

[Factors Influencing the Progression Trend of Early Lung Cancer and CT Findings].

BACKGROUND: It has been known that the volume doubling time (VDT) of different lung nodule types is different. At present, there is still a lack of studies about the volume doubling time of lung cancer with different pathological types. The purpose of the study is to explore the factors influencing the progression of the early-stage adenocarcinoma, and provide some reference for the follow-up strategy of lung nodules by retrospective analysis of the image data of 143 early-stage adenocarcinoma. METHODS: 143 cases of the early adenocarcinoma were classified according to the 2015 World Health Organization Classification of Lung Tumors and the Eighth edition of the tumor-node-metastasis (TNM) classification of lung cancer. The volume doubling time was calculated with reference to the revised Schwartz formula. RESULTS: Among the 143 cases of the early adenocarcinoma, 50 cases (34.97%) were in progression. By multivarIate analysis, there were several factors associated with the progression of the early adenocarcinoma: the follow-up time, the dimension of nodule, the pathological type, the nodule type and the pathological stage. The VDT of lepidic predominant adenocarcinoma (LPA) is (594±272) d. The VDT of the invasive adenocarcinoma with lepidic part, but not predominant, is (520±285) d. The VDT of the invasive adenocarcinoma without lepidic part is (371±183) d. CONCLUSIONS: About 35% of the early adenocarcinoma is in progress. Whether with the lepidic component is a positive factor to the speed of tumor progression.

[Advance in Diagnose and Treatment Strategies of Adenocarcinoma in Situ].

Adenocarcinoma in situ (AIS) is a new concept which was introduced to the 2011 The International Association for the Study of Cancer (IASLC)/ American Thoracic Society (ATS)/ European Respiratory Society (ERS) International Multidisciplinary Classification of Lung Adenocarcinoma firstly and an important supplement of The 2015 World Health Organization Classification of Lung Tumors. Because AIS is at an early stage of development of lung adenocarcinoma, the deepening understanding of its pathology, differential diagnosis, treatment strategies, has an important significance for the improvement of the prognosis of lung adenocarcinoma. This review will provide a systematic review of the main progress of occurrence and development, pathological characteristics, differential diagnosis and treatment strategy of AIS, in order to provide theoretical basis for the further research of AIS.

[Analysis on the Prognostic and Survival Factors of Synchronous Multiple Primary Lung Cancer].

BACKGROUND: Synchronous multiple primary lung cancer (sMPLC) is a sparse disease in the past, but there has been a gradual increase in the morbidity of sMPLC recently. However, studies on large sample have never been undertaken. The purpose of this study is to investigate the diagnosis, treatment and prognosis of sMPLC through analyzing the clinical data, and provide supports for the management of sMPLC. METHODS: According to Martini-Melamed criteria, 357 patients were diagnosed sMPLC. The pathological staging is on the basis of the 8th edition tumor-node-metastasis (TNM) staging from International Association for the Study of Lung Cancer (IASLC). RESULTS: There were 269 patients with double primary lung cancer, 65 patients with triple primary lung cancer and 23 patients with four or more primary lung cancer. Lesions (68.55%, 571/833) were frequently in upper lobe, especially the right upper lobe. Adenocarcinoma (95.56%, 796/833) was the mainly pathological type, followed by squamous cell carcinoma (2.40%, 20/833). The acinar predominant subtype was the main part (70.81%, 313/442) of the all adenocarcinoma specimens. Most of the lesions (68.35%, 244/357) were stage Ib or low. Among the initial lesion and the following lesions ,patients who had the same pathological type (92.72%, 331/357) were more than the different (7.28%, 26/357), of which adenocarcinoma-adenocarcinoma occupied the major proportion (99.40%, 329/331). The 3-year overall survival (OS) and 5-year overall survival were respective 91.93% and 84.37%. Multivariate analysis found that smoking history (P=0.012), the diameter of the maximum lesion (P=0.027), lymph node metastasis (P=0.015) and pleural invasion (P<0.001) were the independent risk factors for prognosis. CONCLUSIONS: Tumours in patients with sMPLC are more frequently in the right upper lobe. Adenocarcinoma was the mainly pathological type. Smoking history, the diameter of the maximum lesion, lymph node metastasis and pleural invasion were the independent risk factors for prognosis. Early diagnosis and active operation can obtain better prognosis.