Polydopamine-Modified 2D Iron (II) Immobilized MnPS3 Nanosheets for Multimodal Imaging-Guided Cancer Synergistic Photothermal-Chemodynamic Therapy.

Manganese phosphosulphide (MnPS3 ), a newly emerged and promising member of the 2D metal phosphorus trichalcogenides (MPX3 ) family, has aroused abundant interest due to its unique physicochemical properties and applications in energy storage and conversion. However, its potential in the field of biomedicine, particularly as a nanotherapeutic platform for cancer therapy, has remained largely unexplored. Herein, a 2D "all-in-one" theranostic nanoplatform based on MnPS3 is designed and applied for imaging-guided synergistic photothermal-chemodynamic therapy. (Iron) Fe (II) ions are immobilized on the surface of MnPS3 nanosheets to facilitate effective chemodynamic therapy (CDT). Upon surface modification with polydopamine (PDA) and polyethylene glycol (PEG), the obtained Fe-MnPS3 /PDA-PEG nanosheets exhibit exceptional photothermal conversion efficiency (η = 40.7%) and proficient pH/NIR-responsive Fenton catalytic activity, enabling efficient photothermal therapy (PTT) and CDT. Importantly, such nanoplatform can also serve as an efficient theranostic agent for multimodal imaging, facilitating real-time monitoring and guidance of the therapeutic process. After fulfilling the therapeutic functions, the Fe-MnPS3 /PDA-PEG nanosheets can be efficiently excreted from the body, alleviating the concerns of long-term retention and potential toxicity. This work presents an effective, precise, and safe 2D "all-in-one" theranostic nanoplatform based on MnPS3 for high-efficiency tumor-specific theranostics.

Enhanced struvite generation and separation by magnesium anode electrolysis coupled with cathode electrodeposition.

Adding magnesium ions (Mg2+) to produce struvite is an important method to recover nitrogen and phosphorus from wastewater. Both the Mg2+ source and subsequent separation of struvite are key factors for the utilization of struvite. In this study, we developed an efficient method to recover nutrient salts from wastewater using sacrificial Mg anodes to generate struvite, with its simultaneous separation through cathode electrodeposition. The anode-released Mg2+ reacted with NH4+-N and PO43--P in bulk solution to form struvite, which was more intense on the cathode surface due to the relatively higher pH environment from hydrogen evolution, resulting in most of the struvite being deposited on the cathode surface and simultaneously separated out of the bulk solution. Using a cathode with a higher solution-cathode interface area and relatively low current density facilitated struvite deposition. Results showed that under optimal electrolysis condition (5.76 A/m2, pH 8.5, 180 min, and 1.2:1.0 Mg:P), 91% of the undissolved substances as the phosphate precipitation were deposited on the graphite cathode surface, and the proportion of struvite in the deposition reached 41.52%. This study provides a novel electrochemical method for struvite synthesis and separation for the recovery of nitrogen and phosphorus from wastewater.

Integrated sulfur- and iron-based autotrophic denitrification process and microbial profiling in an anoxic fluidized-bed membrane bioreactor.

The integrated sulfur- and Fe0-based autotrophic denitrification process in an anoxic fluidized-bed membrane bioreactor (AnFB-MBR) was developed for the nitrate-contaminated water treatment in order to control sulfate generation and avoid alkalinity supplement. The nitrate removal rate of the AnFB-MBR reached 1.22 g NO3--N L-1d-1 with NO3--N ranging 40-200 mg L-1 at hydraulic retention times of 1.0-5.0 h. The denitrification in the integrated system was simultaneously carried out by sulfur- and Fe0-oxidizing autotrophic denitrifiers. The effluent sulfate generation was decreased by 29.3-70.3% and 31.2-50.9% due to the functional role of Fe0-based denitrification in the integrated system. Alkalinity produced by Fe0-oxidizing autotrophic denitrification could compensate for the alkalinity consumption by sulfur-based autotrophic denitrification. The sulfur- and Fe0-oxidizing autotrophic denitrifying bacterial consortium was composed mainly of bacteria from Thiobacillus, Sulfurimonas, and Geothrix genera. The integrated modes leads to a harmonious co-existence of sulfur- and Fe0-oxidizing denitrifying microbes, which may make a difference to the functional performance of the bioreactor. Overall, the integrated sulfur- and Fe0-based autotrophic denitrification could overcome the shortcomings of excess sulfate generation and external alkalinity supplementation compared to the sole sulfur-based autotrophic denitrification, indicating further potential for the technology in practice.

Removal characteristics of microplastics by Fe-based coagulants during drinking water treatment.

Microplastics have caused great concern worldwide recently due to their ubiquitous presence within the marine environment. Up to now, most attention has been paid to their sources, distributions, measurement methods, and especially their eco-toxicological effects. With microplastics being increasingly detected in freshwater, it is urgently necessary to evaluate their behaviors during coagulation and ultrafiltration (UF) processes. Herein, the removal behavior of polyethylene (PE), which is easily suspended in water and is the main component of microplastics, was investigated with commonly used Fe-based salts. Results showed that although higher removal efficiency was induced for smaller PE particles, low PE removal efficiency (below 15%) was observed using the traditional coagulation process, and was little influenced by water characteristics. In comparison to solution pH, PAM addition played a more important role in increasing the removal efficiency, especially anionic PAM at high dosage (with efficiency up to 90.9%). The main reason was ascribed to the dense floc formation and high adsorption ability because of the positively charged Fe-based flocs under neutral conditions. For ultrafiltration, although PE particles could be completely rejected, slight membrane fouling was caused owing to their large particle size. The membrane flux decreased after coagulation; however, the membrane fouling was less severe than that induced by flocs alone due to the heterogeneous nature of the cake layer caused by PE, even at high dosages of Fe-based salts. Based on the behavior exhibited during coagulation and ultrafiltration, we believe these findings will have potential application in drinking water treatment.

Ultrafiltration membrane fouling induced by humic acid with typical inorganic salts.

Severe ultrafiltration (UF) membrane fouling is always induced by humic acid (HA). However, little attention has been paid to the influence of inorganic salts, and even the studies related have been limited to only a single kind of salt. In addition, the concentration of the inorganic salts reported in previous studies is much high. Herein, the effect of HA on UF membrane performance was investigated in the presence of typical inorganic salts, with concentrations similar to those in natural waters or actually used in most current water plants. The results showed that membrane performance was influenced little by monovalent inorganic salts (NaCl and KCl), while divalent inorganic salts (CaCl2 and MgCl2) could exacerbate the membrane fouling. For trivalent inorganic salts (AlCl3·6H2O and FeCl3·6H2O), floc adsorption was the dominant HA removing mechanism, and AlCl3·6H2O behaved better than FeCl3·6H2O. Relating to the floc properties, severe membrane fouling occurred with low dosage, while it was mitigated with high dosage. Compared with the trivalent inorganic salts, more severe membrane fouling was caused by divalent inorganic salts. Additionally, little synergistic or inhibitory effect occurred with mixtures of divalent inorganic salts and trivalent inorganic salts. Furthermore, analysis with the classical fouling models showed that cake filtration was the main fouling mechanism with/without inorganic salts. Based on the findings, we believe these different HA behaviors exhibited during coagulation process with inorganic salts will have a large potential application in UF membrane fouling alleviation in water treatment.

Effects of copper(II) and copper oxides on THMs formation in copper pipe.

Little is known about how the growth of trihalomethanes (THMs) in drinking water is affected in copper pipe. The formation of THMs and chlorine consumption in copper pipe under stagnant flow conditions were investigated. Experiments for the same water held in glass bottles were performed for comparison. Results showed that although THMs levels firstly increased in the presence of chlorine in copper pipe, faster decay of chlorine as compared to the glass bottle affected the rate of THMs formation. The analysis of water phase was supplemented by surface analysis of corrosion scales using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDX). The results showed the scales on the pipe surface mainly consisted of Cu(2)O, CuO and Cu(OH)(2) or CuCO(3). Designed experiments confirmed that the fast depletion of chlorine in copper pipe was mainly due to effect of Cu(2)O, CuO in corrosion scales on copper pipe. Although copper(II) and copper oxides showed effect on THMs formation, the rapid consumption of chlorine due to copper oxide made THM levels lower than that in glass bottles after 4h. The transformations of CF, DCBM and CDBM to BF were accelerated in the presence of copper(II), cupric oxide and cuprous oxide. The effect of pH on THMs formation was influenced by effect of pH on corrosion of copper pipe. When pH was below 7, THMs levels in copper pipe was higher as compared to glass bottle, but lower when pH was above 7.

Coagulation and disinfection efficiency of an electrochemically prepared dual-function reagent in municipal wastewater.

A novel dual-function chemical reagent was successfully prepared by electrolysis process. With high content of Al13 species and active chlorine, the electrochemically prepared polyaluminum chlorine (E-PACl) as the dual-function chemical reagent presented the integrated properties of coagulation and disinfection in water treatment. The results obtained from jar tests in municipal wastewater and hydrolyzed Al (III) speciation distribution characterization confirmed that the Al13 species was the most effective polymeric Al species in PACl responsible for coagulation. The solid-state 27Al NMR spectra for precipitates revealed that the precipitates structure formed from Al coagulants with various pre-hydrolysis degrees were significantly different, and proved that the preformed Al13 polymer is quite stable during the coagulation process. E-PACl performed well on both particulate and organic matter removals in municipal wastewater treatment. The higher the degree of pre-hydrolysis, the lower the efficiency of the coagulant removed phosphorus from water. The active chlorine in E-PACl was an effective disinfectant to inactivate fecal coliforms. When dosed 24 mg Al/L E-PACl, effective coagulation and disinfection in municipal wastewater could be achieved simultaneously. E-PACl may have a great potential to domestic use and small treatment plants for municipal wastewater reuse.