Whose Oxygen Atom Is Transferred to the Products? A Case Study of Peracetic Acid Activation via Complexed MnII for Organic Contaminant Degradation.

Identifying reactive species in advanced oxidation process (AOP) is an essential and intriguing topic that is also challenging and requires continuous efforts. In this study, we exploited a novel AOP technology involving peracetic acid (PAA) activation mediated by a MnII-nitrilotriacetic acid (NTA) complex, which outperformed iron- and cobalt-based PAA activation processes for rapidly degrading phenolic and aniline contaminants from water. The proposed MnII/NTA/PAA system exhibited non-radical oxidation features and could stoichiometrically oxidize sulfoxide probes to the corresponding sulfone products. More importantly, we traced the origin of O atoms from the sulfone products by 18O isotope-tracing experiments and found that PAA was the only oxygen-donor, which is different from the oxidation process mediated by high-valence manganese-oxo intermediates. According to the results of theoretical calculations, we proposed that NTA could tune the coordination circumstance of the MnII center to elongate the O-O bond of the complexed PAA. Additionally, the NTA-MnII-PAA* molecular cluster presented a lower energy gap than the MnII-PAA complex, indicating that the MnII-peroxy complex was more reactive in the presence of NTA. Thus, the NTA-MnII-PAA* complex exhibited a stronger oxidation potential than PAA, which could rapidly oxidize organic contaminants from water. Further, we generalized our findings to the CoII/PAA oxidation process and highlighted that the CoII-PAA* complex might be the overlooked reactive cobalt species. The significance of this work lies in discovering that sometimes the metal-peroxy complex could directly oxidize the contaminants without the further generation of high-valence metal-oxo intermediates and/or radical species through interspecies oxygen and/or electron transfer.

Symptom burden and emotional distress in advanced lung cancer: the moderating effects of physicians' communication skills and patients' disease understanding.

PURPOSE: The elevated physical symptom burden in advanced lung cancer can disrupt patients' emotional well-being, and current literature suggests that physicians' good communication skills might be a buffer. However, little is known about for which group of patients this buffering effect is most effective. Based on a cross-sectional study in patients with advanced lung cancer, the present study examined whether the moderating effect of physicians' communication skills on the association between physical symptoms and emotional distress would further depend on patients' perceived disease understanding. METHODS: Patients with advanced lung cancer (n = 199) completed a questionnaire including measures of physical symptoms related to lung cancer, anxiety, and depressive symptoms, perceptions of physicians' communication skills, and self-reported understanding of their disease. RESULTS: Hierarchical regression analyses indicated a significant three-way interaction among physical symptoms, perceptions of physicians' communication skills, and perceived disease understanding on both anxiety and depression. Specifically, physicians' good communication skills exerted a buffering effect only for patients with lower levels of disease understanding. CONCLUSION: Our findings indicate that improving physicians' communication skills may be especially beneficial for reducing the maladaptive emotional reactions to symptom burden for patients with limited disease understanding. When time and resources for communication are restricted, enhanced awareness and focused training may be directed at communicating with patients who possess limited knowledge about their disease.

Correlation Analysis of the Carboxyl and Carbonyl Groups of Natural Organic Matter and the Formation Potential of Trihalomethanes and Chloral Hydrate.

Natural organic matter (NOM) has always been considered the main precursor of disinfection by-products (DBPs) during the chlorine disinfection of drinking water. This research focuses on investigating the correlation between the functional group (carboxyl and carbonyl groups) content of NOM and the formation of trichloromethane (TCM) and chloral hydrate (CH). The quantitative determination of carboxyl groups, carbonyl groups, TCM, and CH were conducted during the drinking water treatment processes with different coagulant dosages and with/without pre-oxidation by KMnO4 or NaClO. The most appropriate coagulant for the removal of conventional components was polyaluminum chloride (PAC), and the dosage was 110 mg/L. Up to 43.7% and 14.5% of the carboxyl and carbonyl groups, respectively, were removed through the coagulation and sedimentation processes, which can be enhanced by increasing PAC dosage. The filtration process further increased the removal rates of these two functional groups to 59.8% and 33.5%, respectively. The formation potential of the TCM and CH decreased as the PAC dosage increased. Pre-oxidation by KMnO4 (0.8-1.0 mg/L) effectively controlled the formation of DBPs while increasing the carboxyl and carbonyl group content. Pre-oxidation by NaClO decreased the formation of TCM rather than CH, and a suitable amount (0.5-1.0 mg/L) decreased the carboxyl and carbonyl groups. It was found that there was a good linear correlation between carboxyl groups and TCM and CH. The linear fit R2 values of the carboxyl groups to TCM and CH were 0.6644 and 0.7957, respectively. The linear fit R2 values of the carbonyl groups to TCM and CH were 0.5373 and 0.7595, respectively.

Effects of Lead (Pb) and Benzo [a] Pyrene (B[a]P) and their Combined Exposure on Element Accumulation in Ryegrass (Lolium perenne L.).

It was observed in this work that application of Pb and B[a]P co-exposure significantly (p < 0.05) reduced Pb content in ryegrass leaves and roots. The effect of Pb dominated the change of N, P, K, Cu, and Cr content in leaves and roots of ryegrass under joint stress of Pb and B[a]P. Principal component analysis showed that the foliar spraying of 400 µmol L-1 Pb and 80 µmol L-1 B[a]P had the best effect on improving the mineral element absorption under combined pollution. Ryegrass has strong resistance and certain Pb and B[a]P absorptive capacities, and can resist combined contamination by transferring N, P, K, Zn, Cu, and Cr contents between the overground and the root. These results highlight the potential capacity of ryegrass for use in the phytoremediation of soils contaminated by Pb and B[a]P.

Performance and potential mechanism of Cr(VI) reduction and subsequent Cr(III) precipitation using sodium borohydride driven by oxalate.

The method of treating high concentrations of Cr(VI) alone by NaBH4 has proved feasible, but the effects of the coexistence of Cr(VI) and organic compounds have not been evaluated. The objective of this study was to explore the potential mechanism by which oxalate affects the reduction of high concentrations of Cr(VI) treated by sodium borohydride (NaBH4) and the subsequent precipitation of Cr(III). The results show that Cr(VI) reduction could be gradually promoted by oxalate (1.0-10 mM). Compared with the control solution, the reduction of Cr(VI) in a 10 mM oxalate solution could be increased from 56.6% to 99.1%. Particularly, the promotion of Cr(VI) reduction attributed to the enhancement of OH- production from NaBH4 hydrolysis due to the increasing concentration of C2O42- species, forming conjugated acid-base pairs in the form HC2O4--C2O42-, which provided an effective buffer. In 0.10-0.40 mM oxalate-Cr(VI)-NaBH4 systems, the resulting Cr(III) could precipitate at different levels within 20 h, and showed settlement rates in the range of 8.8% and 95.8%, but no precipitate was found in 1.0-10 mM oxalate-Cr-NaBH4 systems. This is related to whether there was a sufficient oxalate dosage, which could be complexed with Cr (III) at a molar ratio of 1:1. The precipitates were analysed by means of electron spin resonance (ESR), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), indicating that Cr (III) could support oxalate coprecipitation. The results of the present study reveal the influence of oxalate on Cr(VI) reduction and subsequent Cr (III) precipitation, which are of great significance to the application of NaBH4 in the treatment of industrial wastewater containing Cr(VI)-oxalate.

Isolation of oxytetracycline-degrading bacteria and its application in improving the removal performance of aerobic granular sludge.

Aerobic granular sludge (AGS) is a type of biofilm with good sedimentation and density, high biomass, high organic load tolerance and toxicity resistance. Oxytetracycline (OTC) is an antibiotic widely used in livestock and aquaculture, and its low absorption and high residue bring many risks and harms to the ecological environment. In this study, an OTC-degrading strain TJ3 was isolated from AGS and identified as Pandoraea sp. The biodegradation characteristics of OTC by strain TJ3 under different environmental conditions were also investigated. The results showed that the optimal initial pH value and temperature for the culture strain were 6.0 and 30 °C, respectively. At an inoculation dose of 6% (v/v), the removal rate of OTC by strain TJ3 was remarkable (59.4%). Furthermore, when the sodium acetate was present as an additional substrate, the biomass and the OTC removal rate of strain TJ3 were improved. The biodegradability of strain TJ3 to OTC was proved by LC-QTOF/MS, and two possible biotransformation products, i.e. m/z 416 and 219, were identified. In the bioaugmentation experiments of AGS by strain TJ3, the average OTC removal rate was 92.89% after the stable operation of bioreactor. The chemical oxygen demand (COD), ammonium nitrogen (NH4+-N) and total phosphorus (TP) were efficiently removed. The microbial community structure had significantly changed at the genus level, and the relative abundance of Zoogloea, Pandoraea, Cloacibacterium and Desulfovibrio increased evidently. These results implied that the OTC removal performance and the structural stability of AGS were improved. In this study, Pandoraea sp. TJ3 was applied to removal OTC for the first time, and results showed that Pandoraea sp. TJ3 may be a new auxiliary bacterial resource for the biodegradation of OTC and a potential candidate in the treatment of antibiotic wastewater.

The key role of inoculated sludge in fast start-up of sequencing batch reactor for the domestication of aerobic granular sludge.

Two types of inoculated sludges, granular sludge that had been stored at -20°C and activated sludge, were investigated for the domestication of aerobic granular sludges (AGSs) in sequencing batch reactors (SBRs). The results showed that using the stored granular sludge as inoculation sludge could effectively shorten the domestication time of AGS and yielded mature granular sludge after 22 days of operation. The AGS domesticated by stored granular sludge had better biomass and sedimentation properties; its MLSS and SVI reached 8.55 g/L and 35.27 mL/g, respectively. The removal efficiencies for chemical oxygen demand (COD), ammonium nitrogen (NH4+-N) and total phosphorus (TP) reached 90.76%, 97.39% and 96.40%, respectively. By contrast, 54 days were needed to obtain mature granules using activated sludge. The microbial community structure was probed by using scanning electron microscopy (SEM) and high-throughput sequencing. The results showed that the diversity of the microbial community in mature granules was reduced when stored granular sludge rather than activated sludge was employed as inoculation sludge, and the dominant microbes were changed. The dominant species in mature granules domesticated using stored granular sludge were Zoogloea, Acidovorax and Tolumonas at the genus classification level, while the dominant species were Zoogloea and TM7-genera in granules developed from activated sludge.

High molecular weight fibroblast growth factor 2 induces apoptosis by interacting with complement component 1 Q subcomponent-binding protein in vitro.

Fibroblast growth factor 2 (FGF2) is a multifunctional cell growth factor that regulates cell proliferation, differentiation, adhesion, migration, and apoptosis. FGF2 has multiple isoforms, including an 18-kDa low molecular weight isoform (lo-FGF2) and 22-, 23-, 24-, and 34-kDa high molecular weight isoforms (hi-FGF2). Hi-FGF2 overexpression induces chromatin compaction, which requires the mitochondria and leads to apoptosis. Complement component 1 Q subcomponent-binding protein (C1QBP) plays an important role in mitochondria-dependent apoptosis by regulating the opening of the mitochondrial permeability transition pore. However, the interaction between C1QBP and hi-FGF2 and its role in hi-FGF2-mediated apoptosis remain unclear. Here, we found that hi-FGF2 overexpression induced depolarization of the mitochondrial membrane, cytochrome c release into the cytosol, and a considerable increase in C1QBP messenger RNA and protein expression. Furthermore, coimmunoprecipitation results showed that the mitochondrial protein, C1QBP, interacts with hi-FGF2. C1QBP knockdown using small interfering RNA significantly decreased the localization of hi-FGF2 to the mitochondria and increased the rate of apoptosis. Our results highlight a novel mechanism underlying hi-FGF2-induced, mitochondria-driven cell death involving the direct interaction between hi-FGF2 and C1QBP and the upregulation of C1QBP expression.

Synthesis of 1,2-Dihydroquinazolines via Rearrangement of Indazolium Salts.

A convenient synthesis of 1,2-dihydroquinazolines via rearrangement of indazolium salts was described. A mechanistic study using isotope labeling experiment revealed that the rearrangement passes through cleavage of N-N bond/ring opening after basic deprotonation of 2-benzyl in indazolium salts to yield intermediate E, which proceeds in an intramolecular N-nucleophilic addition to form the observed product. Computational analyses imply that the pathway of the rearrangement is determined by the energy barriers of the ring-closing process and the stability of the product.

Interface Mechanisms of Catalytic Ozonation with Amorphous Iron Silicate for Removal of 4-Chloronitrobenzene in Aqueous Solution.

Iron silicate was synthesized and characterized as an efficient ozonation catalyst. Results indicated that iron silicate is a microporous material with poor crystallinity. Fe-O-Si and Fe-O bonds were observed on its surface. The Fe-O bonds belonged to α-Fe2O3. Heterogeneous catalytic ozonation test was performed in batch reaction mode, and 4-chloronitrobenzene was used as model organic compounds. Amorphous iron silicate exhibited high catalytic activity, ozone utilization efficiency, and stability in catalytic ozonation. Hydroxyl radical was the dominant oxide species in this process. The reaction mechanism at the solid-water interface indicates that Fe-Si binary oxides on iron silicate surface inhibited ozone futile decomposition. This behavior resulted in enhanced probability of the reaction between ozone and α-Fe2O3 on the iron silicate surface to generate hydroxyl radicals, which promoted 4-chloronitrobenzene removal in aqueous solution.

Copper Corrosion Products Catalyzed Reduction of N-Nitrosodimethylamine with Iron.

Copper corrosion products (Cu(OH)2, Cu2O, CuO and Cu2CO3(OH)2) were applied to catalyze the reduction of N-Nitrosodimethylamine (NDMA) with iron. All the copper corrosion products showed catalytic abilities. Lower pH values and DO concentrations facilitated NDMA reduction in most cases. 1,1-dimethylhydrazine (unsymmetrical dimethylhydrazine, UDMH) and dimethylamine (DMA) formed during the degradation of NDMA. There were also some undetected products. Catalytic hydrogenation was proposed as the mechanism. The catalytic systems did not promote the formation of hydrogen atoms. The dissolved copper ions in these systems were too sparse to enhance the reaction. The smooth iron surface and formation of Cu2O in each catalytic system explained the enhancement of NDMA removal. Different surface morphologies and states of Cu2O accounted for the differences in NDMA removal and kinetics between the reaction systems. This technique could be an alternative for NDMA reduction and could broaden the application of copper corrosion products.

Effects of Complex Pollution of Pb and B[a]P on the Growth and Physiological and Biochemical Indexes of Ryegrass.

Effects of complex pollution of Pb and B[a]P on the growth and physiological and biochemical indexes of ryegrass were investigated in a potted soil. The results showed that under single Pb treatment condition, low-concentration (0-100 mg kg-1) Pb stimulated the increase of ryegrass biomass while high-concentration (200-400 mg kg-1) Pb obviously inhibited ryegrass growth. Under single B[a]P pollution condition, low-concentration (0-30 mg kg-1) B[a]P facilitated the growth of ryegrass while high-concentration (50-100 mg kg-1) B[a]P had toxic effect on ryegrass. Under joint impacts of Pb and B[a]P at low concentrations, biomass, chlorophyll content and carotenoid content as well as POD and CAT activities of ryegrass presented firstly rising and then descending trends, SOD accumulation increased slightly and MDA didn't experience obvious change. Under co-existence of Pb and B[a]P, Pb was the main toxic factor for ryegrass growth and it controlled the variation trend of whole growth cycle of ryegrass.

Response surface methodology investigation into optimization of the removal condition and mechanism of Cr(â ¥) by Na2SO3/CaO.

The removal of Cr(Ⅵ) by chemical reduction-precipitation is widely applied in wastewater treatment plants. Nevertheless, the formation of Cr(OH)3 with gel properties has weak settlement performance, making it necessary to add a coagulant aid to reduce the settling time and improve the settling effect. In this investigation, a high concentration of Cr(Ⅵ) was removed using Na2SO3 as a reducing agent and CaO as a coagulant. An improved reduction and precipitation experiment was modeled by applying a three-factor central composite experimental design (CCD). To reveal as many mechanisms as possible for CrT removal, other verification experiments were performed. The CrT removal efficiency decreased, which can be explained by the following three reasons: dissolution of Cr(Ⅲ), competition for adsorption between Ca2+ and Cr(Ⅲ) at different coagulation times, and formation of a solubility complex with Cr(Ⅲ) due to the surplus SO32- in solution. The increasing CrT removal efficiency can be explained by the following two reasons: dissolved Ca2+ from CaO can neutralize CrO2- that is produced by the dissolution of Cr(OH)3 in alkaline solution and can broaden the optimal final pH range of coagulation. Ca2+ could also strengthen the CrT removal through adsorption bridging and co-precipitation with CaO as the core of flocs.

Removal of pharmaceuticals from synthetic wastewater in an aerobic granular sludge membrane bioreactor and determination of the bioreactor microbial diversity.

Five types of pharmaceuticals and personal care products (PPCPs) substances were selected as pollutants in this study. The effects of the removal of these pollutants and the microbial succession process in a granular sludge membrane bioreactor (GMBR) were investigated. Results showed that wastewater containing PPCPs influenced the performance of granular sludge. The removal of the five PPCPs from the GMBR had different effects. The removal rates of prednisolone, norfloxacin and naproxen reached 98.5, 87.8 and 84 %, respectively. The degradation effect in the GMBR system was relatively lower for sulphamethoxazole and ibuprofen, with removal efficiency rates of 79.8 and 63.3 %, respectively. Furthermore, the microbial community structure and diversity variation of the GMBR were analysed via high-throughput sequencing technology. The results indicated the structural and functional succession of the microbial community based on the GMBR process. The results indicate the key features of bacteria with an important role in drug degradation.

Effect of nitrogen/phosphorus concentration on algal organic matter generation of the diatom Nitzschia palea: Total indicators and spectroscopic characterization.

Critical algal blooms in great lakes increase the level of algal organic matters (AOMs), significantly altering the composition of natural organic matters (NOMs) in freshwater of lake. This study examined the AOM's characteristics of Nitzschia palea (N. palea), one kind of the predominant diatom and an important biomarker of water quality in the great lakes of China, to investigate the effect of AOMs on the variation of NOMs in lakes and the process of algal energy. Excitation-emission matrix fluorescence (EEM) spectroscopy, synchronous fluorescence (SF) spectroscopy and deconvolution UV-vis (D-UV) spectroscopy were utilized to characterize AOMs to study the effects of nutrient loading on the composition change of AOMs. From results, it was revealed that the phosphorus is the limiting factor for N. palea's growth and the generation of both total organic carbon and amino acids but the nitrogen is more important for the generation of carbohydrates and proteins. EEM spectra revealed differences in the composition of extracellular organic matter and intracellular organic matter. Regardless of the nitrogen and phosphorus concentrations, aromatic proteins and soluble microbial products were the main components, but the nitrogen concentration had a significant impact on their composition. The SF spectra were used to study the AOMs for the first time and identified that the protein-like substances were the major component of AOMs, creating as a result of aromatic group condensation. The D-UV spectra showed carboxylic acid and esters were the main functional groups in the EOMs, with -OCH3, -SO2NH2, -CN, -NH2, -O- and -COCH3 functional groups substituting into benzene rings.

Study on the growth and photosynthetic characteristics of wheat seedlings under [C4mim][OAc] (1-butyl-3-methyl-imidazolium acetate) with Cd²âº stress.

In this paper, the joint effect of 0.5 mmol·L(-1) Cd(2+) and various concentrations (50-400 mg·L(-1)) of the ionic liquid 1-butyl-3-methyl-imidazolium acetate ([C4min][OAc]) on the growth and photosynthetic performance of wheat seedlings in hydroponic culture was investigated. Seedlings grown in presence of Cd(2+) and [C4min][OAc] showed significant (p < 0.05) improvement in growth (shoot and root lengths and dry weights) and photosynthetic performance (photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll a but not chlorophyll b) compared to seedlings grown in the presence of Cd(2+) but without [C4min][OAc]. However, this only happened under the lower range of [C4min][OAc] concentrations (50-200 mg·L(-1)). In addition, significant reduction in the level of Cd(2+) was also observed in the leaf tissue of wheat seedlings grown in the presence of 0.5 mmol·L(-1) Cd(2+) and 100 mg·L(-1) [C4min][OAc]. Overall, Cd(2+) exerted a stronger inhibition than [C4min][OAc] on the growth and photosynthetic performance of wheat seedlings. However, when both Cd(2+) and [C4min][OAc] were present in the culture, the toxicity of Cd(2+) could be mitigated by lower concentrations of [C4mim][OAc]. This phenomenon could be due to [C4mim][OAc] forming metal complexes with Cd(2+), thus reducing the toxicity of Cd(2+).

PPCPs removal by aerobic granular sludge membrane bioreactor.

An aerobic granular sludge membrane bioreactor (GMBR) was applied to the treatment of pharmaceutical and personal care products (PPCPs) wastewater. The influence of granular sludge on five antibiotic and antiphlogistic PPCPs wastewater and the removal effect of methyl alcohol and conventional organic matter were investigated while constantly reducing the density of inflow organic matter. The results showed that the sludge granulation process in the system was rapid but unstable, and that the system exhibits a dissolution-reunion dynamic equilibrium. The reactor demonstrated varying removal effects of PPCPs on different objects. The use of a GMBR was more effective for the removal of prednisolone, naproxen, and ibuprofen; the first two drugs were lower the average removal rate of which reached 98.46 and 84.02 %, respectively; whereas the average removal rate of ibuprofen was 63.32 %. By contrast, the GMBR has an insignificant degradation effect on antibiotics such as amoxicillin, indicating that such antibiotic medicine is not easily degraded by microorganisms, which plays different roles in system operation. Because of the different chemical structures and characteristics of drugs that result in various degradation behavior. During the GMBR granulation process, the value of mixed liquor volatility suspended solids (MLVSS) gradually increases from 1.5 to 4.1 g/L during the GMBR granulation process, and the removal rate of CODCr reaches up to 87.98 %. After reducing the density of organic matter is reduced, the removal rates of NH3-N and TP both reach more than 90 %, respectively. Moreover, the proposed technique is considerably effective in the removal of methanol.

Adsorption kinetics of benzotriazole and its derivatives by nano Zn-Al-O.

Benzotriazole and its derivatives are important industrial auxiliaries, which are serious pollution sources in the natural aquatic environment. Benzotriazole and its derivatives adsorption by a novel nano absorbent (nano Zn-Al-O binary metal oxide, named as ZAO) being explored as an effective water treatment method, was carried out in this study. Results showed that benzotriazole and its derivatives were all effectively adsorbed from water by ZAO. Removal efficiencies of benzotriazole, 5-methyl-benzotriazol and 5,6-dimethyl-benzotriazole with 5 g/L adsorbent dosage achieved 89%, 81% and 92%, respectively. The adsorption kinetics and isotherm models were used to express the adsorption process and discuss the adsorption mechanism. The adsorption kinetics well followed pseudo-second-order model, indicating that chemical adsorption dominated the adsorption. Adsorption isotherm was well expressed by Freundlich model. Structure characteristics of benzotriazole and its derivatives had great effect on their adsorption. Hydrogen-bond interaction was considered as the main mechanism for the surface adsorption. However, hydrophobic interactions played an important role in 5,6-dimethyl-benzotriazole adsorption due to its weak polarity.

Performance of aerobic granular sludge in different bioreactors.

Inoculated sludge from the Brewery wastewater treatment plant was cultured in a sequencing batch reactor (SBR). The granular sludge was then used to process the artificial simulation wastewater to compare the performance and efficiency of the granular sludge in organic matter removal by using SBR and granular membrane bioreactor (GMBR). Results showed that the granular sludge in the SBR exhibited desirable characteristics and good removal efficiency. The mixed liquor suspended solids (MLSS) and the sludge volume index (SVI) were approximately 2.56 g/L and 78.13 mL/g, respectively, and it exhibited a satisfactory settling ability. The removal efficiency of the resulting chemical oxygen demand (COD), NH3-N and total phosphorus (TP) reached 89.35%, 96.49% and 83.76%, respectively. The removal efficiency of both nitrate nitrogen and total nitrogen (TN) reached 90%. The performance of the granular sludge as well as the removal efficiency of the organic matter in the GMBR was subsequently observed. Results showed that the process influenced the characteristics and microbial biomass of the granular sludge. The SVI and the MLSS were about 175.82 mL/g and 1.14 g/L, respectively. The removal efficiency of COD and TP increased to 93.17% and 90.42%, respectively. The removal efficiency of NH3-N was slightly affected, whereas that of both nitrate nitrogen and TN increased to 95%. In this study, the physical properties and the removal efficiency of granular sludge in different bioreactors were compared. The comparison demonstrated that granulation membrane bioreactors perform more efficiently compared with SBR in wastewater treatment for organic matter removal.

Effects of [C2mim][OAc] (1-ethyl-3-methyl-imidazolium acetate) on the growth of wheat seedlings under Cd²âº stress.

The joint effect on the growth of wheat seedlings under Cd(2+) stress (0, 0.5 mmol L(-1)) and [C2mim][OAc] with a series of concentrations (0, 100, 200, 300, 400, 500 mg L(-1)) was investigated. Physiological characteristics including superoxide dismutases, peroxidases, catalase and malondialdehyde were studied in hydroponic and soil cultures. Results indicated that, compared to samples treated under Cd(2+) stress alone, joint treatment groups showed Cd(2+) stress was mitigated by ionic liquid at appropriate concentrations (≤ 400 mg L(-1) in hydroponic treatments and ≤ 300 mg L(-1) in soil culture treatments). Use of inductively coupled plasma mass spectroscopy showed less Cd(2+) in organelles in the joint treatment group. This phenomenon could be due to [C2mim][OAc] forming metal complexes with Cd(2+), thus reducing the amount of free Cd(2+) available for absorption by the seedlings.