Recovery Of Cr Research Articles

The recovery of metals as high value powders and nanopowders from industrial wastewaters using potential-controlled electrolysis

The objective of the presented study was the recovery of Zn, Cr, Cu and Co in the form of powders and nanopowders from various types of industrial wastewaters. Powders and nanopowders as products of high added value find a wide applications in nanotechnology and material science and engineering. The metallic powders were obtained using potentiostatic electroreduction (potential-controlled electrolysis). The chosen method offers better control of the purity and structure of the products. The structure and size of crystallites depend on the value of electrolysis potentials and time, cathode material, concentrations of metal ions. In this investigation, the powders of different sizes ranging from 90 to 230 nm for Cr, 100–4000 nm for Zn, 25–100 nm for Co and 40–660 nm for Cu were deposited. The compositions, purity and size of the cathode deposits were confirmed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Presented metal recovery method is a promising technique for industrial application, given its simplicity, economic viability and environmental sustainability. It can be used on a wide range of solutions and help in reducing the problem of the growing amounts of industrial wastewater.

Surface Complexes of Cr(VI) by Eucalyptus Barks

The sorption mechanism of hexavalent chromium sorption on eucalyptus barks was evaluated as a function of solution pH for different adsorbent dosages, surface coverage, and the amount of adsorbent. The chromium retention was evaluated based on the distribution coefficient (D), and this retention is attributed to species, which is predominant between pH 1 and 6.5. The biosorption of Cr(VI) ions onto barks achieved at pH 2.0 in the highest sorbet conditions corresponding to [Cr(VI)] = 10–5 mol (V = 100 mL) is examined for various surface coverage. The surface complexes formed between chromate and eucalyptus barks were found to be > S (HCrO4) and > S (CrO4). Logarithmic stability for log K1–1 and the log K10 values of the complexes were measured and found to be -5.93 in acidic medium and -0.76 in alkaline medium, respectively. Pointed out that the adsorption of Cr(VI) on eucalyptus bark was greater than 90% in all cases, Cr(VI) recovery is strongly acidic dependent and shows maximum retention, for various sorbent amounts, at pH around 2, and this retention is attributed to species, which is predominant between pH 1 and 6.5, the morphological surface of eucalyptus barks were examined by Scanning Electron Microscope (SEM) connected to a micro analyzer EDS.

Retrieval of trivalent chromium by converting it to its dichromate state from soil using a bipolar membrane electrodialysis system combined with H2O2 oxidation

When a bipolar membrane electrodialysis (BMED) system is used to remove Cr(III) from the soil, the existing metal cations easily affect this removal owing to the migration competition of metal cations. To address this problem, herein, a BMED system combined with H2O2 oxidation was used to recover Cr(III) from soil in the form of Na2CrO4. The experimental results show that H2O2 can oxidise Cr(III) to Cr(VI), which can be recovered as Na2CrO4. The concentrations of electrolyte and humic acid in soil, current densities and addition time of H2O2 influenced Cr(III) recovery, current efficiency and specific energy consumption. Under optimal experimental conditions of a current density of 2 mA/cm2 and H2O2 addition time of 2 h after the BMED system was powered on, more than 69 % of Cr(III) could be recovered. When the number of equipped soil compartments increased from one to two and then to three, the current efficiency increased from 9.9 % to 19.8 % and then to 29.1 % and the specific energy consumption of chromium removal decreased from 7.04 × 10−2 to 5.51 × 10−2 and then to 4.72 × 10−2 kW∙h/g, respectively. When the BMED system was used to recover Cr(III) from actual soil, the recovery rate decreased to 55.9 % owing to the low Cr(III) oxidation rate resulting from more residual state Cr(III) being present in actual soil. Following treatment, the remaining Cr(VI) in soil can be reduced to Cr(III) by adding a reductant. Therefore, the BMED system combined with H2O2 oxidation can be regarded as an effective method for recovering Cr(III) from soil.

In-tube gel electro-membrane combined with microfluidic paper-based device: A green and miniaturized extraction mode for the chromium speciation

• In-tube gel electro-membrane was for the first time introduced as a scaled-down version of G-EME. • Extractions in transparent tube enable visual monitoring during the extraction processes. • With this new set-up, the DP/AP volume ratio can be easily increased to achieve a high enrichment factor. • Gel membrane and microfluidic paper-based analytical devices (µPADs) were a homemade fabrication. • The proposed workflow shows the ease of operation and is highly environmentally friendly. For the first time, in-tube gel electro-membrane microextraction (IT-G-EME) system followed by microfluidic paper-based analytical devices (µPADs) as a low-cost reading platform was fabricated for the speciation of trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)) as model cationic and anionic compounds. In this new miniaturized extraction mode, a transparent narrow-bore polymeric tube was used as housing of the aqueous acceptor phase (AP, 30 µL), while an agarose gel membrane was placed as a micro plug (2.5 mm) at the beginning of the tube. A circular shape vial (1.5 mL, pH 5.5) containing chromium species as donor phase (DP) was connected between two tubes which previously filled with gel membrane and aqueous AP. By applying electric potential, the positively charged Cr(III) and negatively charged Cr(VI) in the DP migrated selectively toward cathodic and anodic tubes, respectively. After extraction, each AP was analyzed by µPAD, which had already been modified with diphenylcarbazide (DPC). Under the optimized extraction conditions, a good limit of detection (LOD) equal to 7.0 µg L –1 was achieved for both analytes, while the extraction recoveries for Cr(VI) and Cr(III) were 72% and 84%. In addition, the developed approach was used for the quantification of chromium species in water samples.

Membrane capacitive deionization (MCDI) for removal of chromium complexes with AC@SiO2-NH2 electrode

Considering the stability and hazard of chromium complexes, their removal and recovery from industrial wastewater is a worthy goal. Membrane capacitive deionization (MCDI) can effectively reduce co-ion adsorption compared with CDI technology and has been demonstrated to be a promising deionization technology. In this study, functionalized activated carbon (AC@SiO2-NH2) was applied as a MCDI eletrode. The AC@SiO2-NH2 adsorbs chromium complexes (Cr(Ⅲ)-EDTA) through electrostatic gravitation of protonated amino groups (-NH3+). With applied voltage of 1.2 V, solution flow rate of 20 mL min−1 and initial concentration of 300 mg L−1, the electrosorption capacity of the AC@SiO2-NH2 electrode for Cr(Ⅲ)-EDTA was 17.70 mg g−1. The Ragone curves verified that the electrosorption rate (SER) of the AC@SiO2-NH2 electrode was positively correlated with voltage and initial concentration. Moreover, the effects of competing ions (K+, Na+, and Mg2+) in a series of single electrolyte solution by the AC@SiO2-NH2 electrode were investigated. It was also verified that the optimum pH was 3 for electrostatic attraction. The energy consumption of the MCDI process is calculated as 0.251 kWh m3 and 0.039 kWh g−1 Cr at 1.2 V. We envisage that the use of AC@SiO2-NH2 electrodes will pave the way for efficient operation of MCDI as well as the preferential recovery of Cr(Ⅲ)-EDTA.

Co-production of a CArdiac Brief INtervention (CABIN) for patients prior to discharge following acute myocardial infarction (AMI)

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Public Health Agency Northern Ireland, Research and Development PhD Fellowship Background Recovery from AMI can be challenging for patients without adequate psychosocial support to overcome anxiety, address misconceptions and initiate lifestyle change (1,2). Reduced length of stay has minimised the opportunity for nurses to evaluate patients’ holistic needs and initiate effective in-hospital interventions (3). Patients and nurses discussed these challenges openly and worked together in this co-design study to develop a brief intervention for the pre-discharge period. Method A multi-site, co-design project was conducted with an exploratory phase of interviewing and focus groups with patients and staff involved in CR. The data from this exploratory phase informed a series of working-group meetings during which this intervention was developed. Results The CABIN (CArdiac Brief INtervention) offers brief, reassuring and compassionate discussions alongside educational content. CABIN consists of 8 components as seen in figure 1. It is designed to be used by nursing staff in the acute setting with patients following their AMI. Staff delivering the intervention must have full understanding of the local CR programme to offer practical advice if necessary. Conclusion CABIN provides a tangible means to emotionally support patients in the acute phase of recovery following AMI. It is envisaged that CABIN will empower acute clinical nursing staff to address the emotional needs of patients in a way which will encourage attendance at CR and subsequent recovery.

Eco-friendly chromium recovery from hazardous chromium-containing vanadium extraction tailings via low-dosage roasting

The Cr recovery from the Cr-containing tailings of vanadium extraction always generates large amounts of hazardous wastewater sludge and solid waste. This work proposed an eco-friendly Cr recovery method based on low-dosage soda roasting for a new kind of Cr-containing tailing, the Mg-based tailing. The low dosage of soda ensures the targeted conversion of Cr-bearing phases in the Mg-based tailing during roasting and minimizes the soda roasting of accompanying phases other than Cr-bearing phases, leading to the minimization of waste discharge. In the optimal condition of low-dosage soda roasting-water leaching, the Cr extraction efficiency is as high as 93.25 %; from the leach liquor, the Cr2O3 product is obtained by Na2S reduction, precipitation, and calcination with total Cr recovery of 92.93 %. For Cr extraction, the soda dosage has been reduced by 20 % while the production rates of hazardous sludge, leach residue, and CO2 have been reduced by 30 %, 18 %, and 20 %, respectively. This work exemplifies the control of targeted phase conversion to minimize hazardous wastes, which provides a novel strategy for eco-friendly resource utilization of hazardous tailings.

Detoxification and comprehensive recovery of stainless steel dust and chromium containing slag: Synergistic reduction mechanism and process parameter optimization

Stainless steel dust and chromium containing slag are representative harmful solid wastes produced in modern iron and steel metallurgy industry. Based on the study of stainless steel dust reduction, the direct reduction process with low energy consumption and high efficiency was obtained by changing the addition amount of chromium containing slag and the conditions of reduction process system. The results show that with the addition of chromium containing slag, the basicity of raw materials decreases, the recovery of metal is improved, and the self-pulverization effect of reducing slag is improved. The optimum process conditions are as follows: the mixing ratio of stainless steel dust to chromium containing slag is 94%: 6%, the reduction temperature is 1400 °C, the reduction time is 25 min, the FC/O is 0.9, the recoveries of Fe, Cr and Ni in the reduction products are 90.5%, 90.6% and 91.2%, respectively, the grades of Fe, Cr and Ni in Fe-Cr-Ni-C alloy are 61.3%, 19.9% and 3.7%, respectively, and the contents of harmful components such as S and P are very low. The self-pulverization rate of reduction slag can reach 92.8%, and the residues of metal Fe, Cr and Ni in reduction slag are 134 ppm, 96 ppm and 129 ppm, respectively.

Treating waste with waste: Metals recovery from electroplating sludge using spent cathode carbon combustion dust and copper refining slag

Electroplating sludge is a hazardous waste and secondary metal resource because of its heavy metal content, which poses a huge threat to environmental safety if not properly disposed. An innovative process of oxidizing roasting followed by water leaching and smelting reduction to recover Cr, Cu, and Ni from electroplating sludge was proposed in this research, in which other two hazardous wastes of spent cathode carbon combustion dust and copper refining slag were co-treated. The NaF from spent cathode carbon combustion dust could convert Cr2O3 to Na2CrO4 using the oxidizing roasting process, resulting in a Cr recovery through the subsequent water leaching. The Na2CrO4 formation was promoted by CaO owing to it transferring the Cr spinel phase of FeCr2O4 [1+] to CaCrO4 and then to Na2CrO4. Under optimal conditions, the Cr recovery reached 97.1 %, and most ‘F’ was solidified into CaF2. In the next smelting reduction of the leaching residue, the Cu and Ni were recovered mainly in the form of Cu-Ni alloy. The addition of copper refining slag promoted their recovery, due to it modifying the molten slag and alloy structures and increasing the Cu-Ni alloy separation from molten slag. Some generated high-melting-point Cu-Ni-Fe and Ni-Fe alloys were converted to a Cu-Ni alloy with a low melting point in presence of Co from the copper refining slag, simultaneously with which the Fe was transferred out from Cu-Ni-Fe and Ni-Fe alloys and combined with Co to form a Fe-Co alloy. It increased Cu-Ni alloy droplets aggregation from molten slag and decreased their contents in the residual slag. Under optimized conditions, the Cu and Ni contents in the residual slag decreased to 0.37 and 0.06 wt%, respectively. Besides, the residual slag mainly composed of CaO, CaF2 and SiO2 could be used to prepare building materials rendering it harmless.

Recovery of Fe, Cr and Ni in pickling sludge with aluminum nitride in secondary aluminum dross

Secondary aluminum dross (SAD) is a hazardous solid waste due to containing aluminum nitride (AlN). In this work, AlN was used to reduce heavy metals in pickling sludge by pyrometallurgy. Reduction extent of Fe, Cr and Ni was up to 97, 91 and 100%. However, it was found that some AlN was oxidized by oxygen. AlN oxidization could be decreased by shortening melting process. The AlN oxidization would be restricted after aluminosilicate was melted. Reduction extent of heavy metals increased from 51% to 86%, when treatment temperature was increased from 1350 to 1400 °C. Meanwhile, AlN oxidization could be exacerbated by increasing CaF2 and soda. The CaF2 and soda could corrode the alumina protective layer on AlN and promote AlN oxidization. Reduction extent of heavy metals decreased from 48% to 19% after adding soda. The AlN oxidization could be restrained by cutting down the air during melting process. After covering the crucible, reduction extent of heavy metals was increased from 48% to 92%, and reduction extent of Fe, Cr and Ni was increased from 58, 18 and 83% to 97, 91 and 100%. After evaluating environment benefit of AlN reducing heavy metals, it was found that utilizing a ton SAD replacing carbon to reduce heavy metals in pickling sludge could reduce carbon emissions of 279 kg. In addition, SAD could be used as reductant to replace Al for chromium metallurgy. Using a ton SAD to replace Al for chromium metallurgy could reduce carbon emission of 3961 kg.

Recovery of chromium (VI) from hazardous APV wastewater using a novel synergistic extraction system

As a well-known hazardous material, chromium (VI) in industrial wastewater has always attracted extensive attention. Many studies have focused on the recovery of Cr (VI) which is still challenging and received considerable interest. In this study, a novel synergistic extraction system using amide as extractant and Cyanex 272 as synergistic extractant was built to recover chromium (VI) from the APV wastewater. After optimizing the process parameters of extractant concentration, initial pH, extraction temperature, extraction time, extraction phase ratio, ammonia concentration and stripping phase ratio, the final extraction and stripping efficiency reached more than 99% and 98%, respectively. The Cr2O3 product with a purity of 99.52 was prepared and the organic phase could be effectively regenerated for recycling. The extraction mechanism of chromium (VI) in the synergistic extraction system was investigated in-depth with slope method, ESI-MS analysis and FT-IR analysis. In addition, molecular electrostatic potentials analysis was used to display visually the formation process of the extract complex. This paper offered a unique approach to guide sustainable chromium (VI) recovery from hazardous wastewater with great industrial and theoretical significance.

The Impact of Natural Deep Eutectic Solvents and Extraction Method on the Co-Extraction of Trace Metals from Fucus vesiculosus.

In recent years, natural deep eutectic solvents (NADES) have been widely investigated for the extraction of food and medicinal plants as well as seaweeds. However, the ability of NADES for trace elements co-extraction from natural sources is not well investigated. The aim of this study was to investigate the ability of common NADES for trace elements co-extraction from Fucus vesiculosus. All of the tested NADES did not recover As and Co (concentration <LOQ). Moreover, all of the tested NADES provided a low recovery (<9%) of Ba, Ca, Fe, Mg, Mn, Sr, and Zn. The method of extraction had not shown a statistically significant effect on the co-extraction of all elements (excluding Ba and Ca). In contrast, the water content in NADES was significantly affected on the recovery of Ba, Ca, Mg, Mn, Sr, and Zn. The recovery of Al and Cr was relatively high and considerably varied (from 1.5 to 59.9%). NADES comprising lactic acid:glucose:H2O (5:3:1) provided the lowest contents of all elements, and the highest extracted amounts were obtained employing water contents of 60–80%. The calculated daily intake of all the elements contained in NADES extracts were less than the daily dose risk estimators. The hazard quotients, hazard indexes, and carcinogenic risk calculated for all trace elements and their combination were considerably less than 1. This evidences no health risk, and carcinogenic risk after topical application of all studied NADES. For the first time, the results of the current study demonstrated that NADES extracts of F. vesiculosus contain a lower amount of trace metals and are safer than the extracts obtained with water and 70% acetone. This indicates a significant advantage for NADES compared with the other solvents.

Sustainable purification of phosphoric acid contaminated with Cr(VI) by Ag/Ag3PO4 coated activated carbon/montmorillonite under UV and solar light: Materials design and photocatalytic mechanism

Wet production of phosphoric acid, the most used low-cost industrial approach, first leads to an impure phosphoric acid contaminated by organic and heavy metal pollutants which requires costly purification before its usage. The present work has investigated for the first time the recovery of Cr(VI), one of the most co-existed heavy metals, from the phosphoric acid medium. For this purpose, three composites based on Ag3PO4 coated on Montmorillonite (MAg3PO4), commercial activated carbon (ACAg3PO4), and synthetic activated carbon (SACAg3PO4) were fabricated. The photocatalytic reduction of Cr(VI) was studied comparatively in the absence and presence of citric acid as a hole scavenger under UV and solar light irradiations. Under UV light, MAg3PO4 was the most efficient, while activated carbon-based photocatalysts showed higher reduction rates under solar light due to the photosensitizing effect. Compared with an aqueous medium, the photocatalytic reduction was very effective without citric acid in a phosphoric acid medium because of the low photogeneration of reactive oxygen species (ROSs). The chemical bonds formed between Ag3PO4 and support materials, as proved by XPS, may boost the photocatalytic activity due to enhanced charges of photogeneration and separation. SACAg3PO4 showed higher reduction ability even at higher Cr(VI) concentrations (100–300 ppm). A comparison study showed that SACAg3PO4 is more effective than as-prepared ACTiO2. This investigation shows promising findings to widen the application of photocatalytic technology in different industrial fields.

A novel process for preparing Fe-Cr-Ni-C alloy: synergetic reduction of stainless steel dust and laterite nickel ore.

In order to improve the recovery ratio of valuable metals in stainless steel dust, reduce environmental pollution, and promote solid waste resource recovery and sustainable development of industry, the synergistic reduction process for preparing Fe-Cr-Ni-C alloy was studied in detail by changing the addition of laterite nickel ore and reduction process conditions. The results show that with the addition of laterite nickel ore, the basicity of raw materials is reduced, the precipitation and aggregation of metal particles are promoted, the separation effect of metals and slags from reduction products is improved, and the metal recovery ratio also improved in the synergistic reduction process. When the ratio of stainless steel dust to laterite nickel ore is 94%:6%, reduction temperature is 1400°C, reduction time is 20min, and FC/O is 0.8, the metals and slags of the reduction product can be separated naturally after cooling; the recoveries of Fe, Cr, and Ni are 90.6%, 90.1%, and 91.2%, respectively. The grades of Fe, Cr, and Ni in the Fe-Cr-Ni-C alloy are 62.7%, 18.9%, and 4.1%, respectively. The content of harmful elements S and P in the alloy is low, so it can be directly used as raw material for stainless steel smelting.

Optimization of sample preparation of Brazilian honeys for TQ-ICP-MS analysis

Mass spectrometry-based techniques have been used to study the chemical profile of honeys to authenticate entomological, botanical and geographical origins. Sample preparation is a crucial step of the analysis to obtaining reliable data and minimizing interference owing to matrix effects. The present work studied the best sample digestion procedure for elemental analysis of Brazilian honeys from Tetragonisca angustula (Jataí) and Apis mellifera sp (Apis) by triple quadrupole inductively coupled plasma mass spectrometry (TQ-ICP-MS). A central composite design with 2² factorial and 3 center points considering different volumes of HNO3 and H2O2 was investigated. There was no statistically significant influence of the amounts of HNO3 and H2O2 on the recoveries of Ag, Al, As, Ba, Be, Ca, Cd, Ce, Co, Cr, Cs, Cu, K, La, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Th, U, V and Zn mass fractions. Machine learning algorithms (Multilayer Perceptron, Random Forest and Support Vector Machine) allowed discriminating entomological origin of honeys based on chemical profile with a classification accuracy of 99%.

Carbon dot-based molecular receptor for the colorimetric sensing of Cr(VI) from aqueous solutions

A novel molecular probe was fabricated by the integration of a smart carbon dot and a Schiff's base viz 4-amino -N-[(2-hydroxyphenyl)methylidene] benzoic acid. The synthesised carbon dot composite was well characterised, and a colorimetric molecular probe derived from ecologically sound carbon dot composite materials was explored for the colorimetric sensing of Cr (VI) in aqueous solutions. The results demonstrated that the developed colorimetric sensor can effectively sense Cr (VI) in aqueous solutions even below the picomolar concentration range. Also, the method's practical applicability was checked by the recovery of Cr(VI) from real tap water samples by the standard addition method and was found to be in the range of 99–109%. Highlights Chromium (VI) is considered as a severe environmental pollutant, due to its highly toxic and carcinogenic properties. Low cost, highly sensitive sensors for the determination of Cr(VI) are highly demanded. We have demonstrated a colorimetric molecular probe for detecting Cr(VI) based on the inner filter effect (IFE). This CD-based nano sensor provides obvious advantages of simplicity, convenience, rapid response, high selectivity, and sensitivity, which have potential application for the detection of Cr(VI) in the environmental industry. The developed colorimetric sensor can be effectively adopted for the sensing of Cr(VI) in aqueous solutions even below the picomolar concentration range. Based on the colorimetric observation we can qualitatively determine the presence of Cr(VI) without the aid of any sophisticated analytical instruments.

Electro-peroxone enables efficient Cr removal and recovery from Cr(III) complexes and inhibits intermediate Cr(VI) generation in wastewater: Performance and mechanism

Available oxidation processes for removing Cr(III) complexes from water/wastewater usually encounter the formation of highly toxic Cr(VI) and the generation of Cr enriched waste sludge, posing challenges on the subsequent disposal. Herein, we achieve efficient removal of Cr(III)-organic complexes and simultaneous recovery of Cr from wastewater with enhanced curtailment of intermediate Cr(VI), by using an electrochemically driven peroxone (i.e., electro-peroxone) process with activated carbon fiber (ACF) electrodes. For Cr(III)-EDTA, electro-peroxone could remove ∼90% total Cr from 11.50 mg/L to 1.20 mg/L and ∼80% total organic carbon, with a strong curtailment of Cr(VI) to less than 0.2 mg/L. Additionally, the process could obtain a complete recovery of the removable Cr, of which 78.3% are enriched at ACF cathode as amorphous Cr(OH)3 deposits and the remaining 21.7% are adsorbed at the anode, thus avoiding the generation of Cr laden sludge. Mechanism studies show the electro-generated H2O2 reacts with O3 to generate abundant HO· for decomplexation, which sequentially oxidizes Cr(III) to Cr(VI), and degrades the released EDTA via stepwise decarboxylated process, as confirmed by HPLC analysis. Multiple pathways including electro-reduction, H2O2 reduction and electro-adsorption synergistically curtail and immobilize the formed intermediate Cr(VI). ACF characterizations and continuous 5-cycle experiments substantiate the excellent reusability of the ACF electrodes. Moreover, this process exhibits satisfactory effectiveness to Cr(III) complexed with other ligands (e.g., citrate and oxalate), and complexed Cr(III) in the real electroplating wastewater. We believe this study would provide an efficient and eco-friendly alternative for Cr(III) complexes removal from wastewater.

Recovery of trivalent and hexavalent chromium from chromium slag using a bipolar membrane system combined with oxidation

Chromium slag (CS) with large quantities of multivalent Cr species (III and VI) generated during chromium salt production is hazardous to nature and living organisms. Furthermore, CS discharge leads to considerable resource wastage. Herein, a bipolar membrane electrodialysis (BMED) system was employed along with hydrogen peroxide (H2O2) oxidation for simultaneously recovering Cr(III) and Cr(VI) from CS in the form of Na2CrO4. A bipolar membrane was used to produce OH− under a direct electric field, providing an alkaline environment for the oxidative conversion of Cr(III) to Cr(VI) in the presence of H2O2, followed by the recovery of Cr(III) and Cr(VI) as Na2CrO4. The effect of H2O2content on Cr(III) oxidation and that of the current density on chromium recovery, current efficiency and specific energy consumption were investigated. Moreover, the morphology of chromium in CS before and after the BMED treatment was analysed. The H2O2 content affected the Cr oxidation rate from Cr(III) to Cr(VI). The current density affected chromium removal, current efficiency and specific energy consumption. At a current density of 2 mA/cm2, the total chromium recovery exceeded 67% and the remaining chromium was mainly in the residual state (RES). When the number of CS compartments increased, the current efficiency was enhanced and the specific energy consumption decreased. Binding state analysis show that Cr(III) and different species of Cr(VI) could be transformed into exchangeable Cr(VI) after H2O2 oxidation and BMED treatment. After the treatment, 92% of the remaining chromium in CS was in the RES. Thus, the employed method can effectively recover chromium from CS and other chromium-contaminated solid waste.

Comparison of Mold Active Triazoles as Primary Antifungal Prophylaxis in Patients With Newly Diagnosed Acute Myeloid Leukemia in the Era of Molecularly Targeted Therapies.

Multiple factors influence the choice of primary antifungal prophylaxis (PAP) in patients with acute myeloid leukemia (AML) undergoing remission induction chemotherapy (RIC) given the recent incorporation of targeted leukemia therapies into these regimens. We evaluated the incidence and characteristics of breakthrough invasive fungal infections (bIFI) in 277 adult patients with newly diagnosed AML undergoing RIC with high-intensity, or low-intensity venetoclax-containing therapy. Patients receiving posaconazole (PCZ), voriconazole (VCZ), or isavuconazole (ISA) for > 5 days as PAP during RIC were included. Echinocandin use prior to, but not concomitantly with, the PAP azole was allowed. IFI (modified EORTC/MSG criteria) occurring after > 5 days of continuous azole exposure or within 14 days of discontinuation were considered bIFI. Proven or probable bIFI were observed in 11 patients (4%). The incidence of bIFI was 2.9% for PCZ, 4.8% for VCZ, and 5.7% for ISA (P = .55). In total, 161 patients (58%) received echinocandin prophylaxis prior to azole initiation. Neither echinocandin exposure nor chemotherapy intensity impacted bIFI rate. Patients with bIFI had a lower rate of absolute neutrophil count recovery > 1000 cells/µL (64% vs 90%, P = .021) or complete remission (CR; 18% vs 66%, P = .002) after RIC. Thirty-eight patients (14%) discontinued PAP due to toxicity, most often hepatotoxicity. Discontinuation due to hepatotoxicity was similar among azoles (PCZ: 13%; VCZ: 15%; ISA: 13%). The rate of bIFI is low during RIC in patients with newly diagnosed AML receiving any of the mold-active triazoles as PAP. Neutrophil recovery and achievement of CR are important for bIFI risk.

Recycling of chromium electroplating sludge using combined calcination-hydrothermal treatment: A risk-reducing strategy for separation of Cr(III) from solid waste

As a kind of hazardous solid waste, electroplating sludge that containing high contents of Cr(III) should be suitably treated to meet the landfill standard. Here we proposed a new way for harm minimization and Cr recovery of the sludge. By employing additional hydrothermal treatment instead of direct leaching after alkali oxidizing calcinations, it shows obvious increase in the Cr removal rate of the sludge. Moreover, the leaching risk of the calcination residue could be lowered down by the hydrothermal treatment. It firstly reveals that the hydrocalumite in the initial sludge will transformed to weak acid soluble CaFe dioxides after calcinations. And the doped Cr(III) in the dioxide will raise the leaching risk of the residue. The hydrothermal leaching enables the decomposition of the dioxide and release of the Cr (III) into the recovered solution of Cr. Furthermore, high purity hematite pigment could be obtained at the same time. This work provides a new insight for reevaluate the feasibility of the heat treatment for Cr containing sludge.