PEDOT Particle Electrodes in a 3D Electrochemical Reactor for Degradation of Organic Contaminants in Water

Photocatalytic degradation of organic contaminants in water by ZnO nanoparticles: Revisited

A semipermeable membrane device (SPMD) is described for passive in-situ monitoring of organic contaminants in water. The device consists of a thin film of neutral lipid (molecular mass generally ≥600 Da), such as triolein, enclosed in thin-walled layflat tubing made of low-density polyethylene or another nonporous polymer. Mathematical models are developed for the device and fitted to concentration data from 2,2',5,5'-tetrachlorobiphenyl and phenanthrene flow-through exposures and dissipation experiments. Model estimates of the average concentrations of test chemical in laboratory exposure water differed from the measured concentrations by <2-fold, indicating that it may be feasible to use the device to determine average concentrations of organic contaminants in natural waters

Ultrasound-assisted heterogeneous peroxymonosulfate activation with Co/SBA-15 for the efficient degradation of organic contaminant in water

Facile one pot in situ synthesis of ZnS–ZnIn2S4 composite for improved photocatalytic applications

Degradation of organic contaminants in water by high-voltage pulse discharges was investigated. The effects of gas flow rate and liquid conductivity on the degradation of 4-chlorophenol were studied. With the increase of time, the liquid conductivity increases, which have an important effect on discharge. Meanwhile, with the increase of time, the concentration of H2O2 increases. Addition of 200 mg/L H2O2, the conversion of 4-chlorophenol was greatly enhanced. This may be due to the synergistic effect of high-voltage pulsed discharge and H2O2. Also, it was found that the influence of quantity of TiO2or CuO on degradation of acetophenone is not apparent, maybe the presence of metal oxides hinders the formation of plasma channel due to increase of collusions between metal oxides and oxygen.

A screening method for multiple classes of pesticides and pharmaceuticals from fish cultivation water was established using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Parallel solid-phase extraction (SPE) with different adsorbents was selected for extracting and purifying analytes with different properties. This method allowed for efficient and economical screening of a virtually unlimited number of compounds without reference standards. In order to evaluate the feasibility of this method, 25 pesticides and pharmaceuticals with different properties were selected. The screening detection limit of this method was 0.015 µg L−1, which was lower than the maximum residue limits. This value showed that the method was suitable for screening organic contaminants in fish cultivation water. In a simulation experiment, the organic contaminants with high intensity (atrazine and carbendazim) were identified by retention time, accurate mass, isotopic pattern, and the main fragment ions. Moreover, the information about the organic contaminants and MS2 spectra was added into a database. Since the QTOF-MS data were traceable, they were saved and could be reexamined for compounds that previously were unexpected. This method provides insight into the screening and identification of organic contaminants in water samples, as well as risk assessment and fishery accident identification.

The degradation of dissolved organic matter in black and odorous water by humic substance-mediated Fe(II)/Fe(III) cycle under redox fluctuation

Recent advances in persulfate activation by magnetic ferrite-carbon composites for organic contaminants degradation: Role of carbon materials and environmental application

In addition to drinking water resources, the need for clean water in many industrial processes is critical. Among potential contaminants, those associated with fuel oxygenate additives (e.g. MTBE) are of concern as they partition into aqueous phases. Development of methods for detection and decontamination, including plasma pollution control, have been the objective of many studies. Here, inductively‐coupled rf plasmas were used for detection of organic contaminants (CH3OH, MTBE) in water. Parent molecule decomposition was followed using actinometric OES. Emission from CO* yielded a detection limit of 0.01 ppm for each compound. Complementary mass spectrometry data were also collected to explore decomposition mechanisms.magnified image

Non-targeted analysis (NTA) methods have been increasingly used to discover organic contaminants in environmental samples. The identification efficiency of conventional NTA workflow is often very low due to many factors such as low fragmentation score between experimental MS2 data and reference MS2 data/in-silico MS2 data. Additionally, the prioritisation of possible candidates is also challenging due to the large number of candidates obtained from MS acquisitions. In this study, a multiplatform data processing workflow applicable to non-targeted LC-MS data is proposed to improve the identification accuracy of organic contaminants in water. This workflow consists of (1) scanning quadrupole data-independent acquisition (SONAR) to acquire relatively clean MS1 and MS2 data, (2) data deconvolution using Progenesis QI Software to filter/select the appropriate ions (MS1 data), (3) the selected MS1 data matching against U.S. EPA Chemistry Dashboard to get a list of the environmentally related candidates with metadata (e.g., data sources, toxicity, and exposure), (4) experimental MS2 data matching against in-silico fragmentation data of the obtained candidate by MetFrag to obtain a fragmentation score, (5) compound identification through ranking the candidates by MetFrag based on fragmentation score and metadata. The identification efficiency of the metadata-based NTA workflow was evaluated using a 33-component mixture of chemicals in a complex sludge water. Out of 33 spiked compounds, 26 compounds had been identified using the defined NTA workflow. Most of the 26 identified compounds were recognized as 1st hit of the candidates obtained from the library searching. Overall, the incorporation of fragmentation score and metadata to rank the candidates has significantly improved the accuracy of the organic contaminant identification in the sludge water, compared to the conventional NTA workflow based solely on the fragmentation score.

Pollution of the aquatic environment with organic contaminants has become a world problem because they are indestructible and most of them have toxic effects on man and organism. This study covers the determination of organic contaminants such as volatile organic compounds (VOCs), total petroleum hydrocarbons (TPHs) oil and grease (O and G) in surface water around tank farms in Oghareki community, Delta State. The samples were collected for a period of twelve months (April 2022 – March 2023) at distances of 100 meters to 1 kilometer away from the tank farms. After sampling, samples were transported to the laboratory for chemical analyses. Each of the samples were tested for the presence of VOCs and TPHs by the use of Gas Chromatography coupled with Flame Ionization Detector (GC/FID) and O and G by Uv / visible spectrophotometer. Data were presented as mean triplicate of analyses and results of organic contaminants in water analyses showed mean O and G in the ranged of 0.002 – 0.006 and 0.004 – 0.007mg/L; mean TPHs in the range of 1.607 – 8.132 and 3.319 – 4.835mg/L, and mean VOCs in the range from 0.014 – 0.409 and 0.122 – 0.354mg/L for months and distances of investigations respective. Observations showed that the surface water around the tank farms are contaminated at some points and polluted at some other points when results of the study locations compared with that of the control. Results of monthly analyses were higher during the dry season than wet season. The contamination / pollution of the environment was attributed to nature of activities around the tank farms. It was therefore recommended that individuals should consider the consequences of their actions and work to improve the quality of soil and water Keywords: Volatile organic compounds, total petroleum hydrocarbons, oil and grease, pollution, contamination, and environment.

Quantitative structure–activity relationship for the oxidation of aromatic organic contaminants in water by TAML/H2O2

Occurrences, sources, and transport of hydrophobic organic contaminants in the waters of Fildes Peninsula, Antarctica

A highly efficient advanced oxidation process for the destruction of organic contaminants in water is reported. The technology is based on the cobalt-mediated decomposition of peroxymonosulfate that leads to the formation of very strong oxidizing species (sulfate radicals) in the aqueous phase. The system is a modification of the Fenton Reagent, since an oxidant is coupled with a transition metal in a similar manner. Sulfate radicals were identified with quenching studies using specific alcohols. The study was primarily focused on comparing the cobalt/peroxymonosulfate (Co/PMS) reagent with the traditional Fenton Reagent [Fe(II)/H2O2] in the dark, at the pH range 2.0-9.0 with and without the presence of buffers such as phosphate and carbonate. Three model contaminants that show diversity in structure were tested: 2,4-dichlorophenol, atrazine, and naphthalene. Cobalt/peroxymonosulfate was consistently proven to be more efficient than the Fenton Reagent for the degradation of 2,4-dichlorophenol and atrazine, at all the conditions tested. At high pH values, where the efficiency of the Fenton Reagent was diminished, the reactivity of the Co/PMS system was sustained at high values. When naphthalene was treated with the two oxidizing systems in comparison, the Fenton Reagent demonstrated higher degradation efficiencies than cobalt/peroxymonosulfate at acidic pH, but, at higher pH (neutral), the latter was proven much more effective. The extent of mineralization, as total organic carbon removed,was also monitored, and again the Co/PMS reagent demonstrated higher efficiencies than the Fenton Reagent. Cobalt showed true catalytic activity in the overall process, since extremely low concentrations (in the range of microg/L) were sufficient for the decomposition of the oxidant and thus the radical generation. The advantage of Co/PMS compared to the traditional Fenton Reagent is attributed primarily to the oxidizing strength of the radicals formed, since sulfate radicals are stronger oxidants than hydroxyl and the thermodynamics of the transition-metal-oxidant coupling.

Preparation of micro-electrolysis material from flotation waste of copper slag and its application for degradation of organic contaminants in water.