Papers by Keyword: Hydroquinone

Abstract: Herein, in order to detect hydroquinone (HQ) and catechol (CC) simultaneously, an electrochemical sensor with good selectivity and sensitivity was developed. It is constructed by electrodeposition of carbon nanodots (CDs) on the surface of multi-walled carbon nanotubes (MWNTs) doped glassy carbon electrode. First, the experimental parameter was optimized. The electrochemical behavior was then evaluated by electrochemical impedance spectroscopy and cyclic voltammetry. The linear range for HQ and CC was 0.1-200 μM, and the detection limit was 0.03 μM. Incorporated the large surface area and fast charge transfer of MWNTs and CDs with electrodeposition technology's stability, high excellent selectivity, sensitivity, stability and good reproducibility was exhibited by the fabricated sensor. Furthermore, the electrode was successfully used to determine the concentration of HQ and CC in tap water, and thus exhibited potential applications environment monitoring.

Abstract: Coal gasification wastewater, as a typical industrial wastewater has poor biodegradability and high toxicity. In this paper, simple anaerobic shaker test was conducted to investigate the degradation of hydroquinone in coal gasification wastewater. Anaerobic sludge shaker test were run for 27, 50 and 73 days, the phenol concentration were adjusted to 300 mg/L and 500 mg/L with pH 7.5, respectively. The experimental results also showed that this system could effectively deal with COD and phenol removal and remain in a stable level when the operational parameters altered while the hydrolysis acidification at 45h is appropriate. Organics degradation and transformation of anaerobic coal gasification wastewater samples at 12h, 24h, 36h, 48h, and 60h were analyzed by GC/MS and it was found that hydrolysis acidification played an important role in degradation of methyl phenol, hydroquinone and refractory compounds. Therefore, the results illustrated that the simple anaerobic shaker process is an easy way for pollutant degradation and treat coal gasification wastewater effectively.

Abstract: A copper doped L-threonine modified electrode was prepared by cyclic voltammetry (CV), and the electrochemical behavior of hydroquinone at the modified electrode had been studied. A novel determination method of hydroquinone using CV, chronoamperometry and differential pulse voltammetry (DPV) was established, and the scan rate and supporting electrolyte factors on catalytic oxidation of hydroquinone in modified electrodes were discussed. The results revealed that the modified electrode had showed obvious electrocatalytic activity for hydroquinone, and anodic peak current increased linearly with the concentration of hydroquinone in the range of 0.8-150 μmol/L with the detection limit of 0.4 μmol/L (S/N=3). The method has been applied to the determination of hydroquinone in water sample with satisfactory results.the recovery ranged from 95.9 % to 105.2 %.

Abstract: Nitrogen doping TiO₂ was prepared and used to degrade acrolein wastewater under simulated solar irradiation acrylic acid. The results showed that the removal of acrolein, hydroquinone and acrylic acid were 0.73, 0.64, 0.26 after 4 hour degradation by TiO₂/UV system. The degradation of acrolein, hydroquinone and acrylic acid using TiO₂/UV system followed pseudo first-order kinetics. It results indicated that this proposed method can be useful for the pretreatment acrolein wastewater.

Abstract: The poly-histidine (poly-HTD) film was prepared at glassy carbon electrode by electropolymerization, and its electrochemical behavior was investigated by cyclic voltammetry. Results show that the behavior of this poly-HTD film is in good agreement with quasi-reversible process characteristic. At low scan rates, the electronic transfer process of electrode reaction is controlled by surface process. At this poly-HTD film modified electrode, an excellent electrocatalytic ability towards the redox of hydroquinone (HQ) and catechol (CC) with decrease of the overpotential and improvement of the redox peak currents was found. Differential pulse voltammetry was used for the simultaneous determination of HQ and CC in their mixture, and the peak-to-peak separation ΔE_p for HQ and CC was 110 mV. Therefore, this polymer modified electrode can be used for the simultaneously selective determination of HQ and CC without interference with each other.

Abstract: As the toxicity even at low concentrations, pollution of phenolic compounds has become an issue of international concern. Adsorption has been proven to be the effective and widely used method for phenolic compounds removal. In this study, porous resins as adsorbents for the removal of hydroquinone from aqueous solutions were evaluated. Activated carbon F400D was employed for comparison. The faster adsorption kinetic was observed on the mesoporous XAD-4, while the higher adsorption capacity was obtained on the microporous NDA150, which had larger surface area. Despite the different surface properties and pore structures of the studied adsorbents, similar trends of pH-dependent adsorption were observed, implying the importance of the hydroquinone molecular species to the adsorption onto the porous adsorbents. This work provided an understanding of adsorption behavior of hydroquinone on porous adsorbents.

Abstract: By the static experiment, we studied the electrochemical oxidation process of simulated hydroquinone wastewater (concentration for 300mg•L-1) in the three-dimensional cell. Experimental inspected how various factors of the packing quality ratio, electrolysis voltage, supporting electrolyte concentration, and the initial pH value influence the effect of the removal of hydroquinone and CODCr. The results of the experiment clearly indicated with the increase of voltage applied the removal rate of hydroquinone and CODCr increased first and then decreased, finally and increased again. In the weak alkali conditions (pH=8.5), the removal rate of hydroquinone and CODCr is the highest, Electrolyte concentration and packing quality ratio to the effect of hydroquinone by electrochemical degradation is the larger. The results of the single factor analysis show that the most suitable processing conditions of simulated hydroquinone wastewater by bipolar electrocatalysis oxidation are the Na2SO4 concentration of 0.03mol•L-1, the electrolytic voltage of 6V, the initial pH value of 8.5, the packing quality ratio of 1:2. With this condition processing 3h, the removal rate of hydroquinone and CODCr reached 83.96% and 39.9%, respectively.

Abstract: Hydroquinone derivatives are studied as inhibitors of microbiological corrosion and hydrogen absorption by mild steel in water salt media that supports development of sulfate reducing bacteria (SRB). The chosen composition of the media is close to sea water containing biogenic H2S. Н2S content, bacterial titer in corrosive media, its pH, Redox potential Eh, and φ of steel together with the quantity of hydrogen absorbed by surface steel sub-layers, were measured. Protective action against corrosion achieved by the best compounds studied, reached the values of 65…84%, while against hydrogen absorption by steel samples − 60…72%. The presence of the studied derivatives of hydroquinone at concentration C= 5 mMoldm–3 resulted in the decrease of SRB cell count at the rate of 48…84%, the suppression rate being at the values of 29…57%.

Abstract: Owing to toxicity of pharmacy wastewater to microbe, commonly used biodegradation is often limited in application; accordingly exploiting new ways of the wastewater treatment with high efficiency is a hot topic. As a new efficient advanced oxidation, pulsed corona discharge combining with ozone is attracting more and more attention. In this study, a special reactor was designed, in addition, the removal of TOC(Total Organic Carbon) and COD (Chemical Oxygen Demand)of simulant pharmacy wastewater containing hydroquinone (500mg/L) by pulsed corona discharge combining with ozone were investigated . It was showed that the TOC and COD removal (53.8% and 72.3%) by the combined technology was much higher than by using the two techniques in series when all the samples were treated 40mins.The two methods in combination have a synergistic effect. TOC and COD removal could be improved obviously when NaCl feed concentration increased from 0 to1000 mg/L, yet further increase in NaCl feed led to a markedly decrease removal efficiency of TOC and COD.

Abstract: Titanate aqueous solution (TTIP-Lac) prepared by direct reaction of titanium tetraisopropoxide (TTIP) with lactic acid (Lac) in water shows characteristics of a polyanion and acts as a dispersant for preparing titanate suspension. Electrophoretic deposition (EPD) of aqueous titania suspensions was investigated with TTIP-Lac as a dispersant and hydroquinone (HQ) as an effective additive for bubble-free EPD of the aqueous system. The oxygen produced electrolytically by the EPD process at basic pH would be consumed by the chemical oxidation of HQ to quinone (Q). Bubble-free titania depositions were fabricated on anodes by EPD. A fired density with 99% theoretical density was obtained.