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Acetaminophen (C8H9NO2, also called paracetamol) is an active metabolite of phenacetin with antipyretic and analgesic effects and has been extensively used as a painkiller. Currently, the problem of pharmaceuticals in water and sewage is common, especially in highly urbanized countries. Laboratory-scale experiments were carried out using an adsorbent—granulated activated carbon (WD-extra)—to remove acetaminophen (ACT) from water. The initial concentration of acetaminophen was 20 mg ACT/dm3. The adsorption kinetics, influence of the pH on adsorption and dose of the used adsorbent were determined under batch conditions. The adsorption of ACT on activated carbon was more efficient when the water solution was acidic (at pH 2, it was the most effective). The highest percentage of removal (99%) was obtained for the WD-extra dose of 10.0 g/dm3. The time taken to establish the dynamic equilibrium of the system was 60 min. The effectiveness of adsorption was determined based on the Freundlich and Langmuir adsorption isotherms. It was found that WD-extra activated carbon effectively removed ACT from water solutions. [ABSTRACT FROM AUTHOR]

• An integral model was developed to determine the nucleation parameters. • A temperature-dependent function of interfacial energy was proposed. • A temperature-dependent pre-exponential factor inversely proportional to the solution viscosity was adopted. • The metastable zone width data of phenacetin in ethanol were analyzed. By incorporating a temperature-dependent function of interfacial energy and a temperature-dependent pre-exponential factor inversely proportional to the solution viscosity, an integral model was developed according to classical nucleation theory to retrieve the nucleation parameters from the metastable zone width (MSZW) data. The developed model was applied to determine the temperature-dependent interfacial energy and pre-exponential factor during the cooling process from the MSZW data for phenacetin in ethanol experimentally measured in this work. For comparison, the interfacial energy and pre-exponential factor for phenacetin in ethanol at various operating temperatures were determined from the induction time data based on the conventional method. The results indicated that the temperature-dependent interfacial energy and pre-exponential factor for phenacetin in ethanol obtained from the MSZW data based on the developed model were consistent with those obtained from the induction time data based on the conventional method. [ABSTRACT FROM AUTHOR]

Electro-Fenton (EF) and solar photoelectro-Fenton (SPEF) processes were employed at different scales to degrade phenacetin (PNT), the first synthetic analgesic. EF experiments were conducted at lab scale, whereas SPEF experiments were performed in an 8 L pre-pilot plant using an electrochemical filter-press cell. Under optimal conditions (25 mg L−1 PNT, 25.3 mg L−1 Fe2+, and current density of 59.5 mA cm−2), EF resulted in degradation and mineralization degrees of 83.9% and 45.2% at 14 and 230 min, respectively. Similarly, PNT was spiked into real wastewater from a municipal secondary treatment plant, resulting in degradation of 68.0% and mineralization of 39.4%, with an energy consumption of 7.0 kWh g−1. The optimal conditions of SPEF (16.8 mg L−1 Fe2+ and current density of 45.9 mA cm−2) led to degradation and mineralization degrees of 55.9% and 37.1% at 36 and 181 min, respectively, with a low energy consumption of 0.142 kWh g−1. Both processes effectively detoxified the solutions, as demonstrated by tests with Artemia salina and Lactuca sativa. Three distinct degradation pathways were proposed based on the identification of eleven reaction intermediates formed upon •OH attack. In conclusion, the low energy cost of the SPEF process underscores its potential for pharmaceutical degradation in wastewater. [Display omitted] • Good prediction of phenacetin removal by EF and SPEF at two different scales. • EF: 68.0% degradation and 39.4% mineralization in actual wastewater at lab scale. • SPEF: 55.9% degradation in 36 min and 37.1% mineralization in an 8 L pre-pilot plant. • SPEF: very low energy consumption, and 11 intermediates from 3 hydroxylation sites. • EF and SPEF reduce effluent toxicity below 0.26 and 0.55 units, respectively. [ABSTRACT FROM AUTHOR]

We have developed a composite electrode containing boron-doped diamond and high graphite content (HGBDD) by microwave plasma chemical vapor deposition system at high methane concentration. The electrode is applied to test the trace level of phenacetin. Scanning rate studies have exhibited that electrochemical oxidation is controlled by adsorption with scanning speed ranging from 20 to 100 mV s−1, while at a higher scanning rate, electrochemical oxidation is controlled by diffusion process. Voltammetry of phenacetin researched on the HGBDD electrode reveals the redox mechanism of phenacetin, the HGBDD has a high current response with a sensitive detection limit of 0.058 μM and a wide linear detection range of 0.5 μM - 400 μM. The high performance could be attributed to the presence of a higher carrier concentration for HGBDD electrode. Based on the density functional theory caculations, the graphite on the diamond surface could adsorb phenacetin strongly and provide more active sites for the redox reaction. Due to the unique properties of diamond, the electrode shows stability, repeatability, and accuracy for detecting phenacetin. [Display omitted] • A phenacetin electrochemical sensor based on graphite/BDD is developed. • Graphite/BDD composite electrode is prepared at high methane concentration. • Graphite on diamond surface adsorbs phenacetin stronger than BDD. • Electrode shows excellent sensibility, reusable, reproducibility and selectivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co-ZrP is successfully prepared through absorbing Co2+ onto ZrP and calcining. • PNT is completely degraded in the Co-ZrP/PMS system within 10 min. • PNT rapid degradation is mainly attributed to •OH and SO 4 •−. • ZrP as a carrier significantly improves the catalytic performance of cobalt oxide. • Co-ZrP exhibits excellent stability, reusability and universality. Herein, zirconium phosphate as a recycled material was used for the first time to support cobalt (Co-ZrP) serving as a catalyst for activating peroxymonosulfate (PMS) to remove phenacetin (PNT). It was found that PNT (5 mg L−1) was completely eliminated in the Co-ZrP (0.2 g L−1)/PMS (2 mM) system in an initial pH range of 5 to 7 within 10 min. The pseudo-first-order rate constant of PNT degradation by PMS combined with Co-ZrP was 0.625 min−1, far faster than those with ZrP (0.0065 min−1) and with Co 3 O 4 (0.104 min−1). The introduction of HA and HCO 3 − significantly inhibited PNT removal, while the addition of H 2 PO 4 − accelerated PNT elimination in the Co-ZrP/PMS system. Nevertheless, PNT could still be completely removed by Co-ZrP-activated PMS in actual water. Recycling experiments indicated that the degradation efficiency of PNT could reach 98 % after four cycles and calcining Co-ZrP could completely restore its catalytic activity. In addition, effective decomposition of chloramphenicol, bisphenol A, sulfamethazine and rhodamine B was also achieved by Co-ZrP-activated PMS within 15 min. Hence, the combination of Co-ZrP and PMS had great potential in removing organic pollutants from water environment. EPR analysis and quenching tests suggested that the rapid degradation of PNT was mainly ascribed to the generation of •OH and SO 4 •− in the Co-ZrP/PMS system. Based on HPLC-HRMS analysis, the main degradation products were determined and the possible degradation pathways were further proposed. [ABSTRACT FROM AUTHOR]

Objective: The pain-relieving effect and safety of compound aminopyrine phenacetin tablets, tramcontin (tramadol hydrochloride sustained-release tablets) and dolantin in the early stage of autologous tendon reconstruction of the anterior cruciate ligament (ACL) of the knee joint were compared., Methods: Retrospective analysis of postoperative pain and drug analgesia in 45 patients performed by the same group from November 2018 to February 2019. The random area group design was divided into two groups according to whether ACL rupture was combined with meniscal injury, group A was 24 patients with ACL reconstruction of knee joint and group B was 21 patients with ACL fracture combined with meniscus injury. The two groups were divided into three subgroups respectively according to the actual treatment of postoperative analgesic drugs received by the patients, including 4 cases of compound aminopyrine phenacetin tablets, 11 cases of oral tramcontin, 9 cases of intramuscular dolantin combined with phenergan in group A; 3 cases of compound aminopyrine phenacetin tablets, 10 cases of oral tramcontin, and 8 cases of intramuscular dolantin combined with phenergan in group B. When the early postoperative patients complain about pain and actively ask for analgesia. When the patients complained about pain after the operation and actively asked for analgesia, they were randomly given painkillers, tramcontin or dolantin combined with phenergan to relieve pain. Pain visual analogue scale (VAS) was used to evaluate pain relief and observe the occurrence of adverse reactions., Results: There were no significant dif-ferences in gender, age, body mass index, and time of hospital stay between the two groups of patients ( P > 0.05). In the patients who used tramcontin and dolantin combined with phenergan to relieve pain judging by VAS score before and 1 h after taking the drug, it was found that the pain situation of the patient was significantly relieved, and the difference before and after taking the drug had statistical significance ( P < 0.05). Pairwise comparisons of the three drugs applied in the two groups showed significantly greater pain relief in the dolantin combined with phenergan group than in the remaining two drugs. There was no significant difference ( P > 0.05). Dolantin was prone to nausea and vomiting, but the application of phenergan was also used to reduce side effects. In terms of adverse reactions, only 1 case of nausea occurred in the tramcontin group for simple ACL reconstruction, and none of the patients in the other groups showed serious complications and allergic reactions., Conclusion: Whether in cruciate ligament reconstruction alone or combined with meniscus molding or suture, compound aminopyrine phenacetin tablets, tramcontin, dolantin combined with phenergan can effectively relieve pain. Among the three drugs, dolantin caused the largest pain relief. At the same time, the combination of phenergan effectively reduced the adverse reactions, such as vomiting and nausea, and increased the drug safety.