Review on demulsification techniques for oil/water emulsion: Comparison of recyclable and irretrievable approaches

Since the establishment of the first global refinery in 1856, crude oil has remained one of the most lucrative natural resources worldwide. However, during the extraction process from reservoirs, crude oil gets contaminated with sediments, water, and other impurities. The presence of pressure, shear forces, and surface-active compounds in crude oil leads to the formation of unwanted oil/water emulsions. These emulsions can take the form of water-in-oil (W/O) emulsions, where water droplets disperse continuously in crude oil, or oil-in-water (O/W) emulsions, where crude oil droplets are suspended in water. To prevent the spread of water and inorganic salts, these emulsions need to be treated and eliminated. In existing literature, different demulsification procedures have shown varying outcomes in effectively treating oil/water emulsions. The observed discrepancies have been attributed to various factors such as temperature, salinity, pH, droplet size, and emulsifier concentrations. It is crucial to identify the most effective demulsification approach for oil/water separation while adhering to environmental regulations and minimizing costs for the petroleum sector. Therefore, this study aims to explore and review recent advancements in two popular demulsification techniques: chemical demulsification and magnetic nanoparticles-based (MNP) demulsification. The advantages and disadvantages of each technique are assessed, with the magnetic approach emerging as the most promising due to its desirable efficiency and compliance with environmental and economic concerns. The findings of this report are expected to have a significant impact on the overall process of separating oil and water, benefiting the oil and gas industry, as well as other relevant sectors in achieving the circular economy.

Randomized controlled trial of trimebutine (anal sphincter relaxant) for pain after haemorrhoidectomy

BACKGROUND

Anal sphincter spasm may aggravate pain after haemorrhoidectomy. The aims of this study were to investigate whether a trimebutine suppository (Proctolog) reduced anal resting pressure and, subsequently, to test its efficacy in relieving pain after haemorrhoidectomy.

METHODS

Ten patients underwent anal manometry before and 4 h after Proctolog application. A controlled randomized trial was then conducted on 160 consecutive patients. A standard haemorrhoidectomy was performed. Eighty patients were then randomized to receive an application of Proctolog immediately after the procedure (group 1). The remaining 80 did not receive a suppository (controls, group 2). An independent, blinded observer determined the pain scores.

RESULTS

Proctolog resulted in a mean 35 per cent reduction in resting anal pressure (P < 0.001). However, there were no differences in the pain score at 4 h after haemorrhoidectomy, maximum pain during the first 24 h, maximum pain during the second postoperative day, ketoprofen requirement or need for intramuscular pethidine injections between groups 1 and 2.

CONCLUSION

Although Proctolog reduced mean resting anal pressure at 4 h after application, this did not affect pain after haemorrhoidectomy.

Biofeedback therapy for excessive stool frequency and incontinence following anterior resection or total colectomy

PURPOSE

Excessive stool frequency and incontinence after anterior resection (AR) or total colectomy (TC) can be refractory to expectancy and antidiarrheal agents. We prospectively assessed efficacy of anorectal biofeedback therapy (BF) in this clinical situation.

METHODS

Thirteen patients (10 men and 3 women; mean age, 62.1 (standard error of the mean (SEM), 4.6) years) had more than six bowel movements per day and/or episodes of incontinence, which did not abate after antidiarrheal agents were given for at least six (mean, 27.9 (SEM, 6.3)) months after surgery. All underwent four sessions of outpatient BF. Assessment was by continence questionnaire and anorectal physiology tests, which were administered before and after BF.

RESULTS

In seven AR patients, daily stool frequency was decreased (8.7 (SEM, 2.1) before and 4.6 (SEM, 1.2) after, P < 0.05), and daily incontinence episodes were reduced (2.7 (SEM, 0.9) before and 0.4 (SEM, 0.2) after, P < 0.05) after BF. Six TC patients also had decreased daily stool frequency (6.2 (SEM, 2.1) before, 3.3 (SEM, 1.6) after; P < 0.05) and incontinence episodes (2.4 (SEM, 0.9) before, 0.5 (SEM, 1) after; P < 0.05) after BF. There were no significant changes in anorectal physiology parameters after BF. At a mean follow-up of 10.6 (SEM, 2.5) months after BF, there were no regressions or complications.

CONCLUSIONS

BF is a safe and effective option for refractory excessive stool frequency and/or incontinence following AR or TC.