Assessment of the Satisfaction of Patients Treated by Undergraduate Dental Students at a Saudi Government University: A Cross Sectional Study.

Purpose: The long-term success of any organization is highly dependent on client satisfaction. This applies to the medical and dental fields, where patient satisfaction is considered an indirect indicator of the quality of service provided. This study aimed to assess the level of satisfaction of patients treated by final-year undergraduate students at King Abdulaziz University Dental Hospital (KAUDH). Patients and Methods: In this cross-sectional study, an online questionnaire was distributed to patients (aged ≥14 years) treated at KAUDH by sixth year students during the academic year 2020/2021. The questionnaire comprised 36 items, including demographic and general data, type of dental problems, type of dental treatment received, and satisfaction assessment based on the Dental Satisfaction Questionnaire. Data were analyzed using one-way ANOVA and independent sample t-tests (α=0.05). Results: A total of 203 responses were received (58% response rate). The reliability of the satisfaction tool (Cronbach's alpha) was 0.88, indicating a high reliability. The overall satisfaction level was 80.1% (±14.2). The satisfaction levels related to pain management, quality of care, and access to care were 76.4% (±19.9), 86.2% (±17.1), and 77.5% (±16.5) respectively. The highest satisfaction level (91.5%) was related to the quality item "The student was always treating me with respect". Age, number of visits, length of treatment, case severity, and treatment complexity were not significantly correlated with patient satisfaction (p ≥ 0.116). New patients who had their files directly opened by a sixth-year student and were treated immediately were more satisfied than patients who already had files at KAUDH and were referred to sixth-year students for treatment (p=0.029). Conclusion: Patients treated by final-year students at KAUDH showed high satisfaction levels in relation to pain management, treatment quality, and access. However, the satisfaction of existing old patients was lower than that of new patients, which warrants further assessment, particularly regarding the hospital referral system.

Impact of source-separation of urine on treatment capacity, process design, and capital expenditure of a decentralised wastewater treatment plant.

In this study, the impact of urine diversion on the treatment capacity, treatment process, and capital costs of a decentralised wastewater treatment plant (WWTP) was simulated using BioWin. The data for simulation including for economic analysis were obtained from a real decentralised WWTP at Sydney. Simulation was conducted for two alternative process design scenarios of a WWTP: membrane bioreactor (MBR) without denitrification and anaerobic MBR in place of aerobic MBR and compared to existing process design. The simulation shows that with about 75% urine diversion (through source separation), the treatment capacity of the existing WWTP can be doubled although above 40% urine diversion, the impact appears less rapid. When the urine diversion exceeds 75%, it was found that the anoxic tank for biological denitrification becomes redundant and the current wastewater treatment process could be replaced with a simpler and much less aeration intensive membrane bioreactor (MBR) producing similar effluent quality with a 24% reduction in capital expenditure (footprint) cost. Anaerobic MBR can be a potential alternative to aerobic MBR although pre-treatment becomes essential before reverse osmosis treatment for water reuse applications. Sensitivity analysis has revealed that by operating the bioreactor at higher mixed liquor suspended solids concentrations (9 g/L instead of 5 g/L) could help increase the WWTP treatment capacity by about 3.5 times at 75% urine diversion. Hence, urine diversion (until nitrogen-limiting conditions occur above 75% urine diversion) can increase the treatment capacity of an existing WWTP and reduce the capital expenses due to reduced plant footprint.

Removal of pharmaceuticals from nitrified urine.

In this study, granular activated carbon (GAC) was examined for the removal of five of the most commonly detected pharmaceuticals (naproxen, carbamazepine, acetaminophen, ibuprofen and metronidazole) from a nitrified urine to make the urine-derived fertiliser nutrient safe for food crops. Batch experiments were conducted to investigate the adsorption kinetics that described the removal of micropollutants (equal concentrations of 0.2 mM) from the synthetic nitrified urine at different GAC dosages (10-3000 mg/L). Artificial neural network modelling was also used to predict and simulate the removal of pharmaceuticals from nitrified urine. Langmuir and Freundlich isotherm models described the equilibrium data, with the Langmuir model providing slightly higher correlations. At the highest dose of 3000 mg/L GAC, all the pharmaceuticals showed a removal rates of over 90% after 1 h of adsorption time and 99% removal rates after 6 h of adsorption time. This study concludes that GAC is able to remove the targeted xenobiotics without affecting the concentration of N and P in the urine, suggesting that nitrified urine could be safely used as a nutrient product in future.