Tackling a Post-COVID-19 Cholecystectomy Waiting List: Are We Meeting the Challenge?

Background and Objectives: The COVID-19 pandemic has led to a tremendous backlog in elective surgical activity. Our hospital trust adopted an innovative approach to dealing with elective waiting times for cholecystectomy during the recovery phase from COVID-19. This study aimed to evaluate trends in overall cholecystectomy activity and the effect on waiting times. Materials and Methods: A prospective observational study was undertaken, investigating patients who received a cholecystectomy at a large United Kingdom hospital trust between February 2021 and February 2022. There were multiple phased strategies to tackle a 533-patient waiting list: private sector, multiple sites including emergency operating, mobile theatre, and seven-day working. The correlation of determination (R2) and Kruskal-Wallis analysis were used to evaluate trends in waiting times across the study period. Results: A total of 657 patients underwent a cholecystectomy. The median age was 49 years, 602 (91.6%) patients had an ASA of 1-2, and 494 (75.2%) were female. A total of 30 (4.6%) patients were listed due to gallstone pancreatitis, 380 (57.8%) for symptomatic cholelithiasis, and 228 (34.7%) for calculous cholecystitis. Median waiting times were reduced from 428 days (IQR 373-508) to 49 days (IQR 34-96), R2 = 0.654, p < 0.001. For pancreatitis specifically, waiting times had decreased from a median of 218 days (IQR 139-239) to 28 (IQR 24-40), R2 = 0.613, p < 0.001. Conclusions: This study demonstrates the methodology utilised to safely and effectively tackle the cholecystectomy waiting list locally. The approach utilised here has potential to be adapted to other units or similar operation types in order to reduce elective waiting times.

Wastewater treatment by microalgal membrane bioreactor: Evaluating the effect of organic loading rate and hydraulic residence time.

Current microalgal based photobioreactors focus on the secondary treated effluent while limited researches attempted for treating the raw domestic wastewater. This study aimed to assess the microalgal biomass production, removal performance, and fouling characteristics of microalgal membrane bioreactors (MMBRs) for treating synthetic wastewater under different conditions of organic loading rate (OLR) and hydraulic residence time (HRT). The 12h/12 h dark/light cycle continuous experiments were performed for four MMBRs at different OLRs and three MMBRs at different HRTs. Results showed that microalgal biomass production rate (as TSS and chlorophyll-a) decreased with increasing OLR and increased with decreasing of HRT. Regardless of the OLR and HRT conditions, MMBRs can achieve up to 94% organic removal by bacterial oxidation without external aeration. Total nitrogen (TN) and total phosphorus (TP) removals were significantly decreased with increasing OLR. Highest TN removal (68.4%) achieved at the OLR of 0.014 kg/(m3 d) which was reduced to 58.1% at 0.028 kg/(m3 d). Removals of total phosphorous significantly decreased from 48.2% to 37.7% with an increase in OLR from 0.011 to 0.014 kg/(m3 d). TN removal was reduced at shorten HRT (2 d), while, the effect of HRT was found insignificant at higher HRT. An effective removal of P can only be achieved at higher HRTs, i.e., 7 days. OLR up to 0.014 kg/(m3 d) and 2 days HRT was found suitable for maintaining the fouling frequency at an optimal level of 0.016/d. Overall the OLR and HRT need to be carefully selected to achieve optimal efficiency of MMBR. The results of this study provide guidelines for designing the microalgal-based membrane bioreactors for the treatment of domestic wastewater.

Source to Tap Risk Assessment for Intermittent Water Supply Systems in Arid Regions: An Integrated FTA-Fuzzy FMEA Methodology.

Water utilities in arid regions deal with multifaceted issues of natural groundwater contamination, high treatment costs, and low water rates. These utilities rely on intermittent supplies resulting in numerous water quality failures at source, treatment, distribution, and in-house plumbing systems. The present research presents an inclusive risk assessment methodology for managing water quality from source to tap. Three-year monitoring data for turbidity, TDS, pH, iron, ammonia, nitrates, residual chlorine, Coliform group, E. coli, and Fecal Streptococci identified the root causes of failures. The cause-effect relationships in the form of a fault tree were solved using multiple failure modes and effect analysis (FMEA) to handle both the Boolean operations. The fuzzy sets addressed the uncertainties associated with data limitations in calculating exceedance probabilities (Pe) and vagueness in expert opinion for subjective evaluation of severity and detectability. The methodology was applied on a smaller system serving 18,000 consumers in Qassim, Saudi Arabia. Potable supplied water underwent reoccurrence of TDS (Pe = 20%), turbidity (Pe = 10%), and Fe (Pe = 2%) failures in distribution that further increased up to 44%, 33%, and 11% at the consumer end. The Pe for residual chlorine failure soared up to 89%. Economic controls reduced the cumulative risk to 50%, while the shift to continuous supply can limit the remaining failures under the acceptable risk. The framework will help utilities manage water quality in intermittent systems from source to tap in Saudi Arabia, the Gulf, and elsewhere.

Performance assessment of artificial neural networks and support vector regression models for stream flow predictions.

Water resources planning, development, and management need reliable forecasts of river flows. In past few decades, an important dimension has been introduced in the prediction of the hydrologic phenomenon through artificial intelligence-based modeling. In this paper, the performance of three artificial neural network (ANN) and four support vector regression (SVR) models was investigated to predict streamflows in the Upper Indus River. Results from ANN models using three different optimization techniques, namely Broyden-Fletcher-Goldfarb-Shannon, Conjugate Gradient, and Back Propagation algorithms, were compared with one another. A further comparison was made between these ANNs and four types of SVR models which were based on linear, polynomial, radial basis function, and sigmoid kernels. Past 30 years' monthly data for precipitation, temperature, and streamflow obtained from Pakistan Surface Water Hydrology Department Lahore were used for this purpose. Three types of input combinations with respect to the main input variables (temperature, precipitation, and stream flow) and several types of input combinations with respect to time lag were tested. The best input for ANN and SVR models was identified using correlation coefficient analysis and genetic algorithm. The performance of the ANN and SVR models was evaluated by mean bias error, Nash-Sutcliffe efficiency, root mean square error, and correlation coefficient. The efficiency of the Broyden-Fletcher-Goldfarb-Shannon-ANN model was found to be much better than that of other models, while the SVR model based on radial basis function kernel predicted stream flows with comparatively higher accuracy than the other kernels. Finally, long-term predictions of streamflow have been made by the best ANN model. It was found that stream flow of Upper Indus River has a decreasing trend.

Investigation of temporal change in glacial extent of Chitral watershed using Landsat data.

Glaciers are also known as solid reservoirs, and in this regard, Pakistan is a blessed country to have enriched glaciers. The change in glacial extent becomes very crucial for rivers whose discharges are associated with glacier melt. Even a little change in the glacial extent may bring a significant change in the resulting river flows. Considering climate change scenarios, many researchers have predicted future flows in such catchments. But in almost all such studies, the reduction in the glaciers is not normally based on any rational. Therefore, research is needed in order to estimate how glaciers are actually behaving under the change of temperature and precipitations to better estimate the future flows. For this purpose, Chitral watershed was considered as the study area. The seasonal change in the snow extent was estimated by using MODIS data for various years that helped to identify the month with minimum glacial extent. With the help of remote sensing, unsupervised classification was performed to estimate the glacier area in Chitral watershed. The results show a definite receding trend with respect to time in the glaciers of the region for the past decade.

Influence of iron, phosphate, and silicate on arsenic removal from groundwater using a low-cost ceramic filter.

The ceramic filter amended with iron (Fe) has proven to be a potential low-cost method for arsenic (As) removal from groundwater. The presence of Fe, phosphate (P), and silicate (Si) significantly affects the As removal efficiency of the ceramic filter, which has not been passably investigated. The present research aimed to examine the effect of Fe, P, and (or) Si presence as single or in combination on As (III) removal from synthetics groundwater by a low-cost iron amended ceramic filter (IACF). Laboratory-scale filtration experiments at different compositions of Fe, P, Si, and As (III) were conducted by the IACF fabricated with a ceramic candle and iron netting box. Fe (II) in synthetic groundwater positively impacted As (III) removal. At a concentration of 2 mg/L of Fe (II), the As levels in the effluent decreased to less than the maximum contamination level (MCL) of 50 µg/L. Groundwater P concentration needed less than 3 mg/L or Si concentrations required less than 35 mg/L to effectively reduce As (III) to below the MCL at 5 mg/L of groundwater Fe (II). The cumulative effect of P and Si on As removal was found to be more significant than distinct contributions. The presence of 2 mg/L P and 35 mg/L or higher Si in the groundwater cumulatively reduced the As removal performance from 92% to 63%, and the MCL was not met. The negative impact of P and Si on As (III) removal followed the order of (P + Si) > P > Si. P competed with As for adsorption sites during the process, while Si inhibited the Fe release and floc formation, significantly reducing As removal performance. The study findings can potentially contribute to optimizing IACF as a low-cost method for As removal from groundwater.

Environmental and socio-economic impacts of pipe drainage in Pakistan.

Many drainage schemes and salinity control projects have been executed world wide. Pipe drainage has widely been used in Pakistan, Egypt and India to control waterlogging. The impact of pipe drainage on land and water was evaluated in this paper using data of three pipe drainage projects in Pakistan namely Khushab Salinity Control and Reclamation Project, Fourth Drainage Project in Faisalabad and Swabi Salinity Control and Reclamation Project. Data by regular monitoring of these projects were collected. The effect of pipe drainage on water table depth at these three locations has been compared. Water quality and soil salinity improvement due to the pipe drainage has also been investigated. Data, related to water table depths and discharges from drain pipes/wells, was collected. Observation wells, installed at various places by the Water and Power Development Authority, were used for collection of this data. To evaluate the impact of the projects on salinity, soil samples from all the three locations were tested. A questionnaire was prepared to get the view of the people about the projects. It was revealed that in these areas, due to subsurface pipe drainage, the percentage of the abandoned land has been considerably decreased. Over drainage was observed in a few places of the projects. The farmers at such places were asked to change their cropping patterns. Ultimately, there has been an increase in area under cultivation, crop yields and cropping intensity in the projects' area.

Development of geomorphologic instantaneous unit hydrograph for a large watershed.

Hill torrents cause a lot of environmental and property damage in Pakistan every year. Proper assessment of direct runoff in the form of hill torrents is essential for protection of environment, property, and human life. In this paper, direct surface runoff hydrograph (DSRH) was derived for a large catchment using the geomorphologic instantaneous unit hydrograph concept. The catchment with hill torrent flows in semi-arid region of Pakistan was selected for this study. It was divided into series of linear cascades and hydrologic parameters required for Nash's conceptual model, and were estimated using geomorphology of the basin. Geomorphologic parameters were derived from satellite images of the basin and ERDAS and ArcGIS were used for data processing. Computer program was developed to systematically estimate the dynamic velocity, its related parameters by optimization and thereby to simulate the DSRH. The data regarding rainfall-runoff and satellite images were collected from Punjab Irrigation and Power Department, Pakistan. Model calibration and validation was made for 15 rainfall-runoff events. Ten events were used for calibration and five for validation. Model efficiency was found to be more than 90% and root mean square error to be about 5%. Impact of variation in model parameters (shape parameter and storage coefficient) on DSRH was investigated. For shape parameter, the number of linear cascades varied from 1 to 3 and it was found that the shaper parameter value of 3 produced the best DSRH. Various values of storage coefficient were used and it was observed that the value determined from geomorphology and the dynamic velocity produced the best results.

Assessment of water quality of Rawal Lake by long-time monitoring.

Water quality of rivers, natural lakes, and reservoirs in developing countries is being degraded because of the contaminated inflows. There is a serious need for appropriate water quality monitoring for future planning and management of clean water resources. Quality of water in Rawal Lake Pakistan has been investigated in this paper. Flows from the upstream of Rawal Lake and its surrounding villages are highly polluted. Lake water quality parameters like pH, turbidity, alkalinity, calcium, nitrite, sulfate, biological oxygen dissolved, dissolved oxygen, chloride, total dissolved solids (TDS), and coliforms were investigated. Samples of water from different locations of Korang River were collected and tested. Most of the data was collected by field sampling and field visits. However, long-term information was taken from different departments. Statistical parameters (standard deviation, maximum, minimum, mean, mode, kurtosis, skew, and Euclidean distance) of variables were determined. A distinct parameter based on the difference of the maximum value the variable and maximum allowable value of that variable defined by World Health Organization was used for analysis. Grouping and clustering of elements was made on the basis of this parameter. Trend of increasing or decreasing of values of variables over a long time was also taken into account for grouping the variables. It was concluded that the concentration of seven contaminants was higher as compared to the permissible limits under environmental standards. These variables need immediate attention. The environmentally bad conditions of Rawal Lake can only be rectified by appropriate lake environmental supervision, watershed management, and implementation of environmental legislation.

Groundwater modeling of Saq Aquifer Buraydah Al Qassim for better water management strategies.

Saudi Arabia is an arid country. It has limited water supplies. About 80-90% of water supplies come from groundwater, which is depleting day by day. It needs appropriate management. This paper has investigated groundwater modeling of Saq Aquifer in Buraydah Al Qassim to estimate the impact of its excessive use on depletion of Saq Aquifer. MODFLOW model has been used in this study. Data regarding the aquifer parameters was measured by pumping tests. Groundwater levels and discharge of wells in the area for the year 2008 and previous record of year 1999 have been collected from Municipal Authority of Buraydah. Location of wells was determined by Garmin. The model has been run for different sets of pumping rates to recommend an optimal use of groundwater resources and get prolonged life of aquifer. Simulations have been made for a long future period of 27 years (2008-2035). Model results concluded that pumping from the Saq Aquifer in Buraydah area will result into significant cones of depression if the existing excessive pumping rates prevail. A drawdown up to 28 m was encountered for model run for 27 years for existing rates of pumping. Aquifer withdrawals and drawdowns will be optimal with the conservation alternative. The management scheme has been recommended to be adopted for the future protection of groundwater resources in Kingdom of Saudi Arabia.

Impact assessment of subsurface drainage on waterlogged and saline lands.

Waterlogging and salinity due to seepage from canals have polluted land and environment in various parts of Pakistan. A sustainable environment requires urgent remedial measures for this problem. The research in this paper presents the impacts of the Fourth Drainage Project, Faisalabad on the twin problem of waterlogging and salinity. Monitoring of the project was made on regular basis. The key performance indicators for the project include the lowering of water table, improvement of water quality and soil salinity, increase in area under cultivation, cropping intensity, and socioeconomic status of the project population. Data regarding water levels and discharge from the drain pipes were collected to monitor the impact on waterlogging. Soil samples were tested to evaluate the impact of drainage on land. It has been found that the percentage of the contaminated land in the project area has considerably been decreased, while the cropping intensities have been increased.

Continuous Performance Improvement Framework for Sustainable Wastewater Treatment Facilities in Arid Regions: Case of Wadi Rumah in Qassim, Saudi Arabia.

In arid regions such as Saudi Arabia, wastewater treatment (WWT) facilities (meeting promulgated standards) need to adapt their continuous performance improvement (CPI) for long-term sustainability. To achieve this, the facilities need to improve their performance to comply with more strict objectives for broader reuse applications of treated effluent. The present research proposes a CPI framework based on performance benchmarking process for the stepwise improvement of WWT facilities. A grey rational analysis water quality index (GWQI) based on exceedance probability was developed. For weights' estimation of 11 physical, chemical, and biological water quality parameters, the entropy method effectively accommodated the changes in relative importance of the parameters with including additional future reuse applications. For existing effluent reuse scenarios of restricted and unrestricted irrigation, the GWQI values were found consistent with the modified version of the Canadian WQI (GWQI). The indices' values (ranged between 0 and 100) greater than 80 showed the efficient operation of four WWT plants in the Qassim Region of Saudi Arabia. Two hypothetical CPI scenarios with future reuse applications (fish, livestock drinking, and recreation) showed an overall decline in the average (of four plants) values of the GWQI (97 to 78) and GWQI (85 to 60). GWQI predicted stricter results for the facilities with parameters' concentrations exceeding the targets with larger margins and was found applicable for the CPI of WWT facilities in arid regions. For existing scenarios, the assessment results suggest the facilities to control and monitor the chlorination practice. For future targets, tertiary treatment needs to be enhanced for desired nutrients and total dissolved solids removal. The proposed CPI framework provides a platform to initiate the performance benchmarking process for WWT facilities at local or regional levels in Saudi Arabia and elsewhere.

Spatiotemporal variations of DOM components in the Kushiro River impacted by a wetland.

Dissolved organic matter (DOM) has been recognized as a serious water quality problem in natural water bodies receiving pollution loads from point and nonpoint sources. The present study investigates the spatiotemporal variability of DOM composition in the Kushiro River and its tributaries (Eastern Hokkaido, Japan) impacted by the Kushiro wetland. Water samples were collected in the wet and dry seasons from several locations of the river and analyzed for DOM characteristics by UV-visible and excitation-emission matrix fluorescence spectroscopy techniques and by developing water quality index. Rather than the spatial effect, significant seasonal impacts on DOM pollution in the Kushiro River were observed. Overall concentrations of DOM decreased during the dry season. The increase of specific ultraviolet absorbance in the dry season indicated an increasing trend of humification, aromaticity and molecular weight of DOM. Five fluorescent peaks, including peaks A, C, M, B, and T were predicted by EEM spectra. Peaks A and C were found to be the most dominating peaks in both the seasons and indicated enrichment of humic-like matters in river water. The intensities of poly-aromatic humic substances as well as DOM components of microbial origin increase in the wet season and proteins like autochthonous DOM increase during the dry season. The study recognized the contribution of freshly produced DOM component by the decomposition of wetland plants in wet season and effect of snowfall in the dry season. Analysis of three fluorescence indices revealed that the river water primarily contains terrestrially dominated DOM. A significant impact of the adjacent WWTPs and wetland to the river water DOM were also observed. The water quality index of river water DOM showed low to medium levels of DOM pollution in the Kushiro River.

Performance assessment of aquatic macrophytes for treatment of municipal wastewater.

The objective of the study was to evaluate the performance of three different aquatic macrophytes for treatment of municipal wastewater collected from Taxila (Pakistan). A physical model of treatment plant was constructed and was operated for six experimental runs with each species of macrophyte. Every experimental run consist of thirty days period. Regular monitoring of influent and effluent concentrations were made during each experimental run. For the treatment locally available macrophyte species i.e. water hyacinth, duckweed & water lettuce were selected to use. To evaluate the treatment performance of each macrophyte, BOD5, COD, and Nutrients (Nitrogen and Phosphorus) were monitored in effluent from model at different detention time of every experimental run after ensuring steady state conditions. The average reduction of effluent value of each parameter using water hyacinth were 50.61% for BOD5, 46.38% for COD, 40.34% for Nitrogen and 18.76% for Phosphorus. For duckweed the average removal efficiency for selected parameters were 33.43% for BOD5, 26.37% for COD, 17.59% for Nitrogen and 15.25% for Phosphorus and for Water Lettuce the average removal efficiency were 33.43% for BOD5, 26.37% for COD, 17.59% for Nitrogen and 15.25% for Phosphorus. The mechanisms of pollutant removal in this system include both aerobic and anaerobic microbiological conversions, sorption, sedimentation, volatilization and chemical transformations. The rapid growth of the biomass was measured within first ten days detention time. It was also observed that performance of macrophytes is influenced by variation of pH and Temperature. A pH of 6-9 and Temperature of 15-38°C is most favorable for treatment of wastewater by macrophytes. The option of macrophytes for treatment of Municipal sewage under local environmental conditions can be explored by further verifying the removal efficiency under variation of different environmental conditions. Also this is need of time that macrophyte system should be used for treatment of wastewater because their performance is comparable to conventional wastewater treatment plants and also the system has very low O&M costs.