Non-target screening and prioritization of organic contaminants in seawater desalination and their ecological risk assessment.

The impact of desalination brine on the marine environment is a global concern. Regarding this, salinity is generally accepted as the major environmental factor in desalination concentrate. However, recent studies have shown that the influence of organic contaminants in brine cannot be ignored. Therefore, a non-targeted screening method based on comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS) was developed for identifying organic contaminants in the desalination brine. A total of 404 compounds were tentatively identified from four seawater desalination plants (three reverse osmosis plants and one multiple effect distillation plant) in China. The identified compounds were prioritized based on their persistence, bioaccumulation, ecotoxicity, usage, and detection frequency. Twenty-one (21) compounds (seven phthalates, ten pesticides, four trihalomethanes) were then selected for further quantitative analysis and ecological risk assessment, including compounds from the priority list along with substances from the same chemical classes. Ecologically risky substances in brine include diisobutylphthalate and bis(2-Ethylhexyl) phthalate, atrazine and acetochlor, and bromoform. Most of the contaminants come from raw seawater, and no high risk contaminants introduced by the desalination process have been found except for disinfection by-products. In brine discharge management, people believed that all pollution in raw seawater was concentrated by desalination process. This study shows that not all pollutants are concentrated during the desalination process. In this study, the total concentration of pesticide in the brine increased by 58.42%. The concentration of ∑PAEs decreased by 13.65% in reverse osmosis desalination plants and increased by 10.96% in the multi-effect distillation plant. The concentration of trihalomethane increased significantly in the desalination concentrate. The change in the concentration of pollutants in the desalination concentrate was related to the pretreatment method and the chemical characteristics of the contaminants. The method and results given in this study hinted a new idea to identify and control the environmental impact factors of brine.

Clinical efficacy of analysis of modified biliary-intestinal anastomosis by pancreaticoduodenec-tomy and influencing factors of postoperative biliary leakage / 中华消化外科杂志

Objective:To investigate the clinical efficacy of modified biliary-intestinal anasto-mosis by pancreaticoduodenectomy and influencing factors of postoperative biliary leakage.Methods:The propensity score matching and retrospective cohort study was conducted. The clinicopatholo-gical data of 165 patients with benign and malignant diseases around the ampullary who underwent pancreaticoduodenectomy in the Affiliated Hospital of Inner Mongolia Medical University from June 2014 to October 2020 were collected. There were 92 males and 73 females, aged (59±10)years. Of the 165 patients, 44 patients undergoing modified biliary-intestinal anastomosis within pancreatico-duodenectomy were divided into the modified group, and 121 patients undergoing traditional biliary-intestinal anastomosis within pancreaticoduodenectomy were divided into the traditional group. Observation indicators: (1) propensity score matching and comparison of general data of patients between the two groups after matching; (2) intraoperative and postoperative situations; (3) analysis of influencing factors of biliary leakage after pancreaticoduodenectomy. Propensity score matching was done by the 1:1 nearest neighbor matching method, with the caliper setting as 0.05. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Univariate analysis was conducted using the corresponding statistical methods based on data type. All indicators in univariate analysis were included in multivariate analysis. Multivariate analysis was conducted using the Logistic regression model. Results:(1) Propensity score matching and comparison of general data of patients between the two groups after matching. Of the 165 patients, 72 cases were successfully matched, including 36 cases in the modified group and 36 cases in the traditional group, respectively. The elimination of jaundice, preoperative reduction of jaundice and hypertension confounding bias ensured comparability between the two groups after propensity score matching. (2) Intraoperative and postoperative situations. All patients in the two groups underwent surgery successfully. The operation time, postoperative pathological type (lower bile duct cancer, pancreatic head cancer, pancreatic cystic tumor, chronic pancreatitis, duodenal cancer), time of no drainage fluid in the drainage tube around biliary-intestinal anastomosis were 371(270,545)minutes, 6, 12, 1, 2, 15, (12±7)days in patients of the modified group, versus 314(182,483) minutes, 13, 14, 1, 4, 4, (16±8)days in patients of the traditional group, showing significant differences in the above indicators between the two groups ( Z=-3.54, χ2=10.01, t=-2.34, P<0.05). Cases with postoperative grade A biliary leakage was 0 in patients of the modified group, versus 6 in patients of the traditional group, showing a significant difference between the two groups ( P<0.05). Cases with postoperative grade B biliary leakage, cases with postoperative grade B pancreatic fistula, cases with postoperative bleeding, cases with abdominal infection, cases with incision infection, cases with delayed gastric emptying, cases undergoing unplanned readmission were 1, 0, 1, 4, 1, 5, 1 in patients of the modified group, versus 0, 1, 2, 5, 2, 5, 2 in patients of the traditional group, showing no significant difference in the above indicators between the two groups ( P>0.05). Cases with postoperative grade A pancreatic fistula, cases with overall complications, cases with Clavien-Dindo grade Ⅰ-Ⅱ complications, cases with Clavien-Dindo grade Ⅲ-Ⅳ complications were 6, 12, 6, 6 in patients of the modified group, versus 7, 14, 8, 6 in patients of the traditional group, showing no significant difference in the above indicators between the two groups ( χ2=0.09, 0.24, 0.36, 0.00, P>0.05). None of patient in the two groups had postoperative grade C biliary leakage and postoperative grade C pancreatic fistula. (3) Analysis of influencing factors of biliary leakage after pancreaticoduodenectomy. Results of multivariate analysis showed that preoperative reduction of jaundice and traditional biliary-intestinal anastomosis were independent risk factors for biliary leakage after pancreaticoduodenectomy ( odds ratio=11.37, 12.27, 95% confidence interval as 1.76-73.35, 1.14-131.23, P<0.05). Conclusions:Compared with traditional biliary-intestinal anastomosis, modified biliary-intestinal anastomosis within pancreaticoduodenectomy is safe and feasible. Preoperative reduction of jaundice and traditional biliary-intestinal anastomosis are independent risk factors for biliary leakage after pancreaticoduodenectomy.