A 20-year shift in China's sewage sludge heavy metals and its feasibility of nutrient recovery in land use.

Recycling resources from wastewater is even more important for developing a more sustainable society. Disposing sewage sludge, which accumulates most pollutants and resources in sewage, is the main challenge in wastewater pollution control and resource utilization. Heavy metals (HMs) are the greatest constraint limiting the application of sewage sludge to land as a sustainable use of this material. We conducted a meta-analysis of the concentrations of HMs in Chinese sewage sludge by combining data from studies published from 2000 to 2019 (N = 8477). Over this period, the reported concentrations of HMs in sewage sludge declined in three stages (a fluctuating stage, a slight decrease stage, and a rapid and stable decrease stage). The results revealed that economic development and environmental policy implementation were the main factors mitigating HM pollution in sewage sludge in China. Moreover, if environmental regulations were strengthened and HM pollution-mitigation strategies were made consistent, such that the proportion of sewage sludge applied to land in China could be increased from 18.6% to 48.0% (the proportion applied to land in the United States), the ecosystem services analysis showed that huge ecological-economic benefits could be realized (3.1 billion Chinese Yuan) and the use of fertilizers could be substantially reduced (the use of nitrogen fertilizers by 8.5% and the use of phosphate fertilizers by 18.1%). This review shows that China should formulate a unified policy and interdepartmental committee for sustainable application of sewage sludge to land and wastewater resource recycling management.

Analysis of clinicopathological features and prognostic factors of breast cancer brain metastasis.

BACKGROUND: Breast cancer (BC) has become the most common malignancy in women. The incidence and detection rates of BC brain metastasis (BCBM) have increased with the progress of imaging, multidisciplinary treatment techniques and the extension of survival time of BC patients. BM seriously affects the quality of life and sur-vival prognosis of BC patients. Therefore, clinical research on the clinicopathological features and prognostic factors of BCBM is valuable. By analyzing the clinicopathological parameters of BCBM patients, and assessing the risk factors and prognostic indicators, we can perform hierarchical diagnosis and treatment on the high-risk population of BCBM, and achieve clinical benefits of early diagnosis and treatment. AIM: To explore the clinicopathological features and prognostic factors of BCBM, and provide references for diagnosis, treatment and management of BCBM. METHODS: The clinicopathological data of 68 BCBM patients admitted to the Air Force Medical Center, Chinese People's Liberation Army (formerly Air Force General Hospital) from 2000 to 2022 were collected. Another 136 BC patients without BM were matched at a ratio of 1:2 based on the age and site of onset for retrospective analysis. Categorical data were subjected to χ2 test or Fisher's exact probability test, and the variables with P < 0.05 in the univariate Cox proportional hazards model were incorporated into the multivariate model to identify high-risk factors and independent prognostic factors of BCBM, with a hazard ratio (HR) > 1 suggesting poor prognostic factors. The survival time of patients was estimated by the Kaplan-Meier method, and overall survival was compared between groups by log-rank test. RESULTS: Multivariate Cox regression analysis showed that patients with stage III/IV tumor at initial diagnosis [HR: 5.58, 95% confidence interval (CI): 1.99-15.68], lung metastasis (HR: 24.18, 95%CI: 6.40-91.43), human epidermal growth factor receptor 2 (HER2)-overexpressing BC and triple-negative BC were more prone to BM. As can be seen from the prognostic data, 52 of the 68 BCBM patients had died by the end of follow-up, and the median time from diagnosis of BC to the occurrence of BM and from the occurrence of BM to death or last follow-up was 33.5 and 14 mo, respectively. It was confirmed by multivariate Cox regression analysis that patients with neurological symptoms (HR: 1.923, 95%CI: 1.005-3.680), with bone metastasis (HR: 2.011, 95%CI: 1.056-3.831), and BM of HER2-overexpressing and triple-negative BC had shorter survival time. CONCLUSION: HER2-overexpressing, triple-negative BC, late tumor stage and lung metastasis are risk factors of BM. The presence of neurological symptoms, bone metastasis, and molecular type are influencing prognosis factors of BCBM.

Peutz-Jeghers syndrome without STK11 mutation may correlate with less severe clinical manifestations in Chinese patients.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is an autosomal dominant genetic disease with skin mucosal pigment spots and gastrointestinal (GI) multiple hamartoma polyps as clinical characteristics. At present, it is considered that the germline mutation of STK11 gene is the genetic cause of PJS. However, not all PJS patients can be detected STK11 germline mutations. The specific clinical characteristics of these PJS patients without STK11 mutation is an interesting clinical question. Or, like wild type GI stromal tumor, whether these PJS without STK11 mutation are also called PJS is worth discussing. Therefore, we designed the study to understand the clinical characteristics of these PJS patients without STK11 mutation. AIM: To investigates whether PJS patients with known STK11 mutations have a more severe spectrum of clinical phenotypes compared to those without. METHODS: A total of 92 patients with PJS admitted to the Air Force Medical Center from 2010 to 2022 were randomly selected for study. Genomic DNA samples were extracted from peripheral blood samples, and pathogenic germline mutations of STK11 were detected by high-throughput next-generation gene sequencing. Clinical-pathologic manifestations of patients with and without STK11/LKB1 mutations were compared. RESULTS: STK11 germline mutations were observed in 73 patients with PJS. Among 19 patients with no detectable STK11 mutations, six had no pathogenic germline mutations of other genes, while 13 had other genetic mutations. Compared with PJS patients with STK11 mutations, those without tended to be older at the age of initial treatment, age of first intussusception and age of initial surgery. They also had a lower number of total hospitalizations relating to intussusception or intestinal obstruction, and a lower load of small intestine polyps. CONCLUSION: PJS patients without STK11 mutations might have less severe clinical-pathologic manifestations than those with.

Clinical features, diagnosis, and treatment of Peutz-Jeghers syndrome: Experience with 566 Chinese cases.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a clinically rare disease with pigmented spots on the lips and mucous membranes and extremities, scattered gastrointestinal polyps, and susceptibility to tumors as clinical manifestations. Effective preventive and curative methods are still lacking. Here we summarize our experience with 566 Chinese patients with PJS from a Chinese medical center with regard to the clinical features, diagnosis, and treatment. AIM: To explore the clinical features, diagnosis, and treatment of PJS in a Chinese medical center. METHODS: The diagnosis and treatment information of 566 cases of PJS admitted to the Air Force Medical Center from January 1994 to October 2022 was summarized. A clinical database was established covering age, gender, ethnicity, family history, age at first treatment, time and sequence of appearance of mucocutaneous pigmentation, polyp distribution, quantity, and diameter, frequency of hospitalization, frequency of surgical operations, etc. The clinical data was retrospectively analyzed using SPSS 26.0 software, with P < 0.05 considered statistically significant. RESULTS: Of all the patients included, 55.3% were male and 44.7% were female. Median time to the appearance of mucocutaneous pigmentation was 2 years, and median time from the appearance of mucocutaneous pigmentation to the occurrence of abdominal symptoms was 10 years. The vast majority (92.2%) of patients underwent small bowel endoscopy and treatment, with 2.3% having serious complications. There was a statistically significant difference in the number of enteroscopies between patients with and without canceration (P = 0.004, Z = -2.882); 71.2% of patients underwent surgical operation, 75.6% of patients underwent surgical operation before the age of 35 years, and there was a statistically significant difference in the frequency of surgical operations between patients with and without cancer (P = 0.000, Z = -5.127). At 40 years of age, the cumulative risk of intussusception in PJS was approximately 72.0%, and at 50 years, the cumulative risk of intussusception in PJS was approximately 89.6%. At 50 years of age, the cumulative risk of cancer in PJS was approximately 49.3%, and at 60 years of age, the cumulative risk of cancer in PJS was approximately 71.7%. CONCLUSION: The risk of intussusception and cancer of PJS polyps increases with age. PJS patients ≥ 10 years old should undergo annual enteroscopy. Endoscopic treatment has a good safety profile and can reduce the occurrence of polyps intussusception and cancer. Surgery should be conducted to protect the gastrointestinal system by removing polyps.

[Characteristics of rainfall and runoff in urban drainage based on the SWMM model.] / 基于SWMM模型的城市排水区域降雨及地表产流特征.

The characteristics of 235 rainfall and surface runoff events, from 2009 to 2011 in a typical urban drainage area in Shanghai were analyzed by using SWMM model. The results showed that the rainfall events in the region with high occurrence frequency were characterized by small rainfall amount and low intensity. The most probably occurred rainfall had total amount less than 10 mm, or mean intensity less than 5 mm·h-1,or peak intensity less than 10 mm·h-1, accounting for 66.4%, 88.8% and 79.6% of the total rainfall events, respectively. The study was of great significance to apply low-impact development to reduce runoff and non-point source pollution under condition of less rainfall amount or low mean rainfall intensity in the area. The runoff generally increased with the increase of rainfall. The threshold of regional occurring runoff was controlled by not only rainfall amount, but also mean rainfall intensity and rainfall duration. In general, there was no surface runoff when the rainfall amount was less than 2 mm. When the rainfall amount was between 2 to 4 mm and the mean rainfall intensity was below 1.6 mm·h-1, the runoff was less than 1 mm. When the rainfall exceeded 4 mm and the mean rainfall intensity was larger than 1.6 mm·h-1, the runoff would occur generally. Based on the results of the SWMM simulation, three regression equations that were applicable to regional runoff amount and rainfall factors were established. The adjustment R2 of the three equations were greater than 0.97. This indicated that the equations could reflect well the relationship between runoff and rainfall variables. The results provided the basis of calculations to plan low impact development and better reduce overflow pollution in local drainage area. It also could serve as a useful reference for runoff study in similar drainage areas.

[Research of controlling condition for aeration stabilization pond dealing with sanitary waste of countryside].

According to research of some problems, such as the hydraulic detention time that aeration stabilization pond deals with sanitary waste of countryside, dissolved oxygen in pond during the process of aeration, the concentration distribution of sludge and different aeration periods affecting on the treatment efficiency, we can acquire good treatment efficiency and energy consumption of economy. The results indicate that under the aeration stabilization pond of this experiment, 4 d is the best hydraulic detention time with this aeration stabilization pond. Time of the discontinuous running aeration should be greater than 15 min. The concentration distribution of sludge can reach equilibrium at each point of aeration stabilization pond between 2 min and 10 min. The best aeration period of dislodging the pollutant is 0.5 h aeration/1.0 h cut-off.

[Performance of new solid carbon source materials for denitrification].

Organic carbon is needed as the electron donor in the process of reduction of nitrate transformation to nitrogen gas, which is essential for biological denitrification. Based on previous research, agriculture wastes including corncob, rice hull, rice straw and sawdust were selected as potential carbon source for denitrification. Using the static organic material of carbon source leaching kinetics test and orthogonal experiments of external factors on carbon emission process, carbon release and its mechanism of a variety of carbon materials were studied. Study showed that release process of various types of carbon source materials follows the second dynamics formula, the release curve displayed a better double-reciprocal relationship. It revealed that release amount of rice straw was the highest and sawdust was the lowest. Results showed that corncob could better be used as carbon source for denitrification. Orthogonal test indicated that the increasing of solid-liquid ratio and water temperature would lead to an enhanced release capacity of carbon, however, the change of pH had no significant effect on release capacity of carbon; according to significant degree of water temperature, pH, solid-liquid ratio impacted on the carbon release, it was sorted by solid-liquid ratio > temperature > pH.

[Nitrate removal from wastewater using rice straw as carbon source and biofilm carrier].

In this research,agriculture waste-rice straw was investigated as the sole carbon source as well as biofilm carrier to remove nitrate from wastewater in up-flow laboratory reactors. The experimental results indicated that the startup of the system was quick and a high nitrate removal efficiency was observed. The accumulation of nitrite was not observed in this process. Moreover, high nitrate concentration in the influent had a significant effect on nitrate removal efficiency. The reactor was able to accommodate a wide range of pH (6.5-8.5) and DO (1.0-3.5 mg/L). A time-dependent decrease in nitrate removal efficiency was observed after 84 days of operation. The results showed that rice straw could be used as an economical and effective carbon source for denitrification.

Biological denitrification using corncobs as a carbon source and biofilm carrier.

In this research, agricultural waste--in particular, comcobs--was investigated for use as the sole carbon source and biofilm carrier to remove nitrate from wastewater in up-flow laboratory reactors. An artificial wastewater with a temperature range of 27 to 33 degrees C was used. Fast startup of the reactor and a high nitrate removal efficiency were observed. The highest denitrification rate of 0.203kg/(m3 x d) was achieved when flow rate and nitrate concentration were 153 L/d and 25.3 mgN/L, respectively. The accumulation of nitrite was not observed in this process. Moreover, flow rate and nitrate concentration of the influent were observed to have a significant effect on nitrate removal efficiency. A sharp decline of nitrate removal efficiency was observed when the flow rate was greater than 50 L/d. The reactor had the ability to accommodate a wide range of pH levels (6.5 to 8.5) and dissolved oxygen (1.5 mg/L to 4 mg/L). A time-dependent decrease in nitrate removal efficiency was observed after 67 days of operation. The addition of fresh corncobs brought about a rapid increase of nitrate removal efficiency. Results showed that corncobs could be used as an economical and effective carbon source for denitrification.

[Dynamic rule of organic matter removal in vertical-flow constructed wetland].

Based upon the analysis of the removal rate and form change of the organic pollutants with the different height of the vertical-flow constructed wetland, it comes to the conclusion of the average longitudinal removal rate of variant forms organics and presents the influent concentration and the hydraulic load curve. The results indicated that: Under this experimental condition, the reduction of the organics in the vertical subsurface flow constructed wetland mainly occurred within the 0-10 cm substrate below the pipe distributor. In the meantime, the smaller the hydraulic load of influent, the higher the removal ratio of the organic pollutants in the substrate section. Under the condition that the vertical subsurface flow constructed wetland used the coarse sands as the substrate and kept the influent hydraulic load less than or equal to 0.5 m3/(m2 x d), the effective height of the organics removal was 60 cm. It also showed that the average degradation rate of different kinds of the organic pollutants has a maximum value in the 0-10 cm substrate section below the pipeline. Moreover, the degradation ratio of different kinds of the organics is in significant decreasing tendency with increasing the depth of the longitudinal direction along the pipe. Using sands as the substrate in the vertical subsurface flow constructed wetland, the relationship of the influent concentration and influent hydraulic load can be expressed by formula:(c(in) - c(out)) x q = 1107.02-2.96 c(in) x q.

[Clogging mechanism in vertical-flow constructed wetland: clogging cause and accumulation distribution characteristics].

In order to solve the problem of clogging in the vertical-flow constructed wetland, the reason of clogging and the distribution rule of clogging substance in the vertical-flow constructed wetland was investigated first. Based on the correlativity of accumulation quantity and banked-up water area or lacuna rate in constructed wetland systems, the results show that the accumulation of non-filter materials is the main reason of clogging. The banked-up phenomenon will occur when the accumulation of non-filter materials is more than 18.23 mg in the per milliliter substrate. Under the condition of this experiment, the clogging phenomenon is easy to take place around current outlet, and accumulation materials mainly distribute in the 10-20 cm upper layer under water pipe. In the substrate, the accumulation degree of that of non-filter inorganic is more obvious than non-filter organic, with the trend of migrating along the water direction. The accumulation of organic and the depth of substrate is negatively correlated, i.e. deeper substrate,less organic content. The organic content in the surface layer of substrate is higher than that in other layers after banking up.

[Difference between subsurface wetlands for different water treatment].

By analysis of oxygen balance and material balance as well as empirical study, contribution of root oxygenation, water-carried oxygen and plant absorbance of nutrient in subsurface wetlands (SW) was examined, and free drainage in substrate was also adopted to check its effect on air transfer. The results showed that plant play important role when SW treating surface water with low concentration of contaminants. In such case, root oxygenation and water-carried oxygen sustains the substrate aerobic and so effluent DO > 0; N and P removal is stable for plant absorbance and media adsorption. However, in the case of higher load, namely domestic wastewater, role of root oxygenation becomes < or = 20% and effluent DO approximately 0. It is also found that amount of nitrate and nitrite bacteria are only 1/1 000 - 1/100 of amonifying bacteria in saturated substrate, which has strong negative effect on anti-clogging and nitrogen removal. Nitrogen removal percentage is often < or = 20%. Phosphorous initial removal percentage is 54%, but decreases to 5% after a year operation for the consumption of absorption capacity. Because pollutants load is too high for root oxygenation and plant absorbance and media absorption, limitations do exist in SW for domestic wastewater treatment. It is necessary to take use of air-reoxygenation in SW. The results showed that COD, NH4(+) -N, TN and TP removal percentage of SW with high water lever was 79%, 34%, 36% and 34% and those of SW with free drainage was 79%, 88%, 14%, 69%, which suggest that only air transfer is used properly, total nitrogen removal could be achieved in single-stage wetland.

[Enhancement strategies in vertical flow constructed wetlands for domestic wastewater treatment].

Because pollutants load is too high for root oxygenation, plant absorbance of nutrient and media absorption in vertical down flow wetland to remove pollutants from domestic wastewater, some deficiency do exist, which were confronted by pre-treatment enhancement, media optimization and technological revolution in this study. The strategies include chemically enhanced settlement, pre-aeration, addition of N-adsorption media and P"adsorption media, high, middle and low water level and dynamic saturation line within the soil profile. Chemically enhanced settlement can not only remove P but reduce 63% of the surface area of the connected wetland, but can not remove N effectively. Pre-aeration just increase 1% of the removal percentage of NH4+-N. The wetland with addition of N-adsorption media has the initial removal percentage of 84 % , which decreases to 64 % for consumption of adsorption capacity in 5 months. The saturation time of P-adsorption media is longer for the lower load of P on wetland. So, nitrogen removal only can be achieved by microorganism. Under stable saturation line, removal percentage of COD, NH+ -N, TN, TP in wetland with high water level is 50% , 21% , 32% , - 26% , and those in wetland with middle water level is 53% , 48% , 48% , - 14%, and those in wetland with low water level is 74 % , 96% , 35 % , 22 % . Dynamic saturation line was proposed and Cyclic Batch Subsurface Wetland (CBSW) was invented in this paper, which achieves removal percentage of 67% , 62%, 53%, 33% individually for COD, NH4+ -N, TN, TP. The result suggest that CBSW enhances N removal ability in single-stage wetland and perform better in anti-clogging, and so is the best enhancement strategy in subsurface wetland for domestic wastewater treatment.