[Remediation Potential of Three Dwarf Bamboos on Farmland Soils Contaminated with Mixed Heavy Metals].

A two-year field experiment was carried out in a Cu-Zn-Cd-Pb-contaminated field with Sasa auricoma, Indocalamus tessellatus, and Shibataea chinensis Nakai to investigate their growth and accumulation characteristics. Based on changes in heavy metal content in the soil, we compared their phytoremediation potentials for the combined pollution of heavy metals. After two years of planting, S. auricoma showed the best tolerance to soil contaminated by heavy metals, with the number of plants being 63.8 times that at the time of planting. For each bamboo type, heavy metals were most concentrated in the root, with the best enrichment ability of Cd and worst ability of Pb. The bioconcentration factor of Cd in the roots was far greater than 1 for all three species, with 17.68 for S. auricoma and 14.63 for I. tessellatus. The accumulation of heavy metals was mainly concentrated in the roots and rhizomes, and the accumulations of Cu, Zn, and Cd in S. auricoma were 157.14, 363.3, and 7.18 g·hm-2, respectively, which were higher than those of I. tessellatus and S. chinensis Nakai. Compared with that before planting, the content of heavy metals in the non-rhizosphere soil decreased after two years of planting, among which Cd content decreased the most, from 39.6%-40.4%. In addition, the contents of Cu, Zn, and Cd in rhizosphere soil of S. auricoma and S. chinensis Nakai were significantly lower than those in non-rhizosphere soil (P<0.05). The results showed that the three species had strong accumulation ability of Cd and could be further studied as Cd-repaired plants. The growth condition and content and accumulation of heavy metals in S. auricoma were excellent among the dwarf bamboos, which showed the highest phytoremediation potential.

[Occurrence Characteristics and Risk Assessment of Antibiotics in the Surface Water of Luoma Lake and Its Main Inflow Rivers].

The concentration levels of 39 antibiotics, including sulfonamides (SAs), quinolones (QUs), tetracyclines (TCs), macrolides (MLs), and penicillins (PLs), in the surface water of Luoma Lake, and its main inflow rivers were analyzed using SPE-UPLC-MS/MS. The contribution rates of pollution of major rivers entering the lake were analyzed, and the potential ecological and health risks of antibiotics were assessed. The results showed that ρ(antibiotics)in 42 sampling sites was between 30.10 ng·L-1 and 582.37 ng·L-1, and a total of four classes of 23 antibiotics were detected. Among them, the average detection concentration of enrofloxacin (ERX) was the highest (88.05 ng·L-1), and the detection rate of lincomycin (LIN) was the highest (100%). The average concentration of antibiotics in the northern region of Luoma Lake was higher than that in the south, and among the two main rivers entering the lake, Yihe River was the main river contributing to the pollution of antibiotics in Luoma Lake, with a contribution rate of 53.91%. The results of risk assessment showed that ERX had the largest risk quotient. For the cumulative risk quotient (RQcum), RQcum of L6, R30, R31, R32, R33, and R42 was between 0.1 and 1, which is considered medium risk, and RQcum of other points was>1, which is considered high risk. The health risk assessment of 11 antibiotics showed that the health risk quotient (RQH) of adults and children ranged from 4.16×10-6 to 2.46×10-3, and there was no health risk to the human body.

In vitro biotransformation of tris(1,3-dichloro-2-propyl) phosphate and triphenyl phosphate by mouse liver microsomes: Kinetics and key CYP isoforms.

As the result of the phase-out on polybrominated diphenyl ethers, organophosphate flame retardants (OPFRs) were widely used as substitutes in the world. Previous studies found that OPFRs were frequently detected in environmental, biological, and human samples. Considering their adverse effects, the absorption, bioaccumulation, metabolism and internal exposure processes of OPFRs attracted more attentions recently, especially for aryl-OPFR and Cl-OPFRs. In the present study, the biotransformation, metabolic kinetics and related CYP450 isoforms of typical Cl-OPFR (tris(1,3-dichloro-2-propyl) phosphate: TDCPP) and aryl-OPFR (triphenyl phosphate: TPhP) were studied in vitro by mouse liver microsomes. Metabolomic analysis revealed that TDCPP may be easier to bio-accumulate in organisms than TPhP, which can be explained by their metabolic rates and half-life values (TDCPP: t1/2 = 1.8083 h; TPhP: t1/2 = 0.1531 h). CYP2E1, CYP2D6, CYP1A2 and CYP2C19 were suggested to be the specific enzymes for the biotransformation of TDCPP via associated inhibition assay. CYP2E1 was the primary CYP450 isoform of metabolism in vitro for TPhP. These findings may provide new insights for the potential mechanism of hepatotoxicity in mammals induced by OPFRs and the detoxification process of OPFRs in hepatocytes.

Distribution, abundance, and risk assessment of selected antibiotics in a shallow freshwater body used for drinking water, China.

With rapid improvements in industrialization and urbanization, antibiotics are now extensively used to prevent and treat human and animal diseases and husbandry and aquaculture. Some research has been conducted to assess the environmental distribution and risk level of antibiotics, but their distribution remains largely uncharacterized. Thus, this study investigated the distribution and abundance of 39 antibiotics belonging to five groups, and their associated risks in surface water around Luoma Lake in the north of Jiangsu province, China. Nineteen antibiotics were detected, at a detection frequency (DF) ranging from 2.27% to 100%. The total antibiotics (ΣABs) concentrations ranged from 34.91 to 825.93 ng/L, with a median concentration of 195.45 ng/L. Among these antibiotics, chlortetracycline (DF: 100%; median: 172.02 ng/L) was the dominant antibiotic, accounting for a median percentage of 91.0% of ΣABs concentrations. Spearman rank correlation method found a significant correlation between clindamycin (DF: 72.7%; median: 2.01 ng/L) and lincomycin (DF: 79.5%; median: 4.58 ng/L). The ecological risk quotient (RQ) values for two out of 44 sampling sites were higher than 1, indicating a high risk; 11.4% of the RQ values fell between 0.1 and 1, indicating a medium risk. Moreover, roxithromycin was found to be the dominant contributor to the ecological risk, accounting for a median of 79.7% of ΣABs. However, the total non-carcinogenic (<6.54 × 10-4) and carcinogenic risks (<1.64 × 10-7) of ΣABs were negligible at the detected concentrations.

[Occurrence and Risk Assessment of Organophosphate Esters in Source Water of the Nanjing Section of the Yangtze River].

We explored the pollution characteristics, spatial and temporal distribution, ecological risk, and human health risk of organophosphate esters (OPEs) in the source water of the Nanjing section of the Yangtze River. Thirteen OPEs were determined by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. The results showed that twelve OPEs were detected to different extents with total concentrations ranging from 85.21 to 1557.96 ng·L-1[excluding tris (2,3-dibromopropyl) phosphate]. Chloroalkyl phosphate was the main compound and tris(2-chloroethyl) phosphate (TCEP) was the most abundant of the thirteen OPEs, which reached up to 447.08 ng·L-1. Seasonal variation of OPEs showed that the concentrations of OPEs in summer ranged from 220-1557.96 ng·L-1, with the average concentration of 493.78 ng·L-1 being 1.7-2.6 times higher than of that in spring and autumn. An ecological risk assessment showed that tricresyl phosphate and 2-ethylhexyl diphenyl phosphate were associated with moderate or high risks to organisms (algae, crustaceans, and fish). At a high exposure concentration, the total non-carcinogenic risk of OPEs in source water ranged from 4.41×10-3-2.91×10-2, with the highest risk being associated with children aged 0-3 months. The total cancer risk value was 5.88×10-7-3.89×10-6, among which TCEP and Tris(1,3-dichloro-2-propyl) phosphate was associated with a potential risk for children. We conclude that the long-term exposure risk for children of OPEs in the source water of the Nanjing section of the Yangtze River deserve more attention.

[Occurrence Characteristics and Risk Assessment of Antibiotics in Source Water of the Nanjing Reach of the Yangtze River].

Occurrence characteristics of antibiotics in the source water of the Nanjing section of the Yangtze River were analyzed preliminarily by solid-phase extraction and high-performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS). The results showed that the cumulative concentration of 16 sampling points ranged from 13.37 ng·L-1 to 780.5 ng·L-1, with an average concentration of 92.95 ng·L-1. Four sulfonamides, three fluoroquinolones, one tetracycline, five macrolides, and one chloramphenicol antibiotic were detected with average concentration ranging from 0.14 ng·L-1 to 49.91 ng·L-1,including enrofloxacin (ERX) and clarithromycin (CLR) with the highest detection rate of 100%, and clindamycin (CLI) with the highest concentration of 739.44 ng·L-1. Overall, the concentration levels of antibiotics in the Nanjing section of the Yangtze River were low compared with other rivers and lakes in China. The risk assessment results showed that the largest cumulative risk of S2 was 0.31, and the environmental risk of sulfamethoxazole (SMX), doxycycline (DOX), and roxithromycin (ROX) had lower risk levels;the health risk indexes of nine antibiotics for different age groups were between 2.22×10-6and 4.86×10-3, while CLI and DOX are the main potential health risk factors for humans.

[Pollution Level and Ecological Risk of Typical Antibiotics in Guiyang Wastewater Treatment Plants].

To determine the removal efficiency of typical antibiotics in Guiyang wastewater treatment plants (WWTPs) and the impact of effluent on aquatic organisms in receiving waters, nine antibiotics in the influent, effluent, and receiving water of two WWTPs in Guiyang City were investigated. The concentrations of antibiotics in the influent and effluent ranged from 0 to 835.60 ng·L-1 and 0 to 286.60 ng·L-1, respectively, and the concentration of ofloxacin (OFX) was highest. Its concentration in the influent was 835.60 ng·L-1 and 539.00 ng·L-1 and in the effluent was 11.74 ng·L-1 and 286.60 ng·L-1, respectively. The removal rate of antibiotics in the WWTPs ranged from -42.29% to 100%, and tetracycline (TC) was completely removed. The concentrations of antibiotics in the influent and effluent of the WWTPs in Guiyang City was less than in other regions of China and in other counties. Through the analysis of the antibiotics in the receiving waters, it was found that the concentrations of OFX were higher than other antibiotics, and the WWTPs effluent was one source of antibiotics in the receiving waters. OFX showed a high risk (RQ>1) for aquatic organisms in the receiving waters, as determined by an ecological risk assessment.

Occurrence, spatial distribution, and ecological risks of typical hydroxylated polybrominated diphenyl ethers in surface sediments from a large freshwater lake of China.

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been frequently observed in marine aquatic environments; however, little information is available on the occurrence of these compounds in freshwater aquatic environments, including freshwater lakes. In this study, we investigated the occurrence and spatial distribution of typical OH-PBDEs, including 2'-OH-BDE-68, 3-OH-BDE-47, 5-OH-BDE-47, and 6-OH-BDE-47 in surface sediments of Taihu Lake. 3-OH-BDE-47 was the predominant congener, followed by 5-OH-BDE-47, 2'-OH-BDE-68, and 6-OH-BDE-47. Distributions of these compounds are drastically different between sampling site which may be a result of differences in nearby point sources, such as the discharge of industrial wastewater and e-waste leachate. The positive correlation between ∑OH-PBDEs and total organic carbon (TOC) was moderate (r = 0.485, p < 0.05), and site S3 and S15 were excluded due to point source pollution, suggesting that OH-PBDEs concentrations were controlled by sediment TOC content, as well as other factors. The pairwise correlations between the concentrations of these compounds suggest that these compounds may have similar input sources and environmental behavior. The target compounds in the sediments of Lake Taihu pose low risks to aquatic organisms. Results show that OH-PBDEs in Lake Taihu are largely dependent on pollution sources. Because of bioaccumulation and subsequent harmful effects on aquatic organisms, the concentrations of OH-PBDEs in freshwater ecosystems are of environmental concern.

[Distribution Characteristics and Potential Risk of Bisphenol Analogues in Surface Water and Sediments of Lake Taihu].

In this study, seven bisphenol analogues were measured in water and sediment samples from Taihu Lake, and potential risk was evaluated. The results showed that BPF, BPS and BPA were the predominant components in water samples from Lake Taihu. In sediment, BPA was always predominant, followed by BPF and BPS, and there was a significant positive correlation between BPs and TOC content. In addition, the high concentration levels of BPF, BPS and BPA were distributed in the tributaries of Lake Taihu(S4-S10). The risk assessment of the target BPs showed that the combined risk quotients posed a low eco-toxicity to aquatic ecosystem, and there was no appreciable risk to human health from potential environmental exposure of drinking water.

[Pollution Level, Distribution Characteristics and Risk Assessment of 32 PPCPs in Surface Water of Luomahu Lake].

A total of 22 water samples collected from Luomahu Lake were determined using high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) to evaluate the pollution level,spatial distribution and ecological risk of 32 PPCPs.23 PPCPs were detected in surface water of Luomahu Lake and the total concentrations of 22 samples were 892-1536 ng·L-1.The concentration of norfloxacin (256-707 ng·L-1) was the highest among the detected PPCPs,followed by ketoprofen (85-438 ng·L-1),acesulfame (101-290 ng·L-1) and naproxen (1.9-112 ng·L-1).Spatial differences were found in concentrations of PPCPs in various sampling sites.Concentrations of PPCPs in northeast of Luomahu Lake were higher than those of southwest.Concentration of PPCPs in Fangtinghe River was high and that of Zhangshanzha River was relatively low.The risk assessment of 13 pharmaceutical PPCPs showed that risk quotients (RQs) of norfloxacin were 0.26-0.72,posing medial risk to aquatic ecosystem.Gemifibrozil posed low ecological risks with RQs>0.01 in most sampling sites.RQs of other 11 PPCPs were less than 0.01,posing no ecological risks.The combined risk quotients of 12 PPCPs in water of Luomahu Lake were 0.29-0.75,indicating that those compounds posed an medial risk to aquatic ecosystem.Human health risk assessment showed that the RQs were less than one for 6 selected PPCPs,indicating that these compounds did not appear to pose an appreciable risk to human health by potential environmental exposure from drinking water.

Occurrence, distribution and risk assessment of suspected endocrine-disrupting chemicals in surface water and suspended particulate matter of Yangtze River (Nanjing section).

The occurrence and distribution of eight selected endocrine-disrupting chemicals were investigated in samples of surface water and suspended particulate matter (SPM) in Nanjing section of Yangtze River over a year (the flow period, the wet period and the dry period). All target compounds were detected at least once in surface water with 4-tert-butylphenol (4-TBP), nonyphenol (NP) and bisphenol A (BPA) as the dominant compounds, with concentrations in the range of 225-1121ng/L, 1.4-858ng/L and 1.7-563ng/L, respectively. Except for December, all selected compounds for the other sampling times were not found in all sampling points. NP (mean concentration 69.8µg/g) and BPA (mean concentration 51.8µg/g) were also the dominant estrogens in SPM. In addition, the highest total compounds concentrations were found in December in both phases, which could be due to the low flow conditions and temperature during this season. Meanwhile, a significant positive correlation was found between the total compounds concentrations in the water phase and those in SPM phase. Risk assessment based on the calculated risk quotients (RQ) showed that low and moderate risk for the aquatic environment from presence of the target compounds at all sampling points with exception of 4-TBP and NP which might pose a high risk to aquatic organisms.

[Anaerobic biodegradation of microcystin by bacterial community from sediment of Dianchi Lake].

Aerobic biodegradation has been identified as the main attenuation mechanism for microcystin, but the role of anaerobic microcystin biodegradation remains unclear. To elucidate this process, we assessed the potential for anaerobic microcystin LR biodegradation by sediment microbial community from Dianchi Lake and evaluated the effects of environmental factors and additional nutrient sources on the rates of anaerobic biodegradation. The results showed that microcystin LR was rapidly degraded from 5 mg/L to below detection limit within 2 days, demonstrating that the indigenous microorganisms can efficiently degrade microcystin LR under anaerobic conditions and can use microcystin LR as a sole nitrogen source. The rates of anaerobic microcystin LR biodegradation increased with increasing incubation temperature within the experimental range of 15-30 degrees C. Anaerobic microcystin LR biodegradation was slower (pH = 5.0) or even ceased (pH = 3.0) at acidic pH, but there was no difference in the rates at neutral (pH = 7.0) and alkaline (pH 9.0, 11.0) conditions. The addition of glucose decreased pH of the culture by producing acidic compounds and therefore significantly inhibited the anaerobic biodegradation of microcystin LR, but with the addition of NO3-, this inhibition disappeared. NO3- amendment also retarded the biodegradation of microcystin LR, demonstrating that NO3- was not used as a terminal electron acceptor. These findings suggest that anaerobic biodegradation might be another main attenuation mechanism for microcystin LR in sediments and present a significant bioremediation potential.