Considerations about the enantioselective transformation of polycyclic musks in wastewater, treated wastewater and sewage sludge and analysis of their fate in a sequencing batch reactor plant

The present work consists of two distinct parts: in the first part enantioselective GC was used to separate the different enantiomeric/diastereomeric polycyclic musks, PCMs (HHCB, AHTN, AHDI, ATII and DPMI) including the main transformation product of HHCB, HHCB-lactone, in wastewater and sewage sludge. After optimization all PCMs were resolved on a cyclodextrin containing Rt-BDEXcst capillary GC column. Enantiomeric ratios of PCMs in a technical mixture were determined and compared to those obtained from enantioselective separation of wastewater and sewage sludge samples. In general, enantiomeric ratios were similar for most materials in influent, effluent and stabilized sewage sludge. However, the ratios for HHCB, AHDI and particularly ATII suggest some stereospecific removal of these compounds. In the second part, a field study was conducted on a wastewater treatment plant comprising a sequencing batch reactor. Concentrations of HHCB, AHTN, ADBI, AHDI, ATII, DPMI and HHCB-lactone were determined by non-enantioselective GC in daily samples of influent, effluent and activated sludge during one week. Mean concentrations in influent were 6900 and 1520 ng/l for HHCB and AHTN, respectively. The other PCMs exhibited contents 200 ng/l. Mean percent removal was between 61% (AHDI) and 87% (HHCB) resulting in mean effluent concentrations below 860 ng/l. HHCB-lactone concentration increased during wastewater treatment with a mean in the influent of 430 ng/l and in the effluent of 900 ng/l, respectively, indicating a degradation of HHCB.     

Input/output balance of estrogenic active compounds in a major municipal sewage plant in Germany

24 h samples of untreated and treated wastewater were taken in parallel from a modern municipal sewage plant in southern Germany in March and June 1998. After solid phase extraction, total estrogenic activity was quantitatively measured with a miniaturized E-screen assay and the levels of nine estrogenic phenolic chemicals analyzed by HRGC/LRMS. 17Beta-estradiol equivalent concentrations (EEQ) were 58 and 70 ng/l in the influent and 6 ng/l in the effluent, indicating that the load of estrogenic activity of the wastewater was reduced by about 90% in the sewage plant. Less than 3% of the estrogenic activity was found in the sludge. 4-t-octylphenol, 4-nonylphenol, bisphenol A, 2-hydroxybiphenyl, and 4-chloro-3-methylphenol were detected in the untreated wastewater at levels from 0.13 to 3.6 microg/l. 4-t-octylphenol, 4-nonylphenol, and bisphenol A were present in the effluent at concentrations from 0.16 to 0.36 microg/l, 2-hydroxybiphenyl and 4-chloro-3-methylphenol were not detectable. The contribution of the quantified levels of phenolic xenoestrogens to total estrogenic activity in the sewage was 0.7-4.3%.     

Microalgae cultured by sewage and organic constituents

The microalgae could be multiplied by supplying only sewage influent or effluent without any additional microalgal stock or nutrient salt. In a semicontinuous culture, the N:P weight ratios consumed were 14:1 and 18:1 for the sewage influent and effluent, respectively. The total cell number and green algae ratio of microalgae cultivated by semicontinuous culture exceeded those of batch culture. No cyanobacterial cells were observed in the semicontinuous culture using the sewage effluent. The organic components in the cultured microalgae using sewage effluent, eluted by n-hexane, were determined. The ratio of unsaturated fatty acid exceeded that of saturated fatty acid, which was possibly attributable to the fluidity of the cell membrane. The squalene was also obtained by the culture using sewage alone, free of any external stock or nutrient salt. The higher heating value of the microalgae of semicontinuous culture using the sewage influent was 25 MJ kg⁻¹, corresponding to the heating value of lignite and showing the potential of the sewage culture microalgae as a means of power generation and combustion aid.     

Toxicity of leather tanning wastewater effluents in sea urchin early development and in marine microalgae

This study was designed to investigate the composition and the toxicity of leather tanning wastewater and conditioned sludge collected at the leather tanning wastewater treatment plant (CODISO) located in Solofra, Avellino (Southern Italy). Samples were analyzed for their conventional parameters (COD, TSS, chromium and ammonia) and for metal content. Effluent samples included raw wastewater, and samples collected following coagulation/flocculation process and biological treatment. A set of toxicity endpoints were tested using sea urchin and marine microalgal bioassays by evaluating acute embryotoxicity, developmental defects, changes in sperm fertilization success and transmissible damage from sperm to the offspring, and changes in algal growth rate. Dose-related toxicity to sea urchin embryogenesis and sperm fertilization success was exerted by effluent or sludge samples according to the following rank: conditioned sludge > coagulated effluent > or = raw influent > effluent from biological treatment. Offspring quality was not affected by sperm exposure to any wastewater or to sludge samples. Algal growth was inhibited by raw or coagulated effluent to a similar extent and, again, the effluent from the biological treatment resulted in a decreased toxicity. The results suggest that coagulated effluent and conditioned sludge result in higher toxicity than raw influent in sea urchin embryos and sperm, whereas the biological wastewater treatment of coagulated effluent, in both sea urchins and algae, cause a substantial improvement of wastewater quality. Hence a final biological wastewater treatment should be operated to minimize any environmental damage from tannery wastewater.     

Determination of clindamycin and its metabolite clindamycin sulfoxide in diverse sewage samples

In a research project on risk management of harmful substances in water cycles, clindamycin and 12 further antibiotics were determined in different sewage samples. In contrast to other antibiotics, an increase of the clindamycin concentration in the final effluent in comparison to the influent of the sewage treatment plant (STP) was observed. A back transformation from the main metabolite clindamycin sulfoxide to clindamycin during the denitrification process has been discussed. Therefore, the concentration of this metabolite was measured additionally. Clindamycin sulfoxide was stable in the STP and the assumption of back transformation of the metabolite to clindamycin was confuted. To explain the increasing clindamycin concentration in the STP, the ratio of clindamycin sulfoxide to clindamycin was observed. The ratio increased in dry spells with concentrated samples and with long dwell time in the sewer system. A short hydraulic retention in waste water system and diluted samples in periods of extreme rainfall lead to a lower ratio of clindamycin sulfoxide to clindamycin concentration. A plausible explanation of this behavior could be that clindamycin was adsorbed strongly to a component of the sewage during this long residence time and in the STP, clindamycin was released. In the common sample preparation in the lab, clindamycin was not released. Measurements of clindamycin and clindamycin sulfoxide in the influent and effluent of STP is advised for sewage monitoring.     

Mass balance assessment of triclosan removal during conventional sewage treatment

The antimicrobial agent triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS) is a member of a larger group of polychlorinated binuclear aromatic compounds frequently associated with adverse environmental and human health effects. Whereas the structure and function of TCS would suggest significant resistance to biotransformation, biological wastewater treatment currently is considered the principal destructive mechanism limiting dispersal of and environmental contamination with this compound. We explored the persistence of TCS in a typical full-scale activated sludge US sewage treatment plant using a mass balance approach in conjunction with isotope dilution liquid chromatography electrospray ionization mass spectrometry (ID-LC-ESI-MS) for accurate quantification. Average influent and effluent concentrations (mean +/- SD) of 4.7+/-1.6 and 0.07+/-0.06 microg 1(-1), respectively, revealed an apparent (liquid-phase) removal efficiency of 98+/-1%. However, further analyses demonstrated that the particle-active TCS (80+/-22% particle-associated in influent) was sequestered into wastewater residuals and accumulated in dewatered, digested sludge to concentrations of 30000+/-11000 microg kg-1. Overall, 50+/-19% (1640+/-610 g d-1) of the disinfectant mass entering the plant (3240+/-1860 g d-1) remained detectable in sludge, and less than half of the total mass (48+/-19%) was biotransformed or lost to other mechanisms. Thus, conventional sewage treatment was demonstrated to be much less effective in destroying the antimicrobial than the aqueous-phase removal efficiency of the plant would make believe. Furthermore, study findings indicate that the common practice of sludge recycling in agriculture results in the transfer of substantial quantities of TCS to US soils used, in part, for animal husbandry and crop production.     

Identification of impurities in technical metalaxyl

Impurities such as 2,6-dimethylaniline, N-methyl-2,6-dimethylaniline, N-(1-methoxycarbonyl-ethyl)-2,6-dimethylaniline, N-methyl-N-(1-methoxycarbonyl-ethyl)-2,6-dimethylaniline, N-methyl-N-(1-methoxyacetyl)-2,6-dimethylaniline, N-(1-methoxyacetyl)-2,6-dimethylaniline and N-ethyl-N-(methoxyacetyl)-2,6-dimethylaniline present in samples of technical metalaxyl were isolated by column chromatography and identified by nuclear magnetic resonance, mass spectroscopy and comparison with reference compounds.     

The occurrence and removal of selected pharmaceutical compounds in a sewage treatment works utilising activated sludge treatment

Pharmaceutical substances have been detected in sewage effluents as well as receiving waters in many parts of the world. In this study, the occurrence and removal of a number of drug compounds were studied within a large sewage treatment plant in the south of England. Samples were processed using solid phase extraction and analysed using gas chromatography-mass spectrometry (GC-MS). The results demonstrate that ibuprofen, paracetamol, salbutamol and mefenamic acid were present in both the influent and effluent of the works while propranolol-HCl was not found above the limit of quantification in any sample. Elimination rates were circa 90% for each compound but several hundred nanograms per litre were still present in the final effluent.     

Synthetic musks in the aquatic environment and personal care products in Shanghai, China

The concentrations and distributions of six polycyclic musks and two nitro musks in Suzhou Creek, influent/effluent of a sewage treatment plant (STP), and household commodities were investigated and discussed in this study. The levels of 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methylcyclopenta(g)-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) in Suzhou Creek were 3-78 ng g(-1) (dry weight) and 2-31 ng g(-1) (dry weight) in sediments, while 20-93 ng l(-1) and 8-20 ng l(-1) in surface waters. The results indicated a low proportion of wastewater burden in this river. The concentrations of HHCB and AHTN in the effluent of the STP were 5- to 6-fold higher than those in Suzhou Creek. The amounts discharged into the aquatic environment from sewage in Shanghai are 1.26 t (HHCB) and 0.38 t (AHTN) in 2007, and the input into the STPs is estimated to be HHCB 0.2 g y(-1) and AHTN 0.06 g y(-1) per inhabitant, respectively. A broad concentration range of HHCB and AHTN could be observed in household commodities. The distributions are in accordance with the profiles of musks in aquatic environment, with HHCB and AHTN being the major components.     

Enantioselective separation and determination of single nonylphenol isomers

It has recently become clear that an isomer specific view of technical 4-nonylphenol (NP) is absolutely necessary for the evaluation of the biological behavior of NP, raising additional questions concerning enantiomer specific effects. For the first time, in this study enantioselective HPLC was applied to enantiomeric separation of chiral NP isomers. A semipreparative separation of two NP isomers could be achieved. A GC-MS method has been developed for the simultaneous detection of three chiral NP isomers in water samples. Investigation of influent and effluent samples from a wastewater treatment plant in Germany indicated that enantioselective degradation could occur in the environment. In one examined influent, an enantiomer ratio of 1.7 for two different isomers was determined.     

Modelling of pharmaceutical residues in Australian sewage by quantities of use and fugacity calculations

A conceptual model is presented for determining which currently prescribed pharmaceutical compounds are most likely to be found in sewage, and for estimating their concentrations, both in raw sewage and after successive stages of secondary sewage treatment. A ranking of the "top-50" pharmaceutical compounds (by total mass dispensed) in Australia over the 1998 calendar year was prepared. Information on the excretion ratios and some metabolites of the pharmaceuticals enabled prediction of the overall rates of excretion into Australian sewage. Mass-balance and fugacity modelling, applied to sewage generation and to a sewage treatment plant, allowed calculation of predicted concentrations of the compounds in raw, primary and secondary treated sewage effluents. Twenty nine of the modelled pharmaceutical residuals were predicted to be present in raw sewage influent at concentrations of 1 microgl(-1) or greater. Twenty of the compounds were predicted to remain in secondary effluent at concentrations of 1 microgl(-1) or greater.     

城市污水厂污水污泥的热值测定分析方法研究

建立热力学指标是污水生物处理过程热力学分析的基础工作,目前仍缺乏污水污泥化学能测试的标准方法。采用IKA C5000型自动热量计对某城市二级污水处理厂进水、出水、初沉污泥、剩余污泥、混合污泥和脱水污泥进行了热值测定,样品前处理采用103～105℃烘干获得干燥基,用苯甲酸进行加标回收。参照煤的发热量测定方法得到样品的高位热值。试验结果显示：出水干燥基的热值为05 kJ/g,进水干燥基的热值为4 kJ/g以上,各工艺段的污泥干燥基热值较高,基本都在12 kJ/g以上,接近右江褐煤水平。测定结果的标准偏差≤±0.452%,相对标准偏差≤±0.136%。通过同一批样品的元素分析及Dulong公式理论推算,发现2种方法可得到相似的结果。     

Biological treatment of a synthetic gold milling effluent

This paper reports on biological sludge acclimatisation and the results concerning the removal of free cyanide, thiocyanate and metallocyanides (copper, iron and zinc) from a synthetic gold milling effluent. The experiments were carried out in a continuous bench-scale bioreactor, and the experimental set-up consisted of two identical units, one of which served as control. The acclimatisation of the biomass was based on a stepwise procedure, in which the proportion of synthetic solution in the influent was gradually increased. The reactors were fed with a mixture of synthetic effluent and sewage, and the treatment efficiency was evaluated through the monitoring of the following parameters: chemical oxygen demand (COD), free cyanide, thiocyanate, copper, iron and zinc concentrations. A well adapted microbial consortium was obtained at the end of the acclimatisation period, which was able to remove more than 95% of free cyanide, thiocyanate, copper and zinc, originally found in the influent. These removal efficiencies were obtained when the reactor was operated with a hydraulic retention time (HRT) of about 8 h. The performance results of experiments carried out with lower HRT (5 h) and higher dissolved oxygen (DO) concentration (6.5 mg litre(-1)) are also presented and discussed in this study.     

The fate of linear alcohol ethoxylates during activated sludge sewage treatment

Model continuous activated sludge (CAS) plants (Husmann units) were used to study the fate of two commercial, alcohol ethoxylate (AE) surfactants during aerobic sewage treatment. The surfactants were produced by the ethoxylation of an essentially linear C(12-15) alcohol (NEODOL 25) with an average of 7 (C(12-15)EO7) or 3 (C(12-15)EO3) moles of ethylene oxide (EO). Recent analytical developments made it possible to measure levels of AE that included the free alcohol and EO1 oligomers across the CAS system, from the influent feed, on the activated sludge, through to the effluent. Measured concentrations of AE (as C(12-15)EO(0-20)) in the synthetic sewage feeds to the test CAS plants lay in the range 11-13 mg/l. During stable operation at 20 degrees C, an average of 5 microg/l AE were present in the C(12-15)EO7 CAS plant effluent, giving a removal (bioelimination) of >99.9%. When levels of AE on the sludge, and polyethylene glycols (PEGs--an expected biodegradation intermediate) in the effluent and on the sludge were also taken into account, biodegradation was considered to be responsible for >98.7% of the observed removal. During operation at a winter temperature (10 degrees C), an average of 26 microg/l AE were present in the C(12-15)EO7 CAS plant effluent, giving a removal of 99.8%. Biodegradation was estimated to be responsible for >97.2% of the observed removal. During operation at 20 degrees C, an average of 7 microg/l AE were present in the C(12-15)EO3 CAS plant effluent, giving a removal of >99.9%. No analysis for PEG was performed in this case but the low level of AE on the sludge (0.2 mg/g dry solids) suggested that biodegradation was responsible for most of the observed removal. Neither surfactant had any adverse effect on the sewage treatment efficiencies of the CAS plants in terms of dissolved organic carbon (DOC) removal, nitrification or biomass levels.     

水解酸化-A~2O污泥减量工艺的运行性能研究

生物处理单元采用水解酸化、多级串联接触曝气、连续流的除磷脱氮A2/O工艺,并辅以外排厌氧富磷污水侧流除磷,开发了一个新型的具有强化除磷脱氮功能的污泥减量HA-A/A-MCO工艺。用该工艺处理校园生活污水发现,在SRT60 d、进水COD 316~407 mg/L、NH4+-N30~40 mg/L、TN35~53 mg/L、TP 8~12 mg/L的条件下,出水COD≤18 mg/L、NH4+-N≤2.1 mg/L、TN≤10.3 mg/L、TP≤0.44 mg/L。研究还发现,水解酸化池处理产生的VFA能有效促进生物除磷脱氮,导致厌氧释磷量达57 mg/L,进入化学除磷池的侧流液量仅相当于进水量的13%;系统最主要的脱氮形式是SND和缺氧反硝化,SND脱氮占脱氮总量的50%,缺氧反硝化占26%;HA-A/A-MCO系统有效实现了生物相分离,并利用生物捕食作用获得较低的污泥产率,0.1 g MLSS/g COD。     

Androgens,oestrogens, and progesterone concentrations in wastewater purification processes measured with capillary electrophoresis

A novel analytical-scale concept to improve reliability of detection and analysis of natural and processed wastewater samples from a purification plant was developed. A sequential sample clean-up system of polymer-based octadecyl and silane-based quaternary amine sorbents were used for concentrating human based steroid hormones and their metabolites and detecting them by UV absorption with capillary electrophoresis (CE). The water samples were collected from influent and effluent processes of the water purification plant in Helsinki, Finland.The CE methods were partial-filling micellar electrokinetic chromatography and capillary zone electrophoresis. The analysis times and method concentration levels were optimized with eight steroids at the range of 0.5–10 mg/L. Since in CE the detectable quantities were higher than the existing amounts in the process waters, the real samples needed matrix removal combined with steroid enrichment. After 20,000-fold concentration testosterone-glucoside, androstenedione, progesterone, and estradiol-glucoside could be determined in the process water samples. The amounts of individual steroids in influent and effluent waters were 0–429 and 0–207 ng/L, respectively. Correspondently, their total amounts were 735 and 212 ng/L with excellent in day and inter-day repeatability. The RSD values were less than 1, 9.7, and 19% in repeated analyses, calculated from 60 analyses during 24 h, and from 130 analyses during 15 months, respectively. The steroid removal in purification process was 65% on average. The solid particles separated in three steps during the water clean-up concept contained 9.8–45 ng/g steroids in combined dry precipitates.     

Steroid estrogens in ocean sediments

This paper gives results from a study measuring the abundance of steroid hormones in ocean sediments in the proximity of a deep ocean sewage outfall. The outfall is discharge point for an enhanced primary sewage treatment plant and sediment samples were taken adjacent and 7 km from the outfall. All samples contained steroid estrogens at nanogram per gram levels with higher concentrations at the 7 km sampling site. The concentration of estrone ranged from (0.16-1.17 ng/g), 17beta-estradiol (0.22-2.48 ng/g) and the synthetic 17alpha-ethinylestradiol (<0.05-0.5 ng/g). The values detected correspond with estimates based on the proportion of estrogens sorbed to particles in the effluent and the expected proportion of particles originating from sewage in the ocean sediments. The results suggest that estrogens associated with the particulate fraction aggregate on contact with high ionic strength seawater and settle to the seafloor after discharge through deep ocean outfalls.     

COD对生物除磷颗粒污泥稳定性影响研究

颗粒污泥稳定性是影响其应用的主要因素之一.以SBR中成熟的生物除磷颗粒污泥为研究对象,探讨进水COD浓度对系统稳定性的影响.结果表明,当进水COD浓度由300 mg/L逐渐升高到500 mg/L时,磷去除率由93%降低到88%;当进水COD浓度在400 mg/L以下时,污泥的最大比释磷速率和比吸磷速率分别为45.2 m...     

Mass balance of decabromodiphenyl ethane and decabromodiphenyl ether in a WWTP

The additive flame retardant decabromodiphenyl ethane (deBDethane) has been identified in the environment, but little is known about its environmental behaviour. It is structurally similar to decabromodiphenyl ether (decaBDE), making it conceivable that it may also become an environmental contaminant of concern. In this study a mass balance of deBDethane and decaBDE was undertaken in a modern WWTP in Stockholm serving 7.05x10(5) inhabitants. Flow proportional samples of plant influent and effluent as well as daily grab samples of digested sludge were collected during two 7-day periods. All samples were analyzed with GC/HRMS using isotope labelled internal standards. The mean mass flows of deBDethane and decaBDE to the WWTP were 6.0 g per day and 55 g per day, respectively. Of this, less than 1% of both BFRs left the WWTP via the effluent, while the bulk was sequestered into the digested sludge, where the mean concentrations of deBDethane and decaBDE were 81 and 800 ng g(-1)d.wt., respectively. It is concluded that the transfer efficiency of deBDethane from the technosphere to the environment via WWTPs is similar to that of decaBDE.     

The arrival and discharge of conjugated estrogens from a range of different sewage treatment plants in the UK

The occurrence of free and conjugated estrogens was examined in a survey of eleven sewage treatment plants (STPs) and their discharge water in the United Kingdom using grab sampling. The STPs included trickling filter with and without tertiary treatment, and activated sludge with tertiary treatment. For three activated sludge plants both influent and effluent samples were compared. For a further 8 STPs only the effluent was examined. The estrone-3-sulphate, estradiol-3-sulphate and estriol-3-sulphate concentrations (up to 20 ng L⁻¹) were typically 5-fold that of the respective free estrogen concentration in the effluents. This represents a substantial additional ‘potential’ estrogen load arriving in the receiving waters. Estrone-3-glucuronide was found at 9 ng L⁻¹, estradiol-3-glucuronide at 7 ng L⁻¹, and estriol-3-glucuronide at 32 ng L⁻¹ in sewage influent. Except on one occasion, no glucuronide conjugates could be found in the effluent. The results suggest in most cases glucuronide conjugates will be completely transformed in sewage treatment whilst sulphate conjugates will only be partially removed.