Compounds In Sewage Research Articles

Assessment of the microbial electrochemical sensor (SENTRY™) as a potential wastewater quality monitoring tool for common pollutants found in Malaysia.

Bioelectrochemical sensors for environment monitoring have the potential to provide facility operators with real-time data, allowing for better and more timely decision-making regarding water and wastewater treatment. To assess the robustness and sensitivity of the Sentry™ biosensor in local conditions, it was tested in Malaysia using domestically available wastewater. The study objectives included (1) enrich the biosensor locally, (2) operate and test the biosensor with local domestic wastewater, and (3) determine the biosensor's responsiveness to model pollutants through pollutant spike and immersion test as well as response to absence of wastewater. Lab-scale operation shows the biosensor was successfully enriched with (1) local University Kebangsaan Malaysia's, microbial community strain collection and (2) local municipal wastewater microflora, operated for more than 50days with a stable yet responsive carbon consumption rate (CCR) signal. Meanwhile, two independent biosensors were also enriched and operated in Indah Water Research Centre's crude sewage holding tank, showing a stable response to the wastewater. Next, a pilot scale setup was constructed to test the enriched biosensors for the spiked-pollutant test. The biosensors showed a proportional CCR response (pollutant presence detected) towards several organic compounds in the sewage, including ethanol, chicken blood, and dilution of tested sewage but less to curry powder, methanol, and isopropanol. Conversely, there was no significant response (pollutant presence not detected) towards hexane, Congo red, engine oil, and paint, which may be due to their non-biodegradability and/or insoluble nature. Additionally, the biosensors were exposed to air for 6h to assess their robustness towards aerobic shock with a positive result. Overall, the study suggested that the biosensor could be a powerful monitoring tool, given its responsiveness towards organic compounds in sewage under normal conditions.

Wastewater Monitoring Program in Abu Dhabi – A Boon to Early Warning & Public Health Issue Prevention

The recent establishment of the wastewater monitoring regime by the Abu Dhabi (United Arab Emirates) Government as a tool to monitor the status of community well-being by studying the excretions from the sewage to steer global benchmarks of excellence in public health has been presented. The relevance of microbes and other chemical compounds in sewage and their significance for public health monitoring within the sampled community has been discussed. The key advantage of wastewater monitoring in establishing baseline data and its benefit in assessing the trend in infectious diseases, antimicrobial resistance, and illicit drugs has been presented. Undoubtedly, it is a classic tool available today for early warning signals and trend analysis for policymakers to monitor and avoid the catastrophic impact of deadly pathogens and chemical contaminants upon addressing the challenges.

Activated carbon preparation from pyrolysis char of sewage sludge and its adsorption performance for organic compounds in sewage

Although sludge pyrolysis has been extensively studied in sludge disposal, it is challenging to utilize sludge pyrolysis products. Here, we report a method for preparing sludge activated carbon (SAC) by activating sludge pyrolysis carbon by zinc chloride. The effect of ZnCl2 concentration, activation temperature and activation time on the activated carbon were investigated. The prepared activated carbons were characterized by thermogravimetric analysis, thermal kinetics analysis, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2 adsorption-desorption. The results show that when the ZnCl2 concentration was 8 mol/L with an activation time of 1 h at an activation temperature of 800 °C, the SAC iodine adsorption value and methylene blue adsorption value were 816.27 mg/g and 95.25 mg/g, respectively. The SAC exhibited a high BET surface area (up to 765.88 m2/g). The experimental results for simulated wastewater adsorption by SAC prepared under the above preparation conditions show that at an initial concentration of dimethyl phthalate (DMP) of 30 mg/L, addition amount of SAC of 20 mg, adsorption time of 30 min and temperature of 25 °C, the removal ratio of DMP can reach 87%. According to the data obtained, sludge pyrolysis char is a suitable precursor for activated carbon preparation. The obtained SAC could be used as a low-cost adsorbent with favorable surface properties.

Preparation of chitosan modified magnetic carbon nanotubes and application in immobilized enzymes

ABSTRACTChitosan (CTS) was selected to combine Fe3O4/CNTs with noncovalent bonds to prepare CTS modified magnetic carbon nanotubes (CTS-Fe3O4/CNTs). The chemical structure, morphology, crystal structure, element and magnetic properties were analyzed by means of FTIR, TEM, XRD, XPS and VSM. CTS-Fe3O4/CNTs was used as immobilized enzyme carrier for the degradation of phenolic compounds in sewage. The results of characterizations demonstrated that CTS had successfully modified the surface of Fe3O4/CNTs, amino groups existed simultaneously on the surface of Fe3O4 and CNTs. The surface modification of CTS did not destroy the crystal structure of Fe3O4/CNTs and CTS-Fe3O4/CNTs had super paramagnetic property. The effects of preparation and reaction conditions of CTS-Fe3O4/CNTs immobilized enzyme were investigated. Compared with free enzyme, the carrier CTS-Fe3O4/CNTs immobilized enzyme restricted conformational change of enzyme and stabilized enzyme relative activities, enhanced higher temperature tolerance, wider pH value, repeated using times and storage time under the optimum conditions of immobilized enzyme.

Municipal wastewater treatment by forward osmosis using seawater concentrate as draw solution

Forward osmosis (FO) has been used in the wastewater treatment due to its advantages including low energy consumption and low membrane fouling. In this study, real municipal wastewater was concentrated by FO process using seawater concentrate as draw solution (DS). The influences of operating conditions such as temperature, flow velocity and sewage pre-filtration on water flux were investigated. Chemical oxygen demand, total nitrogen, ammonia nitrogen and total phosphorus could not be enriched by 4 times while sewage was reduced to 1/4 volume. Excitation and emission matrix fluorescence spectrum showed that a fraction of dissolved organic compounds in sewage transported across membrane into DS. Membrane fouling was evaluated by scanning electronic microscope analysis that a dense cake layer was formed on the membrane surface after sewage filtration. However, water flux of the fouled membrane was highly recovered after 1 h of physical cleaning.

The Brookside Farm Wetland Ecosystem Treatment (WET) System: A Low-Energy Methodology for Sewage Purification, Biomass Production (Yield), Flood Resilience and Biodiversity Enhancement

Wastewater from domestic developments, farms and agro-industrial processing can be sources of pollution in the environment; current wastewater management methods are usually machine-based, and thus energy consuming. When Permaculture Principles are used in the creation of water purification and harvesting systems, there can be multiple environmental and economic benefits. In the context of energy descent, it may be considered desirable to treat wastewater using minimal energy. The constructed wetland design presented here is a low-entropy system in which wastewater is harvested and transformed into lush and productive wetland, eliminating the requirement for non-renewable energy in water purification, and also maximising benefits: biodiversity, flood resilience and yield. In permaculture design, the high concentrations of nitrogen and phosphorous compounds in sewage are viewed as valuable nutrients, resources to be harvested by a constructed wetland ecosystem and converted into useful yield. Similarly, rainwater runoff is not viewed as a problem which can cause flooding, but as a potential resource to be harvested to provide a yield. This paper presents a case study, with both water quality and productivity data, from Brookside Farm UK, where the use of Permaculture Design Principles has created a combined wastewater management and purification system, accepting all site water.

Non-targeted analyses of organic compounds in urban wastewater.

A large number of organic pollutants that cause damage to the ecosystem and threaten human health are transported to wastewater treatment plants (WWTPs). The problems regarding water pollution in Latin America have been well documented, and there is no evidence of substantive efforts to change the situation. In the present work, two methods to study wastewater samples are employed: non-targeted 1D ((13)C and (1)H) and 2D NMR spectroscopic analysis to characterize the largest possible number of compounds from urban wastewater and analysis by HPLC-(UV/MS)-SPE-ASS-NMR to detect non-specific recalcitrant organic compounds in treated wastewater without the use of common standards. The set of data is composed of several compounds with the concentration ranging considerably with treatment and seasonality. An anomalous discharge, the influence of stormwater on the wastewater composition and the presence of recalcitrant compounds (linear alkylbenzene sulfonate surfactant homologs) in the effluent were further identified. The seasonal variations and abnormality in the composition of organic compounds in sewage indicated that the procedure that was employed can be useful in the identification of the pollution source and to enhance the effectiveness of WWTPs in designing preventive action to protect the equipment and preserve the environment.

Activated sludge inhibition capacity index

Toxic compounds in sewage or industrial wastewater may inhibit the biological activity of activated sludge impairing the treatment process. This paper evaluates the Inhibition Capacity Index (ICI) for the assessment of activated sludge in the presence of toxicants. In this study, activated sludge was obtained from industrial treatment plants and was also synthetically produced. Continuous respirometric measurements were carried out in a reactor, and the oxygen uptake rate profile obtained was used to evaluate the impact of inhibiting toxicants, such as dissolved copper, phenol, sodium alkylbenzene sulfonate and amoxicillin, on activated sludge. The results indicate that ICI is an efficient tool to quantify the intoxication capacity. The activated sludge from the pharmaceutical industry showed higher resistance than the sludge from other sources, since toxicants are widely discharged in the biological treatment system. The ICI range was from 58 to 81% when compared to the synthetic effluent with no toxic substances.

Content of components in some grass species irrigated with purified sewage

Soil is a unique laboratory of transformations and energy flow, and in particular of biological sorption and synthesis of mineral components that can originate from various sources. The introduction of biomass or sewage into soil contributes to its nutrient enrichment. This can lead to periodical excess of these elements in soil and cause their migration from the soil system to underground waters, and eventually to open waters. Grass communities belong to a group of plants that make excellent use of nutrients present in soil and perform a very important role in additional purification of sewage after its mechanical purification. Grasses demonstrate resistance to the presence of large quantities of harmful compounds in sewage; they accumulate and neutralise them physiologically, thus preventing their dissemination. The aim of this paper was to evaluate content of some macro- and microelements as well as heavy metals in chosen grass species irrigated with purified sewage. In 1997-2000, research was conducted near the Hajdow Sewage Works, using purified sewage for irrigation of grass communities. Three rates of irrigation (a – control without irrigation; b – irrigation in quantity 600 mm and c – irrigation in quantity 1200 mm) as well as two grass mixtures were tested. Content of basic macroelements (N, P, K, Ca, Mg), microelements (Cu, Zn, Mn) as well as heavy metals (Cd, Pb) in dominant grass species (Alopecurus pratensis, Phalaris arundinacea, Festuca arundinacea, Festuca pratensis and Phleum pratense) were determined. The content of the analyzed components in biomass was varied and depended on the grass species in the analyzing mixtures as well as on the applied rates of irrigation. Festuca pratensis and Festuca arundinacea were characterized by the largest capacity to take up calcium (Ca) and magnesium (Mg), Phalaris arundinacea – phosphorus (P) and zinc (Zn), while Alopecurus pratensis – cadmium (Cd) and lead (Pb). Biomass of Alopecurus pratensis was characterized by the lowest content of most of the ele

Fate and removal of selected endocrine‐disrupting compounds in sewage using activated sludge treatment

AbstractThe variation and fate of four endocrine‐disrupting compounds (EDCs) composed of 4‐n‐nonylphenol (4‐n‐NP), bisphenol A (BPA), 17β‐estradiol (E2) and 17α‐ethinylestradiol (EE2) were investigated along treatment units in a sewage treatment plant (STP), China with anaerobic, anoxic and aerobic activated sludge processes. The mean concentrations were 64.8 ng/L (E2), 115.3 ng/L (4‐n‐NP), 171.5 ng/L (EE2), and 920.7 ng/L (BPA) in the influents, and 22.8 ng/L (E2), 50.9 ng/L (4‐n‐NP), 49.9 ng/L (EE2), and 84.3 ng/L (BPA) in the effluents. The biological treatment was more effective in removing NP, BPA and E2 from the aqueous phase than the primary treatment, while the latter could effectively remove EE2. Their possible removal mechanisms during the biological treatment with activated sludge were further explored through spiked batch experiments under three oxygen‐supplying conditions (anaerobic, anoxic and aerobic). The batch experiments showed that 4‐n‐NP, E2 and BPA were removed from the aqueous phase through biodegradation. The combination of sludge sorption and biodegradation accounted for the removal of EE2. Anoxic activated sludge showed the most rapid degradation of 4‐n‐NP, while E2 could be removed most effectively by aerobic activated sludge, and sludge sorption had a remarkable effect on its removal within the initial 15 min of the experiments under three oxygen‐supplying conditions.

Chlorophene degradation by combined ultraviolet irradiation and ozonation

Ozonation combined with UV irradiation (UV/O3) is an advanced oxidation technique that is very promising for the destruction of organic compounds in aqueous solution. In this study, chlorophene was chosen as a model substrate to investigate the effects of pH, initial substrate concentration, ozone dose, and UV light intensity in degradation experiments. The pseudo–first-order rate constant for total organic carbon (TOC) removal was 2.4 × 10−2, 9.8 × 10−4, and 6.4 × 10−2 min−1 for O3, UV, and UV/O3 treatment, respectively. Clearly, UV-enhanced ozonation leads to a synergetic increase in the overall degradation efficiency. Comparative experiments were performed to investigate the effect of the matrix (distilled water or sewage) on chlorophene removal. The organic compounds in sewage retarded the rate of chlorophene removal by 38%, probably by competitively reacting with the oxidizing agent and screening light. The compound 2-benzoylbenzo-1,4-quinone, benzo-1,4-quinone, hydroquinone and maleic acid were identified as primary intermediates by gas chromatography-mass spectrometry. The concentrations of acetic, formic and oxalic anions were detected by ion chromatography. A possible degradation pathway is proposed on the basis of the reaction products identified.

G020044 下水を用いた微生物燃料電池の開発([G02004]バイオエンジニアリング部門一般セッション(4))

Microbial fuel cells (MFC), which convert chemical energy of organic compounds to electric energy, have developed in recent years. MFCs may play an important role in sewage plants, where organic compounds in sewage are removed by microbes. We examined three kinds of sewage, i.e. inflow sewage that flowed into the plant, precipitation sewage, which was obtained by removing solid particles by precipitation from the former, and activated sludge, which was mixed with microbes and incubated to remove organic compounds. We observed the maximum electric power, 0.33 gW/cm2, in the inflow sewage. The output of the MFC depended on the kind of the sewage and stored time of the sewage. It was suggested that some microbes in the sewage enhanced the performance of the MFC.

Removal Capacity of Caffeine, Hormones, and Bisphenol by Aerobic and Anaerobic Sewage Treatment

The number of chemical compounds in sewage and consequently their release into the environment is increasing. Some of them are toxic and many of them are considered endocrine disrupters. Here, the capacity of three wastewater treatment plants (WWTPs) to remove caffeine, hormones and bisphenol-A was investigated. Bisphenol-A and caffeine are highly water-soluble compounds, as opposed to hormones (estradiol, estriol, and ethynilestradiol) which are hydrophobic compounds. In the Sewage Treatment Plant (SWT)1 the sewage is treated by activated sludge process, in the second plant, SWT2, sewage is treated by upflow anaerobic sludge blanket reactors followed by dissolved air flotation, and in the third, SWT3 sewage is treated by stabilization lagoons. The first lagoon is 3.5 m deep, thus facultative and polishment processes occur. It was speculated that there was a difference in efficiency between the three plants in removing micropollutants. Small differences were found in the amounts removed, probably accounted for by retention time. The caffeine and bisphenol-A were almost completely removed, higher than 90% for both compounds (bisphenol-A and caffeine) in all WWTPs. The hormones, however, had a smaller rate of removal, between 70% and 87%. It is suspected that retention time is essential for removal efficiency, together with type of treatment. In fact, the hormones, caffeine, and bisphenol-A found in the environment definitely come from untreated sewage.

Determination of sulfonamide compounds in sewage and river by mixed hemimicelles solid-phase extraction prior to liquid chromatography–spectrophotometry

Mixed hemimicelles-based solid-phase extraction was investigated for the preconcentration of five sulfonamides from environmental water samples prior to HPLC–spectrophotometry determination in this paper. A comparative study on the use of sodium dodecyl sulfate (SDS) coating γ-alumina or octadecyltrimethylammonium bromide (OTMABr) and OTMABr coating silica as sorbent materials were presented. The five analytes (sulfadiazine (SDA), sulfathiazole (STA), sulfapyridine (SPD), sulfamethazine (SMZ) and sulfamethoxazole (SMX)) were quantitatively adsorbed on OTMABr-γ-alumina and OTMABr-silica mixed hemimicelles, but OTMABr-γ-alumina was not adopted because it worked at a high pH (around 10), instead, OTMABr-silica was selected to overcoming the pH restriction. The analytes retained on the cartridge were quantitatively desorbed with suitable amounts of methanol. Factors influencing the extraction efficiency, such as the amount of surfactant, pH of sample and breakthrough volume were discussed. The proposed method had been applied to determining the five sulfonamides in several environmental water samples and concentration factors of 300 and 600 for SDA and other four analytes were achieved, respectively. Detection limits obtained ranged between 0.15 and 0.35 μg/L for this five sulfonamides under the optimized conditions. The accuracy of the method was evaluated by recovery measurements on spiked samples, and good recovery results (89–113%) with precision of 3–6% were achieved.

Analytical methodologies for determining the occurrence of endocrine disrupting chemicals in sewage treatment plants and natural waters

In this study, a method for assessing the occurrence of trace amounts of 12 representative estrogenic compounds in sewage and surface waters was developed. The selected substances were the phytoestrogens daidzein, genistein and biochanin A, the alkylphenols bisphenol A and 4-nonylphenol, the natural hormones 17β-estradiol, estrone, estriol and the synthetic hormone 17α-ethynylestradiol and the mycoestrogens zearalenone and two of its metabolites (α-zearalanol and β-zearalanol). The procedure consists in solid phase extraction (SPE) performed with OASIS cartridges followed by liquid chromatography coupled with tandem mass spectrometry (LC–MS–MS). Recoveries were all above 80% for each analyzed aqueous matrices. The developed method was applied to verify the occurrence of endocrine disrupters in environmental samples of sewage influents and effluents of an Italian STP. Phytoestrogens were present in effluents at concentrations ranging from 3 to 83 ng/l, whereas the levels detected for alkylphenols were in the range 13–36 ng/l for bisphenol A and up to 1 μg/l for nonylphenol. Estrogens and zeranols were determined at levels below 30 ng/l. Analysis of a river (Tiber) receiving effluent waters revealed high quantities of bisphenol A (15–29 ng/l) and nonylphenol (up to 1.2 μg/l), whereas the presence of all the other compounds were at levels of few ng/l.

Mutagenic activities of exhaust gas and ash from sludge incineration plants

We have found that the exhaust gas from many incineration plants of municipal solid wastes (MSW) show significant mutagenic activities. The mutagenic activities of exhaust gas from incineration plants of the other wastes have not been studied in detail. Here, we analyzed the mutagenic activities and compounds in exhaust gas and ash from seven sludge incineration plants. Some samples of the exhaust gas from the sludge incineration plants showed high mutagenic activities; although, none of the ash residues showed mutagenic activities. There was no relationship between the mutagenic activities and furnace types, the plant size or the apparent residence time of the gas in the furnace. The mutagenic activities of the exhaust gas were produced during incomplete combustion at lower temperatures. Direct mutagenic activities without S9 mix were higher than indirect mutagenic activities with S9 mix which was made from rat liver homogenate and was used to test mutagenic activity after metabolism. These results are different to those of MSW incineration plants. We analyzed the mutagenic compounds in the exhaust gas by GC/MS after fractionation by HPLC, but they could not be identified. We found that the mutagenic compounds in the exhaust gas were different from the compounds that were produced from the MSW incineration plants. We believed that these mutagenic compounds might be non-volatile and more polar than the heterocyclic amines, Trp-P-2, Trp-P-1 and Glu-P-1, which are typical mutagenic compounds in sewage and sludge.

Determination of butyltin species in sewage and sludge by gas chromatography-atomic absorption spectrometry.

A method for the extraction and determination of butyltin compounds in sewage and sludge is reported. Sewage and sludge samples are acidified and shaken for 2 h. The various butyltin species are extracted quantitatively by tropolone (cycloheptatrienone) in toluene, followed by ethylation to their tetraalkyl-substituted forms, BuSnEt3, Bu2SnEt2, Bu3SnEt and Et4Sn, all of which can be separated and determined by a gas chromatographic-atomic absorption spectrometric technique. The non-pesticidal octyltin species and acid-leachable SnIV species can also be determined by this method. Detection limits expressed as Sn are 40 ng dm-3 and 2 ng g-1 dry mass for sewage and sludge, respectively. Analyses of some samples from Canadian treatment plants are given.

Role of chemical concentration and second carbon sources in acclimation of microbial communities for biodegradation.

A study was conducted to determine the role of concentration of the test chemical, of a second organic compound, and of mutation in the acclimation period before the mineralization of organic compounds in sewage. The acclimation period for the mineralization in sewage of 2 micrograms of 4-nitrophenol (PNP) per liter increased from 6 to 12 days in the presence of 10 mg of 2,4-dinitrophenol per liter. The extension of the acclimation period was equivalent to the time required for mineralization of 2,4-dinitrophenol. In contrast, the time for acclimation for the degradation of 2 micrograms of PNP per liter was reduced when 10 or 100 mg of phenol per liter was added. Lower phenol levels increased the acclimation period to 8 days. The length of the acclimation period for PNP mineralization decreased as the initial concentration of PNP increased from 2 micrograms to 100 mg/liter. The acclimation period for phenol mineralization was lengthened as the phenol concentration increased from 100 to 1,400 mg/liter. The length of the acclimation period for PNP and phenol biodegradation was reproducible, but it varied among replicates for the biodegradation of other nitro-substituted compounds added to sewage or lake water, suggesting that a mutation was responsible for acclimation to these other compounds. The acclimation period may thus reflect the time required for the destruction of toxins, and it also may be affected by the concentration of the test compound or the presence of other substrates.

Role of protozoa in microbial acclimation for mineralization of organic chemicals in sewage

The role of protozoa in affecting the length of the acclimation period for the mineralization of organic compounds in sewage was investigated. The acclimation periods for the mineralization of 2 ng of p-nitrophenol, 100 ng of 2,4-dichlorophenoxyacetic acid, and 100 ng of 2,4-dichlorophenol per milliliter were markedly shortened or eliminated when the indigenous protozoa were inhibited with cycloheximide and nystatin. The extent of mineralization of the test compounds decreased when the protozoa were suppressed. Inhibition of the protozoa increased the total number of bacteria and the density of organisms able to mineralize 2 ng of p-nitrophenol/mL of sewage. Addition of Tetrahymena thermophila to sewage in which the indigenous protozoa were not active lengthened the acclimation period for the mineralization of p-nitrophenol. The addition of T. thermophila to a culture containing a low density of a p-nitrophenol-degrading Pseudomonas sp. did not affect the acclimation period prior to mineralization of the substrate, but the ciliate increased the acclimation period in the presence of high densities of Enterobacter aerogenes added as an alternative prey species. We suggest that protozoan grazing may be responsible for the acclimation period prior to the mineralization of certain organic compounds in sewage.

Effect of Ionic Composition of Suspending Solution on Virus Adsorption by a Soil Column

The effect of various electrolytes on the adsorption of poliovirus was measured in 250-cm-long soil columns with ceramic samplers at different depths. Viruses suspended in deionized water moved much farther through the soil than those suspended in tap water, whereas movement in sewage water was intermediate. The salt content of the tap water and sewage water promoted virus adsorption, but evidently the organic compounds in sewage retarded adsorption. When viruses were suspended in chloride solutions of K, Na, Ca, and Mg, virus adsorption increased as the cation concentration and valence increased. The depth of virus penetration was related to the ionic strength of the solutions. Virus penetration data for NO(3), SO(4), and H(2)PO(4) salts of K, Na, and Ca indicated that other anions were more effective than Cl in promoting virus adsorption. Also, NH(4) was more effective than other cations in limiting the penetration depth of viruses. It seems that ions composed of radicals are more effective than ions composed of single atoms in promoting virus adsorption. Al was the most effective ion in limiting virus penetration, probably owing to flocculation of the viruses. Adding AlCl(3) concentrations to secondary sewage effluent to provide an Al concentration of 0.1 mM reduced the virus penetration depth to 40 cm. These studies show that the ionic composition of the suspending solutions must be considered in predicting virus penetration depths, and it may be practical to add low concentrations of a flocculating agent such as AlCl(3) to sewage water to limit virus movement through very porous soils.