Displaying publications 161 - 180 of 215 in total

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  1. Treatment of p-nitrophenol in an adsorbent-supplemented sequencing batch reactor
    Loo YM, Lim PE, Seng CE
    Environ Technol, 2010 Apr 14;31(5):479-87.
    PMID: 20480823 DOI: 10.1080/09593330903514482
    The objective of this research was to evaluate the treatment ofp-nitrophenol (PNP) as a sole organic carbon source using a sequencing batch reactor (SBR) with the addition of adsorbent. Two types of adsorbents, namely powdered activated carbon (PAC) and pyrolysed rice husk (PRH) were used in this study. Two identical SBRs, each with a working volume of 10 L, were operated with fill, react, settle, draw and idle periods in the ratio of 2:8:1:0.75:0.25 for a cycle time of 12 h. The results showed that, without the addition of adsorbent, increasing the influent PNP concentration to 200 mg/L resulted in the deterioration of chemical oxygen demand (COD) removal efficiency and PNP removal efficiency in the SBRs. Improvement in the performance of the SBR was observed with the addition of PAC. When the dosage of 1.0 g PAC/cycle was applied, COD removal of 95% and almost complete removal of PNP were achieved at the influent PNP concentration of 300 mg/L. The kinetic study showed that the rates of COD and PNP removal can be described by the first-order kinetics. The enhancement of performance in the PAC-supplemented SBR was postulated to be due to the initial adsorption of PNP by the freshly added and the bioregenerated PAC, thus reducing the inhibition on the microorganisms. The PRH was found to be ineffective because of its relatively low adsorption capacity for PNP, compared with that of PAC.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  2. Effects of adsorbents and copper(II) on activated sludge microorganisms and sequencing batch reactor treatment process
    Ong SA, Lim PE, Seng CE
    J Hazard Mater, 2003 Oct 31;103(3):263-77.
    PMID: 14573344
    Wastewater treatment systems employing simultaneous adsorption and biodegradation processes have proven to be effective in treating toxic pollutants present in industrial wastewater. The objective of this study is to evaluate the effect of Cu(II) and the efficacy of the powdered activated carbon (PAC) and activated rice husk (ARH) in reducing the toxic effect of Cu(II) on the activated sludge microorganisms. The ARH was prepared by treatment with concentrated nitric acid for 15 h at 60-65 degrees C. The sequencing batch reactor (SBR) systems were operated with FILL, REACT, SETTLE, DRAW and IDLE modes in the ratio of 0.5:3.5:1:0.75:0.25 for a cycle time of 6 h. The Cu(II) and COD removal efficiency were 90 and 85%, respectively, in the SBR system containing 10 mg/l Cu(II) with the addition of 143 mg/l PAC or 1.0 g PAC per cycle. In the case of 715 mg/l ARH or 5.0 g ARH per cycle addition, the Cu(II) and COD removal efficiency were 85 and 92%, respectively. ARH can be used as an alternate adsorbent to PAC in the simultaneous adsorption and biodegradation wastewater treatment process for the removal of Cu(II). The specific oxygen uptake rate (SOUR) and kinetic studies show that the addition of PAC and ARH reduce the toxic effect of Cu(II) on the activated sludge microorganisms.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  3. Simultaneous adsorption and biodegradation processes in sequencing batch reactor (SBR) for treating copper and cadmium-containing wastewater
    Lim PE, Ong SA, Seng CE
    Water Res, 2002 Feb;36(3):667-75.
    PMID: 11827329
    The application of simultaneous adsorption and biodegradation processes in the same reactor is known to be effective in the removal of both biodegradable and non-biodegradable contaminants in various kinds of wastewater. The objective of this study is to evaluate the efficacy of the two processes under sequencing batch reactor (SBR) operation in treating copper and cadmium-containing synthetic wastewater with powdered activated carbon (PAC) as the adsorbent. The SBR systems were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in the ratio of 0.5: 3.5: 1.0: 0.75 :0.25 for a cycle time of 6 h. In the presence of 10 mg/L Cu(II) and 30 mg/L Cd(II), respectively, the average COD removal efficiencies were above 85% with the PAC dosage in the influent solution at 143 mg/L compared to around 60% without PAC addition. Copper(II) was found to exert a more pronounced inhibitory effect on the bioactivity of the microorganisms compared to Cd(II). It was observed that the combined presence of Cu(II) and Cd(II) did not exert synergistic effects on the microorganisms. Kinetic study conducted for the REACT period showed that the addition of PAC had minimized the inhibitory effect of the heavy metals on the bioactivity of microorganisms.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  4. Wavelet neural networks applied to pulping of oil palm fronds
    Zainuddin Z, Wan Daud WR, Pauline O, Shafie A
    Bioresour Technol, 2011 Dec;102(23):10978-86.
    PMID: 21996481 DOI: 10.1016/j.biortech.2011.09.080
    In the organosolv pulping of the oil palm fronds, the influence of the operational variables of the pulping reactor (viz. cooking temperature and time, ethanol and NaOH concentration) on the properties of the resulting pulp (yield and kappa number) and paper sheets (tensile index and tear index) was investigated using a wavelet neural network model. The experimental results with error less than 0.0965 (in terms of MSE) were produced, and were then compared with those obtained from the response surface methodology. Performance assessment indicated that the neural network model possessed superior predictive ability than the polynomial model, since a very close agreement between the experimental and the predicted values was obtained.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  5. A mini-review on rare earth metal-doped TiO2 for photocatalytic remediation of wastewater
    Saqib NU, Adnan R, Shah I
    Environ Sci Pollut Res Int, 2016 Aug;23(16):15941-51.
    PMID: 27335012 DOI: 10.1007/s11356-016-6984-7
    Titanium dioxide (TiO2) has been considered a useful material for the treatment of wastewater due to its non-toxic character, chemical stability and excellent electrical and optical properties which contribute in its wide range of applications, particularly in environmental remediation technology. However, the wide band gap of TiO2 photocatalyst (anatase phase, 3.20 eV) limits its photocatalytic activity to the ultraviolet region of light. Besides that, the electron-hole pair recombination has been found to reduce the efficiency of the photocatalyst. To overcome these problems, tailoring of TiO2 surface with rare earth metals to improve its surface, optical and photocatalytic properties has been investigated by many researchers. The surface modifications with rare earth metals proved to enhance the efficiency of TiO2 photocatalyts by way of reducing the band gap by shifting the working wavelength to the visible region and inhibiting the anatase-to-rutile phase transformations. This review paper summarises the attempts on modification of TiO2 using rare earth metals describing their effect on the photocatalytic activities of the modified TiO2 photocatalyst.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  6. Nitrification of high-strength ammonium landfill leachate with microbial community analysis using fluorescence in situ hybridization (FISH)
    Yusof N, Hassan MA, Yee PL, Tabatabaei M, Othman MR, Mori M, et al.
    Waste Manag Res, 2011 Jun;29(6):602-11.
    PMID: 21447612 DOI: 10.1177/0734242X10397581
    Nitrification of mature sanitary landfill leachate with high-strength of N-NH(4) + (1080-2350 mg L(-1)) was performed in a 10 L continuous nitrification activated sludge reactor. The nitrification system was acclimatized with synthetic leachate during feed batch operation to avoid substrate inhibition before being fed with actual mature leachate. Successful nitrification was achieved with an approximately complete ammonium removal (99%) and 96% of N-NH(4) + conversion to N-NO(-) (3) . The maximum volumetric and specific nitrification rates obtained were 2.56 kg N-NH(4) (+) m(-3) day(-1) and 0.23 g N-NH(4) ( +) g(-1) volatile suspended solid (VSS) day(-1), respectively, at hydraulic retention time (HRT) of 12.7 h and solid retention time of 50 days. Incomplete nitrification was encountered when operating at a higher nitrogen loading rate of 3.14 kg N-NH(4) (+) m(-3) day(-1). The substrate overloading and nitrifiers competition with heterotrophs were believed to trigger the incomplete nitrification. Fluorescence in situ hybridization (FISH) results supported the syntrophic association between the ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria. FISH results also revealed the heterotrophs as the dominant and disintegration of some AOB cell aggregates into single cells which further supported the incomplete nitrification phenomenon.
    Matched MeSH terms: Waste Disposal, Fluid/methods
  7. Landfill leachate treatment by an experimental subsurface flow constructed wetland in tropical climate countries
    Ujang Z, Soedjono E, Salim MR, Shutes RB
    Water Sci Technol, 2005;52(12):243-50.
    PMID: 16477992
    Municipal leachate was treated in an experimental unit of constructed wetlands of subsurface flow type. The parameters studied were organics (BOD and COD), solids and heavy metals (Zn, Ni, Cu, Cr and Pb). Using two types of emergent plants of Scirpus globulosus and Eriocaulon sexangulare, more than 80% removal was achieved for all the parameters. E. sexangulare removed organics and heavy metals better than Scirpus globulosus. A higher concentration of heavy metals in the influent did not change the removal efficiency.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  8. Solid waste collection and recycling in Nibong Tebal, Penang, Malaysia: a case study
    Isa MH, Asaari FA, Ramli NA, Ahmad S, Siew TS
    Waste Manag Res, 2005 Dec;23(6):565-70.
    PMID: 16379126
    The implementation of a suitable solid waste management programme with appropriate methods of recycling as an inherent element is vital to the alleviation of the problems associated with solid waste generation, handling and disposal, environmental conservation, public hygiene, etc. The present work is a case study on solid waste collection and recycling practices in Nibong Tebal town, Penang, Malaysia. The amount and types of domestic waste generated, household participation in recycling, identification of existing problems related to the implementation of the recycling programme, etc. formed the basis of this study. Surveys (interviews/questionnaires) and on-site observations were conducted to gather information on the solid waste collection and recycling practice of the residents. A focus group of 60 individuals was selected and their response to a questionnaire, prepared according to a Likert scale, was obtained and analysed. The majority of the respondents expressed concerns about recycling and wanted more to be done in this regard. Illegal collection, aesthetically displeasing sites and a lack of public awareness were problems of major concern. Issues related to inadequate funding and manpower as well as end market are also addressed and suggestions made.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  9. Post-treatment of palm oil mill effluent (POME) using combined persulphate with hydrogen peroxide (S2O8(2-)/H2O2) oxidation
    Lin CK, Bashir MJ, Abu Amr SS, Sim LC
    Water Sci Technol, 2016 Dec;74(11):2675-2682.
    PMID: 27973372
    The aim of the current study is to evaluate the effectiveness of combined persulphate with hydrogen peroxide (S2O8(2-)/H2O2) oxidation as a post-treatment of biologically treated palm oil mill effluent (POME) for the first time in the literature. The removal efficiencies of chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N), and suspended solids (SS) were 36.8%, 47.6%, and 90.6%, respectively, by S2O8(2-) oxidation alone under certain operation conditions (i.e., S2O8(2-) = 0.82 g, pH 11, and contact time 20 min). Nevertheless, the combined process (S2O8(2-)/H2O2) achieved 75.8% and 87.1% removals of NH3-N and SS, respectively, under 2.45/1.63 g/g H2O2/S2O8(2-), pH 11, and 20 min oxidation. Moreover, 56.9% of COD was removed at pH 8.4.
    Matched MeSH terms: Waste Disposal, Fluid/methods
  10. Decomposition and biodegradability enhancement of textile wastewater using a combination of electron beam irradiation and activated sludge process
    Mohd Nasir N, Teo Ming T, Ahmadun FR, Sobri S
    Water Sci Technol, 2010;62(1):42-7.
    PMID: 20595752 DOI: 10.2166/wst.2010.239
    The research conducted a study on decomposition and biodegradability enhancement of textile wastewater using a combination of electron beam irradiation and activated sludge process. The purposes of this research are to remove pollutant through decomposition and to enhance the biodegradability of textile wastewater. The wastewater is treated using electron beam irradiation as a pre-treatment before undergo an activated sludge process. As a result, for non-irradiated wastewater, the COD removal was achieved to be between 70% and 79% after activated sludge process. The improvement of COD removal efficiency increased to 94% after irradiation of treated effluent at the dose of 50 kGy. Meanwhile, the BOD(5) removal efficiencies of non-irradiated and irradiated textile wastewater were reported to be between 80 and 87%, and 82 and 99.2%, respectively. The maximum BOD(5) removal efficiency was achieved at day 1 (HRT 5 days) of the process of an irradiated textile wastewater which is 99.2%. The biodegradability ratio of non-irradiated wastewater was reported to be between 0.34 and 0.61, while the value of biodegradability ratio of an irradiated wastewater increased to be between 0.87 and 0.96. The biodegradability enhancement of textile wastewater is increased with increasing the doses. Therefore, an electron beam radiation holds a greatest application of removing pollutants and also on enhancing the biodegradability of textile wastewater.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  11. Parenteral cytotoxic drug wastage at a tertiary hospital in Kuala Lumpur: How much and why?
    Ang ZY, Cheah KY, Abdullah NB, Samsuri SB, Lee SH, Yem AW, et al.
    J Oncol Pharm Pract, 2020 Sep;26(6):1306-1317.
    PMID: 31810422 DOI: 10.1177/1078155219891209
    PURPOSE: To identify the cost and reasons of returned parenteral chemotherapy regimens at a tertiary hospital in Kuala Lumpur, Malaysia.

    METHODS: Data were retrospectively extracted from all the Chemotherapy Return Forms in 2016, which is a compulsory documentation accompanying each return of parenteral chemotherapy regimen. The following data were extracted: patient's diagnosis, gender, location of treatment (i.e. ward/daycare clinic), start date of chemotherapy regimen, type of cytotoxic drug returned, dose of cytotoxic drug returned, number of cytotoxic drug preparations returned and reason for return as well as whether the returned cytotoxic drug preparations could be re-dispensed. The cost of wastage was calculated based on the cost per mg (or per unit) of the particular returned cytotoxic drug.

    RESULTS: One hundred and fifty-nine cases of returned chemotherapy regimen comprising of 231 parenteral cytotoxic drug preparations were analysed. The total cost of returned chemotherapy regimen for 2016 was €3632, with €756 (20.8%) worth of chemotherapy regimens returned due to preventable reasons and €2876 (79.2%) worth of chemotherapy regimens returned due to non-preventable reasons. Approximately 50% of cases returned chemotherapy regimen were due to deterioration of patient's clinical condition and another 24.5% of cases of returned chemotherapy regimen were attributed to adverse drug reactions.

    CONCLUSION: Wastage associated to non-preventable reasons such as adverse drug reactions and preventable causes like refusal of patients can be further reduced by using newer healthcare innovations and establishment of written institutional protocols or standard operating procedures as references for in-charge healthcare personnel when cytotoxic drug-related issues occur. Adoption of cost-saving strategies that have been proven by studies could further improve current cost containment strategies.

    Matched MeSH terms: Waste Disposal, Fluid/methods*
  12. A decade development in the application of chitosan-based materials for dye adsorption: A short review
    Sadiq AC, Olasupo A, Ngah WSW, Rahim NY, Suah FBM
    Int J Biol Macromol, 2021 Nov 30;191:1151-1163.
    PMID: 34600954 DOI: 10.1016/j.ijbiomac.2021.09.179
    The presence of dyes in the aquatic environment as a result of anthropogenic activities, especially textile industries, is a critical environmental challenge that hinders the availability of potable water. Different wastewater treatment approaches have been used to remediate dyes in aquatic environments; however, most of these approaches are limited by factors ranging from high cost to the incomplete removal of the dyes and contaminants. Thus, the use of adsorption as a water treatment technology to remove dyes and other contaminants has been widely investigated using different adsorbents. This study evaluated the significance of chitosan as a viable adsorbent for removing dyes from water treatment. We summarised the literature and research results obtained between 2009 and 2020 regarding the adsorption of dyes onto chitosan and modified chitosan-based adsorbents prepared through physical and chemical processing, including crosslinking impregnation, grafting, and membrane preparation. Furthermore, we demonstrated the effects of various chitosan-based materials and modifications; they all improve the properties of chitosan by promoting the adsorption of dyes. Hence, the application of chitosan-based materials with various modifications should be considered a cutting-edge approach for the remediation of dyes and other contaminants in aquatic environments toward the global aim of making potable water globally available.
    Matched MeSH terms: Waste Disposal, Fluid/methods
  13. Production and recovery of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from biodiesel liquid waste (BLW)
    Martla M, Umsakul K, Sudesh K
    J Basic Microbiol, 2018 Nov;58(11):977-986.
    PMID: 30095175 DOI: 10.1002/jobm.201800279
    Polyhydroxyalkanoates (PHAs) has been paid great attention because of its useful thermoplastic properties and complete degradation in various natural environments. But, at industrial level, the successful commercialization of PHAs is limited by the high production cost due to the expensive carbon source and recovery processes. Pseudomonas mendocina PSU cultured for 72 h in mineral salts medium (MSM) containing 2% (v/v) biodiesel liquid waste (BLW) produced 79.7 wt% poly(3-hydroxybutyrate) (PHB) at 72 h. In addition, this strain produced 43.6 wt% poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with 8.6 HV mol% at 60 h when added with 0.3% sodium propionate. The synthesized intracellular PHA granules were recovered and purified by the recently reported biological method using mealworms. The weight average molecular weight (Mw ) and number average molecular weight (Mn ) of the biologically extracted PHA were higher than that from the chloroform extraction with comparable melting temperature (Tm ) and high purity. This study has successfully established a low-cost process to synthesize PHAs from BLW and subsequently confirmed the ability of mealworms to extract PHAs from various kinds of bacterial cells.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  14. Removal of lead from aqueous solutions on palm shell activated carbon
    Issabayeva G, Aroua MK, Sulaiman NM
    Bioresour Technol, 2006 Dec;97(18):2350-5.
    PMID: 16321520
    The performance of a commercially available palm shell based activated carbon to remove lead ions from aqueous solutions by adsorption was evaluated. The adsorption experiments were carried out at pH 3.0 and 5.0. The effect of malonic and boric acid presence on the adsorption of lead ions was also studied. Palm shell activated carbon showed high adsorption capacity for lead ions, especially at pH 5 with an ultimate uptake of 95.2mg/g. This high uptake showed palm shell activated carbon as amongst the best adsorbents for lead ions. Boric acid presence did not affect significantly lead uptake, whereas malonic acid decreased it. The diffuse layer surface complexation model was applied to predict the extent of adsorption. The model prediction was found to be in concordance with the experimental values.
    Matched MeSH terms: Waste Disposal, Fluid/methods
  15. Anaerobic degradation of palm oil mill effluent (POME)
    Yoochatchaval W, Kumakura S, Tanikawa D, Yamaguchi T, Yunus MF, Chen SS, et al.
    Water Sci Technol, 2011;64(10):2001-8.
    PMID: 22105121 DOI: 10.2166/wst.2011.782
    The biodegradation characteristics of palm oil mill effluent (POME) and the related microbial community were studied in both actual sequential anaerobic ponds in Malaysia and enrichment cultures. The significant degradation of the POME was observed in the second pond, in which the temperature was 35-37 °C. In this pond, biodegradation of major long chain fatty acids (LCFA), such as palmitic acid (C16:0) and oleic acid (C18:1), was also confirmed. The enrichment culture experiment was conducted with different feeding substrates, i.e. POME, C16:0 and C18:1, at 35 °C. Good recovery of methane indicated biodegradation of feeds in the POME and C16:0 enrichments. The methane production rate of the C18:1 enrichment was slower than other substrates and inhibition of methanogenesis was frequently observed. Denaturing gradient gel electrophoresis (DGGE) analyses indicated the existence of LCFA-degrading bacteria, such as the genus Syntrophus and Syntorophomonas, in all enrichment cultures operated at 35 °C. Anaerobic degradation of the POME under mesophilic conditions was stably processed as compared with thermophilic conditions.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  16. The application of iron mesh double layer as anode for the electrochemical treatment of Reactive Black 5 dye
    Mook WT, Ajeel MA, Aroua MK, Szlachta M
    J Environ Sci (China), 2017 Apr;54:184-195.
    PMID: 28391928 DOI: 10.1016/j.jes.2016.02.003
    In this work a novel anode configuration consisting of an iron mesh double layer is proposed for the electrochemical treatment of wastewater. The removal of Reactive Black 5 dye (RB5) from synthetic contaminated water was used as a model system. At a constant anode surface area, identical process operating parameters and batch process mode, the iron mesh double layer electrode showed better performance compared to the conventional single layer iron mesh. The double layer electrode was characterized by RB5 and chemical oxygen demand (COD) removal efficiency of 98.2% and 97.7%, respectively, kinetic rate constant of 0.0385/min, diffusion coefficient of 4.9×10(-5)cm(2)/sec and electrical energy consumption of 20.53kWh/kgdye removed. In the continuous flow system, the optimum conditions suggested by Response Surface Methodology (RSM) are: initial solution pH of 6.29, current density of 1.6mA/cm(2), electrolyte dose of 0.15g/L and flow rate of 11.47mL/min which resulted in an RB5 removal efficiency of 81.62%.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  17. Vermicomposting of cattle and goat manures by Eisenia foetida and their growth and reproduction performance
    Loh TC, Lee YC, Liang JB, Tan D
    Bioresour Technol, 2005 Jan;96(1):111-4.
    PMID: 15364088
    Vermicomposting is commonly adopted for the treatment of livestock organic wastes. In the present study, two types of livestock manure were used for culturing of the earthworm, Eisenia foetida. Each treatment group consisted of six replicates and worm vermicasts were examined after 5 weeks. The concentrations of total C, P and K in goat manure vermicasts were higher than those in cattle manure vermicasts. Cattle vermicasts had a higher N content than goat vermicasts but the C:N ratio of fresh manure was higher than that of vermicasts for both materials. Earthworm biomass and reproductive performance, in terms of number of worms after 5 weeks of experiment, were higher in cattle manure than in goat manure. The cocoon production per worm in cattle manure was higher than in goat manure. However, the hatchability of cocoons was not affected by manure treatments. In conclusion, cattle manure provided a more nutritious and friendly environment to the earthworms than goat manure.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  18. Application of biochemical products as a bioremediation technique for domestic sewage treatment plants
    Salmiati, Salim MR, Hassan RM, Tan KY
    Water Sci Technol, 2007;56(7):33-40.
    PMID: 17951865
    Biochemical products have been widely used for treatment of various types of wastewater. The treatment processes with the addition of biochemical products are quite attractive because of their simplicity, minimal use of equipment, they are environmentally friendly and are suitable for the removal of organic pollutants. The purpose of these products is to enhance the activities of beneficial microbes in order to improve treatment performance. This study was carried out to determine the potential of applying biochemical products in assisting and improving the performance of sewage treatment plants. In this study, four biochemical products, namely: Zeolite, Bio-C, Eco-B and Was-D, were applied to the sewage treatment plant. Analyses were carried out on several water quality parameters such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), oil & grease (O&G), phosphorus (P), ammoniacal nitrogen (AN) and sludge thickness (ST). From the results obtained, it can be seen that the overall performance of the treatment plant improved with most of the parameters studied were found to fulfill the DOE Standard B requirements. The performance of Bio-C was found to give better results than other products.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
  19. Viable blastocystis cysts in Scottish and Malaysian sewage samples
    Suresh K, Smith HV, Tan TC
    Appl Environ Microbiol, 2005 Sep;71(9):5619-20.
    PMID: 16151162
    Blastocystis cysts were detected in 38% (47/123) (37 Scottish, 17 Malaysian) of sewage treatment works. Fifty percent of influents (29% Scottish, 76% Malaysian) and 28% of effluents (9% Scottish, 60% Malaysian) contained viable cysts. Viable cysts, discharged in effluent, provide further evidence for the potential for waterborne transmission of Blastocystis.
    Matched MeSH terms: Waste Disposal, Fluid/methods
  20. Organic matter and nitrogen removal at planted wetlands treating domestic septage with varying operational strategies
    Jong VS, Tang FE
    Water Sci Technol, 2014;70(2):352-60.
    PMID: 25051484 DOI: 10.2166/wst.2014.237
    A two-staged engineered wetland-based system was designed and constructed to treat raw domestic septage. Hydraulic loading rates (HLRs) of 8.75 and 17.5 cm/d were studied with four and eight daily dosings at the second stage of the system to investigate the influence of the regimes on septage treatment. Removal of organic matter (OM) was found to be HLR dependent, where the results indicated that the increase of HLR from 8.75 to 17.5 cm/d impaired the overall level of treatment in the wetland units. Effluent of wetland fed at HLR 17.5 cm/d presented significantly lower oxygen reduction potential and dissolved oxygen values than wetland fed at 8.75 cm/d, indicative of the occurrence of less aerobic and reductive conditions in the bed. The reoxygenation capability of the wetland units was found to be heavily affected by the dosing frequency especially under high hydraulic load (17.5 cm/d). NH3-N degradation was found to decrease with statistical importance when the wetland was flushed two times more frequently with smaller batches of influent. The number of hydraulic load fractionings did not seem to affect the level of treatments of OM and ammonia for both the wetlands fed under the lower HLR of 8.75 cm/d. Prediction of hydraulic limits and management of the feeding strategies are important in the vertical type of engineered wetlands to guarantee the treatment performance and minimize the chances of filter clogging.
    Matched MeSH terms: Waste Disposal, Fluid/methods*
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