Displaying publications 121 - 140 of 376 in total

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  1. On relaxation of the influences of treated sewage effluent on an adjacent seaweed farm in a tidal strait
    Zhang X, Uchiyama Y, Nakayama A
    Mar Pollut Bull, 2019 Jul;144:265-274.
    PMID: 31179996 DOI: 10.1016/j.marpolbul.2019.04.050
    An Eulerian passive tracer model coupled with a quadruple-nested 3D circulation model was used to assess the coastal dispersal of treated wastewater effluent from a sewage treatment plant and the associated impacts on an adjacent seaweed farm using three different operational scenarios. When the discharged volume and source effluent fluxes were decreased by ~16.7%, the accumulated effluent in the farm was reduced by ~25.4%. A tracer flux budget analysis revealed the apparent predominance of the transient component that accounts for the nonlinear interactions primarily from tidal currents and eddies. The transient flux promoted the effluent influx to impede effluent accumulation in the farm, whereas the mean flux contributed to the outgoing flux. A source flux reduction caused a remarkable decrease in the transient flux and thus an even greater effluent accumulation reduction. In turn, a modified source density scenario without total effluent volume change did not work as expected.
    Matched MeSH terms: Waste Disposal, Fluid
  2. Hydrolysis kinetics for solubilizing waste activated sludge at low temperature thermal treatment derived from multivariate non-linear model
    Liew CS, Raksasat R, Rawindran H, Kiatkittipong W, Lim JW, Leong WH, et al.
    Chemosphere, 2022 Apr;292:133478.
    PMID: 34979202 DOI: 10.1016/j.chemosphere.2021.133478
    Low temperature thermal pre-treatment is a low-cost method to break down the structure of extracellular polymeric substances in waste activated sludge (WAS) while improving the sludge biodegradability. However, previous models on low temperature thermal pre-treatment did not adequately elucidate the behaviour of sludge hydrolysis process for the duration ranging from 5 to 9 h. Therefore, this work had developed an inclusive functional model to describe the kinetics of sludge hydrolysis for a wide range of treatment conditions (30 °C-90 °C within 0 and 16 h). As compared with treatment duration, the treatment temperature played a greater impact in solubilizing WAS. Accordingly, the 90 °C treatment had consistently produced WAS with the highest degree of solubility. Nonetheless, the mediocre discrepancies between 90 °C and 75 °C may challenge the practicality of increasing the treatment temperatures beyond 75 °C. The effects of treatment duration on soluble chemical oxygen demand, soluble carbohydrate and soluble protein were only significant during the first 4 h, except for humic substances release that continued to increase with treatment duration. Finally, a good fit with R2 > 0.95 was achieved using an inclusive multivariate non-linear model, substantiating the functionality to predict the kinetics of sludge hydrolysis at arbitrary treatment conditions.
    Matched MeSH terms: Waste Disposal, Fluid
  3. Artificial intelligence and machine learning-based monitoring and design of biological wastewater treatment systems
    Singh NK, Yadav M, Singh V, Padhiyar H, Kumar V, Bhatia SK, et al.
    Bioresour Technol, 2023 Feb;369:128486.
    PMID: 36528177 DOI: 10.1016/j.biortech.2022.128486
    Artificial intelligence (AI) and machine learning (ML) are currently used in several areas. The applications of AI and ML based models are also reported for monitoring and design of biological wastewater treatment systems (WWTS). The available information is reviewed and presented in terms of bibliometric analysis, model's description, specific applications, and major findings for investigated WWTS. Among the applied models, artificial neural network (ANN), fuzzy logic (FL) algorithms, random forest (RF), and long short-term memory (LSTM) were predominantly used in the biological wastewater treatment. These models are tested by predictive control of effluent parameters such as biological oxygen demand (BOD), chemical oxygen demand (COD), nutrient parameters, solids, and metallic substances. Following model performance indicators were mainly used for the accuracy analysis in most of the studies: root mean squared error (RMSE), mean square error (MSE), and determination coefficient (DC). Besides, outcomes of various models are also summarized in this study.
    Matched MeSH terms: Waste Disposal, Fluid
  4. Removing microplastics from wastewater using leading-edge treatment technologies: a solution to microplastic pollution-a review
    Priya A, Anusha G, Thanigaivel S, Karthick A, Mohanavel V, Velmurugan P, et al.
    Bioprocess Biosyst Eng, 2023 Mar;46(3):309-321.
    PMID: 35301580 DOI: 10.1007/s00449-022-02715-x
    Microplastics (MPs) in environmental studies have revealed that public sewage treatment plants are a common pathway for microplastics to reach local surroundings. Microplastics are becoming more of a worry, posing a danger to both marine wildlife and humans. These plastic items not only contribute to the macrocosmic proliferation of plastics but also the scattering of microplastics and the concentration of other micropollutant-containing objects, increasing the number of pollutants identified. Microplastics' behavior, movement, transformation, and persistence mechanisms, as well as their mode of action in various wastewater effluent treatment procedures, are still unknown. They are making microplastics made from wastewater a big deal. We know that microplastics enter wastewater treatment facilities (WWTPs), that wastewater is released into the atmosphere, and that this wastewater has been considered to represent a threat to habitats and ground character based on our literature assessment. The basic methods of wastewater and sewage sludge, as well as the treatment procedure and early characterization, are covered throughout the dissection of the problematic scientific conceptualization.
    Matched MeSH terms: Waste Disposal, Fluid
  5. A review of antibiotic removal from domestic wastewater using the activated sludge process: removal routes, kinetics and operational parameters
    Chen CX, Aris A, Yong EL, Noor ZZ
    Environ Sci Pollut Res Int, 2022 Jan;29(4):4787-4802.
    PMID: 34775565 DOI: 10.1007/s11356-021-17365-x
    Many advanced technologies have shown encouraging results in removing antibiotics from domestic wastewater. However, as activated sludge treatment is the most common sewage treatment system employed worldwide, improving its effect on antibiotic removal would be more desirable. Understanding the removal mechanisms, kinetics and factors that affect antibiotic removal in the activated sludge process is important as it would allow us to improve the treatment performance. Although these have been discussed in various literature covering different types of antibiotics and wastewater, a specific review on antibiotics and domestic wastewater is clearly missing. This review paper collates, discusses and analyses the removal of antibiotics from sewage in the activated sludge process along with the removal mechanisms and kinetics. The antibiotics are categorised into six classes: β-lactam, dihydrofolate reductase inhibitor, fluoroquinolone, macrolide, sulfonamides and tetracycline. Furthermore, the factors affecting the system performance with regard to antibiotic removal are examined.
    Matched MeSH terms: Waste Disposal, Fluid
  6. Fulltext Column-based removal of high concentration microplastics in synthetic wastewater using granular activated carbon
    Amirah Mohd Napi NN, Ibrahim N, Adli Hanif M, Hasan M, Dahalan FA, Syafiuddin A, et al.
    Bioengineered, 2023 Dec;14(1):2276391.
    PMID: 37942779 DOI: 10.1080/21655979.2023.2276391
    Microplastic (MP) is an emerging contaminant of concern due to its abundance in the environment. Wastewater treatment plant (WWTP) can be considered as one of the main sources of microplastics in freshwater due to its inefficiency in the complete removal of small MPs. In this study, a column-based MP removal which could serve as a tertiary treatment in WWTPs is evaluated using granular activated carbon (GAC) as adsorbent/filter media, eliminating clogging problems commonly caused by powder form activated carbon (PAC). The GAC is characterized via N2 adsorption-desorption isotherm, field emission scanning electron microscopy, and contact angle measurement to determine the influence of its properties on MP removal efficiency. MPs (40-48 μm) removal up to 95.5% was observed with 0.2 g/L MP, which is the lowest concentration tested in this work, but still higher than commonly used MP concentration in other studies. The performance is reduced with further increase in MP concentration (up to 1.0 g/L), but increasing the GAC bed length from 7.5 to 17.5 cm could lead to better removal efficiencies. MP particles are immobilized by the GAC predominantly by filtration process by being entangled with small GAC particles/chips or stuck between the GAC particles. MPs are insignificantly removed by adsorption process through entrapment in GAC porous structure or attachment onto the GAC surface.
    Matched MeSH terms: Waste Disposal, Fluid
  7. Aerobic granular sludge formation for high strength agro-based wastewater treatment
    Abdullah N, Ujang Z, Yahya A
    Bioresour Technol, 2011 Jun;102(12):6778-81.
    PMID: 21524907 DOI: 10.1016/j.biortech.2011.04.009
    The present study investigates the formation of aerobic granular sludge in sequencing batch reactor (SBR) fed with palm oil mill effluent (POME). Stable granules were observed in the reactor with diameters between 2.0 and 4.0mm at a chemical oxygen demand (COD) loading rate of 2.5 kg COD m(-3) d(-1). The biomass concentration was 7600 mg L(-1) while the sludge volume index (SVI) was 31.3 mL g SS(-1) indicating good biomass accumulation in the reactor and good settling properties of granular sludge, respectively. COD and ammonia removals were achieved at a maximum of 91.1% and 97.6%, respectively while color removal averaged at only 38%. This study provides insights on the development and the capabilities of aerobic granular sludge in POME treatment.
    Matched MeSH terms: Waste Disposal, Fluid/methods*; Waste Disposal, Fluid/statistics & numerical data
  8. Phosphorus removal using nanofiltration membranes
    Leo CP, Chai WK, Mohammad AW, Qi Y, Hoedley AF, Chai SP
    Water Sci Technol, 2011;64(1):199-205.
    PMID: 22053475
    A high concentration of phosphorus in wastewater may lead to excessive algae growth and deoxygenation of the water. In this work, nanofiltration (NF) of phosphorus-rich solutions is studied in order to investigate its potential in removing and recycling phosphorus. Wastewater samples from a pulp and paper plant were first analyzed. Commercial membranes (DK5, MPF34, NF90, NF270, NF200) were characterized and tested in permeability and phosphorus removal experiments. NF90 membranes offer the highest rejection of phosphorus; a rejection of more than 70% phosphorus was achieved for a feed containing 2.5 g/L of phosphorus at a pH <2. Additionally, NF90, NF200 and NF270 membranes show higher permeability than DK5 and MPF34 membranes. The separation performance of NF90 is slightly affected by phosphorus concentration and pressure, which may be due to concentration polarization and fouling. By adjusting the pH to 2 or adding sulfuric acid, the separation performance of NF90 was improved in removing phosphorus. However, the presence of acetic acid significantly impairs the rejection of phosphorus.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
  9. Renewable and sustainable bioenergies production from palm oil mill effluent (POME): win-win strategies toward better environmental protection
    Lam MK, Lee KT
    Biotechnol Adv, 2010 Jan-Feb;29(1):124-41.
    PMID: 20940036 DOI: 10.1016/j.biotechadv.2010.10.001
    Palm oil industry is one of the leading agricultural industries in Malaysia with average crude palm oil production of more than 13 million tonne per year. However, production of such huge amount of crude palm oil has consequently resulted to even larger amount of palm oil mill effluent (POME). POME is a highly polluting wastewater with high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in which can caused severe pollution to the environment, typically pollution to water resources. On the other hand, POME was identified as a potential source to generate renewable bioenergies such as biomethane and biohydrogen through anaerobic digestion. In other words, a combination of wastewater treatment and renewable bioenergies production would be an added advantage to the palm oil industry. In line with the world's focus on sustainability concept, such strategy should be implemented immediately to ensure palm oil is produced in an environmental friendly and sustainable manner. This review aims to discuss various technologies to convert POME to biomethane and biohydrogen in a commercial scale. Furthermore, discussion on using POME to culture microalgae for biodiesel and bioethanol production was included in the present paper as a new remedy to utilize POME with a greater beneficial return.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
  10. Review of technologies for oil and gas produced water treatment
    Fakhru'l-Razi A, Pendashteh A, Abdullah LC, Biak DR, Madaeni SS, Abidin ZZ
    J Hazard Mater, 2009 Oct 30;170(2-3):530-51.
    PMID: 19505758 DOI: 10.1016/j.jhazmat.2009.05.044
    Produced water is the largest waste stream generated in oil and gas industries. It is a mixture of different organic and inorganic compounds. Due to the increasing volume of waste all over the world in the current decade, the outcome and effect of discharging produced water on the environment has lately become a significant issue of environmental concern. Produced water is conventionally treated through different physical, chemical, and biological methods. In offshore platforms because of space constraints, compact physical and chemical systems are used. However, current technologies cannot remove small-suspended oil particles and dissolved elements. Besides, many chemical treatments, whose initial and/or running cost are high and produce hazardous sludge. In onshore facilities, biological pretreatment of oily wastewater can be a cost-effective and environmental friendly method. As high salt concentration and variations of influent characteristics have direct influence on the turbidity of the effluent, it is appropriate to incorporate a physical treatment, e.g., membrane to refine the final effluent. For these reasons, major research efforts in the future could focus on the optimization of current technologies and use of combined physico-chemical and/or biological treatment of produced water in order to comply with reuse and discharge limits.
    Matched MeSH terms: Waste Disposal, Fluid/economics; Waste Disposal, Fluid/methods*
  11. Effect of full and partial-bed configuration on carbon removal performance of biological aerated filters
    Suja F, Donnelly T
    Water Sci Technol, 2008;58(5):977-83.
    PMID: 18824794 DOI: 10.2166/wst.2008.454
    A comparative study to explore the characteristics of partially and fully packed biological aerated filters (BAFs) in the removal of carbon pollutant, reveals that the partial-bed reactor can perform comparably well with the full-bed reactor. The organic removal rate was 5.34 kg COD m(-3) d(-1) at Organic Loading Rates (OLR) 5.80+/-0.31 kg COD m(-3) d(-1) for the full-bed, and 5.22 kg COD m(-3) d(-1) at OLR 5.79+/-0.29 kg COD m(-3) d(-1) for the partial-bed. In the partial-bed system, where the masses of biomass were only 41-51% of those of the full-bed, the maximum carbon removal limit was still between 5 to 6 kg COD m(-3) d(-1). At organic loadings above 5.0 kg COD m(-3) d(-1), the carbon removal capacity in both systems was limited by the mass and activity of microorganisms. The SRT in the full and partial-bed reactors was primarily controlled by the biomass loss in the effluent and during backwash operation. The SRT was reduced from 20.08 days at OLR 4.18+/-0.20 kg COD m(-3) d(-1) to 7.62 days at OLR 5.80+/-0.31 kg COD m(-3) d(-1) in the full-bed, and from 7.17 days to 4.21 days in the partial-bed. After all, SRT values in the partial-bed were always lower than those in the full-bed.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation*; Waste Disposal, Fluid/methods*
  12. Biological treatment of sewage treatment plant sludge by pure bacterial culture with optimum process conditions in a stirred tank bioreactor
    Alam MZ, Muyibi SA, Jamal P
    J Environ Sci Health A Tox Hazard Subst Environ Eng, 2007 Sep;42(11):1671-9.
    PMID: 17849310
    Biological treatment of sewage treatment plant (STP) sludge by potential pure bacterial culture (Bacillus sp.) with optimum process conditions for effective biodegradation and bioseparation was carried out in the laboratory. The effective and efficient bioconversion was evaluated with the treatment of pure bacterial culture and existing microbes (uninnoculated) in sludge. The optimum process conditions i.e., temperature, 40 degrees C; pH, 6; inoculum, 5% (v/v); aeration, 1 vvm; agitation speed, 50 rpm obtained from the previous studies with chemical oxygen demand COD at 30 mgL(-1) were applied for the biological treatment of sludge. The results indicated that pure bacterial culture (Bacillus sp.) showed higher degradation and separation of treated sludge compared to treatment with the existing mixed microbes in a stirred tank bioreactor. The treated STP sludge by potential pure bacterial culture and existing microbes gave 30% and 11%; 91.2% and 59.1; 88.5% and 52.3%; 98.4% and 51.3%; 96.1% and 75.2%; 99.4% and 72.8% reduction of total suspended solids (TSS, biosolids), COD, soluble protein, turbidity, total dissolved solids (TDS) and specific resistance to filtration (SRF), respectively within 7 days of treatment. The pH was observed at 6.5 and 4 during the treatment of sludge by pure culture and existing microbes, respectively.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
  13. Comparison of the efficiencies of attached- versus suspended-growth SBR systems in the treatment of recycled paper mill wastewater
    Muhamad MH, Sheikh Abdullah SR, Abu Hasan H, Abd Rahim RA
    J Environ Manage, 2015 Nov 1;163:115-24.
    PMID: 26311084 DOI: 10.1016/j.jenvman.2015.08.012
    The complexity of residual toxic organics from biologically treated effluents of pulp and paper mills is a serious concern. To date, it has been difficult to choose the best treatment technique because each of the available options has advantages and drawbacks. In this study, two different treatment techniques using laboratory-scale aerobic sequencing batch reactors (SBRs) were tested with the same real recycled paper mill effluent to evaluate their treatment efficiencies. Two attached-growth SBRs using granular activated carbon (GAC) with and without additional biomass and a suspended-growth SBR were used in the treatment of real recycled paper mill effluent at a chemical oxygen demand (COD) level in the range of 800-1300 mg/L, a fixed hydraulic retention time of 24 h and a COD:N:P ratio of approximately 100:5:1. The efficiency of this biological treatment process was studied over a 300-day period. The six most important wastewater quality parameters, namely, chemical oxygen demand (COD), turbidity, ammonia (expressed as NH3-N), phosphorus (expressed as PO4(3)-P), colour, and suspended solids (SS), were measured to compare the different treatment techniques. It was determined that these processes were able to almost completely and simultaneously eliminate COD (99%) and turbidity (99%); the removals of NH3-N (90-100%), PO4(3)-P (66-78%), colour (63-91%), and SS (97-99%) were also sufficient. The overall performance results confirmed that an attached-growth SBR system using additional biomass on GAC is a promising configuration for wastewater treatment in terms of performance efficiency and process stability under fluctuations of organic load. Hence, this hybrid system is recommended for the treatment of pulp and paper mill effluents.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation*; Waste Disposal, Fluid/methods*
  14. Role of macrophyte and effect of supplementary aeration in up-flow constructed wetland-microbial fuel cell for simultaneous wastewater treatment and energy recovery
    Oon YL, Ong SA, Ho LN, Wong YS, Dahalan FA, Oon YS, et al.
    Bioresour Technol, 2017 Jan;224:265-275.
    PMID: 27864130 DOI: 10.1016/j.biortech.2016.10.079
    This study investigates the role of plant (Elodea nuttallii) and effect of supplementary aeration on wastewater treatment and bioelectricity generation in an up-flow constructed wetland-microbial fuel cell (UFCW-MFC). Aeration rates were varied from 1900 to 0mL/min and a control reactor was operated without supplementary aeration. 600mL/min was the optimum aeration flow rate to achieve highest energy recovery as the oxygen was sufficient to use as terminal electron acceptor for electrical current generation. The maximum voltage output, power density, normalized energy recovery and Coulombic efficiency were 545.77±25mV, 184.75±7.50mW/m3, 204.49W/kg COD, 1.29W/m3 and 10.28%, respectively. The variation of aeration flow rates influenced the NO3- and NH4+ removal differently as nitrification and denitrification involved conflicting requirement. In terms of wastewater treatment performance, at 60mL/min aeration rate, UFCW-MFC achieved 50 and 81% of NO3- and NH4+ removal, respectively. E. nuttallii enhanced nitrification by 17% and significantly contributed to bioelectricity generation.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
  15. 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/economics; Waste Disposal, Fluid/methods*
  16. Preparation, characterization, and dye removal study of activated carbon prepared from palm kernel shell
    García JR, Sedran U, Zaini MAA, Zakaria ZA
    Environ Sci Pollut Res Int, 2018 Feb;25(6):5076-5085.
    PMID: 28391459 DOI: 10.1007/s11356-017-8975-8
    Palm oil mill wastes (palm kernel shell (PKS)) were used to prepare activated carbons, which were tested in the removal of colorants from water. The adsorbents were prepared by 1-h impregnation of PKS with ZnCl2 as the activating agent (PKS:ZnCl2 mass ratios of 1:1 and 2:1), followed by carbonization in autogenous atmosphere at 500 and 550 °C during 1 h. The characterization of the activated carbons included textural properties (porosity), surface chemistry (functional groups), and surface morphology. The dye removal performance of the different activated carbons was investigated by means of the uptake of methylene blue (MB) in solutions with various initial concentrations (25-400 mg/L of MB) at 30 °C, using a 0.05-g carbon/50-mL solution relationship. The sample prepared with 1:1 PKS:ZnCl2 and carbonized at 550 °C showed the highest MB adsorption capacity (maximum uptake at the equilibrium, q max = 225.3 mg MB / g adsorbent), resulting from its elevated specific surface area (BET, 1058 m2/g) and microporosity (micropore surface area, 721 m2/g). The kinetic experiments showed that removals over 90% of the equilibrium adsorptions were achieved after 4-h contact time in all the cases. The study showed that palm oil mill waste biomass could be used in the preparation of adsorbents efficient in the removal of colorants in wastewaters.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
  17. Characteristics of treated effluents and their potential applications for producing concrete
    Noruzman AH, Muhammad B, Ismail M, Abdul-Majid Z
    J Environ Manage, 2012 Nov 15;110:27-32.
    PMID: 22705857 DOI: 10.1016/j.jenvman.2012.05.019
    Conservation and preservation of freshwater is increasingly becoming important as the global population grows. Presently, enormous volumes of freshwater are used to mix concrete. This paper reports experimental findings regarding the feasibility of using treated effluents as alternatives to freshwater in mixing concrete. Samples were obtained from three effluent sources: heavy industry, a palm-oil mill and domestic sewage. The effluents were discharge into public drain without danger to human health and natural environment. Chemical compositions and physical properties of the treated effluents were investigated. Fifteen compositional properties of each effluent were correlated with the requirements set out by the relevant standards. Concrete mixes were prepared using the effluents and freshwater to establish a base for control performance. The concrete samples were evaluated with regard to setting time, workability, compressive strength and permeability. The results show that except for some slight excesses in total solids and pH, the properties of the effluents satisfy the recommended disposal requirements. Two concrete samples performed well for all of the properties investigated. In fact, one sample was comparatively better in compressive strength than the normal concrete; a 9.4% increase was observed at the end of the curing period. Indeed, in addition to environmental conservation, the use of treated effluents as alternatives to freshwater for mixing concrete could save a large amount of freshwater, especially in arid zones.
    Matched MeSH terms: Waste Disposal, Fluid/economics; Waste Disposal, Fluid/methods*
  18. Extraction and recovery of methylene blue from industrial wastewater using benzoic acid as an extractant
    Muthuraman G, Teng TT, Leh CP, Norli I
    J Hazard Mater, 2009 Apr 15;163(1):363-9.
    PMID: 18782652 DOI: 10.1016/j.jhazmat.2008.06.122
    Liquid-liquid extraction (LLE) of methylene blue (MB) from industrial wastewater using benzoic acid (extractant) in xylene has been studied at 27 degrees C. The extraction of the dye increased with increasing extractant concentration. The extraction abilities have been studied on benzoic acid concentration in the range of 0.36-5.8x10(-2) M. The distribution ratio of the dye is reasonably high (D=49.5) even in the presence of inorganic salts. Irrespective of the concentration of dye, extraction under optimal conditions was 90-99% after 15 min of phase separation. The extracted dye in the organic phase can be back extracted into sulphuric acid solution. The resultant recovered organic phase can be reused in succeeding extraction of dye with the yield ranging from 99 to 87% after 15 times reused, depending on the concentration of the initial feed solution. Experimental parameters examined were benzoic acid concentration, effect of diluent, effect of pH, effect of initial dye concentration, effect of equilibration time, various stripping agents, aqueous to organic phase ratio in extraction, organic to aqueous phase ratio in stripping and reusability of solvent.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
  19. Phytoremediation of palm oil mill secondary effluent (POMSE) by Chrysopogon zizanioides (L.) using artificial neural networks
    Darajeh N, Idris A, Fard Masoumi HR, Nourani A, Truong P, Rezania S
    Int J Phytoremediation, 2017 May 04;19(5):413-424.
    PMID: 27748626 DOI: 10.1080/15226514.2016.1244159
    Artificial neural networks (ANNs) have been widely used to solve the problems because of their reliable, robust, and salient characteristics in capturing the nonlinear relationships between variables in complex systems. In this study, ANN was applied for modeling of Chemical Oxygen Demand (COD) and biodegradable organic matter (BOD) removal from palm oil mill secondary effluent (POMSE) by vetiver system. The independent variable, including POMSE concentration, vetiver slips density, and removal time, has been considered as input parameters to optimize the network, while the removal percentage of COD and BOD were selected as output. To determine the number of hidden layer nodes, the root mean squared error of testing set was minimized, and the topologies of the algorithms were compared by coefficient of determination and absolute average deviation. The comparison indicated that the quick propagation (QP) algorithm had minimum root mean squared error and absolute average deviation, and maximum coefficient of determination. The importance values of the variables was included vetiver slips density with 42.41%, time with 29.8%, and the POMSE concentration with 27.79%, which showed none of them, is negligible. Results show that the ANN has great potential ability in prediction of COD and BOD removal from POMSE with residual standard error (RSE) of less than 0.45%.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
  20. Influence of high temperature on the performance of aerobic granular sludge in biological treatment of wastewater
    Ab Halim MH, Nor Anuar A, Abdul Jamal NS, Azmi SI, Ujang Z, Bob MM
    J Environ Manage, 2016 Dec 15;184(Pt 2):271-280.
    PMID: 27720606 DOI: 10.1016/j.jenvman.2016.09.079
    The effect of temperature on the efficiency of organics and nutrients removal during the cultivation of aerobic granular sludge (AGS) in biological treatment of synthetic wastewater was studied. With this aim, three 3 L sequencing batch reactors (SBRs) with influent loading rate of 1.6 COD g (L d)(-1) were operated at different high temperatures (30, 40 and 50 °C) for simultaneous COD, phosphate and ammonia removal at a complete cycle time of 3 h. The systems were successfully started up and progressed to steady state at different cultivation periods. The statistical comparison of COD, phosphate and ammonia for effluent from the three SBRs revealed that there was a significant difference between groups of all the working temperatures of the bioreactors. The AGS cultivated at different high temperatures also positively correlated with the accumulation of elements including carbon, oxygen, phosphorus, silicon, iron, aluminium, calcium and magnesium that played important roles in the granulation process.
    Matched MeSH terms: Waste Disposal, Fluid/instrumentation; Waste Disposal, Fluid/methods*
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