Effect of redox conditions in the degradation of (RS)-MCPP during biological treatment of synthetic wastewater in an anaerobic membrane bioreactor (AMBr)

PhD ThesisThe aim of this research is to investigate the effect of mecoprop (RS-MCPP) degradation in an anaerobic membrane bioreactor (AMBr) under a range of redox conditions (methanogenic, nitrate reducing and sulphate reducing). A method was developed for the analysis of (RS)-MCPP in aqueous form using High Performance Liquid Chromatography (HPLC). The study was carried out in five phases. Initially, Phase I investigated the effect of elevated (RS)-MCPP on AMBr under methanogenic conditions. In this phase, increasing concentrations of (RS)-MCPP (5 - 200 mg. L-1) promoted a progressive increases in the (RS)-MCPP substrate utilisation rate (SUR) (0.15 to 3.19 [ig-mgVSS' 1. d"'). However, the COD removal efficiency decreased gradually from 98 % to 94 % as the (RS)-MCPP concentration increased in the feed from 50 - 200 mg. L-1, respectively. Phase II investigated the effect of denitrifying conditions on (RS)-MCPP degradation. Results showed that (RS)-MCPP removal efficiency and (RS)-MCPP SUR improved from 2- 47 % and 0.5 to 60.7 Rg. mgVSS-l. d-1, respectively as the COD/N-NO3-1 ratio and OLR were reduced from 250 to 0.2 and 1.51 to 0.07 kgCOD M, 3 A-1, respectively. Phase III investigated the effect of sulphate-reducing conditions on (RS)-MCPP degradation. Results showed that sulphidogenic conditions were less effective than nitrate reducing conditions with an average (RS)-MCPP removal and (RS)-MCPP SUR at 20(±10.7) % and 16.4 ýtgm. gVSS-lffl, respectively. Phase IV investigated the effect of HRT on the kinetics of (RS)-MCPP degradation. The robustness and stability of AMBr was also investigated in response to hydraulic shock loads on the biomass imposed. Results showed that the AMBr is stable to a large transient hydraulic shock loads, and it recovered rapidly to baseline performance after the hydraulic shock load had ended. High (RS)-MCPP degradation (up to 75 %) and utilisation rates (43 gg. mgVSS'1. d") were observed at long HRT (16.9 days). Phase V was a confirmatory experiment study to investigate the possible effects of trace quantities of oxygen that had been present in the reactor headspace and the effluent tank during Phase IV. This confirmed that the system performance towards (RS)-MCPP biodegradation had not been affected by trace oxygen levels when comparison are made. The molecular-based method, fluorescent in situ hybridisation (FISH) was used for the direct identification and enumeration of microbial communities in the AMBr sludge. In general, FISH results showed populations were dominated by methanogenic archaea in methanogenic phase (Phase I and IV) comprising between 55-66 % of the DAPI count. However, as anoxic condition were introduced in Phase II and III (nitrate reducing and sulphate reducing), the results identified a definite population shift, with the predominance of eubacteria (70-86 % of the DAPI count). The two methanogenic genera detected were Methanosaeta and Methanosamina. Of these two genera, the former was dominant in the reactor accounting for 57-100 % of the total methanogenic archaea. Furthermore, a comparison of (RS)-MCPP utilisation rates in each phase of the research revealed wide ranges (RS)-MCPP degradation efficiency and (RS)-MCPP SUR, however, although changes were observed in the composition of the bacterial population, no direct linkage could be made with any of the individual groups identified by FISH

Determination of theobromine and caffeine in some Malaysian beverages by liquid chromatography-time-offlight mass spectrometry

Purpose: To determine the concentration of theobromine (TB) and caffeine (CF) in tea and other beverages using liquid chromatography-time of flight-mass spectrometry (LC-TOF-MS).Methods: The extract of caffeine and theobromine from tea and other beverages was filtered by 0.45 μm nylon micro-syringe and then injected into a LC-ToF-MS system. Theobromine and caffeine were separated using Thermo Scientific C18-column (length 250 mm, width 2.1 mm and diameter 5 μm). Acetonitrile-methanol (ACN – MeOH, 3:1 v/v) was used as mobile phase B, while mobile phase A was 0.1 % FA in DIW. The volume injected was 30 μL at a rate of 0.3 mL/min.Results: Good linearity was obtained in the range of 0.3 – 400 and 0.2 – 200 mg/L for theobromine and caffeine, respectively (regression coefficient (R2) > 0.970). The limits of detection were 0.15 and 0.05 μg/mL for theobromine and caffeine,  respectively. The highest concentrations of caffeine and theobromine determined in tea samples were 159.1 and 255.8 mg/L, respectively.Conclusion: Theobromine and caffeine have been successfully analysed in tea, coffee and soft drinks. LC-TOF-MS is an accurate and promising instrument for the  determination of the studied compounds in beverages.Keywords: Theobromine, Caffeine, Tea, Coffee, LC-TOF/M

Flash flood susceptibility mapping of sungai pinang catchment using frequency ratio

Flash flood are natural disasters that frequently occur in Malaysia especially in urban areas. Due to this, the development of flash flood susceptibility mapping one of the tools used to aid the local authority in reducing and managing the flash flood impact. Frequency Ratio (FR) is a popular method in predictive modeling because of its capabilities to determine the critical conditioning factor of flash flood. The aim of this research was to compare the standalone FR with Ensemble FR-AHP. This ensemble method uses pair-wise comparison method between Frequency Ratio and Analytical Hierarchy Process (AHP). For this research, ten conditioning factors were selected which were slope, aspect, curvature, Topographic Wetness Index (TWI), Stream Power Index (SPI), Normalized Difference Vegetation Index (NDVI), distance from river, rainfall, elevation, and land use/land cover (LULC). The flash flood inventory was obtained from local authorities where the flash flood occurred in Penang, Malaysia on November 2017. 70% of 110 flooded locations were used as training dataset to assess the spatial distribution of flooding whereas the remaining 30% flooded locations were used as validation dataset. Based on the results, the prediction rate of FR-AHP method is slightly better accuracy compared to FR method which 88.33% (FR-AHP) and 85.62% (FR). The output of this research is crucial to assist local authority in land use planning and drainage system of the study area

Flash flood susceptibility modelling: a review

Flash flood is common problem in the developed or developing country especially in urban areas. This is due to the changes of land use, poor planning of drainage system, deforestation and unplanned land use and etc. Flash flood susceptibility modelling (FFSM) for urban area is important to avoid the loss and etc. FFSM can be vital component and essential tools for planning and management of natural disaster and environmental. The objective of this paper is to review selected paper on flash flood susceptibility modelling using Geographic Information System (GIS) coupling empirical models. A lot of methods have been coupling with GIS to developed flood susceptibility modelling, for example, Weight of Evidence, Random Forest, etc. However, there is still lack of susceptibility model for flash flood. The GIS coupling method can improve the accuracy of flood susceptibility modelling. Thus, this paper will review the ability of GIS coupling with empirical models for the flash flood susceptibility modelling

Ulva lactuca for nutrients biofiltration in a recirculating shrimp effluent treatment system

An outdoor tank scale shrimp cultivation system was developed with integration of green macroalgae species, Ulva lactuca. Intensive shrimp farming produces large amount of waste nutrients, due to excess uneaten feed and excretion. Prior harvesting, shrimp effluent discharged without proper treatment and alleviates water quality of receiving water bodies. Coastal water degradation consequently causes negative environmental impact. This integrated system with U. lactuca, greatly reduced the nutrient loads and incorporated into its biomass. Phosphate removal was 90%, followed by ammonium and nitrate with removal efficiencies of 70% and 42%, respectively. The mean specific growth rate of U. lactuca was 2.25 ± 0.9 % day-1 and shrimp was 0.76 ± 0.09 % day-1. Shrimp growth rate in control tank was significantly lower compared to the treatment tank (P<0.001) and survival rate declined throughout the experimental period. Integration of U. lactuca significantly enhanced the dissolved oxygen with mean value of 5.49±0.06 mg/L and creates a stable pH values compared to control treatment tank. Thus, U. lactuca is a prominent biofilter with rapid growth rate and greatly reduces the overall environmental impact of aquaculture water degradation and stabilize the culture environment and this study highly recommended utilization of U. lactuca as a biofilter component in an integrated multitrophic aquaculture treatment system

Flood Hazard Information Map Using Geographical Information System (GIS) For Residential Community Resilience

The purpose of this research is to develop the residential flood hazard information map using Geographical Information System (GIS) for residential community resilience. The review approach is based on related literature contributing to identifying themes such as “flood hazard information map” and “geographical information system”. Integration of data will be sourced from Department of Irrigation and Drainage (DID), National Property Information Centre (NAPIC) and Jabatan Ukur dan Pemetaan Malaysia (JUPEM) using Unique Parcel Identifier (UPI) for respective residential land parcels. An extensive review of previous studies of flood hazard information map of residential community resilience for different flood disaster studies is considered to be the main restrictive factor resulting in a lack of empirical studies in this field. The development of residential property needs to be imposed with the elements for building specifications and materials that have flood resistance and resilience to protect the community life and property.Keywords: Community resilience, Floods, Geographical Information System (GIS), Residential propertyeISSN: 2398-4287 © 2019. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning &amp; Surveying, Universiti Teknologi MARA, Malaysia.DOI: https://doi.org/10.21834/e-bpj.v4i10.163

Fabrication polyethersulfone mixed matrix membrane incorporated with silica nanoparticles for BPA removal

The introduction of inorganic nanoparticles in polymeric dope solution for the fabrication process of membrane can potentially enhance the separation performances of membrane without negatively affecting its permeability. In this study, hollow fiber mixed matrix membranes were prepared by incorporating polyethersulfone (PES) membranes with silicon dioxide (SiO2) nanoparticles at different concentration. Prior to separation tests, the prepared membranes were characterized by SEM, EDX, DSC, water contact angle, and FTIR-ATR in order to study the impact of silica nanoparticles on the properties of the membranes. Bisphenol A (BPA) was selected as the subject compound of this study because it is one of the emerging pollutants that have been frequently detected in the water treatment plant (WTP). BPA was spike into the pre-treated water sample taken from the WTP and was used as the feed solution to evaluate the membrane performance in terms of water flux and removal rate. The addition of SiO2 was reported to improve the hydrophilicity of membrane and induce greater micro-voids formation in the membrane structures, leading to increased water flux during BPA filtration process. The presence of more silanol (Si-OH) and siloxane (Si-O-Si) bonding groups resulted from increased SiO2 contents in membrane has improved membrane adsorption rate and further increased BPA removal

Structural, locational and environmental attributes effects the residential property value in flood risk area

The arts and science in determining the residential property value make property value has evolved due to the changing in external factors such as economy, environmental and social. This research is aim to determine the residential property value by taking into account the economic attributes that could affect the value of residential property in flood risk areas. The economic attributes consist of structural, locational and environmental attributes involved in residential property valuation in relations with flooding. This paper will discover the significance and effect of each economic attributes in determining residential property value in flood risk area. An extensive review of previous studies in economic valuation of property for different floods disaster studies. It is considered to be the main restrictive factor resulting in lack of empirical studies in this field. Practitioners and researchers will find this study useful in developing an improved understanding of the economic valuation of flooding. The finding reveals that the economic attributes response to floods for a residential property value with positive, negative and none expected effects

Fabrication of mixed matric membrane incorporated with modified silica nanoparticles for bisphenol a removal

The introduction of inorganic nanoparticles in polymeric dope solution for the fabrication process of membrane can potentially enhance the separation performances of membrane without negatively affecting its permeability. In this study, hollow fiber mixed matrix membranes were prepared by incorporating polyethersulfone (PES) membranes with silicon dioxide (SiO2) nanoparticles at different concentration. Prior to separation tests, the prepared membranes were characterized by SEM, EDX, DSC, water contact angle, and FTIR-ATR in order to study the impact of silica nanoparticles on the properties of the membranes. Bisphenol A (BPA) was selected as the subject compound of this study because it is one of the emerging pollutants that have been frequently detected in the water treatment plant (WTP). BPA was spike into the pre-treated water sample taken from the WTP and was used as the feed solution to evaluate the membrane performance in terms of water flux and removal rate. The addition of SiO2 was reported to improve the hydrophilicity of membrane and induce greater micro-voids formation in the membrane structures, leading to increased water flux during BPA filtration process. The presence of more silanol (Si-OH) and siloxane (Si-O-Si) bonding groups resulted from increased SiO2 contents in membrane has improved membrane adsorption rate and further increased BPA remova

Effectiveness of Anaerobic Technologies in the Treatment of Landfill Leachate

Improper Solid Waste Management leads to the generation of landfill leachate at the landfills. To reduce the negative impacts of highly toxic and recalcitrant leachate on the environment, several techniques have been used. A lot of research is conducted to find suitable methods for the treatment of landfill leachate such as biological processes, chemical oxidation processes, coagulation, flocculation, chemical precipitation, and membrane procedures. The biological process is still being used widely for the treatment of leachate. The current system of leachate treatment consists of various unit processes which require larger area, energy and cost. In addition, the current aerobic treatment is not able to treat entirely the pollutants which require further treatment of the leachate. Anaerobic wastewater treatment has gained considerable attention among researchers and sanitary engineers primarily due to its economic advantages over conventional aerobic methods. The major advantages of anaerobic wastewater treatment in comparison to aerobic methods are: (a) the lack of aeration, which decreases costs and energy requirements; and (b) simple maintenance and control, which eliminates the need for skilled operators and manufacturers. Several anaerobic processes have been used for leachate treatment such as up-flow anaerobic sludge blanket (UASB) reactor, anaerobic filter, hybrid bed reactor, anaerobic sequencing batch reactor and Anaerobic baffled reactor. The following chapter provides an insight to the solid waste management at the landfills, generation of leachate and details of some of the highly efficient anaerobic treatment systems that are used for the overall treatment of landfill leachate