Photocatalytic removals of imidacloprid insecticide in TiO- and FeO-immobilized porous geopolymer granules.

In this study, geopolymer catalysts were synthesized by incorporating different TiO (0, 7, and 14 wt%) and FeO content (0, 7, 14, and 20 wt%) into porous metakaolin-based geopolymer granules. TiO- and FeO-immobilized geopolymer granules were applied for photocatalytic removals of imidacloprid under UV-C irradiation. The analysis of the surface morphology of the FeO catalyst revealed its larger surface area predominated with meso- and macro-pores thus providing a larger area for photocatalysis.

Enhancement of sulfide removal and sulfur recovery in piggery wastewater via lighting-anaerobic digestion with bioaugmentation of phototrophic green sulfur bacteria.

Anaerobic pig wastewater treatment commonly generates high sulfide concentrations in the treated wastewater. This study aims to apply phototrophic green sulfur bacteria (PGB) to promote sulfide removal in lighting-anaerobic digestion (lighting-AD) treating pig wastewater. Initially, batch AD tests of pig wastewater with/without PGB addition were carried out under dark (D) and light (L) conditions.

TiO-immobilized porous geopolymer composite membrane for removal of antibiotics in hospital wastewater.

This experimental research proposes an environment-friendly and low-cost porous geopolymer composite membrane (PGCM) to treat antibiotics in hospital wastewater. The proposed PGCM consisted of two layers: a porous support layer and a dense coating layer. The dense coating layer was synthesized by incorporating variable TiO content (0, 2, 6, and 10 wt%) into the geopolymer matrix.

Reduction of antibiotic-resistant-E. coli, -K. pneumoniae, -A. baumannii in aged-sludge of membrane bioreactor treating hospital wastewater.

A pilot-scale of membrane bioreactor (MBR) had functioned without sludge withdrawal for six months, proposed to minimize antibiotic-resistant bacteria (ARB) dissemination from hospital wastewater. With this proposal, an aging sludge in MBR has concerned as preserved-severe multidrug-resistant microorganisms. Thus, this study aims to investigate resistance alteration of ARB in the aging-sludge compared to that in the wastewater.

Alteration of antibiotic-resistant phenotypes and minimal inhibitory concentration of Escherichia coli in pig farming: Comparison between closed and open farming systems.

The prevalence of antibiotic residues and antibiotic-resistant Escherichia coli (ARE) in closed (CSF) and open (OSF) pig farming systems was analysed. Results showed that a high level of E. coli populations, antibiotic contamination in supplied water, and additional antibiotics used, such as neomycin (NEO) or colistin (CLT), were observed in OSF.

Methane and nitrous oxide emissions from shallow windrow piles for biostabilisation of municipal solid waste.

Shallow windrow piles were applied as a low-cost option for biostabilisation of municipal solid wastes (MSW) prior to their utilization as refuse-derived fuel (RDF). A considerable amount of greenhouse gas (GHG) emissions can be emitted during the biostabilisation of MSW, especially when in operation under high moisture conditions such as there are in tropical Asia. This study investigated the emission of methane (CH) and nitrous oxide (NO) from shallow windrow piles - with heights of 0.

Effect of sludge recirculation on removal of antibiotics in two-stage membrane bioreactor (MBR) treating livestock wastewater.

Two-stage MBR consisting of anaerobic and aerobic reactors was operated at total hydraulic retention time (HRT) of 48 h for the treatment of livestock wastewater containing antibiotics, i.e. amoxicillin (AMX), tiamulin (TIA), and chlortetracycline (CTC), under the (1st) absence and (2nd) presence of sludge recirculation between the reactors.

Long-term removals of organic micro-pollutants in reactive media of horizontal subsurface flow constructed wetland treating landfill leachate.

In this work, the removals of organic micro-pollutants (OMPs), i.e. DEP, DBP, 2,6-DTBP, BHT, and DEHP in sand, clay and iron powder mixed media of horizontal subsurface flow constructed wetland (HSSF) from landfill leachate were investigated over 3 years period.

Optimization of reactive media for removing organic micro-pollutants in constructed wetland treating municipal landfill leachate.

The removal of organic micro-pollutants (OMPs) from landfill leachate in constructed wetland (CW) media having different material mixtures of sand (S), clay (C), and iron powder (Fe) was investigated using experimental column study. The use of S:C:Fe media consisting of 60:30:10% (w/w) and cattail as vegetation was found optimum for the removals of 2,6-DTBP, BHT, DEP, DBP, and DEHP at 67.5-75.

Removals of pharmaceutical compounds at different sludge particle size fractions in membrane bioreactors operated under different solid retention times.

Removals of 10 pharmaceutical compounds by microbial sludge in membrane bioreactors (MBR) operated under infinite and limited solid retention time (SRT) were investigated. High removal (>80%) of DCF, TMP, NPX, IBP, and TCS were achieved but CBZ removals were low (<20%). The residual pharmaceutical compounds leftover from the biodegradation in different sludge particle size fractions was quantified through physical separation and filtration in series.

Bioleaching of heavy metals from harbor sediment using sulfur-oxidizing microflora acclimated from native sediment and exogenous soil.

The harbor sediment containing high concentration of heavy metals may pose serious impacts on the marine ecosystem and environmental quality. The bioleaching process has been considered as an environmentally friendly and cost-effective alternative for removing heavy metals from contaminated sediments. In this study, a series of experiments were performed to investigate the feasibility of bioleaching process for removing heavy metals from the contaminated harbor sediments.

The effectiveness of passive gas ventilation on methane emission reduction in a semi-aerobic test cell operated in the tropics.

Two landfill test cells, with and without gas vents, were used to investigate the effectiveness of passive aeration, through basal leachate pipes, in mitigating methane emissions from municipal solid waste disposal in the tropical climate of Thailand. Surface methane emission rate, as well as methane content in the landfill gas, were determined for a period of three years. The results indicate that the average methane emission rate from the test cell with passive gas vents (42.

Genotoxicity Assessment of Volatile Organic Compounds in Landfill Gas Emission Using Comet Assay in Higher Terrestrial Plant.

Genotoxicity model is developed to assess the individual subacute toxicity of benzene, toluene, ethylbenzene, and xylene (BTEX) at very low levels as in a landfill gas. Golden Pothos (Epipremnum aureum), a higher plant, was tested under variation of benzene 54-5656 ng/L, toluene 10-4362 ng/L, ethylbenzene 28-4997 ng/L, xylene 53-4845 ng/L, for 96 h. DNA fragmentation in plant leaves were investigated via comet assay.

Enhanced biodegradation of phenolic compounds in landfill leachate by enriched nitrifying membrane bioreactor sludge.

The role of autotrophic nitrification on the biodegradation of toxic organic micro-pollutants presented in landfill leachate was assessed. A two-stage MBR system consisting of an inclined tube incorporated anoxic reactor followed by aerobic submerged membrane reactor was operated under long sludge age condition in which nitrifying bacteria could be enriched. During the reactor operation, organic removal efficiencies were more than 90% whereas phenolic compounds including bisphenol A (BPA) and 4-methyl-2,6-di-tert-butylphenol (BHT) were removed by 65 and 70% mainly through biodegradation in the aerobic reactor even at high feed concentrations of 1000μg/L for both compounds.

Kinetics of phenolic and phthalic acid esters biodegradation in membrane bioreactor (MBR) treating municipal landfill leachate.

The kinetic of phenolic and phthalic acid esters (PAEs) biodegradation in membrane bioreactor (MBR) treating municipal landfill leachate was investigated. Laboratory-scale MBR was fed with mixture of fresh and stabilized landfill leachate containing carbon to nitrogen (C/N) ratio of 10, 6, 3 and operated under different solid retention time (SRT) of 90, 15 and 5 d. Batch experiments using MBR sludge obtained from each steady-state operating condition revealed highest biodegradation rate constant (k) of 0.

Impacts of urbanization on the prevalence of antibiotic-resistant Escherichia coli in the Chaophraya River and its tributaries.

River water samples were taken from 32 locations around the basin of Chaophraya River and its four major tributaries in Thailand to investigate resistance ratios of Escherichia coli isolates to eight antibiotic agents of amoxicillin, sulfamethoxazole/trimethoprim, tetracycline, doxytetracycline, ciprofloxacin, levofloxacin, norfloxacin and ofloxacin. Principal component analysis was performed to characterize resistance patterns of the samples. Relevancy of the obtained principal components with urban land use and fecal contamination of the river were examined.

Evaluation of treated sewage reuse potential and membrane-based water reuse technology for the Bangkok Metropolitan area.

Only 3.4% of total water use in the Bangkok Metropolitan area is reused treated sewage. This study anticipates that further treated-sewage reuse in industrial sectors, commercial buildings and public parks, in addition to present in-plant and street cleaning purposes, would increase total water reuse to about 10%.

Effects of mixed liquor pH on membrane fouling and micro-pollutant removals in membrane bioreactors for municipal landfill leachate treatment.

This research investigated the membrane fouling and micro-pollutant removals in treatment of municipal landfill leachate at various pH levels (i.e. 5.