Identification of bacteria species in aquaponics system using RapID system and 16S rRNA sequencing

Aquaponics is an integrated production system of aquaculture and hydroponics. Beneficial bacteria convert the ammonia and solid wastes produced by fish in the aquaculture component into essential nutrients for plant growth in hydroponics. The objective of the present study was to identify the bacteria community in the aquaponics system. This study was set by using barb fish and basils as organisms of cultivation. The fish tank (aquaculture) water was pumped into the treatment tank containing bio-ring functions as nitrifying bacteria by converting ammonia to nitrates. The nutrient-rich water from the treatment tank was then pumped into the hydroponics containing lightweight expanded clay aggregate (LECA) and plants. Water samples from the treatment tank and hydroponics were pipetted and transferred onto different agar plates for colony growth. Another set of soil growth plant was used for comparison in bacteria community between aquaponics and conventional land agriculture. RapID system and 16S rRNA gene were used to identify gram-negative and gram-positive bacteria respectively. The identified bacteria species from the hydroponics (LECA) and treatment tank (Bio-ring) were Moellerella wisconsensis, Achromobacter xylosoxidans, Bacillus cereus, Burkholderia pseudomallei and Bacillus sp. respectively whereas the bacteria species isolated from soil were Bacillus sp. and Bacillus pumilus.

Characterization and toxicological evaluation of leachate from Bacolod city sanitary landfill using tilapia (Oreochromis niloticus): a preliminary study

This study was carried out to characterize and assess the toxicity of Bacolod City Landfill leachate using Tilapia as bio-indicator species. Acclimatized Oreochromis niloticus fishes (length of 14 cm ± 2.0 cm and weight of 11.8 g ± 0.9 g) were introduced into each treatment tank containing three different concentrations of leachate in duplicates (10 ppm, 50 ppm and 100 ppm) and a control group. Physical reactions were observed such as erratic swimming, loss of reflex, hyperactivities, and surfacing. Reactions and mortality rate increased with increasing concentration and duration of exposure. Mortality rate using One-way Analysis of Variance (ANOVA) and Duncan’s Multiple Range Test (DMRT) revealed a significant difference between treatment groups and exhibited 100 ppm as the most potent concentration. Heavy metal analysis of Cu and Pb as well as physicochemical analysis of color, Chimecal Oxygen Demande (COD) and Total dissolved Solids (TDS) exceeded the country’s environmental standard set by DENR. The 96 h bioassay stemmed the median lethal concentration (LC50) at 57.688 ppm. The study provides a biomarker database in taking action for the responsible enactment and enforcement of laws to upgrade, enhance and install framework for proper treatment of sanitary landfill leachate in cities and municipalities in the country.

The Removal of Residual Concentration of Hazardous Metals in Wastewater from a Neutralization Station Using Biosorbent—A Case Study Company Gutra, Czech Republic

This article deals with the possibility of using a biosorbent in the form of a mixture of cones from coniferous trees to remove the residual concentration of hazardous metals contained in hazardous waste, which is disposed of in a neutralization station. The efficiency of the tested biosorbent in removing Ni, Zn, Cu, and Fe was monitored here. Laboratory research was carried out before the actual testing of the biosorbent directly in the operation of the neutralization station. With regard to the planned use of the biosorbent in the operational test, the laboratory experiments were performed in a batch mode and for the most problematic metals (Ni and Zn). The laboratory tests with real wastewater have shown that the biosorbent can be used to remove hazardous metals. Under the given conditions, 96% of Ni and 19% of Zn were removed after 20 min when using NaOH activated biosorbent with the concentration of 0.1 mol L−1. The inactivated biosorbent removed 93% of Ni and 31% of Zn. The tested biosorbent was also successful during the operational tests. The inactivated biosorbent was applied due to the financial costs. It was used for the pre-treatment of hazardous waste in a preparation tank, where a significant reduction in the concentration of hazardous metals occurred, but the values of Ni, Cu, and Zn still failed to meet the emission limits. After 72 h, we measured 10 mg L−1 from the original 4,056 mg L−1 of Ni, 1 mg L−1 from the original 2,252 mg L−1 of Cu, 1 mg L−1 from the original 4,020 mg L–1 of Zn, and 7 mg L−1 from the original 1,853 mg L−1 of Fe. However, even after neutralization, the treated water did not meet the emission limits for discharging into the sewer system. The biosorbent was, therefore, used in the filtration unit as well, which was placed in front of the Parshall flume. After passing through the filtration unit, the concentrations of all the monitored parameters were reduced to a minimum, and the values met the prescribed emission limits. The biosorbent was further used to thicken the residual sludge in the waste pre-treatment tank, which contributed to a significant reduction in the overall cost of disposing of residual hazardous waste. This waste was converted from liquid to solid-state.

Simulation of un industrial waste treatment tank

The objective of the present work was to evaluate the operation of an industrial sedimentation tank used in the separation of solid waste from the petrochemical industry. The depth data were obtained through a “interface float”, while the diameters and the positions of the particles through the CFD simulation. The computational fluid dynamics simulator (FLUENT 6.3.26) was used to perform a multiphase simulation using the Euler-Lagrange approach and was used to determine the particles trajectories and cotours of solids accumulated in the bottom of the tank. This allowed a better understanding of solids accumulation and improvement of the cleaning process. In the simulation of the tank a large computational mesh comprising 464,094 computational nodes was designed. The use of the Euler-Lagrange approach meant that a discrete phase model had to be established and the parameters of Rosin-Rammler solids distribtion model for the boundary conditions of the simulation had to be determined.

Evaluation of Domestic Wastewater as a Basis for the Design of Communal Domestic Wastewater Installation of Kandang Kampong, Condongcatur Village, Yogyakarta

As population increases, domestic wastewater generated will increase as well. Domestic wastewater needs to be treated properly so as not to pollute the recipient's water body. Kampung Kandang already has a communal domestic wastewater treatment plant (WWTP) to treat domestic wastewater generated by citizens. The problem from the citizens is that the WWTP needs to be rehabilitated because the amount of sludge floating in the first biological treatment tank and still has a disturbing odor. Alternative solution for this problem is by rehabilitating WWTPs so that their functions are more optimal. The purpose of this study was to evaluate domestic wastewater in Kampung Kandang. The methods used in evaluating the wastewater i.e. analysis of primary data, calculation of standard stream evaluation and calculation of removal percentage. Communal Domestic WWTP needs to remove COD, BOD, TSS, Ammonia, and Total Coliforms parameters of 97.7%, 98.9%, 42.7%, 95.6%, and 99.9%. WWTP has already removed the TSS and ammonia. BOD, COD, and total coliform should be reduced by WWTP as much for each parameter are 25, 9%, 35%, and 95, 83%. Wastewater evaluation data can be used as a basis for the design of rehabilitation to be carried out at the Communal Domestic WWTP in Kampung Kandang.

A Research on the Effect of Treated Grey Water on Workability and Strength of Plainconcrete

Water from the kitchens, bathrooms, showers, tubs, and washing machines are referred as the grey water. Even though the grey water looks dirty, the treated grey water can be made useful in several beneficial purposes like irrigation and laundry purposes. The aim of this experimental study is to use the treated grey water in concrete making and to analyse its effects on the workability and strength aspects which can be utilized in concrete structures. The waste water samples were collected from the secondary treatment tank located in Kumaraguru College of Technology. The collected samples were analysed for various chemical parameters like pH, TSS, BOD, COD in the laboratory and tested for their suitability of use in concrete. The setting time of cement, workability, compressive strength have been tested for concrete casted using potable water and for the concrete casted using effluent from grey water treatment. The result from the various test of concrete confirms that the usage of secondary treated grey water in concrete increases both the workability and also the strength of the concrete when compared with the concrete casted using ordinary potable water. Since the treated grey water contains some organic matter in it, it is evident the decomposition of which causes corrosion of concrete if it is meshed with steel bars. The results from the test suggest that the treated grey water can be used only in case of plain cement concrete works.

Contamination by Antibiotic-Resistant Bacteria in Selected Environments in Thailand

This study determined the presence of important antibiotic-resistant bacteria in selected environments in Thailand, including wastewater samples from 60 hospitals; washed fluid, leachate, flies, cockroaches, and rats collected from five open markets; washed fluid from garbage trucks; and stabilized leachate from a landfill facility. At least one type of antibiotic-resistant bacteria was isolated from all samples of influent fluid before treatment in hospitals, from wastewater treatment tank content in hospitals, and from 15% of effluent fluid samples after treatment with chlorine prior to draining it into a public water source. Antibiotic-resistant bacteria were recovered from 80% of washed market fluid samples, 60% of market leachate samples, all fly samples, 80% of cockroach samples, and all samples of intestinal content of rats collected from the open markets. Antibiotic-resistant bacteria were recovered from all samples from the landfill. Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and/or Klebsiella pneumoniae were the most common antibiotic-resistant bacteria recovered from all types of samples, followed by carbapenem-resistant E. coli and/or K. pneumoniae. Colistin-resistant Enterobacteriaceae, carbapenem-resistant Psuedomonas aeruginosa, carbapenem-resistant Acinetobacter baumannii, colistin-resistant Enterobacteriaceae, vancomycin-resistant Enterococci, and methicillin-resistant S. aureus were less common. These findings suggest extensive contamination by antibiotic-resistant bacteria in hospital and community environment in Thailand.

Application of hybrid modified UASB - MBBR technology for wastewater treatment of Sao Thai Duong Pharmaceuticals and Cosmetics Factory

Wastewater of Sao Thai Duong Pharmaceuticals & Cosmetics Factory contains high concentration (more than 1000 mg/l) COD and BOD. Besides, some persistent substances are also found such as surfactants, emulsion oil and ammonium. Especially, the quite low BOD/COD ratio of 0.3 makes the treatment process of organic matters more complicated. Furthermore, the troublesome settlement of oil emulsions inhibits the wastewater biological treatment process which results in difficulties for selection of a stable and sustainable technology. For these reasons, it is recommended to use the Upflow Anaerobic Sludge Blanket Filtration (UASB) technique combined with the use of the bio-logical named carriers DHY-01 and DHY-02 (produced by Vinse Company). DHY carriers have a high porosity (92-96%), large surface area (10000-12000 m2) and apparent specific weight of 33 g/l. The anaerobic treatment tank (Upflow Blanket Filter - UBF) has a retention time of 10-12 hours. Influent COD concentration is about 1000-2000 mg/l, reduced by 65-70% after treatment. Influent BOD concentration is 200-600mg/l, reduced by about 60-65% after treatment. Aerobic tank (moving bed biofilm reactor - MBBR) has a retention time of 4-6 hours. COD and ammonium removal efficiency is about 85-90%.

Performance of a storage tank coupled with UV light on enteric virus inactivation in drinking water

Water destined for personal and household consumption should be safe and acceptable in taste, odor and color. However, complaints about drinking water quality are a common issue among the Brazilian population. Also, due to the pollution of water bodies, social groups that are not supplied by treated water may be exposed to different contaminants. The aim of this study was to assess the efficiency of a water treatment tank coupled with UV light on the inactivation of enteric viruses and the reduction of chlorine concentration for use in residences, as well as in rural and isolated communities. Viral disinfection and chlorine concentration decay assays were performed in a tank with capacity of 300 L and a 36-W UV lamp coupled, with controlled temperature. Recombinant human adenovirus (AdHu5-GFP) and murine norovirus (MNV-1) infectivity were assessed after 0, 3, 6 and 12 h of water recirculation. 99.99% inactivation was reached after 12 h for AdHu5-GFP and before 6 h for MNV-1. Chlorine concentration had a decay of 0.77 mg/L after 12 h. Regarding the efficiency observed, a product model was designed. This tank model was efficient in ensuring viral inactivation as well as in reducing residual chlorine and can be adjusted to other scales.

Effects of Structured Fibre on Mechanical and Tribological Properties of Phenolic Composites for Application to Friction Brakes

Jute fibres were processed with different types of structures, and these fibres were applied to prepare friction composites through compression moulding. The Structured Jute fibres reinforced Friction composites (SJF) were heat-treated using a heat treatment tank, and the mechanical and tribological properties of the SJF were investigated with a friction-wear tester. The surface morphologies of friction composites were observed using Scanning Electron Microscopy (SEM). The experimental results showed that structured jute fibres could improve impact strength of SJF, but they had no obvious effect on their density and hardness. The friction-wear tests revealed the specimens to present a remarkable fade phenomenon when the test temperature was above 200°C. The presence of the structured jute fibres could decrease the wear rates (V) of SJF when the temperatures were in the range of 250 to 350°C, especially for specimens containing beaded jute fibres and specimens containing dumbbell-shaped jute fibres. They also increased the friction stability and decreased the wear rates of the friction composites. For all specimens, wear rates of the SJF increased with the test temperature. The results of this study could be useful in many applications, such as automobile brake system, clutches and friction gearings.