Analysis of Particulates and SO2 Removal from Coal Combustion Emissions Using Cyclone and Wet Scrubber With Textile Wastewater Feed

Reuse of wastewater in the industry is mostly accomplished for watering plants. In a closed cycle, however, industrial wastewater can be returned through treatment to save water usage. This study aims to analyze textile wastewater's ability to be used as scrubbing liquid in the SO2 gas and particulate removal from coal combustion using a packed wet scrubber. Usually, the textile industry uses boiler fueled by coal and discharging base/alkaline wastewater. The method is carried out experimentally using a prototype device using a combination of cyclone and scrubber, with a source of coal combustion gas emissions. We did experiments using textile wastewater four times and two times using clean water as a control. We monitor the SO2, particulate emission in the gas stream, and pH, sulfate levels, and TSS levels in collected wastewater according to SNI. SO2 gas and particulates from coal combustion will be absorbed by the scrubber's wastewater spray so that SO2 will dissolve into sulfate, particulate matter into TSS. The study results using textile wastewater showed the removal efficiency of particulates on cyclone by 34-78%. The removal efficiency of SO2 on wet scrubber was only 24.7%. There was an increase in TSS levels after passing through the scrubber by 46%. The rise in TSS and sulfate concentrations in the wastewater indicates the absorption of SO2 and particulates into wastewater. Based on this result, we can use textile wastewater for controlling the emission of SO2 and particulate from coal combustion by feeding it for the scrubber. However, the efficiency of this process is not optimal.

Low cost drinking water treatment using nonwoven engineered and woven cloth fabrics

The study investigated two engineered fabrics and five cloth fabrics for low cost drinking water treatment. An optimized fabric filtration method has been developed and tested. Numerical models for predicting particulate removal efficiency have been developed for each fabric as support tools for selecting optimal process configuration. Both engineered fabrics showed better performance and achieved the most effective particulate removal for the highest number of layers used. Sequential filtration was done on eight layers for representative fabrics of each type and recorded higher contaminant removal than one filtration run. Geotextile 1 was better than geotextile 2 in particulate removal and recorded Escherichia coli removals of up to 1.4 log removal value (LRV) for eight-layer normal filtration and 3.0 LRV for four-pot sequential filtration. Brushed cotton was best among the cloth fabrics in particulate removal but performed below expectation in bacterial removal. It recorded E. coli removals of only 0.04 LRV and 0.2 LRV for eight-layer normal filtration and four-pot sequential filtration, respectively. Effluent turbidity decreased exponentially with number of fabric layers, in line with porous media filtration theory. The optimized filtration method produced very clear drinking water of relatively safe quality using geotextile 1. Appropriate disinfection is still recommended to ensure continued water safety.

Factors affecting particulate removal efficiency of kraft recovery boiler electrostatic precipitators: a technical review

Electrostatic precipitators (ESPs) are used in most pulp mills to remove particulate from recovery boilers, power boilers, and lime kilns. As environmental regulations have become increasingly stringent in recent years, maintaining high ESP performance is of vital importance in mill operation. This paper discusses results of a literature review of the ESP technology used in industrial combustion units, including recovery boilers, as well as results of a parametric study using the well-known Deutsch-Anderson equation to correlate recovery boiler operating conditions with ESP collection efficiency. The results show that for particles up to about 0.3 μm, the ESP collection efficiency decreases drastically with increased particle size and with decreased temperature. For particles larger than 0.5 μm, however, the trend reverses; the collection efficiency increases with increased particle size and decreased temperature. The results also suggest that the particle concentration (or loading) in the flue gas has no effect on collection efficiency and that sodium chloride particles are more readily captured than sodium sulfate particles. The latter prediction, however, appears to be in contradiction with mill experience that sodium chloride particles are more difficult to capture.

The design of the botanical indoor air biofilter system for the atmospheric particle removal

Indoor environmental quality (IEQ) objective generally focus on providing energizing and comfortable environments for occupants and minimizing the risk of building-related health problems. Living green walls are natural air-filters that creates a cleaner and revitalizing work environment that will lead to better IEQ. The research presented here describes the design (the new concept) of the botanical indoor air biofilter (BIAB) and modelling conducted to determine the effectiveness of the system in reducing the indoor airborne particulate matter levels. The BIAB was also evaluated for its single-pass filtration for particles ranging in diameter from 2.5 to 10 Μ along with total suspended particles. The system is comprised of three functional components; a region of vertically grown plants as botanical section, an evaporative cooling pad as cooling section (additional section from a commercial BIAB), and a mechanical ventilation system that supply cool filtered air to surrounding. The complete system recorded highest removal efficiencies of 85% for TSP, 75.2% for PM2.5, and 71.9% for PM10. It indicated that with the additional component in the BIAB system (cooling component), it provides enhancement of the particulate removal due to the ability in absorbing the dust particles and filtration dynamics as the polluted air pass through the wetted cooling pad and the light shower of water.