What Next-Way Forward

Source – SUSTENT Consulting Pvt. Ltd

 5.12 List of Best Practices

Some of the techniques described as air abatement techniques which can be installed in enterprises for air pollution minimisation include:

Cyclones Dust Collector at the point of air pollution origin

• Used for separation of large particles (> 10 µm) by using centrifugal forces
• Large particles reach the cyclone wall and are collected in a bottom hopper, whereas small particles leave the cyclone with the exiting gas.
• The average lifetime of a cyclone (replacement) is from 10 to 20 years.
• Low capital cost
• Relatively less space requiring
• Dry Collection and disposal

Bag Filters

• Bag filter or fabric filter systems work by passing air containing particulates through a filter medium which traps the particles as the air is forced through the filter media.
• Although the investment costs of bag filters are relatively low, maintenance costs are high as the filter material must be changed every two to five years.
• Filters use significantly less energy than cyclones and produce less noise.
• Bag filters may reduce dust emissions to < 5 mg/Nm³

Figure 9: Bag Filter

Source: Santonja, G.G., Karlis, P., Stubdrup, K.R., Brinkmann, T. and Roudier, S., 2019. Best Available Techniques (BAT) reference document for the food, drink and milk industries. Industrial Emissions Directive 2010/75/EU (Integrated Pollution Prevention and Control), 3.

Electrostatic Precipitator at the stack

• Used to separate solid or liquid particles from waste gases.
• Here, particles are charged and separated under the influence of an electrical field.
• Their separation rates are of up to 99.9%, effective separation of particles even lower than 0.1 µm
• Cost of electrostatic precipitators includes electricity consumption cost, maintenance expenses and the transfer of the precipitated ash, but generally they are cost-effective devices for reducing dust emissions (fine dust particles)

Wet Scrubbers at the stack

• The technique is used for the separation and purification of gaseous streams which contain high concentrations of VOC, especially compounds soluble in water such as alcohols, acetone
• Used on the principle of absorption where there is mass transfer between a soluble gas and a solvent
• Generally used for capturing ammonia, or volatile organic compounds and reduction of odour emissions.

Apart from these methods, the company/ facility should have a dedicated air quality professionals (part/full time) who can work to minimize the impact of air pollution on workers. The best practices that can be followed in the enterprise are:

Having Management Commitment

Management commitment is essential for continuous and long-term efforts.

Follow Collaborative Approach

The best way to successfully implement an initiative is to get the whole team behind it. It is essential to provide them the necessary training on standard operating procedures and need to do such project which will help them to know the purpose of starting such projects.

Set Targets

A well-defined target for a particular timeframe is needed to be established for continual improvement in the system. Communicate with others what you want to achieve. For example, to decrease the amount of carbon dioxide inside facility by having indoor plants inside facility.

Spreading and speeding up technology transfer

It is essential to be well informed about the latest technologies and to implement them wherever possible for minimizing the effect of air pollution on environment and health. Also, make others informed about the same for spreading awareness.

Behavioural Change

Attitude is important when you are trying to bring a necessary change. Working in a team with staff become easier by understanding their attitude and then implementing solutions. To reduce the impact of indoor air pollution, workers should

• Prohibit tobacco smoke inside facility
• Maintain hygienic conditions in their surroundings
• Wear masks while engaged in food processing activities so as to reduce their exposure to indoor air pollution
• Ensure proper ventilation system

5.13 Emerging Technologies

As identified from literatures, some of the indoor dust sensor that are currently in use include:

Table 8: Emerging Technologies

Author	Device and Size Range	Concentration Range	Sensor Used	Specification
Manikonda et al, 2016	Speck 2.0 DSM501A (0.5 – 3 µm)	0-640 µg/m3	Speck DSM501A	13Measure the particle concentration with the detected scattered light
Besser and Heimbinder. 2014 (Habitat Map, 2014)	Air Beam Air Casting (0.5-2.5 µm)	0-400 µg/m3	Shinyei PPD60PV	14Sensor of PM2.5, relative humidity, and temperature. Use internal fan to pull air in particle sensing region
Sousan et al., 2016	DC-1700 (>0.5µm)	0–106  particles /cm3	DC-1700 sensor	15Fitted with fan used to pull out air. Provides number concentration of fine and coarse particles
Sousan et al., 2017	Foobot Analyser (0.3 – 2.5 µm)	0-1300 µg/m3	Sharp GP2Y 10 AU0F	16Provides display of indoor pollutants by using LED It provides real time data and do plotting on pollution patterns and identify the relevant sources

¹³Manikonda, A., Zíková, N., Hopke, P.K. and Ferro, A.R., 2016. Laboratory assessment of low-cost PM monitors. Journal of Aerosol Science, 102, pp.29-40. Moore, D., 2014. Handbook of Spectroscopy. s.I.:Wiley-VCH verlag

¹⁴Air Beam Technical Specifications, Operation & Performance. The HabitatMap & AirCasting.

¹⁵Sousan, S., Koehler, K., Hallett, L. and Peters, T.M., 2016. Evaluation of the Alphasense optical particle counter (OPC-N2) and the Grimm portable aerosol spectrometer (PAS-1.108). Aerosol Science and Technology, 50(12), pp.1352-1365.

¹⁶Sousan, S., Koehler, K., Hallett, L. and Peters, T.M., 2017. Evaluation of consumer monitors to measure particulate matter. Journal of aerosol science, 107, pp.123-133.