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conferenceseries
.com
Volume 8
International Journal of Waste Resources
ISSN: 2252-5211
Recycling Expo 2018
June 25-26, 2018
June 25-26, 2018 | Berlin, Germany
8
th
World Congress and Expo on Recycling
Treatment of wastewater from microelectronic industry: Process analysis of a combined process
scheme
F Veglio
1
, V Innocenzi
1
, I De Michelis
1
, F Tortora
1
, M Prisciandaro
1
and
G Mazziotti di Celso
2
1
University of L’Aquila, Italy
2
University of Teramo, Italy
T
he production of semiconductors requires a series of specific treatments in which a large amount of ultra-pure water is
used. As a consequence of this, a large amount of polluted process water is produced that must be treated before discharged
into the sewer. The treatment cost of the wastewater is a significant effect on the industrial total cost and the microelectronics
industry is trying to adopt production processes accompanied by water treatment processes for production of ultra-pure water
at a reasonable cost, involving water reuse. The principal pollutants are inorganic compounds such as mineral acids (sulfuric,
nitric, hydrofluoric, phosphoric acids), ammonium hydroxide, heavy metals (copper, cobalt) and organic solvents. The mineral
acids and the metals are successfully removed by most of the treatment processes of the semiconductor sewage industry. There
are some problems in the treatment of organic compounds, among these is tetramethyl ammonium hydroxide (TMAH),
(CH
3
)
4
NOH. This last is corrosive, slow to biodegrade and eutrophic to aquatic environments. Disposal of TMAH wastewaters
from an industrial plant is a difficult and costly issue. The scientific literature shows that it is possible to remove this pollutant
by using chemical/physical processes (e.g. advanced oxidation processes (AOP) and adsorption) as well as biological processes
(e.g. anaerobic digestion). In this paper, an integrated process stream is proposed for the treatment of wastewater produced
by electronic industry. A combination of chemical-physical and biological processes for the removal of TMAH and other
pollutants as nitric and acetic acid is described in order to purify the water. Firstly, a series of experimental results obtained
in the laboratory scale is reported, after in accordance with these results a process scheme is proposed and simulated with
commercial software in order to investigate the technical feasibility and describe the overall mass balance of the whole scheme.
Figure 1:
Block scheme of the process proposed for the removal of TMAH and other pollutant from industrial electronics wastewater.The process was conducted
within Life Bitmaps project
Recent Publications
1. Prisciandaro M, Capocelli M, Barba D and Piemonte V (2016) Process analysis applied to water reuse for a “closed water
cycle” approach. The Chemical Engineering Journal 304:602–608.
2. HuangC J and Liu J C (1999) Precipitation flotation of fluoride-containingwastewater fromsemi-conductormanufacture.
Water Research 33(16):3403-3412.
3. Lin H L, B K Chen, H P Hsia, G H Yang, Y F Yang, Y C Chao and S S Cheng (2011) Use of two-stage biological process
in treating thin film transistor liquid crystal display wastewater of tetramethyl ammonium hydroxide. Sustainable
Environment Research 21:155-160.
4. Ballard T, N Chowdhury, B Heiniger, D Horner, A Lau, S Mehta, B Schilling, R Ubaldi and J Williamson (2013) Novel
process for the treatment of wastewaters from the microelectronics industry. IWC 13-34.
F Veglio et al., Int J Waste Resour 2018, Volume 8
DOI: 10.4172/2252-5211-C1-011