Abstract
Determination of the status of water quality of a river or any other water source is highly indeterminate. It is necessary to have a competent model to predict the status of water quality and to show the type of water treatment that would be used to meet different demands. By exploring the behavior and limitations of conventional methods for quality evaluation, a better overall index for water quality in Iran and its application in Karoon River is proposed. Six variables are employed for the quality assessment. Numerical scales relating to the degree of quality are established for each variable to assess variations in quality and to convey findings in a comprehensive manner. The unit operates in a fuzzy logic mode including a fuzzification engine receiving a plurality of input variables on its input and being adapted to compute membership function parameters. A processor engine connected downstream of the fuzzification unit will produce fuzzy set, based on fuzzy variable namely dissolved oxygen (DO), total dissolved solids (TDS), turbidity, nitrate, fecal coliform and pH. It has a defuzzification unit which operates to translate the inference results into a discrete crisp value of water quality index. The development of the fuzzy model with one river system is explained in this paper. Water quality index in most countries is only referring to physico-chemical parameters due to great efforts needed to quantify the biological parameters. This study ensures a better method to include special parameters into water quality index due to superior capabilities of fuzzy logic in dealing with non-linear, complex and uncertain systems. Key words: Water quality index, fuzzification, monitoring, inference system.
Highlights
Water quality index (WQI) is an attempt used to give an imperfect answer to non-technical questions about water quality
Comparison has been done between fuzzy water quality (FWQ) and the existing WQ indices such as National Sanitation Foundation water quality index (NSFWQI), Oregon, Malaysian Department of Environ-ment water quality index (DOE-WQI), CPCB-WQI, Kaurish and Younos, and Ahmed Saied
This study comprised the evolution of a new index called the Fuzzy water quality index
Summary
Water quality index (WQI) is an attempt used to give an imperfect answer to non-technical questions about water quality. It has no unit, with number ranging from 1 to 100; a higher number is indicative of better water quality. An index is most useful for comparative purposes (what stations have poor water quality?) and for general questions (how is the water quality of my stream?). Indexes are less suited to specific questions. An index is a useful tool for “communicating water quality information to the lay public and to legislative decision makers”; it is not a complex predictive model for technical and scientific application. An index is a useful tool for “communicating water quality information to the lay public and to legislative decision makers”; it is not a complex predictive model for technical and scientific application. Landwehr (1979) points out that an index is a performance measurement that aggregates information into a usable form, which reflects the composite influence of significant physical, chemical and biological parameters of water quality
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
