Continuous Performance Improvement Framework for Sustainable Wastewater Treatment Facilities in Arid Regions: Case of Wadi Rumah in Qassim, Saudi Arabia.

Husnain Haider,Md Shafiquzzaman,Hussein Thabit,Ibrahim Al-Salamah,Abdul Ghumman,Mohammed Alhetari

doi:10.3390/ijerph18136857

Abstract

In arid regions such as Saudi Arabia, wastewater treatment (WWT) facilities (meeting promulgated standards) need to adapt their continuous performance improvement (CPI) for long-term sustainability. To achieve this, the facilities need to improve their performance to comply with more strict objectives for broader reuse applications of treated effluent. The present research proposes a CPI framework based on performance benchmarking process for the stepwise improvement of WWT facilities. A grey rational analysis water quality index (GWQI) based on exceedance probability was developed. For weights’ estimation of 11 physical, chemical, and biological water quality parameters, the entropy method effectively accommodated the changes in relative importance of the parameters with including additional future reuse applications. For existing effluent reuse scenarios of restricted and unrestricted irrigation, the GWQI values were found consistent with the modified version of the Canadian WQI (CWQI). The indices’ values (ranged between 0 and 100) greater than 80 showed the efficient operation of four WWT plants in the Qassim Region of Saudi Arabia. Two hypothetical CPI scenarios with future reuse applications (fish, livestock drinking, and recreation) showed an overall decline in the average (of four plants) values of the GWQI (97 to 78) and CWQI (85 to 60). CWQI predicted stricter results for the facilities with parameters’ concentrations exceeding the targets with larger margins and was found applicable for the CPI of WWT facilities in arid regions. For existing scenarios, the assessment results suggest the facilities to control and monitor the chlorination practice. For future targets, tertiary treatment needs to be enhanced for desired nutrients and total dissolved solids removal. The proposed CPI framework provides a platform to initiate the performance benchmarking process for WWT facilities at local or regional levels in Saudi Arabia and elsewhere.

Highlights

IntroductionSurface water resources in the semi-arid and arid regions are facing challenges in meeting their intended uses, due to extreme low flows and the inadequate treatment of point and non-point pollution sources [1,2,3]
Maximum total dissolved solids (TDS) levels in wastewater treatment plants (WWTPs)-2 and WWTP-3 comply with the target concentrations for scenario 1 and scenario 2, while the effluent of WWTP-4 meets the target concentration for scenario 3 as well
The water quality index based on exceedance probability was developed using grey rational analysis and named grey rational analysis water quality index (GWQI)

Summary

Introduction

Surface water resources in the semi-arid and arid regions are facing challenges in meeting their intended uses, due to extreme low flows and the inadequate treatment of point and non-point pollution sources [1,2,3]. Depleting freshwater resources and low annual rainfalls have raised the need for wastewater reuse for different purposes (e.g., unrestricted and restricted irrigation, fishery, and recreation) based on the effluent quality produced by the wastewater treatment (WWT) plants [4,5]. To improve the circular economy and conserve water resources, the effluent standards are generally established based on the socio-economic benefits of wastewater reuse in a given geographical region [6,7].

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Discussion

Conclusion