Cluster analysis and quality assessment of logged water at an irrigation project, eastern Saudi Arabia

A multivariate statistical technique, cluster analysis, was used to assess the logged surface water quality at an irrigation project at Al-Fadhley, Eastern Province, Saudi Arabia. The principal idea behind using the technique was to utilize all available hydrochemical variables in the quality assessment including trace elements and other ions which are not considered in conventional techniques for water quality assessments like Stiff and Piper diagrams. Furthermore, the area belongs to an irrigation project where water contamination associated with the use of fertilizers, insecticides and pesticides is expected. This quality assessment study was carried out on a total of 34 surface/logged water samples. To gain a greater insight in terms of the seasonal variation of water quality, 17 samples were collected from both summer and winter seasons. The collected samples were analyzed for a total of 23 water quality parameters including pH, TDS, conductivity, alkalinity, sulfate, chloride, bicarbonate, nitrate, phosphate, bromide, fluoride, calcium, magnesium, sodium, potassium, arsenic, boron, copper, cobalt, iron, lithium, manganese, molybdenum, nickel, selenium, mercury and zinc. Cluster analysis in both Q and R modes was used. Q-mode analysis resulted in three distinct water types for both the summer and winter seasons. Q-mode analysis also showed the spatial as well as temporal variation in water quality. R-mode cluster analysis led to the conclusion that there are two major sources of contamination for the surface/shallow groundwater in the area: fertilizers, micronutrients, pesticides, and insecticides used in agricultural activities, and non-point natural sources.     

缺水、海水淡化与污染

全世界快速的人口增长、城市化和高标准生活加剧了水的短缺,已经导致许多国家(特别是在干旱与半干旱地区)不得不采用海水淡化技术,首要满足家庭需求.在1950与1960年代,海水淡化业商业化.随着成本的大幅度降低和效率的提高,特别是自从1970年代以来,海水淡化已经变成满足家庭需要的一项战略和可靠来源.     

Physical properties of PVDF-GO/black-TiO2 nanofibers and its photocatalytic degradation of methylene blue and malachite green dyes

Environmental Science and Pollution Research - Black TiO2 and graphene oxide (GO) have attracted intensive attention as an effective catalyst on visible light driven for photodegrading of dyes. In...     

Treatment of hydrophobic VOCs in trickling bed air biofilter: Emphasis on long-term effect of initial alternate use of hydrophilic VOCs and microbial species evolution

The main research objective of this study is to enhance the removal of recalcitrant compounds that are not readily bioavailable due to limiting mass transfer rate between the liquid and gas phases. Four trickle-bed air biofilters (TBABs), loaded with pelletized diatomaceous earth support media, were run at an empty bed residence time (EBRT) of 120 sec. After an acclimation period at constant loading rate (LR) of n-hexane (13.2 g m^?3 hr^?1) and intermittent feeding of methanol, n-hexane influent LR was then increased in step-wise fashion to 47.7 g m^?3 hr^?1 for biofilters receiving acidic nutrients (pH 4), and to 36.3 g m^?3 hr^?1 for biofilters receiving nutrient at pH 7. The results have shown that for TBABs receiving nutrient at pH 4, greater elimination capacities were obtained as compared to TBABs working at pH 7. n-Hexane removal efficiency of more than 84% at LR up to 47.7 g m^?3 hr^?1 was obtained for pH 4 nutrient-fed biofilters, while for biofilters with nutrients fed at pH 7, the removal efficiency did not exceed 64% for n-hexane LR of 36.3 g m^?3 hr^?1. The microbial analysis revealed that no fungal community was detected in TBABs run at neutral pH. The fungi communities that were initially acclimating TBABs run at pH 4, namely, Aspergillus niger and Fusarium solani, were not detected at the end of the experiment, while Gibberella moniliformis (Fusarium verticillioides) genus became the dominant species. Gibberella moniliformis (Fusarium verticillioides) was present along all the biofilter media and sustained very high n-hexane elimination at steady-state condition.

Implications:With growing apprehension about sustainability and environmental protection, with limited resources available, and with the passage of the 1990 Amendments to the Clean Air Act, there is more need for using air pollution control techniques that are sound economically and proven environmentally friendly. Biofiltration systems, namely, trickle-bed air biofilters, were for decades recognized as efficient in treating air pollutants. Thus, the application of this technique over a wide industrial spectrum would certainly contribute to reduction of hazardous gas emissions.