Assessment of water quality and hyperaccumulator-based purification of contaminated springs across the district Muzaffarabad, Azad Kashmir, Pakistan.

Abstract

In a developing country like Pakistan, drinking water leads to health issues that spread to plants and food chains. Therefore, the current study was designed to assess the quality of spring water available in different localities in Muzaffarabad, Azad Jammu and Kashmir Districts, Pakistan, and to evaluate the efficacy of phyto-hyperaccumulators, including Brassica rapa and Spinacia oleracea in the purification of spring water. Physicochemical parameters such as pH, temperature, electrical conductivity, turbidity, total dissolved solids, dissolved oxygen, chemical oxygen demand, biological oxygen demand, and heavy metals were analyzed. B. rapa and S. oleracea were grown to purify the contaminated spring water. The results of physicochemical parameters before hyperaccumulator treatment were recorded as temperature (14.03 ± 0.80°C to 18.76 ± 1.52°C), pH (6.5-8.5), electrical conductivity (245.0 ± 7.54 μS/cm to 365.13 ± 13.89 μS/cm), turbidity (0.6 ± 1.00 NTU to 2.6 ± 2.51 NTU), total dissolved solids (122.0 ± 1.00 ppm to 247.6 ± 3.21 ppm), biological oxygen demand (4.1 ± 0.9 mg/l to 8.06 ± 0.550 mg/l) along with the maximum levels of heavy metals (Cd, Zn, Cu, Ni, Pb, Cr). Heavy metals constitute a serious risk to human health, according to the contamination factor, risk index, hazard quotient of potentially toxic components, and non-carcinogenic risk in spring water. After hyperaccumulator treatment, B. rapa and S. oleracea treated spring water not only declined the values of physicochemical parameters but significantly reduced the heavy metals efficiently at p < 0.001. After treatment, physicochemical parameters were recorded as pH (7.67 ± 0.58 and 7.43 ± 0.06 to 8.0 ± 0.00), temperature (12.4 ± 0.36°C to 13.2 ± 0.26°C and 12.4 ± 0.61°C to 13.27 ± 0.15°C), electrical conductivity (245.0 ± 7.54 μS/cm to 365.13 ± 13.89 μS/cm), turbidity (0.6 ± 1.0 NTU to 2.6 ± 2.51 NTU), total dissolved solids (122.0 ± 1.00 ppm to 247.6 ± 3.21 ppm), dissolved oxygen values were recorded in B. rapa (4.6 ± 0.53 mg/l to 7.9 ± 0.1 mg/l) and S. oleracea (4.53 ± 0.42 mg/l to 6.8 ± 0.7 mg/l), BOD values of B. rapa treated spring water (4.07 ± 0.85 mg/l to 4.97 ± 0.06 mg/l) and S. oleracea treated spring water (5.1 ± 0.1 mg/l to 5.13 ± 0.15 mg/l. It was observed that contaminated spring water did not affect the sprouting and growth of B. rapa compared to S. oleracea. Results revealed that B. rapa showed maximum accumulation of heavy metals compared to S. oleracea. Bioconcentration factor, remediated metal fraction (mg/kg), and planting season remediation (%) supported the efficient use of these plants as hyperaccumulators. The entire study concluded that hyperaccumulators purified and remedied heavy metals from spring water via phytoextraction (absorption and translocation), rhizofiltration (adsorption and concentration), and phytostabilization (immobilization). The environmentally favorable method for lowering contaminants and naturally purifying spring water in the future will be in situ phytoremediation. PRACTITIONER POINTS: B. rapa and S. oleracea were selected as hyperaccumulators to purify and remediate heavy metals from spring water Composition and properties of the used medium for phytoremediation are important for the contaminated water purification Utilization of plant species to reduce the heavy metals in water is commonly used nowadays Eco-friendly and cost-effective technology.