Nutrient Deportation Efficiency of Selected Natural and Synthetic Adsorbents from Municipal Wastewater for Environmental and Economic Benefits

摘要

bBackground and Objective:/b In view of scarcity of water resources due to huge amount of wastewater generated from population increase and industrialization, it has become a challenge to protect and conserve these water resources through proper treatment driven reuse. The present study was aimed at assessing the effectiveness of some natural and synthetic-adsorbent for eutrophication control by phosphate-P and nitrate-N removal from wastewater so that the resulting water can be safely reused for various economic-driven-activities. bMaterials and Methods:/b Phosphate-P and nitrate-N removal potentials from municipal-wastewater of some natural (fly-ash, coarse- sand and cattle-dung-cake-ash and their mixture-combination) and synthetic (Ferrosorp, ferric-hydroxide, activated -alumina and their mixture-combination) adsorbents were tested in batch-experiment for 10 days at room temperature (30°C). Ten gram of each adsorbent was added to 500 mL of wastewater in battery jar. Different parameters (pH, phosphate-P, nitrate-N and available-P) were monitored using the standard protocol. Desorption of saturated Ferrosorp was also examined using different extractants. The fertilizer value of spent adsorbent (Ferrosorp) was tested for the growth of Bengal gram ( Cicer arietinum ) in pot. bResults:/b Synthetic-adsorbents (activated-alumina, Ferrosorp and ferric-hydroxide) removed 92-93% phosphate-P, whereas both synthetic and natural (fly-ash, coarse-sand and cattle-dung-cake-ash) removed 100% NOsub3/sub-N from wastewater within 10 days of contact time. The nutrient removal capacity of the test adsorbents was correlated with their porosity and surface area. Cattle-dung-cake-ash and fly-ash were also good adsorbents for removal of NOsub3/sub-N. Though the amount of phosphate-P adsorbed by water with saturated Ferrosorp was relatively less (47.58%) than other extractants (75.50%), the spent Ferrosorp with soil revealed a pronounced effect on growth of Cicer arietinum . bConclusion:/b It is reasonable to conclude that Ferrosorp would be a low-cost and environmentally-sound sorbent for the treatment of phosphorous contaminated effluents and generated spent Ferrosorp could be used as potential fertilizer for enhancing crop-production.