A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling t...A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling tower blow-down, plating, electroplating, rinse water sources, anodizing baths etc. are the main sources of Cr (VI) contamination. The Cr (VI) is not only non-biodegradable in the environment but also carcinogenic to living population. It is still difficult to treat Cr contaminated waste water effectively, safely, eco-friendly, and economically. As a result, many techniques have been used to treat Cr (VI)-polluted wastewater, including adsorption, chemical precipitation, coagulation, ion-exchange, and filtration. Among these practices, the most practical method is adsorption for the removal of Cr (VI) from aqueous solutions, which has gained widespread acceptance due to the ease of use and affordability of the equipment and adsorbent. It has been revealed that Fe-based adsorbents’ oxides and hydroxides have high adsorptive potential to lower Cr (VI) content below the advised threshold. Fe-based adsorbents were also discovered to be relatively cheap and toxic-free in Cr (VI) treatment. Fe-based adsorbents are commonly utilized in industry. It has been discovered that nanoparticles of Fe-, Ti-, and Cu-based adsorbents have a better capacity to remove Cr (VI). Cr (VI) was effectively removed from contaminated water using mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.). Initial findings suggest that Cr (VI) removal from wastewater may be accomplished by using magnesium ferrite nanomaterials as an efficient adsorbent.展开更多
A variety of wastes are generated due to human activities. Organic waste usage in agriculture plays a significant role in the steady supply of plant nutrients through improving soil quality. An in vitro incubation stu...A variety of wastes are generated due to human activities. Organic waste usage in agriculture plays a significant role in the steady supply of plant nutrients through improving soil quality. An in vitro incubation study was conducted to measure the release of the major nutrients viz. available nitrogen (N), phosphorus (P), and potassium (K) in alkaline soil amended by recycled organic soil conditioners. The soil was amended by compost (Cm) and vermicompost (VC) @5 tha<sup>−1</sup> and a mixture of compost and vermicompost (Cm + VC) @2.5 tha<sup>−1</sup>. Chemical fertilizers (Cf) were added @of 98.842 kg⋅ha<sup>−1</sup> of urea and 64.99 kg⋅ha<sup>−1</sup> of triple superphosphate (TSP), with amended soils being incubated for 120 days maintaining 50% field moisture holding capacity. Due to the sufficient content of potassium in experimental soil for plant growth, extra potassium was not added. Available soil N, P, and K were determined at every 0, 15, 30, 45, 60, 90, and 120 days of incubation. The highest available N and K release was found in VC treated soils at the incubation period of 45 days. On the other hand, the highest P release was recorded in Cm treated soils at the incubation period of 45 days. In this experiment, the addition of Cm, VC and Cm + VC showed better release of cumulative plant available N, P and K than either control (C) or Cf and were arranged as VC > Cm > Cm + VC > Cf > C, Cm > Cm + VC > VC > Cf > C and Cm + VC > VC > Cm > C > Cf for N, P and K, respectively. The results of this experiment revealed that the addition of compost and/or vermicompost is predominant over chemical fertilizer in supplying of major nutrients for crops in alkaline soil.展开更多
文摘A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling tower blow-down, plating, electroplating, rinse water sources, anodizing baths etc. are the main sources of Cr (VI) contamination. The Cr (VI) is not only non-biodegradable in the environment but also carcinogenic to living population. It is still difficult to treat Cr contaminated waste water effectively, safely, eco-friendly, and economically. As a result, many techniques have been used to treat Cr (VI)-polluted wastewater, including adsorption, chemical precipitation, coagulation, ion-exchange, and filtration. Among these practices, the most practical method is adsorption for the removal of Cr (VI) from aqueous solutions, which has gained widespread acceptance due to the ease of use and affordability of the equipment and adsorbent. It has been revealed that Fe-based adsorbents’ oxides and hydroxides have high adsorptive potential to lower Cr (VI) content below the advised threshold. Fe-based adsorbents were also discovered to be relatively cheap and toxic-free in Cr (VI) treatment. Fe-based adsorbents are commonly utilized in industry. It has been discovered that nanoparticles of Fe-, Ti-, and Cu-based adsorbents have a better capacity to remove Cr (VI). Cr (VI) was effectively removed from contaminated water using mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.). Initial findings suggest that Cr (VI) removal from wastewater may be accomplished by using magnesium ferrite nanomaterials as an efficient adsorbent.
文摘A variety of wastes are generated due to human activities. Organic waste usage in agriculture plays a significant role in the steady supply of plant nutrients through improving soil quality. An in vitro incubation study was conducted to measure the release of the major nutrients viz. available nitrogen (N), phosphorus (P), and potassium (K) in alkaline soil amended by recycled organic soil conditioners. The soil was amended by compost (Cm) and vermicompost (VC) @5 tha<sup>−1</sup> and a mixture of compost and vermicompost (Cm + VC) @2.5 tha<sup>−1</sup>. Chemical fertilizers (Cf) were added @of 98.842 kg⋅ha<sup>−1</sup> of urea and 64.99 kg⋅ha<sup>−1</sup> of triple superphosphate (TSP), with amended soils being incubated for 120 days maintaining 50% field moisture holding capacity. Due to the sufficient content of potassium in experimental soil for plant growth, extra potassium was not added. Available soil N, P, and K were determined at every 0, 15, 30, 45, 60, 90, and 120 days of incubation. The highest available N and K release was found in VC treated soils at the incubation period of 45 days. On the other hand, the highest P release was recorded in Cm treated soils at the incubation period of 45 days. In this experiment, the addition of Cm, VC and Cm + VC showed better release of cumulative plant available N, P and K than either control (C) or Cf and were arranged as VC > Cm > Cm + VC > Cf > C, Cm > Cm + VC > VC > Cf > C and Cm + VC > VC > Cm > C > Cf for N, P and K, respectively. The results of this experiment revealed that the addition of compost and/or vermicompost is predominant over chemical fertilizer in supplying of major nutrients for crops in alkaline soil.
