Non-conventional low-cost adsorbents for dye removal: A review

Application of low-cost adsorbents for dye removal – A review

Adsorption of methylene blue on low-cost adsorbents: A review

Biosorbents for heavy metals removal and their future

Application of chitosan, a natural aminopolysaccharide, for dye removal from aqueous solutions by adsorption processes using batch studies: A review of recent literature

A review of potentially low-cost sorbents for heavy metals

Current literature values of 2,4,6-trinitrotoluene (TNT) solubility in water vary widely from 100 to 200 mg/L at room temperature. We investigated the effects of temperature and pH on the solubility of both reference TNT and field neat TNT obtained from the Alabama Army Ammunition Plant (AAAP), Childersburg, AL. The TNT solubility determined from this study was significantly lower than that of Taylor and Rinkenbach, which was cited by several reference chemical handbooks and articles. However, the values reported by the Merck Index and the Lange's Handbook of Chemistry compared well with our values. TNT solubility dropped rapidly as the pH increased. Three unknown HPLC peaks were observed at high pH, indicating a possibility of forming unknown transformation products. Both reference and field neat TNT solubility agreed well. A semiempirical solubility correlation was developed to predict the solubility of TNT at a temperature range from 6 °C to 42 °C.

Solubility of 2,4,6-Trinitrotoluene (TNT) in Water

The purpose of this paper is to evaluate and analyze the kinetic data from both the laboratory and the field, and relate it to the Trinitrotoluene transport and biotransformation in the overall bioremediation process. Laboratory batch experiment results indicate that TNT dissolution mass transfer coefficients from TNT nuggets is 4.13 cm/h. The TNT desorption mass transfer coefficient from soil is 0.28 cm/h, and the TNT biotransformation rate constant in presence of Stonwort plant is 1.1 1/h.wt. In the field pool study the TNT biotransformation coefficient values fluctuate between 1.4–180 1/h.wt in presence of parrot feather plant. It has been found that the TNT dissolution and desorption rates are slower than biotransformation rate which leads to the main conclusion that TNT transport is controlling the overall bioremediation process.

Aquatic plant augmented TNT degradation : Analysis of reaction kinetics

A reasonable field‐scale operational scenario was developed as the hypothetical TNT bioremediation unit. II is described in Appendix A and termed the Riffle‐Pool Reactor. The two‐stage system consists of TNT leach‐bed followed by a plant‐pool bioreactor. Water is recirculated either continuously or intermittently over the riffle‐bed TNT extractor and into the plant‐pool reactor. A previously published manuscript entitled “Aquatic Plant Augmented TNT Degradation ‐ Analysis of Reactor's Kinetics”; contains the kinetic parameter estimates needed to estimate equipment design and operating parameters. This include the Monod rate constant, dissolution constants and other kinetic parameters. This manuscript demonstrates how that basic information is incorporated into the design of the pilot, field‐scale demonstration unit.

D. Dean Adrian

Papers

A review of potentially low-cost sorbents for heavy metals

Solubility of 2,4,6-Trinitrotoluene (TNT) in Water

Aquatic plant augmented TNT degradation : Analysis of reaction kinetics

A proposal for a field-scale pilot demonstration unit for bioremediation of TNT contaminated soil