Remediation of Kalyani River water using plant-bacterial cell synergism

The purpose of this research was to evaluate the potential of plant-immobilized bacterial cells synergism for enhanced remediation of polluted river water. The polluted river water sample was collected from Kalyani river, Uttarakhand, India and characterized by high concentration of COD (1010 mg/l), BOD (230 mg/l), NO3−-N (30 mg/l), PO43−-P (48.9 mg/l), and Pb(1.028 mg/l). This water sample was treated on a lab scale with immobilized bacterial cells and Epipremnum aureum in various treatment setups. The treatment system 3 using a combination of immobilized bacterial cells and Epipremnum aureum had the highest pollutant removal efficiency of all the treatment setups tested. At 96 hours, the total COD, BOD, NO3−-N, PO43−-P and Pb contents of polluted river water sample were reduced to 60 mg/l, 20 mg/l, 2.4 mg/l, 11.7 mg/l, and 0.065 mg/l, respectively. Based on the findings, it is possible to conclude that utilizing plant-immobilized bacterial cell synergism is an environmentally friendly and cost-effective approach for enhanced remediation and rejuvenation of polluted river water. Furthermore, a field-scale application of plant-immobilized bacterial cell synergism via floating wetland construction for on-site treatment of contaminated water on the Kalyani river is recommended.

Interfacial Mass Transfer in Trichloroethylene/Surfactants/ Water Systems: Implications for Remediation Strategies

The fate of dense non-aqueous phase liquids (DNAPLs) in the environment and the consequential remediation problems have been intensively studied over the last 50 years. However, a scarce literature is present about the mass transfer at the DNAPL/water interface. In this paper, we present a fast method for the evaluation of the mass transfer performance of a surfactant that can easily be employed to support an effective choice for the so-called enhanced remediation strategies. We developed a lab-scale experimental system modelled by means of simple ordinary differential equations to calculate the mass transfer coefficient (K) of trichloroethylene, chosen as representative DNAPL, in the presence and in the absence of two ethoxylated alcohols belonging to the general class of Synperonic surfactants. Our findings revealed that it exists an optimal surfactant concentration range, where K increases up to 40% with respect to pure water.

Remediation of High Concentration Chromium Contaminated Soil by Enhanced Electrodynamic Method

High concentration of chromium salt has caused serious pollution to the environment since its production. The long-standing chromium residue has polluted the soil, and the total chromium concentration of some polluted soil has reached 30000 mg / kg. For the remediation of chromium contaminated soil, the enhanced electrodynamic method was proposed. In order to improve the efficiency of electrokinetic remediation of chromium contaminated soil, two enhanced electrokinetic remediation technologies were proposed: Electrokinetic oxidation enhanced remediation technology and electrokinetic enhanced remediation technology. (III) in soil was polluted by oxidant chromium oxide to increase the content of dissolved (VI),so as to improve the efficiency of electric repair, in order to find a suitable PRB medium as a breakthrough to improve the repair efficiency. The experimental results show that compared with the traditional electrodynamic technology, the enhanced electrodynamic method can effectively improve the removal rate of total chromium in the soil, and provide technical support for the enhanced electrodynamic remediation of chromium contaminated soil. The pH control system makes the pH of anode and cathode electrolyte always maintain acidic, and the H+ migration speed is faster than that of OH-, and the pH of soil near the anode is lower than that near the cathode.