Predictive modeling to determine oxygen and ozone doses applicable to in situ remediation of polluted water bodies

This work shows the results for the first time of calibrating and validating a mathematical model, capable of predicting the amounts of O3 and O2 necessary to reduce pollution levels in a lake based on the Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Total nitrogen (TN), Total phosphorus (TP) and Fecal coliforms (FC) concentrations. The model was designed to treat a natural or artificial lake as though it were an aerated lagoon operating as an idealized Continuous flow complete-mix reactor. The O3 yield constant for eliminating the non-biodegradable fraction of COD and for deactivating fecal coliforms were laboratory derived and calibrated with field values. Based on the field parameters, the model accurately predicted a reduction in BOD5, COD, TN, TP and FC of 53 %, 51 %, 39 %, 42 % and 98 %, respectively. The model proved to be effective in predicting O2 and O3 demand and time of recovery of a polluted water body.

Improved the in-Situ Remediation Effect of Sediment Microbial Fuel Cells by Optimizing the Anode Structure

Six 60-L benthic microbial electrochemical systems (BMES) were built for the bioremediation of river sediment. Carbon mesh anodes with honeycomb-structure supports were compared with horizontal anodes, and the system was tested using different cover depths and anode densities. The pollutant removal, electricity generation, and electrochemistry of the six BMES with different anodes was examined using the Ashi River (Harbin, China) as a case study. Total organic carbon (TOC) and total nitrogen (TN) removal from sediments in BMES with three-dimensional anodes were 20%~30% and 20%~33% higher for the other reactors. Moreover, the honeycomb-structure of the anode also resulted in higher power density and improved humus removal.

Reclamation of Abandoned Mine Soil: A Review on Properties and Remediation Techniques

The environment which is a part of ecosystem is being polluted due to urbanization, rapid industrialization increased demands for resources in our day to day lives have left no resources untouched. Various anthropogenic activities such as mining and milling operations, which include grinding, screening, concentrating ores and removal of tailings, disposal of mine and mill waste water release toxic metals into the natural environment affecting the lithosphere. Reclamation is the process of restoring the environmental soundness of these distressed mine lands. It consists of governing all kinds of physical, chemical and biological inconvenience of land area or soil such as fertility, pH, microbial activities and different soil nutrient cycles that make the destructed land soil fertile. The main aim of the reclamation is to bring back the fertility of soil by increasing its N, P, K values and Carbon contents. There are various remediation technologies available for removal of heavy metal from contaminated mine soil, in this paper we have discussed in-situ remediation, physical remediation, chemical remediation and biological remediation technologies which are implemented across the globe.