The main objective of this work is to conduct literatures reviews of the in-situ analysis techniques for future development and regulation. Also, although using carbon nanotubes (CNTs) electrodes for gas and biochemical sensing has been studied extensively, there are very little researches related to using such electrodes for the environmental water quality analysis. Another goal of this work is to reviewworks of electrochemical analysis by CNTS electrode and water quality analysis by electrochemical methods.We have collected various in-situ monitoring techniques for BOD, CODand ammonia. The mechanisms, advantages and disadvantages have also been discussed. With the advances in data storage, BOD can be determined within few hours to 3 days by measuring the oxygen uptake frequently and analyzing the data by model fitting. The literature review of carbon nanotube electrodes has focused on theperformance of composite metal/CNTS electrodes, effects of functional groups/polymers on the signals, and COD analysis via TiO2. TiO2/MWCNTs composite particles have been synthesized. The printed-screen carbon electrode has been modified by raw MWCNTs, acid-treated MWCNTs and TiO2/MWCNTs. All three modified electrodes were used to conduct cyclic voltammetry (CV) and linear sweep voltammetry (LSV) for the modeled COD solutions made of KHP or glucose.The results showed that, for the KHP solution, the peak current has good correlation to the COD concentration. The electrode modified by TiO2/MWCNTs has the best performance. However, such good correlation were not found, which may be because the peak currents were too small. The LSV of the wastewater of four industries are different. This suggests that analysis of COD by measuring the current at a fixed applied voltage may underestimate the COD.

cyclic voltammetry, linear sweep voltammetry, chemical oxygen demand