Evaluation of approaches to quantify total residual oxidants in ballast water management systems employing chlorine for disinfection

Abstract

With the maturation and certification of several ballast water management systems that employ chlorine as biocide to prevent the spread of invasive species, there is a clear need for accurate and reliable total residual oxidant (TRO) technology to monitor treatment dose and assure the environmental safety of treated water discharged from ship. In this study, instruments used to measure TRO in wastewater and drinking water applications were evaluated for their performance in scenarios mimicking a ballast water treatment application (e.g., diverse hold times, temperatures and salinities). Parameters chosen for testing these technologies in the past do not reflect conditions expected during ballast water treatment. Salinity, temperature, and oxidant concentration all influenced the response of amperometric sensors. Oxidation reduction potential (ORP) sensors performed more consistently than amperometric sensors under different conditions but it may be difficult to correlate ORP and TRO measurements for the multitude of biogeochemical conditions found naturally in ballast water. N,N-diethyl-p-phenylenediamine (DPD) analyzers and amperometric sensors were also tested under intermittent sampling conditions mimicking a ballasting scenario, with cyclical dosage and discharge operations. When sampling was intermittent, amperometric sensors required excessive response and conditioning times, whereas DPD analyzers provided reasonable estimates of TRO under the ballasting scenario.

Combining ballast water treatment and ballast water exchange: Reducing colonization pressure and propagule pressure of phytoplankton organisms

“…While it will be difficult for crew and port authorities to analyze what species of organic carbon is in the water, the option exists to adjust the dose. In addition, it is possible to track free chlorine in real time using electronic sensors in the tanks (Zimmer-Faust et al 2014).…”

LED Module Calibration Strategy to Improve Measurement Accuracy of TRO Concentration

“…In the same way, we record the output frequencies of the green and blue wavelength region. The absorbance is calculated by substituting the two types of output frequencies measured in the 1st and 2nd order to the Beer's Lambert law and is shown in Equation (1). This law states that the negative logarithm of the ratio of the intensity of light incident on a material (I) and the intensity of transmitted light (I o ) is proportional to the absorbance of the transmission layer.…”

“…We know that the influx of alien species caused by the movement of ballast water to balance ships with the increase of international trade causes serious problems in the marine ecosystem [1,2]. For this reason, in 2004, the International Maritime Organization (IMO) adopted the "Convention on the Control and Management of Ballast Water and Sediment Emissions" [3].…”

Potentiometry for the determination of oxidant activity

“…Ozone and chlorine are challenging objects of study in terms of their oxidative properties and the use of chlorination and ozonation for disinfection of drinking water as well as water for swimming pools, and toxicity of residual chlorine and ozone. 22 On the other hand, ozone is considered a safe and environmentally friendly tool for the seafood industry, which is used to improve fresh seafood safety, 23 and its monitoring is also important here.…”