Treatment of Bilge Water by Fenton Oxidation Followed by Granular Activated Carbon Adsorption

Due to its high oil content, the discharge of bilge water from ships is one of the most important pollutants in marine ecosystem. In this research, we investigated the treatment of bilge water for Haydarpasa Waste Collection Plant by Fenton oxidation followed by granular activated carbon (GAC) adsorption. We applied the following optimum operational conditions for Fenton oxidation: [Fe2+]: 6 mM; [H2O2]: 30 mM; and the ratio of [Fe2+]/[H2O2]: 1/5. Adsorption was performed in the effluent sample of Fenton oxidation. The effects of different adsorption periods, adsorbent concentrations, temperature, and pH were examined. Additionally, Freundlich and Langmuir isotherm models were applied. We obtained the following optimum operational conditions: 24 h, 2 g of GAC L−1, 20 °C, and pH = 6. We observed an 89.5 ± 1.9% of Chemical Oxygen Demand (COD) removal efficiency under these conditions. Data generated from the experiments fit both isotherm models well, though we preferred the Langmuir isotherm model to the Freundlich isotherm model because the former’s regression coefficient (0.90) was larger than that reported for the Freundlich isotherm model (0.78). The potential to treat bilge water by Fenton oxidation followed by granular activated carbon is promising for the Haydarpasa Waste Collection Plant.

Untapped Potential of Moving Bed Biofilm Reactors with Different Biocarrier Types for Bilge Water Treatment: A Laboratory-Scale Study

Two labscale aerobic moving bed biofilm reactor (MBBR) systems, with a different type of biocarrier in each (K3 and Mutag BioChip), were operated in parallel for the treatment of real saline bilge water. During the operation, different stress conditions were applied in order to evaluate the performance of the systems: organic/hydraulic load shock (chemical oxygen demand (COD): 9 g L-1; hydraulic retention time (HRT): 48–72 h) and salinity shock (salinity: 40 ppt). At the same time, the microbiome in the biofilm and suspended biomass was monitored through 16S rRNA gene analysis in order to describe the changes in the microbial community. The dominant classes were Alphaproteobacteria (families Rhodospirillaceae and Rhodobacteraceae) and Bacteroidia (family Lentimicrobiaceae), being recorded at high relative abundance in all MBBRs. The structure of the biofilm was examined and visualized with scanning electron microscopy (SEM) analysis. Both systems exhibited competent performance, reaching up to 86% removal of COD under high organic loading conditions (COD: 9 g L-1). In the system in which K3 biocarriers were used, the attached and suspended biomass demonstrated a similar trend regarding the changes observed in the microbial communities. In the bioreactor filled with K3 biocarriers, higher concentration of biomass was observed. Biofilm developed on Mutag BioChip biocarriers presented lower biodiversity, while the few species identified in the raw wastewater were not dominant in the bioreactors. Through energy-dispersive X-ray (EDX) analysis of the biofilm, the presence of calcium carbonate was discovered, indicating that biomineralization occurred.

Reagent treatment of bild water in ship separators

В работе представлены результаты экспериментальных исследований флотационной очистки судовых льяльных вод. Установлена целесообразность предварительной реагентной обработки судовых льяльных вод, направляемых на флотационную очистку. В качестве реагентов апробированы высокомолекулярные флокулянты: Праестол 852, Праестол 853 и К 1020. Определен наиболее эффективный флокулянт – Праестол 852. Обоснована целесообразность применения во флотационных машинах судовых сепараторов диспергаторов воздуха, выполненных из синтетического каучука. Использование синтетического каучука позволяет повысить эффективность извлечения нефтяных загрязнений, а также обеспечить бесперебойность и долговечность работы установки. Методом анализа размерностей получено критериальное уравнение процесса флотации нефтяных загрязнений из раствора льяльных вод. Исследовано влияние следующих технологических параметров процесса: интенсивности подачи воздуха, высоты слоя обрабатываемой жидкости, физико-химических характеристик жидкости, расхода воздуха и льяльной воды. Разработана математическая модель процесса флотации. Определены оптимальные параметры процесса. The paper presents the results of experimental studies of flotation treatment of ship bilge waters. The expediency of preliminary reagent treatment of ship bilge water sent for flotation treatment has been established. High molecular weight flocculants were tested as reagents: Praestol 852, Praestol 853. K 1020. The most effective flocculant, Praestol 852, has been determined. The expediency of using in flotation machines of ship separators of air dispersers made of synthetic rubber has been substantiated. The use of synthetic rubber makes it possible to increase the efficiency of the extraction of oil contaminants, as well as to ensure the uninterrupted and durable operation of the installation. The criterion equation of the process of flotation of oil pollution from a bilge water solution was obtained by the method of dimensional analysis. The influence of the following technological parameters of the process was investigated: the intensity of the air supply, the height of the treated liquid layer, the physicochemical characteristics of the liquid, the air and bilge water consumption. A mathematical model of the flotation process has been developed. The optimal parameters of the process have been determined.

Oil–Water Separation Techniques for Bilge Water Treatment

Discharging accumulated bilge water from the ship is very important in order to maintain its stability and safety. However, the bilge water that contains contaminants, including waste oils and oily wastes, must be treated prior discharging to the sea. The International Convention for the Prevention of Pollution from Ships (MARPOL) has set strict oil discharge limit in order to minimize sea pollution. Thus, an efficient oil–water separator must be installed to separate the oil from the bilge water. This chapter introduces and discusses the working mechanisms, as well as advantages and disadvantages of the available oil–water separation techniques for bilge water treatment, which include gravitational, centrifugation, flotation, coagulation and flocculation, biological processes as well as absorption and adsorption.

Statistical Modeling of Bilge Water Discharge from Ships During Normal Operation

This study estimated the amount of bilge water spilled from ships during normal operation and identified the contributing factors of the discharge by building a statistical model. To build the statistical model, we collected as much information as possible about the amount of bilge water in ships, then used the collected information to formulate a probability distribution of the discharge amount according to Bayesian statistics, and determined the parameters included in the model by applying a Markov Chain Monte Carlo method. The analysis of those parameters shows that the integrated bilge treatment system (IBTS) primarily contributes to reductions in the discharge amount, and that the container-type ship is involved with especially large discharge amounts.