Carbon nanodots (CNDs) are 0D quasi-spherical nanoparticles that are less than 10 nm in size. CNDs that possess surface functional groups such as hydroxyl, amino, and carboxyl groups have been demonstrated to scavenge free radicals efficiently and effectively, resulting in them being beneficial for cosmetic and cosmeceutical applications. In this study, we successfully prepared novel CNDs, namely black VC, using vitamin C (VC) as a promising precursor. Black VC was prepared by a facile one-step method based on short-time microwave irradiation. The properties of black VC were characterized by transmission electron microscopy (TEM) analysis, X-ray diffraction (XRD), high-resolution X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and UV–vis spectrophotometry. Radical scavenging, cell viability, and anti-pollution activity assays were also conducted to demonstrate the functionalities of black VC. The developed black VC exhibited lower cytotoxicity and better antioxidant, metal chelating ability, and anti-pollution activities than its precursor. These results provide a new approach for developing advanced antioxidants for innovative cosmetic formulations using a simple microwave treatment method. However, black VC retained some problems of its precursor in the form of low stability, which is likely to be a challenge for its cosmeceutical application.

Physical smothering in a long time and toxic components due to the oil spill and oil slick disasters can not only affect directly, very seriously marine creatures, plants and life of other animals but also they pollute the air environment and reduce the health of human. Some activities such as the waterway accidents, the tanker or bilge discharges, and the acts of wanton vandalism are the main causes that pollute the ocean environment. The regulations of many countries such as the prevention of oil spill, reducing maximally the effects of the oil spill, and speeding up the oil spill degradation are to aim at treating and recovering fast, efficiently oil spills and oil slicks. The selection of suitable techniques for oil spill recovery and treatment depends on many factors such as the spilled oil volume, oil type, weather conditions (wind velocity), sea conditions (current velocity and wave height), cost and the fact situations of each country. In this paper, four methods used for oil spill recovery including physical-, chemical-, thermal-, and biodegradation method are introduced. The structure of mechanical devices including booms, skimmers and absorbent materials, the properties of chemicals such as dispersants and solidifies, the methods based on the thermal technologies, the major microorganisms for oil degradation for oil spill recovery, treatment and cleanup are analyzed. Each mentioned method also shows the advantages and disadvantages, as well as its applicability. The selection of suitable method for oil spill recovery purpose on the basis of the available equipment and techniques must be ensure that the collected oil spill volume is the largest, the period of time for recovery process is the shortest, aiming at minimizing the negative effects on the human, marine ecosystem, social economy.

In order to study the change of pollution loads flowing into Mokpo harbour after the operation of Mokpo Municipal Sewage Treatment Plant (MMSTP) and to evaluate the contribution of MMSTP operation to the improvement of marine water quality of Mokpo harbour, the pollution loads flowing into Mokpo harbour from land in dry weather were surveyed and estimated on the bases of the seasonal flow rates and the seasonal water qualities of streams and effluents located around Mokpo harbour from summer, 1997 to spring, 1998 before the operation of MMSTP, and the pollution loads of the inflow and the effluent of MMSTP were also surveyed and estimated from winter, 1998 to spring, 1999 after the operation of MMSTP. The treatment rates of MMSTP were shown to be about 49% in COD, 76% in TSS, 79% in VSS, 3% in T-N, 7% in DIP, 29% in T-P and -32% in DIN. The change rates of pollution loads flowing into the inner harbour of Mokpo due to the operation of MMSTP were shown to be about 56% In COD, 78% in TSS, 84% in VSS, 45% in DIN, 22% in T-N, 34% in T-P and -14% in DIP. The contribution rates of MMSTP operation to the reduction of total pollution loads flowing into the entire Mokpo harbour were found to be about 3% in COD, 3% in 755,5% in VSS,1% in DIP, 3% in T-P and -1% in DIN.