Sedimentary environment and relative sea level changes revealed by marine biological membrane.

Marine pollution has a deleterious impact, both on the conditions of the ecosystem and the biodiversity of the ocean. Researchers in the field of marine chemistry have been putting effort into the creation of efficient catalysts for the purification of seawater. There has been extensive research done on membrane technology for the activation of peroxymonosulfate, which is an extremely effective therapy for saltwater. The sediment of QX03, which was obtained from the western coast of Bohai, is located very close to the modern coastline. The uppermost 15 m of this sector were thoroughly analyzed in sedimentary petrology, grain size, shell, and sediment chroma dating to reconstruct the sedimentary environment and relative sea-level during the time period of 44.80 ka cal BP. This indicates that a sea-retreating and retreating process has taken place; VI (5.2-0 m), Terrestrial deposition, is separated into swamp wetlands (VI-1) and flood plain (VI-2). The changes in sedimentary levels had a fairly strong correlation with the changes in sea level. Within the scope of this study, we conducted an in-depth investigation of the innovative membrane technology for the treatment of seawater by means of aqueous phase advanced oxidation close to the Bohai. The results of this study present a prospective technique that could make it possible to use membrane technology in the process of environmental restoration in marine settings.

137Cs and 239+240Pu in the Bohai Sea of China: Comparison in distribution and source identification between the inner bay and the tidal flat.

We investigated artificial radionuclides (239+240Pu and 137Cs) in surface sediments and sediment cores collected from the Bohai Bay and the tidal flat of the Liaodong Bay, China. Increasing trends for 239+240Pu activities and 240Pu/239Pu atom ratios (˃0.18) were observed from land to sea and from north to south in the Bohai Bay. This spatial pattern implied that the scavenging process between riverine sediments and Pacific Proving Ground (PPG) source Pu transported by the currents such as Yellow Sea Warm Current had occurred in the Bohai Bay. In contrast, relatively lower 240Pu/239Pu atom ratios in the tidal flat of Liaodong Bay were due to the mixing process between more global out and less PPG source Pu. The riverine Pu contributions to the total global fallout Pu in the Haihe River (32.8%) were much lower than those in the Yangtze River estuary (77%-80%), indicating better soil conservation in the Haihe River Catchment.

Historical variation in black carbon deposition and sources to Northern China sediments.

Black carbon (BC) in fine particulate matter (PM2.5) is an important air pollutant in a large area of China. We have reconstructed a 100-year-long history of BC deposition based on analyses of sediment samples in the coastal area of the Northern China Plain (NCP). During 1900-2010, the sedimentary BC concentrations at three cores increased from 0.2 to 1.3, from 0.2 to 2.3, and from 0.2 to 1.9 mg g-1, and the ranges for the BC deposition fluxes were 0.1-4.7, 0.1-8.2, 0.2-7.4 g m-2 a-1, suggesting the increase of ten times from the pre-industrial era. The BC deposition fluxes showed abrupt variation with two peaks in the 1970s and 2010s. Residential energy consumption and biomass burning (i.e., low-temperature combustion sources; thus, large-scale wildfires with high temperature may not be included) were responsible for the BC increase in the 1970s. Fossil fuel combustion generated by the industrial sectors, including industry, power plants, and transportation, was negligible before 1990 but significantly increased during 1990-2010. The historical increase in the BC deposition was accurately predicted by climate models, specifically the Coupled Model Intercomparison Project Phase 5 (CMIP5). However, the BC fluxes in the NCP sediments were an order of magnitude greater than those of the simulated depositions, suggesting an underestimation of the BC deposition in the severely polluted area in China.

Plio-Pleistocene evolution of Bohai Basin (East Asia): demise of Bohai Paleolake and transition to marine environment.

The Bohai Basin was transformed to an inner shelf sea hundreds of thousands years ago. This youngest land-sea transition participated in the significant modification of the distribution of fresh water, sediment fluxes and climate in East Asia, and played an important role in the origin of the Asian marginal seas. Here we present the results of a magnetostratigraphic investigation and propose a conceptual model for the land-sea transition. Our findings indicate that the transition probably started several million years ago, from a fluvial system during the late Miocene and early Pliocene, to a lacustrine environment between the late Pliocene and Middle Pleistocene, and finally to a marine system in the late Pleistocene. Comparison of our results with previous research suggests that the Bohai Paleolake was initiated from the late Pliocene, was fully developed prior to ~1.0 Ma, and terminated around the late Middle Pleistocene. The Miaodao Islands formed the eastern "barrier" of the basin and since the Pliocene or earlier they played a significant role in blocking the lake water and sediments. They deformed from ~1.0 Ma, subsided significantly at ~0.3 Ma and completely by ~0.1 Ma, resulting in the maturation of the basin as an inner shelf sea.