Interaction of Ca and Fe in co-precipitation process induced by Virgibacillus dokdonensis and its application.

Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods. The reinjection water from oilfields containing an exceedingly high concentration of calcium and ferric ions will pose a major hazard in production. However, the utilization of biomineralization for precipitating these ions has been scarcely investigated due to limited tolerance among halophiles towards such extreme conditions.

Co-removal and recycling of Ba and Ca in hypersaline wastewater based on the microbially induced carbonate precipitation technique: Overlooked Ba in extracellular and intracellular vaterite.

This study investigates the co-precipitation of calcium and barium ions in hypersaline wastewater under the action of Bacillus licheniformis using microbially induced carbonate precipitation (MICP) technology, as well as the bactericidal properties of the biomineralized product vaterite. The changes in carbonic anhydrase activity, pH, carbonate and bicarbonate concentrations in different biomineralization systems were negatively correlated with variations in metal ion concentrations, while the changes in polysaccharides and protein contents in bacterial extracellular polymers were positively correlated with variations in barium concentrations. In the mixed calcium and barium systems, the harvested minerals were vaterite containing barium.

Effect of Ba on the biomineralization of Ca and Mg ions induced by Bacillus licheniformis.

The effect of barium ions on the biomineralization of calcium and magnesium ions is often overlooked when utilizing microbial-induced carbonate precipitation technology for removing barium, calcium, and magnesium ions from oilfield wastewater. In this study, Bacillus licheniformis was used to bio-precipitate calcium, magnesium, and barium ions. The effects of barium ions on the physiological and biochemical characteristics of bacteria, as well as the components of extracellular polymers and mineral characteristics, were also studied in systems containing coexisting barium, calcium, and magnesium ions.

Interaction of microorganisms with carbonates from the micro to the macro scales during sedimentation: Insights into the early stage of biodegradation.

The assembly process of Organic Matter (OM) from single molecules to polymers and the formation process of Ca-CO ion-pairs are explored at the micro-scale, and then the relationship between OM and carbonate based on the results of microbially-induced carbonate precipitation (MICP) laboratory experiments is established at the macro-scale. Molecular dynamics (MD) is used to model the assembly of OM (a) in an aqueous solution, (b) on surfaces of calcite (10 1‾ 4) crystals and (c) on defective calcite (101‾ 4) crystal surfaces. From the MICP experiments, carbonate minerals containing abundant OM were precipitated and were characterized by Scanning Electron Microscopy (SEM), X-Ray Diffractometry (XRD) and Fourier Transform Infrared Spectroscopy (FTIR).

Microbial-mineral interaction experiments and density functional theory calculations revealing accelerating effects for the dolomitization of calcite surfaces by organic components.

Carbonates represent major sedimentary rocks in on the continental and oceanic crust of Earth and are often closely related to microbial activities. However, the origin of magnesium-containing carbonates, such as dolomites, has not yet been fully resolved and was debated for many years. In order to reveal the specific role of organic components and microbes on the precipitation of magnesium ions, different dolomitization experiments were carried out with various setups for the presence of eight amino acids and microbes.

Mn recycling in hypersaline wastewater: unnoticed intracellular biomineralization and pre-cultivation of immobilized bacteria.

Microbially induced manganese carbonate precipitation has been utilized for the treatment of wastewater containing manganese. In this study, Virgibacillus dokdonensis was used to remove manganese ions from an environment containing 5% NaCl. The results showed a significant decrease in carbonic anhydrase activity and concentrations of carbonate and bicarbonate ions with increasing manganese ion concentrations.

Distribution, contamination and provenance of heavy metals in sediments from the nearshore area of Weihai City, eastern Shandong Peninsula, China.

We analyzed eight heavy metals (Cu, Pb, Zn, Cr, Cd, Hg, As, and Ni) in 85 seabed sediments off the coast of Weihai City, eastern Shandong Peninsula, China, to reveal their distributions, enrichment status, and pollutant sources. Cu, Pb, Zn, Cr, As, and Ni were enriched in all bays in both the inner and outer waters. However, Cd and Hg were more abundant in Weihai Bay, followed by Rongcheng Bay and Chaoyang Port, with denser populations and more developed industries near the coast.

The incorporation of Mg ions into aragonite during biomineralization: Implications for the dolomitization of aragonite.

Bacteria can facilitate the increase of Mg content in biotic aragonite, but the molecular mechanisms of the incorporation of Mg ion into aragonite facilitated by bacteria are still unclear and the dolomitization of aragonite grains is rarely reported. In our laboratory experiments, the content of Mg ions in biotic aragonite is higher than that in inorganically-precipitated aragonite and we hypothesize that the higher Mg content may enhance the subsequent dolomitization of aragonite. In this study, biotic aragonite was induced by Y at different Mg/Ca molar ratios.

Calcium ion removal at different sodium chloride concentrations by free and immobilized halophilic bacteria.

Much attention has been paid to Ca ion removal by biomineralization due to the dangers of Ca on industrial processes and human health. However, Ca removal from hypersaline water by biomineralization is quite difficult due to there being few halophilic bacteria tolerating higher salinities. In this study, free and immobilized Virgibacillus massiliensis C halophilic bacteria exhibiting carbonic anhydrase activity were used to remove Ca ions from water at different NaCl concentrations.

Sources and cycling of dissolved organic and inorganic carbon on the northern Qinghai-Tibetan Plateau: Radiocarbon results from Qinghai Lake.

Tibetan Plateau lakes are sensitive to climate variabilities and affect regional temperature, precipitation and ecosystems. In this study, we investigated the concentrations and carbon isotope (C and C) compositions of dissolved organic and inorganic carbon (DOC and DIC) along with the concentrations of major lithologic ions (Na, Mg, K, Ca) and dissolved silicate (DSi) in a large lake, namely, Qinghai Lake, and its seven inflowing rivers on the northeastern Qinghai-Tibetan Plateau of China. Our results revealed large differences in concentrations and isotopic compositions between DOC and DIC, as well as differences in the concentrations of major ions between the rivers and lake.

Difference in calcium ion precipitation between free and immobilized Halovibrio mesolongii HMY2.

Biomineralization has become a research focus in wastewater treatment due to its much lower costs compared to traditional methods. However, the low sodium chloride (NaCl)-tolerance of bacteria limits applications to only water with low NaCl concentrations. Here, calcium ions in hypersaline wastewater (10% NaCl) were precipitated by free and immobilized Halovibrio mesolongii HMY2 bacteria and the differences between them were determined.

Calcium ion biorecovery from industrial wastewater by Bacillus amyloliquefaciens DMS6.

Calcium ions in industrial wastewater needs to be removed to prevent the production of limescale, which can have negative consequences. Biomineralization has become the focus due to its lower costs than traditional methods of remediation. In this study, calcium ions were bio-precipitated under the action of free and immobilized Bacillus amyloliquefaciens DMS6 bacteria, and the calcium ion removal efficiency was also compared.

Dissolved black carbon is not likely a significant refractory organic carbon pool in rivers and oceans.

Rivers are the major carriers of dissolved black carbon (DBC) from land to ocean; the sources of DBC during its continuous transformation and cycling in the ocean, however, are not well characterized. Here, we present new carbon isotope data for DBC in four large and two small mountainous rivers, the Yangtze and Yellow river estuaries, the East China Sea and the North Pacific Ocean. We found that the carbon isotope signatures of DBC are relatively homogeneous, and the DBC C ages in rivers are predominantly young and increase during continuous transport and cycling in the ocean.

Sources and sink of black carbon in Arctic Ocean sediments.

The concentrations and carbon isotopic (C, C) compositions of total organic carbon (TOC) and black carbon (BC) were measured for four sediment cores collected from the shelf to slope in the Arctic Ocean. Contents of TOC and BC ranged from 0.46% to 1.