Factors influencing the purification efficiency of photosynthetic bacteria

One strain of photosynthetic bacteria (PSB) was isolated from substrate sludge offresh-water fishpond. Influence of the use level of PSB culture solution, illumination condition,temperature, salinity, the use level of copper sulfate and dipterex on the purification efficiency was investigated. The results showed that the optimum use level of PSB culture solution was 10 mg/L,and the purification efficiency at illumination was higher than that at black, and if the temperature was lower than 15℃, or the use level of sodium chloride, copper sulfate and dipterex were higherthan 10 000 mg/L, 0.4 mg/L and 2.0 mg/L, respectively, the purification efficiency dropped distinctly.     

Biomarkers in fluid inclusions of polymetallic deposit of Qixiashan, Nanjing

Conclusions Organic fluid involved in Pb-Zn mineralization in the polymetallic deposit of Qixiashan probably derives from bacteria and algae, and is similar to that of the mature crude oil system. Part of lead and zinc in fluids can be transported by organic complexes, while their precipitation is caused by organic reduction. Biomarkers in ores can indicate the source of organic matter in fluids, but organic matter in inclusions must be studied to ascertain organic metallogenesis because of the EOM difference between ores and inclusions. The host strata of Upper Carboniferous (C2) and Lower Permian (PI) in Qixiashan deposit are both oil-bearing in the region. Identification of organic fluid and its biomarkers in the deposit provides significant information for further studies on the relationship between ore deposits and oil pools in the region.     

Experimental study of gold distribution in the algae-organic matter-fluid system

Conclusion Gold distribution and transformation in algae-organic matter-fluid system is very complicated. Gold is first concentrated in kerogen after algae died. With the increase of dissolved organic matter owing to the increase of temperature and pressure, part of gold simultaneously emigrates from kerogen to DOM. When DOM forms organic fluid and emigrates from the strata, gold is simultaneously carried away by organic fluid in acidic condition, but by water in alkali condition. When the auriferous fluid flows through carbonaceous strata, gold in fluid is unloaded by kerogen. Gold migration in the system, accompanied by the evolution of algae-organic matter-fluid, provides the basic information of biometallogenetic evolution of gold.     

Effects of hydrolysis and bacterial degradation in the cells on hydrocarbons and biomarkers generated by pyrolysis of green algaChlorella protothecoides

The relative contents of normal alkanes and isoprenoid alkanes from pyrolysed pmducts of green algaChlorella protothecoides increased when the algal cell subject to hydrolysis and bacterial degradation were wed. Their value of C₂₃-/C ₂₄+ and the rate of Pr/C₁₇ increased greatly whereas the contents of C₂₀ alkenes were remarkably low compared with that from untreated sample (as control). These results are more analogous to the formation process of hydrocarbons derived from algae in natural geological environment.     

碳酸盐岩烃源岩有机岩石学特点和有机组分分类

采用反光、透光、荧光和透射电镜相结合，全岩光片和干酪根光片相对比的有机岩石学方法，对我国不同时代碳酸盐烃源岩有机岩石学特点和有机组分特征进行了分析，并提出碳酸盐烃源岩有机组分分类。     

Sedimentary records of black carbon in the sea area of the Nansha Islands since the last glaciation

Core 17962 taken from the sea area of the Nansha Islands recorded a sedimentary history of more than 30 000 years. The black carbon data from the core, which can inform us of the history of vegetation fires, show that during the last glaciation, especially during the last glacial maximum at about 18 kaBP, the fluctuation of the concentration and accumulation rate of the black carbon was relatively great, whereas it was small during the Holocene. The isotope composition of the black carbon indicates that the precursors of black carbon were mainly grasses from the last glaciation to the Holocene. The sub-alpine and alpine vegetation zones covered mainly with grass and bush on the lands around the southern South China Sea were probably the sources of black carbon. The altitudinal vegetation changes from the last glaciation to the Holocene gave rise to the changes of the sedimentary characteristics of black carbon.     

High-resolution sedimentary record of hydrocarbon contaminants in a core from the major reaches of the Pearl River, China

The concentrations and compositions of hydrocarbon contaminants, and molecularmarker indices in modern sediments from a core in the major reaches of the Pearl River were investigated. The sedimentary record of hydrocarbons in the core, in combination with 210pb-dating,was used to reconstruct the pollution history of hydrocarbon pollutants in the Pearl River in the past 100 years.     

Identification of long chain isoprenoid hydrocarbons from pyrolytic product ofDunaliella

In the pyrolytic research on Dunaliella salina cultured under natural conditions, abundant long chain regular isoprenoid hydrocarbons have been first detected and identified from algal pyrolytic product. Specially, the discovery of high abundant 2,6,10,14,18-pentamethyle-icosane indicated that regular iC25 probably originated from specific holophilic algae in hyper-saline environments. The result gave new referable evidence both for the distinguishment of biological origins of long chain isoprenoids found in sediments and petroleum and for the judgement of paleoenvironments.     

Characteristics and possible origins of atmospheric monoterpenes from nonliving plants in Guangzhou

Monoterpenes in ambient air were determined in various sites in Guangzhou, and it was revealed that monoterpene concentrations in some special sites, like landfills, were even higher than those in locations with much more vegetation. On the average, monoterpene contents in samples from streets and highways were 1.9 μg/m3; from gardens, plantations and wooded lands, 2.2 μg/m3; from farmlands, 1.5 μg/m3; but from landfills, 4.1 μg/m3. So other sources like landfills, apart from living plants, might also contribute to the biogenic non-methane hydrocarbons (NMHCs) in the atmospheric environment. On the other hand, the composition pattern of monoterpenes in air samples from landfills were obviously different compared with those from living plants, this might result from the different synthesis pathways of monoterpenes, the oxygen-depleted environment and the microbiogenic process might affect the synthesis in landfills.     

Dating hydrocarbon generation and migration based on bitumen reflectance

On the basis of thermal maturation theories of organic matter in sediments and an improved Karweil’s method, a method for dating hydrocarbon generation and migration by means of bitumen reflectance has been suggested. A few representative boreholes in the Tazhong Area of the Tarim Basin was investigated by this method. The results indicate that the three phases of bitumen from the Tazhong Area formed during Middle and Late Ordovician, Late Cretaceous-Early Tertiary, and Late Tertiary, respectively. This implicates that there were three phases of hydrocarbon generation and migration occurring in this area during geological history. This study provided a new idea for the geological application of geochemical data of bitumen.