Effects of mussel shell addition on the chemical and biological properties of a Cambisol

The use of a by-product of the fisheries industry (mussel shell) combined with cattle slurry was evaluated as soil amendment, with special attention to the biological component of soil. A wide number of properties related to soil quality were measured: microbial biomass, soil respiration, net N mineralization, dissolved organic carbon, dissolved organic nitrogen, dissolved inorganic nitrogen, dehydrogenase, β-glucosidase, urease and phosphomonoesterase activities. The amendments showed an enhancement of soil biological activity and a decrease of aluminium held in the cation exchange complex. No adverse effects were observed on soil properties. Given that mussel shells are produced in coastal areas as a by-product and have to be managed as a waste and the fertility constraints in the local soils due to their low pH, our research suggest that there is an opportunity for disposing a residue into the soil and improving soil fertility.     

Holocene dynamics of invertebrate fauna in the littoral zone of Adak,the Aleutian Islands,according to archaeozoological data

Studies on invertebrate remains from the cultural layer of an ancient Aleut settlement on Adak Island have shown that the faunistic composition of invertebrates in the study area had not changed significantly during the Late Holocene. The traditional mode of natural resource use by the ancient Aleuts had no impact on the abundance of valuable species and biodiversity in general. Changes in the temperature regime were found to have taken place in the history of deposit formation. The period from the 8th to the mid-11th century was relatively cold. Climate warming took place between the mid-11th and the mid-12th centuries and between the mid-16th and the 19th centuries, with an intervening cooling period (from the mid-12th to the mid-16th century). This cooling was most distinct between the 15th and the mid-16th centuries.     

化学活化法制备麻疯树果壳活性炭的实验研究

以麻疯树果壳为原料,KOH为活化剂,通过化学活化法制备活性炭。考察了反应温度、反应时间和碱炭比（KOH与麻疯树果壳炭化料的质量比）等因素对活化结果的影响,并利用N2吸附和BET等现代分析测试方法来表征活性炭的结构特征。结果表明,化学活化法制备的活性炭吸附剂性能较好,且当活化温度为850℃,活化时间为240min,碱炭比R=4时制得活性炭产品的质量最好;化学活化法制备的活性炭为微孔吸附剂,在最佳条件下得到最大的碘吸附值和比表面积分别为2218．44mg／g和1890m^2／g。     

改性花生壳对水中镉的动态吸附研究

采用高锰酸钾改性花生壳吸附剂对镉离子进行固定床吸附实验,考察了床层高度(30～50 cm)、初始离子浓度(0.55～11.00 mg.L-1)、进料流速(15.11～37.00 mL.min-1)等操作参数对镉吸附特性的影响,同时对吸附穿透曲线进行拟合.实验结果表明,改性花生壳固定床对水中镉具有较好的吸附效果,在吸附操作初期,吸附柱出水镉离子浓度几乎为0(<0.001mg.L-1),吸附操作时间根据不同的操作条件可达2～62 h,镉离子总去除率均大于54%.传质区长度主要受初始离子浓度、进料流速影响.床层高度的增加使得穿透时间增加,但传质区长度几乎保持不变;初始离子浓度和进料流速增加,穿透时间缩短,传质区长度增加.在低浓度条件下,BDST模型实验穿透曲线拟合效果较好(R2>0.99),运用该模型能准确预测吸附柱的操作时间.     

改性花生壳对Cd(Ⅱ)和Pb(Ⅱ)的吸附机理

以前期制得改性块状花生壳为对象,测定改性花生壳等电点,考察离子强度对改性花生壳吸附Cd2+和Pb2+的影响、吸附前后吸附质溶液pH变化情况及蒸馏水、NaCl、HNO3、柠檬酸和EDTA 5种解吸液对Cd2+和Pb2+的解吸效果,并通过X-射线光电子能谱仪和傅里叶变换红外光谱仪对吸附前后的改性花生壳进行表征,推测并证实了改性花生壳对Cd2+和Pb2+可能的吸附机理。结果表明,改性花生壳对Cd2+和Pb2+可能的吸附机理是:Cd2+是通过外层络合、离子交换和内层络合的联合作用被吸附的;Pb2+主要是与改性花生壳上的O、N等活性基团发生内层络合;此外,改性花生壳表面生成的二氧化锰对Cd2+和Pb2+的吸附也起到一定的作用。     

Distribution of organophosphate insecticides in a Thai biomass-water system

Sorption and leaching of the organophosphate (OP) pesticides chlorpyrifos, profenofos, methyl parathion and malathion were investigated with four different types of biomass: coconut husk, rice husk, peat moss and peanut shell. Organic carbon contents of the biomass were in the range of 35.4–45.4%. Sorption studies were carried out by the batch (equilibrium) method at 4 different OP spike concentrations and at pH 3–7. Sorption isotherms conformed to a linear Freundlich equation and the Freundlich constant or sorption coefficient (K_D) confirmed that biomass organic carbon content was the principal sorbent factor affecting OP sorption. For a given sorbent, correlation of the extent of sorption with sorbate chemical properties was examined. Column leaching experiments involving different masses of coconut husk and peanut shell pre-spiked with OPs at the level equivalent to actual spraying concentrations in some Thai tangerine orchards were conducted. These experiments included repeated spikings and leaching. A water flow rate of 20 mL min^?1 was employed corresponding to the current average watering regime. Retardation and biodegradation with these sorbents were also examined.     

长柄扁桃核壳活性炭的制备及表征

以长柄扁桃核壳为原料采用磷酸活化法制备活性炭,分别研究了温度、时间、浸渍比和磷酸浓度对活性炭吸附性能的影响;进而采用氮气吸附曲线和SEM对最佳工艺条件下的活性炭进行了表征。结果表明,长柄扁桃核壳是一种优质的活性炭原料;当温度为400℃,活化时间2 h,浸渍比2：1,磷酸浓度60%时,得到产率为46.46%,碘吸附值和亚甲基蓝吸附值分别为1 073 mg/g、255 mg/g,比表面积高达1 740 m²/g,中孔率为73.12%的孔隙发达的高中孔率活性炭。     

鱼贝植物组合对上海白莲泾生态修复效应研究

将鱼、贝、植物组合成3种浮岛生态系统,对上海市黄浦江支流白莲泾污染治理和生态修复,效果明显。结果表明:银纹金线蒲+鲢鳙鱼+三角帆蚌组合对总氮去除率60.7%,总磷去除率43.7%,高锰酸盐去除率35.0%,叶绿素-a降低38.2%;血草+鲢鳙鱼+三角帆蚌组合对总氮去除率55.2%,总磷去除率37.2%,高锰酸盐指数去除率42.5%,叶绿素-a降低44.3%;菖蒲+鲢鳙鱼+三角帆蚌组合对总氮去除率55.1%,总磷去除率29.7%,高锰酸盐指数去除率28.3%,叶绿素-a降低26.0%。总体上,3种浮岛生态系统能将水体总磷从Ⅲ类达到至Ⅱ类;总氮从劣Ⅴ类达到至Ⅳ类;高锰酸盐指数从Ⅳ类达到至Ⅲ类。鱼、贝、植物组合的浮岛生态系统生态效应优于单一生物因子的生态效应,该系统内生物多样性较丰富,生长良好,生态景观性明显。     

Effects of different pretreatment methods on the enzymatic hydrolysis of oak shell

Sawtooth Oak (Quercus acutissima) shells were used as a renewable and low-cost agricultural residue for bioethanol production for the first time. The efficiency of H₂SO₄, NaOH, steam explosion and the combination of these methods was compared in terms of delignification, saccharification efficiency and yield. The structural features of samples were characterized by SEM, XRD and FTIR. Results show H₂SO₄/steam explosion resulted in the highest hemicellulose reduction (98.5%) and cellulose recovery yield (99.9%). NaOH /steam explosion resulted in the highest delignification level (31.5%). Steam explosion exhibited the highest enzymatic digestibility of 98.8% and total product yield of glucose of 84.8%, an increase of 130.8% and 98.1% than that of untreated oak shell, respectively, which seemed to be the most effective for improving enzymatic saccharification. The results of structural features showed the structure and surface of shells were changed that is in favor of the following enzymatic hydrolysis.     

Mercury removal using ground and calcined mussel shell

We determined mercury retention on calcined and ground mussel shell, in presence and absence of phosphate, using batch and stirred flow chamber experiments. In batch experiments the calcined shell exhibited higher Hg adsorption, with good fitting to Freundlich equation （R^2： 0.925-0.978）; the presence of phosphate increased Hg adsorption; mercury desorption was 13% or lower, diminishing up to 2% under the presence of phosphates. In stirred flow chamber experiments calcined shell retained more Hg than ground shells （6300 vs. 4000-5200 μmol/kg）; Hg retention increased an additional 40% on calcined shell and up to an additional 70% on ground shells when phosphates were present; mercury desorption was quite similar in all shell types （20%-34%）, increasing up to 49%-60% in ground shells when phosphates were present. The higher Hg adsorption on calcined shell would be related to its calcite and dolomite concentrations; mercury-phosphate interactions would cause the increase in Hg retention when phosphates are present. Data on Hg desorption suggest that Hg retention was not easily reversible after batch experiments, increasing in the stirred flow chamber due to convective flow. Calcined and ground mussel shells could be recycled removing Hg from water, with the presence of phosphates in solution improving efficacy.