Improving Anammox start-up with bamboo charcoal

Three Upflow Anaerobic Sludge Blanket (UASB) reactors were compared for Anammox enrichment using synthetic wastewater with Spherical Plastic (SP) and Bamboo Charcoal (BC) addition, and without carrier (CK). After four months of operation, the Anammox activity occurred in all reactors allowing continuous removal of ammonium and nitrite. Ammonium and nitrite removal efficiencies were all higher than 98% in steady phase with the effluent concentrations below 1 mg L⁻¹. The start-up time could be shortened from 117 to 97 d in CK and SP reactor to 85 d in BC amendment reactor. Quantitative PCR (q-PCR) analyses indicated a significant increase in the number of Anammox bacteria in BC amended reactor as compared with CK and SP during the entire start-up periods. The copy numbers of Anammox of 16S rRNA gene in the reactor with BC amendment could reach up to 6 × 10⁹ copies g⁻¹ Volatile Suspended Solids, around 22.5 times and 12.3 times greater than that in CK and SP reactor, respectively. BC addition could accelerate the start-up of Anammox and significantly increase the Anammox bacteria number.     

响应面法优化烧烤竹炭对水中磷的吸附条件

采用响应面法优化烧烤竹炭(BBC)对水中磷的吸附条件。用Box-Behnken Design实验设计考察初始磷质量浓度、BBC粒径、BBC加人量和初始溶液pH等因素对磷去除率的影响。实验结果表明:各因素对磷去除率影响的大小顺序依次为初始溶液pHBBC粒径初始磷质量浓度BBC加入量;BBC吸附水中磷的最佳反应条件为初始磷质量浓度26.81 mg/L,BBC粒径0.15 mm,BBC加入量10.6 g/L,初始溶液pH 4.42;在最佳反应条件下,BBC对磷的去除率达90.04%。     

Charcoal burning as a source of polyaromatic hydrocarbons in waterpipe smoking

Polyaromatic hydrocarbons (PAH) content from seven commercial waterpipe charcoals were determined during the smoking process to estimate how much PAHs would not be trapped by the water trap and could reach the lungs of the smokers. Naphthalene, 2-methylnaphthalene, acenaphthylene, acenaphthene, phenanthrene and fluoranthene were the most abundant PAH compounds produced during smoking. Naphthalene was the highest in all of the smoke contents and levels of 5 to 405 μg/15 minutes could be inhaled by the smoker. The amounts of PAHs produced during the smoking events in absence of tobacco varied greatly among different brands of charcoal. The amount and composition of the emitted PAH were not related to the amount and composition of the original chemicals in the charcoal prior to burning. Our findings suggest that public health agencies should regulate smoked charcoal products alongside tobacco.     

室内装潢甲醛污染治理研究

针对室内装修所产生的甲醛污染危害,对不同甲醛清除剂去除甲醛的效果进行研究.结果表明,在所研究的用量内,甲醛清除剂的去除效果显著高于活性炭,且持久性较好;最佳量的甲醛清除剂处理不同板材所含同一甲醛浓度时,中密度板的去除效果要高于木板、细木工板和装饰单面贴面胶合板;环境温度升高时,最佳量的甲醛清除剂去除甲醛的效率有所降低.     

Paleoecological Assessment of Watershed History in PRIMENet Watersheds at Acadia National Park, USA

Paleoecological reconstructions of forest stand histories for two upland watersheds at Acadia National Park in Maine were completed to support related watershed chemistry studies. The project hypothesis was that forest type and fire history influence long-term cycling and storage of atmospheric mercury and nitrogen within watersheds. The reconstructions document differences in major vegetation composition and disturbance between the burned and unburned watersheds during the past several centuries. Pollen and charcoal stratigraphies from organic sediment accumulations in forested wet depressions indicate that the present experimental design of contrasting disturbance and forest histories has persisted during recent centuries. The unburned watershed has been dominated by spruce (Picea rubens) and fir (Abies balsamea) for 500 years or more and has not recently burned or been substantially cleared. The burned watershed is dominated by a heterogeneous forest of patchy hardwood, mixed wood, and softwood stands. A large portion of this watershed burned severely in 1947 and probably more than once in the 1800s, and has supported heterogeneous successional forests for 200 years or longer. Overall, these results support the underlying premise that the experimental design of this watershed research can be used to infer landscape controls on biogeochemical processes.     

净化剂对猪场沼液中COD的去除及其应用条件的响应面优化

利用活性炭为载体结合微生物菌株制备畜禽养殖厌氧污水(即沼液)净化剂,选取净化剂的投加量、沼液的水力停留期(HRT)和温度这3个主要影响因素,以COD降解率、BOD5降解率作为应用过程响应指标,运用响应面法(RSM)优化沼液净化剂应用条件。随着沼液水力停留期的延长,COD降解率随之升高,而BOD5降解率随之降低,采用Design-expert软件设计响应面实验可以得到两者共同的优化条件。结果表明,沼液净化剂最佳应用条件为:净化剂投加量为11 g/L、水力停留期为3.26 d、温度为26.4℃,在此条件下,利用净化剂去除沼液中COD、BOD5,沼液中COD、BOD5降解率分别为85.6%和80.3%,该研究为净化剂的应用推广提供理论参数。     

水合氧化铁改性竹炭去除水中磺胺甲噁唑

研究了水合氧化铁(HFO)改性竹炭对水中磺胺甲噁唑的去除效果,考察了磺胺甲噁唑初始浓度与初始pH对去除效果的影响,并对去除过程中磺胺甲噁唑及其产物的发光细菌的急性毒性进行了评价。实验结果表明,采用X射线光电子能谱(XPS)及红外光谱(FTIR)对改性竹炭进行表征确定水合氧化铁负载改性的方法是可行的,改性竹炭能显著提高竹炭对水中磺胺甲噁唑的去除效果,在磺胺甲噁唑20、40和80 mg/L 3个初始浓度条件下,在HFO改性竹炭反应体系中,其反应速率常数为原竹炭的19.0~32.2倍;改性竹炭对水中磺胺甲噁唑的去除过程符合准一级动力学,反应速率常数随初始浓度的升高而减小,反应速率常数随pH的变化规律为pH 8>pH 4>pH 1,表明水中磺胺甲噁唑以阴离子形态存在时更易于去除;改性竹炭去除磺胺甲噁唑的过程中有反应产物生成,发光细菌毒性测定结果表明,反应体系的发光抑制率从反应起始时的96.1%下降到了84.2%(144 h),说明采用HFO改性竹炭去除磺胺甲噁唑有利于减弱反应体系的毒性。     

卤化铵改性竹炭对单质汞吸附性能的影响

为了研究廉价吸附剂竹炭的脱汞性能,将经过CO2活化并采用NH4Cl、NH4I超声浸渍改性的竹炭（BC）应用于单质汞的吸附,并对比不同负载量的NH4Cl以及NH4I改性和温度等因素对竹炭的汞脱除性能的影响。采用了元素分析、扫描电镜分析、XPS表征、比表面积及孔径分布等对材料进行研究。结果表明,NH4Cl和NH4I改性显著提高竹炭的脱汞能力,并且在同等条件下NH4I改性剂效果优于NH4Cl。研究表明提高负载量会造成吸附材料孔堵塞,但在0~8wt.%的负载量情况下,孔道的堵塞不足以抵消化学吸附带来的积极作用,表明改性竹炭对汞的吸附主要表现为化学吸附。同时改性竹炭存在随着温度升高其吸附效率先降低后升高的趋势,暗示竹炭对汞的吸附在低温时物理吸附占优势,温度升高时化学吸附占优势。     

松针炭载铈材料对罗丹明B的吸附性能研究

在氮气氛围下热解制备松针炭,采用浸渍法将硝酸铈负载到松针炭上,在300℃氛围中焙烧2 h,制得铈改性松针炭.用罗丹明B溶液模拟染料废水,分别研究松针炭和铈改性松针炭对罗丹明B的吸附效果.实验表明:加热温度为300℃、升温速率为10℃/min、加热时间为2 h时,制备的松针炭对罗丹明B的去除率为68.8％;浸渍浓度为0....     

Land‐use history as a guide for forest conservation and management

Conservation efforts to protect forested landscapes are challenged by climate projections that suggest substantial restructuring of vegetation and disturbance regimes in the future. In this regard, paleoecological records that describe ecosystem responses to past variations in climate, fire, and human activity offer critical information for assessing present landscape conditions and future landscape vulnerability. We illustrate this point drawing on 8 sites in the northwestern United States, New Zealand, Patagonia, and central and southern Europe that have undergone different levels of climate and land‐use change. These sites fall along a gradient of landscape conditions that range from nearly pristine (i.e., vegetation and disturbance shaped primarily by past climate and biophysical constraints) to highly altered (i.e., landscapes that have been intensely modified by past human activity). Position on this gradient has implications for understanding the role of natural and anthropogenic disturbance in shaping ecosystem dynamics and assessments of present biodiversity, including recognizing missing or overrepresented species. Dramatic vegetation reorganization occurred at all study sites as a result of postglacial climate variations. In nearly pristine landscapes, such as those in Yellowstone National Park, climate has remained the primary driver of ecosystem change up to the present day. In Europe, natural vegetation–climate–fire linkages were broken 6000–8000 years ago with the onset of Neolithic farming, and in New Zealand, natural linkages were first lost about 700 years ago with arrival of the Maori people. In the U.S. Northwest and Patagonia, the greatest landscape alteration occurred in the last 150 years with Euro‐American settlement. Paleoecology is sometimes the best and only tool for evaluating the degree of landscape alteration and the extent to which landscapes retain natural components. Information on landscape‐level history thus helps assess current ecological change, clarify management objectives, and define conservation strategies that seek to protect both natural and cultural elements.