Co-digestion of kitchen waste and fruit–vegetable waste by two-phase anaerobic digestion

The high salinity and fat contents of kitchen waste (KW) inhibits the effect of two-phase anaerobic digestion system. This research introduces fruit–vegetable waste (FVW) to alleviate the inhibition effect caused by salinity and fat concentrations, and tries to achieve an optimal addition ratio of FVW, an optimal hydraulic remain time (HRT) of acidogenic-phase reactor and methanogenic-phase reactor. A two-phase anaerobic digestion (AD) system was developed to co-dispose KW and FVW. Four sets of experiments were run with different mass proportions between KW and FVW (25–75, 50–50, 75–25, and 100–0 %?m/m). Considering the biodegradation rate and the acidification degree, the system with 25 % KW had the best performance during the acidogenic phase. When the system was run with 50 % KW, it not only had the best stability performance but also had a bigger capacity to treat KW than the system with 25 % KW. The system with 50 % KW was the best ratio in this two-phase AD system. Co-digestion of KW and FVW by two-phase AD is feasible. The addition of FVW can reduce the inhibition effect caused by salinity and fat concentrations, reduce the HRT, and lead to a higher degree of acidification.     

纳滤去除饮用水中的PFOS

全氟辛烷磺酸类物质（PFOS）是一种新型持久性有机污染物,对人类健康存在很大威胁,目前世界范围内的水体中均检测到不同浓度的PFOS。研究如何安全有效去除这类新型污染物十分必要。利用HYDRA—COPe10纳滤膜进行PFOS去除研究,在不同操作压力下研究pH、电解质以及与腐殖酸共存对PFOS截留效果的影响。结果表明,随着pH值的增加,截留率上升;二价盐对PFOS截留率的影响要高于一价盐,并且随着二价盐离子强度的增加,截留率上升;腐殖酸共存时截留效率有显著增加,尤其在1mmol／L钙离子存在条件下,PFOS的截留率可达到95．8％,但会引起膜通量下降及膜污染的发生。     

纳米SiO2对微污染物HA、SDS及NH3-N的助凝特性研究

以聚合氯化铝PAC为混凝剂,纳米SiO₂为助凝剂,对含有下列微污染物：十二烷基硫酸钠（SDS）、氨氮（NH₃-N）或腐植酸（HA）的高岭土悬浊液进行混凝沉降实验。借助形态学理论、电镜观察与图像分析技术,研究纳米SiO₂对微污染物的助凝作用效果、吸附特性与絮体结构的形态学特征。结果表明：（1）在含有HA、SDS、NH₃-N的模拟原水中,污染物去除率与浊度去除率的相关性随污染物分子量的增大而增强;（2）纳米SiO     

南四湖农业面源污染现状及控制措施

近年来南四湖水质污染严重,农业面源污染是导致水体污染和富营养化的最主要因素;阐述了南四湖流域种植业、养殖业及农村生活污染三大污染源现状和危害;总结了国外对农业面源污染控制措施及研究动态,重点评述了农业面源污染的来源解析方法,提出了农业面源污染需要进一步研究的方向,对南四湖农业面源污染的研究具有一定的指导意义。     

榆林市生态环境承载力评价分析

榆林市是我国重要的能源矿产资源的富集地,近年来,随着社会经济的快速发展,该市的生态系统(包括资源、环境)能否承受人类社会经济活动带来的压力,以榆林市的实际情况出发,建立生态环境承载力指标体系进行评价论证,得出水资源、土地资源和固废排放等的问题最为突出,为此提出了相应的对策建议。     

双介质阻挡放电法再生吸附五氯酚的活性炭

采用双介质阻挡放电等离子体反应器对吸附了五氯酚的活性炭进行放电再生处理,考察了放电电压、放电时间、氧气流量和活性炭再生次数对再生活性炭的五氯酚去除率的影响.实验结果表明,活性炭再生的最佳条件为:放电电压23 kV,放电时间1.5h,氧气流量2.0 L/min.随活性炭再生次数增加,再生活性炭的五氯酚去除率和活性炭再生率...     

基于生态足迹的香格里拉县生态安全趋势预测

香格里拉县是世界自然遗产三江并流地区的核心部分,其生态安全备受世人关注。基于生态足迹模型分析了香格里拉县2002~2008年的生态足迹及生态承载力的变化过程。结果表明:该县人均生态足迹从0.549ghm2上升到0.717 ghm2,年均增加4.37%;生态承载力从0.768 8 ghm2下降到0.621 7 ghm2,年均下降2.73%。根据生态压力指数分析,2002~2004年属于生态较安全期,2005~2007年属于生态稍不安全期,从2008年起生态盈余成为生态赤字进入较不安全期。运用灰色系统方法预测了2009~2013年生态压力指数的动态变化,预测从2011年起已进入生态很不安全期,到2013年已接近生态极不安全期。说明生态安全恶化有加速的趋势,恢复和保护生态环境刻不容缓。本研究为香格里拉县可持续发展提供了依据,并实证了生态足迹模型在高山峡谷地区的应用。     

Concurrent sorption of antimony and lead by iron phosphate and its possible application for multi-oxyanion contaminated soil

Environmental Science and Pollution Research - Concurrent stabilization of oxyanions such as antimony (Sb), arsenic (As), and heavy metals including lead (Pb) and manganese (Mn) in contaminated...     

Chromium phytoextraction and physiological responses of the hyperaccumulator Leersia hexandra Swartz to plant growth-promoting rhizobacterium inoculation

● Improved Cr phytoextration efficiency was achieved by B. cereus inoculation. ● B. cereus could produce plant-beneficial PGPR factors at diverse Cr stresses. ● Enhanced resistance of inoculated L. hexandra towards elevated Cr stress. ● The majority of Cr existed in the stable forms in the tissues of L. hexandra. Phytoextraction is a promising option for purifying hexavalent chromium (Cr(VI))-laden wastewater, but the long remediation period incurred by poor growth rate of Cr hyperaccumulators remains a primary hindrance to its large-scale application. In this study, we performed a hydroponic experiment to evaluate the feasibility of promoting the growth and phytoextraction efficiency of Cr hyperaccumulator Leersia hexandra Swartz (L. hexandra) by inoculating plant growth-promoting rhizobacteria (PGPR) Bacillus cereus (B. cereus). In batch tests, the Cr(VI) removal rates of L. hexandra and B. cereus co-culture were greater than the sum of their respective monocultures. This was likely due to the microbial reduction of Cr(VI) to Cr(III), which is amiable to plant uptake. Besides, the PGPR factors of B. cereus, including indoleacetic acid (IAA) production, 1-aminocyclopropane-1-carboxylic acid deamination (ACCd) activity, phosphate solubilization capacity, and siderophore production, were quantified. These PGPR factors helped explain the biomass augmentation, root elongation and enhanced Cr enrichment of the inoculated L. hexandra in pot experiments. Despite the increased Cr uptake, no aggravated oxidative damage to the cell membrane was observed in the inoculated L. hexandra. This was attributed to its capacity to confront the increased intracellular Cr stress by upregulating both the activities of antioxidative enzymes and expression of metal-binding proteins/peptides. Moreover, L. hexandra could always conserve the majority of Cr in the residual and oxalic integrated forms with low mobility and phytotoxicity, irrespective of the B. cereus inoculation. These results highlight the constructed Cr hyperaccumulator-rhizobacteria consortia as an effective candidate for decontaminating Cr(VI)-laden wastewater.     

节肢动物体内的总汞和甲基汞含量研究

分析了汞污染区河流沿岸草本植物及节肢动物样品中的汞含量.结果表明,节肢动物飞蝗、中华蚱蜢总汞含量分别为0 .032～0 .402 mg·kg^-1、0 .023～0 .362 mg·kg^-1,高于非污染区1个数量级.飞蝗、中华蚱蜢甲基汞含量分别为0 .003～0 .031mg·kg^-1、0 .004～0 .015 mg·kg^-1,占总汞比例分别为3 .5%～49 .7%和2 .0%～44 .4%.飞蝗、中华蚱蜢体内（一级消费者）汞含量低于其食物草本植物,与未受污染地区不同;螳螂体内（二级消费者）汞明显累积.飞蝗体内总汞含量随着个体长度增长呈下降的趋势,在中华蚱蜢体内则先增长后下降,甲基汞随着个体长度增长呈上升趋势;节肢动物个体不同部位中汞含量明显不同,腹>胸>头.节肢动物体内汞和甲基汞可能导致野生鸟类、家禽、两栖类生态风险.