Phosphorus recovery from biogas fermentation liquid by Ca-Mg loaded biochar

Shortage in phosphorus(P) resources and P wastewater pollution is considered as a serious problem worldwide. The application of modified biochar for P recovery from wastewater and reuse of recovered P as agricultural fertilizer is a preferred process. This work aims to develop a calcium and magnesium loaded biochar(Ca–Mg/biochar) application for P recovery from biogas fermentation liquid. The physico-chemical characterization, adsorption efficiency, adsorption selectivity, and postsorption availability of Ca-Mg/biochar were investigated. The synthesized Ca–Mg/biochar was rich in organic functional groups and in Ca O and Mg O nanoparticles. With the increase in synthesis temperature, the yield decreased, C content increased, H content decreased, N content remained the same basically, and BET surface area increased. The P adsorption of Ca–Mg/biochar could be accelerated by nano-Ca O and nano-Mg O particles and reached equilibrium after 360 min.The process was endothermic, spontaneous, and showed an increase in the disorder of the solid–liquid interface. Moreover, it could be fitted by the Freundlich model. The maximum P adsorption amounts were 294.22, 315.33, and 326.63 mg/g. The P adsorption selectivity of Ca–Mg/biochar could not be significantly influenced by the typical p H level of biogas fermentation liquid. The nano-Ca O and nano-Mg O particles of Ca–Mg/biochar could reduce the negative interaction effects of coexisting ions. The P releasing amounts of postsorption Ca–Mg/biochar were in the order of Ca–Mg/B600 Ca–Mg/B450 Ca–Mg/B300. Results revealed that postsorption Ca–Mg/biochar can continually release P and is more suitable for an acid environment.     

藻类对有机污染物生物吸附的研究进展

随着工业的迅猛发展,越来越多的有毒有机污染物被排放到环境中,进而引起一系列环境问题。大量研究表明,生物吸附已经成为去除有毒有机污染物的重要方法,而藻类作为一种理想的生物吸附剂,具有良好的吸附和降解有机污染物的能力。概述了藻类对染料、酚类、多环芳烃三种具有代表性的有毒有机污染物的生物吸附。     

废弃放射源处理措施探讨

随着石油化工企业应用放射源数量的不断增多,放射源的安全管理已经成为石化企业安全管理工作的重要组成部分,尤其是废弃、闲置的放射源,存放不当或保存时间过久很容易丢失.对此,国家和中国石化集团公司高度重视,陆续颁布了一系列新的法规、规定.如国务院新修订的<放射性同位素与射线装置安全和防护条例>从2005年12月1日起实施,中国石化集团公司安全环保局也于2004年新修订了<放射防护管理规定>,并实行射线作业票制度.在中国石化集团公司历年安全大检查中,加大了对放射源的安全检查力度,放射源安全检查成为每次安全检查的必检内容.     

Two-stage fuzzy-stochastic robust programming: a hybrid model for regional air quality management

In this study, a hybrid two-stage fuzzy-stochastic robust programming (TFSRP) model is developed and applied to the planning of an air-quality management system. As an extension of existing fuzzy-robust programming and two-stage stochastic programming methods, the TFSRP can explicitly address complexities and uncertainties of the study system without unrealistic simplifications. Uncertain parameters can be expressed as probability density and/or fuzzy membership functions, such that robustness of the optimization efforts can be enhanced. Moreover, economic penalties as corrective measures against any infeasibilities arising from the uncertainties are taken into account. This method can, thus, provide a linkage to predefined policies determined by authorities that have to be respected when a modeling effort is undertaken. In its solution algorithm, the fuzzy decision space can be delimited through specification of the uncertainties using dimensional enlargement of the original fuzzy constraints. The developed model is applied to a case study of regional air quality management. The results indicate that reasonable solutions have been obtained. The solutions can be used for further generating pollution-mitigation alternatives with minimized system costs and for providing a more solid support for sound environmental decisions.     

油污染土壤气体抽排去污模型及影响因素

为了开展适合我国实际情况的有机污染土壤气体抽排净化技术研究,在对油污染土壤的通风去污过程机理进行分析的基础上,建立了一个简化机理模拟模型.以华北地区典型土壤为实验土样,油污染物为例,通过一维土柱实验,研究了抽排气体流速、土壤含水率和土质对去污过程的影响.实验表明抽排气体流速存在最佳值,土壤含水率对不同土质土壤净化时间影响不同,对粉砂土,含水率升高,净化效率增强;而对粘质土壤,结果正好相反.对模型预测结果进行实验验证表明,本文建立的模拟模型在实验限定条件范围内是准确和适用的.     

Progress in the ecology and conservation of giant pandas

Giant panda (Ailuropoda melanoleuca) conservation is a possible success story in the making. If extinction of this iconic endangered species can be avoided, the species will become a showcase program for the Chinese government and its collaborators. We reviewed the major advancements in ecological science for the giant panda, examining how these advancements have contributed to panda conservation. Pandas’ morphological and behavioral adaptations to a diet of bamboo, which bear strong influence on movement ecology, have been well studied, providing knowledge to guide management actions ranging from reserve design to climate change mitigation. Foraging ecology has also provided essential information used in the creation of landscape models of panda habitat. Because habitat loss and fragmentation are major drivers of the panda population decline, efforts have been made to help identify core habitat areas, establish where habitat corridors are needed, and prioritize areas for protection and restoration. Thus, habitat models have provided guidance for the Chinese governments’ creation of 67 protected areas. Behavioral research has revealed a complex and efficient communication system and documented the need for protection of habitat that serves as a communication platform for bringing the sexes together for mating. Further research shows that den sites in old‐growth forests may be a limiting resource, indicating potential value in providing alternative den sites for rearing offspring. Advancements in molecular ecology have been revolutionary and have been applied to population census, determining population structure and genetic diversity, evaluating connectivity following habitat fragmentation, and understanding dispersal patterns. These advancements form a foundation for increasing the application of adaptive management approaches to move panda conservation forward more rapidly. Although the Chinese government has made great progress in setting aside protected areas, future emphasis will be improved management of pandas and their habitat.     

湖南木兰科植物资源的调查研究

本文分析了湖南木兰科分布的自然条件,结合其形态性状讨论了它们的分类学问题、地理分布特点、资源状况以及自然生长状况。文末提出了湖南省木兰科的保护植物名单。     

城镇生活污水就近引浇防沙治沙工程林

城镇生活污水排入水体 ,严重影响水资源的使用价值。沙漠地区因缺水 ,造成许多地方造林失败。本文提出了将城镇生活污水就近引浇防沙治沙工程林的构想 ,并从经济和环境影响两个方面详细论述了该方案的比较优势     

超临界水氧化有机废水动力学分析

根据推流式超临界水氧化 (SCWO)反应器处理有机废水的动力学方程式 ,结合近年来超临界水氧化降解各种有机废水的实验研究情况 ,对超临界水氧化有机废水的反应动力学影响因素进行了综合分析 ,同时指出了该技术在有机废水处理中的应用优势和存在问题。