煤制气废水处理技术研究进展综述

基于中国能源结构特点,新型煤化工产业近年来得到大力推进,尤其煤制气项目发展迅速,而煤化工废水处理及综合利用成为限制其发展的瓶颈因素之一。文中介绍了煤制气废水来源、特点、处理难度,依照煤制气废水的常规处理流程,从预处理、生化处理、深度处理三个方面详细介绍国内外煤制气废水处理应用实例及技术研究现状,指出废水处理关键问题,为解决煤制气产业废水治理问题提供参考。     

保护性耕作下小麦田土壤呼吸及碳平衡研究

为了研究小麦农田生态系统土壤碳排放与作物碳蓄积特征,采用LI6400-09在重庆北碚西南大学教学试验农场对平作(T)、垄作(R)、平作+覆盖(TS)、垄作+覆盖(RS)这4种处理下的西南紫色土丘陵区小麦/玉米/大豆套作体系中小麦生长季节的土壤呼吸及植株生长动态进行了观测.利用根系生物量外推法(root biomass regression,RBR)和根排除法(root exclusion,RE)这2种方法比较分析根系呼吸对土壤总呼吸的贡献,并估算小麦农田碳收支状况.结果表明,土壤呼吸介于0.62~2.91μmol·(m2·s)-1,平均值为1.71μmol·(m2·s)-1.T、R、TS、RS各处理日均土壤呼吸速率分别为1.29、1.59、1.99、1.96μmol·(m2·s)-1,表现为T相似文献   

苹果园土壤呼吸的变化及生物和非生物因素的影响

了解果园土壤呼吸变化及其影响因素,有利于深入理解退耕还果条件下黄土高原地区土壤碳源汇功能.在长武农田生态系统国家野外站,以盛产期果园(2000年建成)为对象,利用土壤碳通量测量系统(Li-COR,Lincoln,NE,USA)于2011、2012年监测了果树冠幅下距树干不同距离处土壤呼吸、土壤水分和温度变化,分析了土壤呼吸的时空变化及其影响因素.结果表明:①土壤呼吸速率随着距树干距离延长而降低.与2 m处相比,0.5 m处土壤累积呼吸量2011年提高20%,2012年提高31%;0.5 m和2 m处土壤呼吸的温度敏感性(Q10)2011年相应依次为1.79和1.56,2012年依次为1.79和1.38.②距树干2 m处温度和水分稍高于0.5 m处,但差异不显著(P>0.05).土壤呼吸与土壤温度均呈显著的指数关系,而与土壤水分的相关性不显著.温度变化可解释土壤呼吸的季节性变化,但并不能解释距离树干不同处的差异.③距离树干不同位置处的根系密度差异是影响果园土壤呼吸空间变化及其温度敏感性的重要生物因素;④冠幅下土壤呼吸的变异系数为23%~31%.估算果园土壤呼吸需考虑其距离树干的空间差异性.     

水煤浆加压气化制合成氨系统的三废排放情况及治理措施

简述了水煤浆加压气化制合成氨系统的特点，着重介绍了该系统制气工段和净化工段的三废排放情况及治理措施，并对仍存在的问题提出了看法。     

Determination of the carbon content of biomass—A prerequisite to estimate the complete biodegradation of polymers

This article presents a method to determine the carbon content of biomass, which is formed when degrading biodegradable polymers in an aerobic aqueous test system. Existing methods for determining the carbon content of biomass (e.g., fumigazation, protein assays, dry solids) have several disadvantages when applied for polymer degradation tests. In this work a protein assay based on the Lowry method was used. It was shown that the ratio between protein and carbon content is not constant but depends on the composition of the microbial population, the growth phase, and the substrate supply. This effect was used for the method presented in this article. For determining the carbon content of biomass the absorbance obtained by the Lowry test is correlated directly with the carbon content of biomass in dependence on the duration of the degradation test. The calibration curves are obtained by a mixed population of microorganisms during the course of a degradation test.     

COORDINATION OF PUBLIC AND PRIVATE AC A CASE STUDY OF LAKE RESTORATION1

ABSTRACT: The potential for joint public and private action for lake restoration is examined using Lake Apopka, Florida, as a case study. Initial calculations indicate that private incentives alone are inadequate to attract investment in a facility to grow and harvest water hyacinths for conversion to methane gas. However, the private externality of water quality improvement associated with harvesting water hyacinths provides a key linkage between the public's water quality objectives and the private gas producer's actions. In order to establish the potential basis for negotiation, the public's willingness-to-pay for environmental services associated with improved water quality is estimated and compared with the estimated subsidy required to induce private action. A conceptual framework is then presented for coordinating actions between private firms and public water management agencies in order to internalize the private externality of water quality improvement while simultaneously achieving the public and private objectives. Results indicate that the subsidization of water hyacinth production and harvesting compares favorably with alternative means of enhancing the water quality of Lake Apopka.     

CHLOROPHYLL-BIOMASS-NUTRIENT RELATIONSHIPS FOR NATURAL ASSEMBLAGES OF FLORIDA PHYTOPLANKTON1

Parallel determination of phytoplankton biomass and chlorophyll a concentration were made on spring and summer phytoplankton samples collected from 165 Florida lakes. There was a significant correlation between chlorophyll a concentration and phytoplankton biomass (r=0.80; P < 0.01). Chlorophyll content per unit phytoplankton biomass ranged over two orders of magnitude. Nitrogen seemed to be a major factor influencing the chlorophyll content of Florida algae. Multiple regression analyses indicated that phytoplankton biomass was dependent on both the total phosphorus and total nitrogen concentration. Nutrient-phytoplankton and Secchi-phytoplankton relationships for the Florida lakes had higher coefficients of determination if chlorophyll a concentrations rather than phytoplankton biomass data were used in regression analyses.     

EFFLUENT IRRIGATION OF PARA GRASS: WATER,NITROGEN, AND BIOMASS BUDGETS1

Para grass, irrigated with secondary domestic sewage effluent, showed excellent response for disposal of large amounts of water, effective nitrogen removal, and high production of excellent fodder. This grass is found throughout the tropics and parts of the subtropics. It endures flooding and forms dense, easily maintained stands. This is the first time its use has been reported for effluent irrigation. Water, nitrogen, and biomass budgets over a 17-month period were measured in eight percolate style lysimeters. Under irrigation rates as great as 98 mm/day, five days/week, evapo-transpiration averaged 4.6 mm/day. With nitrogen applications of 130 to 2,600 kg/ha/yr, ≥ 79 percent of applied nitrogen was harvested in the grass; 3 percent percolated; and ≤ 28 percent was denitrified. With the highest effluent irrigation rates, nitrate-nitrogen levels remained below the 10 mg/L maximum recommended for potable water. Crop productivity for full effluent treatments averaged 110 t/ha/yr, dry weight. Maximum calculated crude protein content was 13 percent. No nitrate-nitrogen level in the forage exceeded 0.1 percent.     

Soil resource availability impacts microbial response to organic carbon and inorganic nitrogen inputs

Impacts of newly added organic carbon （C） and inorganic nitrogen （N） on the microbial utilization of soil organic matter are important in determining the future C balance of terrestrial ecosystems. We examined microbial responses to cellulose and ammonium nitrate additions in three soils with very different C and N availability. These soils included an organic soil（ 14.2% total organic C, with extremely high extractable N and low labile C）, a forest soi1（4.7% total organic C, with high labile C and extremely low extractable N）, and a grassland soil（1.6% total organic C, with low extractable N and labile C）. While cellulose addition alone significantly enhanced microbial respiration and biomass C and N in the organic and grassland soils, it accelerated only the microbial respiration in the highly-N limited forest soil. These results indicated that when N was not limited, C addition enhanced soil respiration by stimulating both microbial growth and their metabolic activity, New C inputs lead to elevated C release in all three soils, and the magnitude of the enhancement was higher in the organic and grassland soils than the forest soil. The addition of cellulose plus N to the forest and grassland soils initially increased the microbial biomass and respiration rates, but decreased the rates as time progressed. Compared to cellulose addition alone, cellulose plus N additions increased the total C-released in the grassland soil, but not in the forest soil. The enhancement of total C- released induced by C and N addition was less than 50% of the added-C in the forest soil after 96 d of incubation, in contrast to 87.5% and 89.0% in the organic and grassland soils. These results indicate that indigenous soil C and N availability substantially impacts the allocation of organic C for microbial biomass growth and/or respiration, potentially regulating the turnover rates of the new organic C inputs.     

环保型煤炭开采与利用技术--煤炭地下气化

介绍了煤炭地下气化技术的开发与应用，相比传统煤炭开采燃用技术，煤炭地下气化实现了煤炭清洁开采与利用，指出煤炭地下气化技术是环保型开采与利用技术，应用积极推广利用。