Analysis of the trade-off between economic growth and the reduction of nitrogen and phosphorus emissions in the Poyang Lake Watershed, China

Lake eutrophication leading to water pollution is a major global concern. In recent years, rapid economic growth and the increase in the intensity of resource exploitation in China have caused the influx of nitrogen and phosphorus into lakes. This in turn has led to more severe lake eutrophication, more frequent outbreaks of algal blooms, and the degradation of lake ecosystems. An effective plan balancing economic growth with the reduction of nitrogen and phosphorus emissions is greatly needed. The design and implementation of such a plan requires the collection and analysis of pertinent data. In this paper, we use the environmental computable general equilibrium (ECGE) model to identify the most effective way to balance economic growth with the reduction of nitrogen and phosphorus emissions. For the multiregional analysis, we use social accounting matrices (SAMs) and a provincial trade matrix based on the assumptions of the gravity model. We consider the Poyang Lake Watershed as a case study to illustrate the utility of the model. Based on present conditions in the Poyang Lake Watershed, restricting nitrogen and phosphorus emissions from sectors with the highest emissions is more effective for balancing economic growth and the reduction of nitrogen and phosphorus emissions than restricting nitrogen and phosphorus emissions from all sectors.     

荷木树干CO2释放通量的个体间差异及树干液流的效应

为研究荷木(Schima superba)个体间树干CO2释放通量(Es)的差异以及树干液流对Es的影响,提高森林生态系统呼吸计算准确性,利用红外气体分析仪及自制式气室于2009年湿季和干季监测了华南荷木人工林5棵样树的Es,并同步监测了树干温度(θs)、气温及液流密度.结果显示:θs与气温之间呈显著线形正相关;Es与树干温度之间存在显著指数函数关系;Es干湿季的差异显著,并呈现明显的季节变化;5株样树之间Es存在显著差异,平均Es分别为3.12、3.60、5.52、6.98、8.09μmol m-2 s-1;同时,样树之间树干CO2释放通量的温度系数(Q10)差异显著(1.97～4.24之间).Tree1、Tree2和Tree4白天的Es与液流速度(v)显著正相关,白天的标准化树干CO2释放通量(R25,温度为25℃时的Es)高于晚上.荷木Es个体之间及时间上的差异主要受树干温度、生长状况和液流速度的影响.图3表6参35     

Organochlorine pesticides in the surface water and sediments from the Peacock River Drainage Basin in Xinjiang, China: a study of an arid zone in Central Asia

Fourteen surface water and nine surface sediment samples were collected from the Peacock River and analyzed for organochlorine pesticides (OCPs) by gas chromatograph?Celectron capture detector (GC-ECD). All the analyzed organochlorine pesticides, except o,p ^??-DDT, were detected in sediments from the Peacock River; but in the water samples, only ??-HCH, HCB, p,p ^??-DDD, and p,p ^??-DDT were detected at some sites. The ranges for total OCPs in the water and sediments were from N.D. to 195 ng l^???1 and from 1.36 to 24.60 ng g^???1, respectively. The only existing HCH isomer in the water, ??-HCH, suggested that the contamination by HCHs could be attributed to erosion of the weathered agricultural soils containing HCHs compounds. Composition analyses showed that no technical HCH, technical DDT, technical chlordanes, endosulfans, and HCB had been recently used in this region. However, there was new input of ??-HCH (lindane) into the Peacock River. The most probable source was water flowing from Bosten Lake and/or agricultural tailing water that was returned directly into the Peacock River. DDT compounds in the sediments may be derived mainly from DDT-treated aged and weathered agricultural soils, the degradation condition was aerobic and the main product was DDE. HCB in the sediment might be due to the input from Bosten Lake and the lake may act as an atmospheric deposition zone. There was no significant correlation between the concentrations of OCPs (including ??HCH, ??DDT, chlordanes, endosulfans, HCB and total OCPs) and the content of fine particles (<63 ??m). The concentrations of OCPs were affected by salinity.     

濮阳市秋冬季大气细颗粒物污染特征及来源解析

濮阳市作为京津冀周边地区大气污染传输通道城市之一,秋冬季重污染天气频发,空气污染问题严峻.为了研究濮阳市秋冬季大气细颗粒物污染特征及其主要来源,于2017年10月15日至2018年1月13日在濮阳市3个国控点对PM_(2.5)进行了手工膜采样与化学组分分析,并结合PMF受体模型,开展了细颗粒物来源解析研究.结果表明,濮阳市2017年秋冬季PM_(2.5)平均质量浓度为94. 16μg·m~(-3),濮水河管理处的污染状况最严重,进入采暖季后3站点均表现为重度及严重污染事件频发,轻度污染发生频率降低,重污染发生时NO_2与CO浓度升高明显. PM_(2.5)中的主要组分为水溶性离子(52. 33%)、碳质组分(25. 32%)和地壳元素(0. 08%),NO_3~-的含量高而SO_4~(2-)的浓度水平较低.重污染发生时,PM_(2.5)中水溶性离子、OC、EC和K浓度都出现了明显的升高,而地壳元素浓度降低.采样期间濮阳市的硫氮转化率水平较高,大气氧化性较强,硫氮转化促进了重污染的发生.濮阳市2017年NOx、CO和VOCs排放量较高,来源解析结果表明,濮阳市秋冬季PM_(2.5)主要来源分别为二次无机盐(37%)、工业源(16%)、二次有机气溶胶SOA(14%)、生物质燃烧源(12%)、移动源(9%)、燃煤源(7%)和扬尘源(4%).可见,二次转化在濮阳重污染的形成过程中起到重要作用,要减轻大气细颗粒物污染,需要重点控制工业源、生物质燃烧、移动源和民用散煤燃烧的排放.     

鸟粪石结晶法回收废水中氮磷的研究进展

采用鸟粪石结晶法处理含氮磷污水,可实现氮磷的去除及回收利用.本文介绍了鸟粪石法处理含氮磷污水的基本原理、现阶段研究热点,总结了目前研究的不足之处,展望了该法处理含氮磷污水的研究方向及发展前景.     

金针菇产漆酶发酵条件的优化

采用液体摇瓶培养方法,探讨了碳源、氮源、pH值、培养时间等各种因素对金针菇分泌漆酶能力的影响,并采用正交试验对主要的影响因素进行了优化.优化培养条件为:pH在5.0-6.0范围内有利于金针菇漆酶的分泌,且以pH5.5为最佳;以葡萄糖为最佳碳源,尿素为最佳氮源,Cu2+浓度为60μmol/L有利于漆酶的分泌.正交试验表明,葡萄糖20g/L、尿素2g/L、250mL容量瓶中装液量50mL、pH5.5,以邻联甲苯胺作底物,经7d培养,金针菇漆酶酶活达最高峰,峰值酶活为328U/mL.     

废液焚烧处置控制系统的设计

介绍并分析了针对废液焚烧处置进行的控制系统（PID）的构成、设计和应用;结合焚烧处置系统的流程及技术要点,通过合理的设计,实现了稳定且功能全面的焚烧装置控制系统。     

GIS技术在土地资源估价中的应用分析

本文主要分析了GIS技术的功能、概念、发展及基于该技术的土地估价信息系统的组成、功能和优越性。为土地估价提供了强有力的技术支持和科学依据     

环烷酸废水离心萃取装置的防垢,除垢研究

通过分析垢的组成和形成原因，提出预防沥青状物质、硫酸（氢）钠结晶、氢氧化铁沉淀进入萃取机，预防氢氧化铁沉淀进入反萃机的防垢措施，实验验证了ＦＡ、ＦＢ溶剂分别为萃取机转鼓积垢和反萃机转鼓积垢的优良洗脱剂．