气提反应器处理中等浓度生活污水的试验研究

对气提反应器处理生活污水进行了试验研究,探讨了生物膜的形成和水力停留时间及曝气量时中低浓度生活污水处理效果的影响.结果表明:最优条件是在HRT为6h,曝气量为0.6 m3/h,进水COD和NH4+-N质量浓度分剐为240.2～298.7 mg/L和29.1～68.9 mg/L条件下,平均COD去除率为83%,NH4+-N去除率为95.1%.     

沙地水分研究现状

沙地水分的研究状况,很大程度代表人类活动与自然环境间相互关系中的许多典型问题。本文简要介绍沙地水分研究现状。     

能源审计在煤炭企业推进节能降耗工作的实践与应用

重点剖析了煤炭企业开展能源审计的特点和方法,对于煤炭企业开展能源审计工作,实现节能降耗具有一定参考价值.     

基于SMOP模型的耕地保护目标决策研究

耕地保护是保证区域社会经济可持续发展的基础所在,保护的程度不够会危及到粮食安全、社会稳定,保护过度又会影响到建设用地的供给。选择合理的耕地保护目标,成为了一个亟待解决的问题。论文在系统研究耕地保护的影响因素,以及耕地与其他各类用地关系的基础上,构建了情景-多目标规划模型(SMOP)。以浙江省为例,通过模型的运算,得出了不同情景模式下耕地的保有量。结果表明,8个情景模式中,只有情景B和F求出了最优解(低人口增长水平、生存用粮自给、较高的粮食单产水平情景以及高人口增长水平、生存用粮自给、较高的粮食单产水平情景)。通过进一步分析,其他情景模式无法得出最优解的原因是耕地需求超过了耕地供给能力。也就是说在其他情景模式下,耕地均存在一定的缺口,粮食安全受到了不同程度的威胁。情景G(高人口增长水平、营养用粮自给、稳定的粮食单产水平情景)的耕地缺口数和耕地压力指数最大。浙江省必须从挖掘耕地生产潜力以及建立健全粮食市场入手才能实现经济发展和粮食安全的双赢。SMOP模型能够较好地体现系统的复杂性和不确定性,其结果真实地反映了浙江省的资源禀赋和未来的发展可能。     

六叉河小流域不同景观结构中径流磷形态差异分析

选取巢湖六叉河小流域,研究了流域内不同类型景观降雨产流过程中径流磷素的形态差异.结果表明,旱地径流中总磷、溶解性总磷、颗粒态总磷、总活性磷、颗粒态活性磷的浓度最高,水稻田次之,河道中最低.颗粒态磷是旱地和水稻田磷索输出的主要形态,颗粒态活性磷占总活性磷的80%以上;而河道径流中各种磷形态浓度值均较低,总磷浓度均值在0.4mg·L-1以下,磷素输出以溶解态磷为主.磷素由旱地经过水稻田向河道传输过程中,颗粒物浓度显著下降,河流中颗粒态磷浓度降低至50%左右,活性组分浓度显著降低.由水塘、沟渠等组成的多水塘系统不仅降低了磷素输出的总量,而且对活性磷有较强的削减作用,在非点源流域控制及水源地水质保护方面有重要意义.     

Fraction distribution and risk assessment of heavy metals in sediments of Moshui Lake

To examine the status and risk of heavy metal pollution in urban lakes, in China, the distribution of several heavy metals (e.g., Cr, Cu, Ni, Pb, Zn) in the sediment of Moshui Lake, Hangyang District, Wuhan City, was characterized. The process of rapid urbanization and industrialization of the district was also studied to find out its relationship with the metal accumulation profile in the sediment. It was found that the total concentration of heavy metals in the sediment was higher than the severe e ect level (SEL), at all sampling sites, except those in the riparian zone. The Cr and Cu maximum concentrations were 1,780 and 1,250 mg/kg, approximately 16 and 11 times as much as the SEL values, and they appeared as deep as 32 cm in one sample. The carbonate and exchangeable fractions of Zn were more than 50% of the total Zn content, resulting in very high risk according to the Risk Assessment Code (RAC). For Cu and Ni, a medium RAC value was found for carbonate and exchangeable fractions of 11%–20%. As sensitive indicators of contaminants in aquatic systems, heavy metals in the sediment reflect the outcome of regional urbanization, industrialization, and environmental management. With rapid urbanization, sedimentary Pb and Zn concentrations increased. The experimental results showed that high sedimentary heavy metal concentrations had resulted from rapid urbanization and industrialization, which would absolutely lead to substantial aquatic environmental decline in urban lakes.     

Effects of operational factors on soluble microbial products in a carrier anaerobic ba ed reactor treating dilute wastewater

The effects of feed strength, hydraulic residence time （HRT）, and operational temperatures on soluble microbial product （SMP） production were investigated, to gain insights into the production mechanism. A carrier anaerobic baffled reactor （CABR） treating dilute wastewater was operated under a wide range of operational conditions, namely, feed strengths of 300-600 mg/L, HRTs of 9- 18 h, and temperatures of 10-28℃. Generally, SMP production increased with increasing feed strength and decreasing temperature. At high temperature （28℃）, SMP production increased with decreasing HRT. As the temperature was decreased to 18 and 10℃, the SMP production was at its peak for 12 h HRT. Therefore, temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand （SCOD） ratio was found at high temperature and long HRT because of complete volatile fatty acid degradation. SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR. As a secondary metabolite, some SMP could be consumed at lower feed strength.     

于桥水库周边农业小流域地表径流和亚表层流的磷素流失浓度特征

选择天津市重要饮用水水源地于桥水库周边2个农业小流域,连续5a进行了磷素流失的实验研究.结果表明,地表径流总磷浓度以果园为最高,浓度超过10 mg·L-1;村庄次之;农田最低,浓度在3 mg·L-1左右.降雨后亚表层流中磷浓度以果园为最高,且变幅最大,菜园次之,农田最低.在流域出口处,曹各庄流域地表径流总磷浓度达到10.07 mg·L-1,而桃花寺流域为0.69mg·L-1.土地利用类型格局和迁移廊道性质是造成2个流域磷素浓度差异的主要原因:曹各庄流域中村庄和果园同水库较近的距离(约200 m),以及道路型季节性河流增加了磷素迁移到受纳水体的风险;桃花寺流域中村庄和果园离受纳水体较远(约1500 m),在迁移过程中磷素被小石坝、植被过滤带和干塘等"汇"型结构所持留,从而减少了向受纳水体迁移的风险.     

暴雨型湿地孔隙水中铁锰的时空变化特征

为了进一步探究湿地的净化机制和生物地球化学循环过程,2004～2006年通过连续3 a对武汉动物园暴雨型人工湿地进行原位定期监测,主要研究了湿地孔隙水中铁锰的时空分布特征及其对氧化还原电位(oxidation reduction potential,ORP)的影响.结果表明,暴雨型湿地水位出现周期性的波动,水位的变化范...     

活性炭催化过二硫酸盐降解水中AO7

过二硫酸盐（persulfate,PS）活化技术是基于硫酸根自由基（SO 4^-.）的一种新型高级氧化技术.用颗粒状活性炭（GAC）常温常压下直接非均相催化PS来降解水中难生化偶氮染料AO7（acid orange 7）.结果表明,GAC/PS体系对AO7不但能够快速脱色,而且有较高的矿化率.n（PS）∶n（AO7）为...