生活废水生物除磷工艺研究

综述了生活废水生物除磷工艺的基本原理以及目前国内流行的几种除磷方法，并且探讨了生物除磷的影响因素，对新工艺做了假想。     

POTENTIAL PHOSPHORUS LOAD REDUCTIONS UNDER THE LAKE OKEECHOBEE REGULATORY PROGRAM1

ABSTRACT: Nutrient loading from beef pastures located within the northern Lake Okeechobee watershed in Florida, has been identified as a source of phosphorus contributing to the accelerated eutrophication of the lake. Since 1989 within the watershed, 557 agricultural drainage sites, mainly beef pasture, have been monitored for compliance under a regulatory program. Of those sites, 154 were actively monitored for phosphorus concentrations from October 1, 1998, to September 30, 1999. Of these 154 sites, 77 were considered to be out of compliance (OOC). An OOC site is defined as having runoff with a 12‐month average phosphorus concentration exceeding the permitted discharge limit. The average annual phosphorous load from the 77 OOC sites for an eight‐year study period from October 1, 1991, to September 30, 1999, was estimated using measured concentration values and simulated runoff obtained from an agricultural nonpoint source pollution model, CREAMS‐WT. The 77 OOC sites produced an estimated average annual 46 metric tonnes of phosphorus load, of which an estimated 22 tonnes of phosphorus reached Lake Okeechobee on an average annual basis. The remaining estimated average annual 24 tonnes of phosphorus load was retained by streams and wetlands in the discharge transport system between the sites and the lake. The estimated average annual load reaching Lake Okeechobee from the OOC sites represented 11 percent of the phosphorus load above a five‐year average annual target load for the lake. However, the OOC site drainage areas represented only 3 percent of the northern watershed that drains into the lake. Of the 77 OOC sites, 12 sites had an average annual phosphorus loading rate equal to or greater than 3.0 kg/ha and were placed on the priority list for the Critical Restoration Project in the Lake Okeechobee watershed. To estimate the possible phosphorus load reductions from the 77 sites, two scenarios were modeled. The first scenario reduced phosphorus concentrations in runoff to the permitted discharge limits under the Lake Okeechobee regulatory program. The second scenario changed current land uses to native rangeland with an estimated annual offsite total phosphorus areal loading rate of 0.114 kg/ha. These two scenarios are hypothetical with assumed concentration values and loading rate. Model results showed that the first management scenario reduced the average annual phosphorus load to the lake by an estimated 15 tonnes. The second scenario reduced the average annual phosphorus load to the lake by an estimated 21 tonnes.     

晶析辅助化学沉淀法处理高含磷废水

在常温条件下,将价格低廉的氯化镁、碳酸氢铵加入到高浓度含磷废水中,不仅有较高的除磷率,且可兼得缓效复合肥MgNH4PO4·6H2O。为了使一次处理液能达标排放,以MgNH4PO4·6H2O作为晶种,采用晶析辅助化学沉淀法进一步除磷。在一次处理液放置时间为2.7h、水力停留时间维持0.1h左右的条件下,处理后的废水可达到Ⅱ类水排放标准(磷质量浓度不超过2.0mg/L)。     

养猪废水的吸附-过滤法初级处理试验研究

以实际养猪废水为对象,采用吸附-过滤法进行预处理,研究稻草滤料和稻草-沸石双层滤料在不同滤速下对养猪废水中CODCr、氨氮和磷的去除效果.结果表明,稻草-沸石双层滤料对CODCr、氨氮和磷的去除效果明显优于稻草滤料.以稻草-沸石双层滤料为过滤介质时,5 m/h的滤速下,CODCr、氨氮和磷的最大去除率分别达47 9%、72 9%和50 1%.研究表明,吸附-过滤预处理不仅能去除养猪废水中的CODCr、氨氮和磷,还能去除一定量的小分子有机物和臭味,同时附着大量固体有机物的稻草和吸附有氨氮、磷的沸石经过处理后可作为土壤改良剂或肥料,从而实现了农业固体废物的资源化利用.     

EVALUATION OF SOME APPROACHES TO ESTIMATING NON-POINT POLLUTANT LOADS FOR UNMONITORED AREAS1

ABSTRACT: Evaluation of the non-point source pollutant load entering a lake from multiple tributaries requires either that all tributaries be monitored or that some extrapolation method be used to estimate loads originating in areas not monitored. Unmonitored areas include not only watersheds of tributaries that are not monitored, but also portions of a monitored tributary's drainage basin downstream from the monitoring site and areas of direct drainage. Significant portions of large lake drainage basins are often not monitored, and loads for these areas are often estimated by extrapolation. Six simple extrapolation procedures were evaluated by using them to estimate loads for areas that had been monitored and comparing the estimated loads with the monitored loads. Three approaches were based on inter-basin ratios of area, C-factor, and discharge. The other approaches used regression relationships between concentration and flow to estimate concentrations for the unmonitored basin. The ratio approaches generally were more reliable than the regression approaches. However, extrapolation by any method tested was not very precise. Some methods also were biased when applied to watersheds of a size different than the monitored one. Extrapolation by any of these methods would compromise the precision of the lake-wide load estimate, if the unmonitored area were a significant part of the entire basin.     

ASSESSMENT OF NUTRIENT EFFECTS AND NUTRIENT LIMITATION IN LAKE OKEECHOBEE1

ABSTRACT: Lake Okeechobee, the third largest lake in the United States, is a shallow, mixing basin with annual total phosphorus concentrations ranging from 50–100 μg P/L. Data, mainly from unpublished agency reports, are analyzed to determine if nutrients limit phytoplankton, to describe spatial and temporal variability in trophic state parameters, and to evaluate conclusions obtained from empirical trophic state models. Algal bioassay experiments that have been used to assess nutrient limitation have produced equivocal results. However, seasonal minima in orthophosphorus and inorganic nitrogen indicate that both nutrients may be limiting seasonally. Strong, but reverse north-south gradients and large seasonal changes in phosphorus and nitrogen concentrations, show that empirical models based on annual phosphorus loadings or concentrations are not adequate to predict chlorophyll concentrations or other trophic state variables. Spatially-segmented, multi-class phytoplankton-nutrient models of seasonal phytoplankton responses that are coupled with hydrodynamic models may provide predictability in assessing effects of changing nutrient loads on phytoplankton composition and standing crop. Successful modeling efforts of responses to nutrients also must deal with resuspended and benthic algae, periphyton, and emergent and submergent aquatic plants that must play important trophic roles in some of the lake basin.     

人工湿地基质除磷研究进展

基质除磷被认为是人工湿地磷去除的主要方式，除磷效果不仅受基质自身物理化学性质的影响，还受水力条件、磷负荷、pH值、季节、温度、有机负荷、溶解氧、干湿交替等因素的影响。本文较系统分析了湿地基质除磷的作用机理和基质除磷效率的影响因素，最后对今后研究的方向进行了展望。     

新型除磷混凝剂的研制与应用＊

实验以处理金属表面所产生的磷化废水为研究对象,系统地分析了在新型混凝剂的使用过程中,pH值、温度、石灰投入量、沉降时间、助剂A等因素对脱磷效果的影响。结果表明,含磷量为18mg/L、COD为300mg/L、SS为150mg/L、pH值为5.7～6.5的废水,石灰投入量为300mg/L、沉降时间为10min左右、温度为25℃、pH值调节至9.0、加入5mL助剂A处理后,废水中磷含量为0.25～0.35mg/L、COD为80mg/L、SS为60mg/L,满足《污水综合排放标准》(GB8978—1996)中的一级标准。     

环境行政执法难的理性分析与实践对策

环境行政执法难是非常态法律现象。从哲学的高度对环境行政执法难进行理性分析，环境行政执法难是多因素群共创的结果。对环境行政执法难的内外因进行解构，分清主次，着重解决影响环境执法难的主因，并适当关注影响环境执法难的助因，同时基于应然立场提出解决问题的实践进路。     

内循环厌氧反应器(IC)的应用与发展

从工程实践的角度对IC反应器的应用与研究现状进行了介绍, 并对IC反应器在工程应用中暴露出来的问题进行了详细分析,最后指出了IC反应器的研究发展趋势,表明IC反应器具有产业化的发展前景.