Coastal water quality impact of stormwater runoff from an urban watershed in southern California

Field studies were conducted to assess the coastal water quality impact of stormwater runoff from the Santa Ana River, which drains a large urban watershed located in southern California. Stormwater runoff from the river leads to very poor surf zone water quality, with fecal indicator bacteria concentrations exceeding California ocean bathing water standards by up to 500%. However, cross-shore currents (e.g., rip cells) dilute contaminated surf zone water with cleaner water from offshore, such that surf zone contamination is generally confined to < 5 km around the river outlet. Offshore of the surf zone, stormwater runoff ejected from the mouth of the river spreads out over a very large area, in some cases exceeding 100 km2 on the basis of satellite observations. Fecal indicator bacteria concentrations in these large stormwater plumes generally do not exceed California ocean bathing water standards, even in cases where offshore samples test positive for human pathogenic viruses (human adenoviruses and enteroviruses) and fecal indicator viruses (F+ coliphage). Multiple lines of evidence indicate that bacteria and viruses in the offshore stormwater plumes are either associated with relatively small particles (< 53 microm) or not particle-associated. Collectively, these results demonstrate that stormwater runoff from the Santa Ana River negatively impacts coastal water quality, both in the surf zone and offshore. However, the extent of this impact, and its human health significance, is influenced by numerous factors, including prevailing ocean currents, within-plume processing of particles and pathogens, and the timing, magnitude, and nature of runoff discharged from river outlets over the course of a storm.     

Seasonal variations in concentrations of pharmaceuticals and personal care products in drinking water and reclaimed wastewater in southern California

Southern California imports nearly all of its potable water from two sources: the Colorado River and the California State Water Project (Sacramento-San Joaquin River Basin). Sewage treatment plant effluent (STPE) heavily impacts both of these sources. A survey of raw and treated drinking water from four water filtration plants in San Diego County showed the occurrence of several polar organic "pharmaceuticals and personal care products" (PPCP). These included phthalate esters, sunscreens, clofibrate, clofribric acid, ibuprofen, triclosan, and DEET. Several of these were also found in the finished water, such as di(ethylhexyl) phthalate, benzophenone, ibuprofen, and triclosan. Occurrence and concentrations of these compounds were highly seasonally dependent, and reached maximums when the flow of the San Joaquin River was low and the quantity of imported water was high. The maximum concentrations of the PPCPs measured in the raw water were correlated with low flow conditions in the Sacramento-San Joaquin Delta that feeds the State Water Project. The PPCP concentrations in raw imported water in the summer months approached that of reclaimed nonpotable wastewater.     

Behavior of the mass transfer zone in a biosorption column

Modeling of the mass transfer zone behavior under variable conditions in a flow-through fixed-bed sorption column enabled the prediction of breakthrough curves for Cu2+ and Ca-preloaded Sargassum fluitans biomass. The mass transfer resistance, particle diffusion, and the axial dispersion were incorporated in the model. The dynamics of the mass transfer zone was described under variable sorption column operating conditions including different column lengths and fluid flow rates. Accurate estimation of the behavior of the mass transfer zone as it progressed through the column, reflected eventually in the breakthrough curve, assisted in its relevant interpretations. Furthermore, the proposed mathematical model of the biosorption process was capable of demonstrating the expanding and broadening of the mass transfer zone linked to the equilibrium sorption isotherm. The fundamental understanding of the mass transfer zone dynamics is particularly important for process scale-up where maintaining the process efficiency is critical.     

聚酰胺层析法分离纯化牛蒡叶中的总黄酮

用聚酰胺层析法分离纯化牛蒡叶中总黄酮,并用分光光度法对其含量进行测定。文中采用水提、纤维素酶提以及纤维素酶乙醇提取方法,得到总黄酮含量不同的提取液,分别使之流经聚酰胺柱,其中的黄酮类物质被聚酰胺吸附后,用体积分数70%乙醇洗脱,考察洗脱曲线及纯度,采用分光光度法进行定量测定。结果显示:纤维素酶乙醇法提取液中黄酮含量最高,纤维素酶法次之,水提取法最低,70%乙醇可以将3种提取方法得到的绝大部分黄酮类化合物洗脱下来,回收率分别为93.0%、92.4%和93.7%,得到的产品纯度分别为15.84%、12.71%和12.33%。纤维素酶乙醇法可有效提高牛蒡叶中总黄酮的提取率,聚酰胺层析法可使总黄酮的纯度有较大幅度的提高。     

Distribution, characteristics, and worldwide inventory of dioxins in kaolin ball clays

Distribution, characteristics, and global inventory of dioxins (polychlorinated dibenzo-p-dioxins [PCDDs] and dibenzofurans [PCDFs] and dioxin like polychlorinated biphenyls) in kaolin clays collected from 10 countries were investigated. Dioxins were found in all kaolin clay samples analyzed, at total concentrations ranging from 1.2 pg/g (Brazil) to 520,000 pg/g (USA). Dioxin concentrations in kaolin clays from a few countries (e.g., Brazil and UK) were lower than those reported for background soils in Japan. Dioxin profiles in kaolin clays were characterized by the domination of the congener octachlorodibenzo-p-dioxin (OCDD), and the concentrations of other congeners decreased in the order of reduction in the levels of chlorination. Furthermore, specific distribution of congeners, with predominant proportions of 1,4,6,9-substituted PCDDs within each homologue group, was found in most clay samples. The ratios of concentrations of PCDD to PCDF and 1,2,3,7,8,9-HxCDD to 1,2,3,6,7,8-HxCDD indicated differences in the profiles found for anthropogenic sources (including pentachlorophenol) and kaolin clays. Concentrations of PCDD/Fs in kaolin clays, except for American ball clays, did not exceed the environmental criteria set by the Law Concerning Special Measures against Dioxins in Japan. Based on the average concentrations measured in our study, inventories of PCDD/Fs from the production/usage of ball clays on a global scale were estimated to be 650 kg/yr; the corresponding value on a TEQ basis is 2400 g-TEQ/yr. More than 480 kg of OCDD is estimated to be released annually from the production of kaolin clays worldwide, suggesting that kaolin clays can be a major contributor for additional source of dioxins, especially OCDD, in the environment.     

Distribution and fluxes of total and methylmercury in Lake Superior

Despite the importance and size of Lake Superior, little is known regarding the biogeochemical cycling or distribution of mercury within its waters. We present the results from two research cruises on total Hg (HgT) and methylmercury (MeHg) distributions in aqueous and particulate phases, and in offshore sediments. Open waters of Lake Superior are similar in HgT content to Lakes Michigan and Ontario (sub-ng L(-1)), whereas MeHg was only 1% of HgT. Seasonality in aqueous HgT distribution was observed, most likely from tributary inputs during Spring snowmelt. Suspended particles were enriched in MeHg relative to water and surficial sediments, suggesting enhanced particle partitioning followed by demethylation in the water column and in surface sediments. Distribution coefficients for mercury in surficial sediments were lower than those in suspended material, likely due to remineralization. Preliminary estimates of mass balance indicate that air-water exchange processes such as evasion and wet deposition dominate the HgT budget, due to the basin's relatively small watershed area relative to lake area. In contrast, methylmercury cycling within Lake Superior is influenced more strongly by watershed sources, as well as by sedimentary sources and photodemethylation. The Hg cycle in Lake Superior is unique in that it is more similar in many aspects to that in marine systems than in small lakes, where management data for freshwaters typically originates.     

Influence of climate change, tidal mixing, and watershed urbanization on historical water quality in Newport Bay, a saltwater wetland and tidal embayment in southern California

Historical coliform measurements (n = 67,269; 32 years) in Newport Bay, a regionally important saltwater wetland and tidal embayment in southern California, have been compiled and analyzed. Coliform concentrations in Newport Bay decrease along an inland-to-ocean gradient, consistent with the hypothesis that this tidal embayment attenuates fecal pollution from inland sources. Nearly 70% of the variability in the coliform record can be attributed to seasonal and interannual variability in local rainfall, implying that stormwater runoff from the surrounding watershed is a primary source of coliform in Newport Bay. The storm loading rate of coliform from the San Diego Creek watershed--the largest watershed draining into Newport Bay--appears to be unaffected by the dramatic shift away from agricultural land-use that occurred in the watershed over the study period. Further, the peak loading of coliform during storms is larger than can be reasonably attributed to sources of human sewage, suggesting that nonhuman fecal pollution and/or bacterial regrowth contribute to the coliform load. Summer time measurements of coliform exhibit interannual trends, but these trends are site specific, apparently due to within-Bay variability in land-use, inputs of dry-weather runoff, and tidal mixing rates. Overall, these results suggest that efforts to improve water quality in Newport Bay will likely have greater efficacy during dry weather summer periods. Water quality during winter storms, on the other hand, appears to be dominated by factors outside of local management control; namely, virtually unlimited nonhuman sources of coliform in the watershed and global climate patterns, such as the El Nino Southern Oscillation, that modulate rainfall and stormwater runoff in southern California.     

Management experiences and trends for water reuse implementation in Northern California

In 2010, California fell nearly 300,000 acre-ft per year (AFY) short of its goal to recycle 1,000,000 AFY of municipal wastewater. Growth of recycled water in the 48 Northern California counties represented only 20% of the statewide increase in reuse between 2001 and 2009. To evaluate these trends and experiences, major drivers and challenges that influenced the implementation of recycled water programs in Northern California are presented based on a survey of 71 program managers conducted in 2010. Regulatory requirements limiting discharge, cited by 65% of respondents as a driver for program implementation, historically played an important role in motivating many water reuse programs in the region. More recently, pressures from limited water supplies and needs for system reliability are prevalent drivers. Almost half of respondents (49%) cited ecological protection or enhancement goals as drivers for implementation. However, water reuse for direct benefit of natural systems and wildlife habitat represents just 6-7% of total recycling in Northern California and few financial incentives exist for such projects. Economic challenges are the greatest barrier to successful project implementation. In particular, high costs of distribution systems (pipelines) are especially challenging, with $1 to 3 million/mile costs experienced. Negative perceptions of water reuse were cited by only 26% of respondents as major hindrances to implementation of surveyed programs.     

Size distribution, sources, and seasonality of suspended particles in southern California marine bathing waters

In this paper we define seasonal and along-shore variations in suspended particle size distributions (PSDs) at two marine bathing beaches in southern California, using a low-angle light scattering instrument (LISST). Empirical Orthogonal Function (EOF) analysis of the LISST data set (n = 55 651) identified three particle size modes that collectively account for > 90% of the variance in the de-meaned PSD data at six sites along the shoreline at Huntington Beach and Newport Beach: a dinoflagellate mode, a large particle mode, and a small particle mode. These three modes exhibit distinct seasonal patterns, and along-shore distributions, reflecting both the sources of particles and environmental factors that trigger their occurrence. Comparison of volume-based PSDs generated from the LISST and from image analysis of optical micrographs indicates that the LISST performs well when measuring the size distribution of particles associated with dinoflagellate blooms. However, LISST measurements on stormwater-impacted samples consistently yield a rising tail at small particle sizes that may be an artifact arising from the non-spherical nature of inorganic particles in terrestrial runoff. The results presented here demonstrate that PSDs measured by light scattering instruments such as the LISST represent a new data resource for assessing water quality, and managing human health risk, at marine bathing beaches.     

Anthropogenic currents and shoreline water quality in Avalon Bay, California

Shoreline concentrations of fecal indicator bacteria (FIB) and fecal indicator viruses (FIV) in Avalon Bay (Catalina Island, California) display a marked diurnal pattern (higher at night and lower during the day) previously attributed to the tidal flux of sewage-contaminated groundwater and the tidal washing of contaminated sediments, coupled with light and dark die-off of FIB and FIV (Boehm, et al., Environ. Sci. Technol. 2009, 43, 8046-8052). In this paper we document the existence of strong (peak velocities between 20 to 40 cm/s) transient currents in the nearshore waters of Avalon Bay that occur between 07:00 and 20:00 each day. These currents, which have a significant onshore component, are generated by anthropogenic activities in the Bay, including prop wash from local boat traffic and the docking practices of large passenger ferries. A budget analysis carried out on simultaneous measurements of FIB at two cross-shore locations indicates that anthropogenic currents contribute to the diurnal cycling of FIB concentrations along the shoreline, by transporting relatively unpolluted water from offshore toward the beach. The data and analysis presented in this paper support the idea that anthropogenic currents represent a significant, and previously overlooked, source of variability in shoreline water quality.     

Scaling and management of fecal indicator bacteria in runoff from a coastal urban watershed in southern California

This paper describes a series of field studies aimed at identifying the spatial distribution and flow forcing of fecal indicator bacteria in dry and wet weather runoff from the Talbert watershed, a highly urbanized coastal watershed in southern California. Runoff from this watershed drains through tidal channels to a popular public beach, Huntington State Beach, which has experienced chronic surf zone water quality problems over the past several years. During dry weather, concentrations of fecal indicator bacteria are highest in inland urban runoff, intermediate in tidal channels harboring variable mixtures of urban runoff and ocean water, and lowest in ocean water at the base of the watershed. This inland-to-coastal gradient is consistent with the hypothesis that urban runoff from the watershed contributes to coastal pollution. On a year round basis, the vast majority (>99%) of fecal indicator bacteria loading occurs during storm events when runoff diversions, the management approach of choice, are not operating. During storms, the load of fecal indicator bacteria in runoff follows a power law of the form L approximately Qn, where L is the loading rate (in units of fecal indicator bacteria per time), Q is the volumetric flow rate (in units of volume per time), and the exponent n ranges from 1 to 1.5. This power law and the observed range of exponent values are consistent with the predictions of a mathematical model that assumes fecal indicator bacteria in storm runoff originate from the erosion of contaminated sediments in drainage channels or storm sewers. The theoretical analysis, which is based on a conventional model for the shear-induced erosion of particles from land and channel-bed surfaces, predicts that the magnitude of the exponent n reflects the geometry of the stormwater conveyance system from which the pollution derives. This raises the possibility that the scaling properties of pollutants in stormwater runoff (i.e., the value of n) may harbor information about the origin of nonpoint source pollution.     

Distribution of enterobacteriaceae in recycled manure bedding on California dairies.

The distribution of coliform organisms on three California dairies which use a system of automatic flushing of alley ways and composted, recycled manure solids as free stall bedding for utilization of waste was studied. There was a wide distribution of Escherichia coli, Klebsiella, and Enterobacter and to less extent Citrobacter organisms. Klebsiella were not commonly in bovine feces. Composting manure solids effectively reduced coliform counts to few or to zero. However, if given proper conditions of moisture and temperature, coliforms could multiply to large numbers again in composted solids whether from survivors or from external contamination. Dried composted manure was satisfactory material for bedding of free stalls provided it was dried properly before application.     

The enzymatic degradation of DDT. 6. The fate of the DDT metabolites dichlorodiphenyldichloroethylene and dichlorodiphenylmonochloroethylene in the rat

DDE is hydrogenated in the rat organism. The distribution of the compound is described. DDMU is degradated to DBP as well as transformed to DDA and DDOH. Excretion and distribution are studied.     

Rapid and automated detection of fluorescent total bacteria in water samples

Traditional methods for the detection and enumeration of bacteria in water samples are growth-based and require several days to obtain the result. New techniques which reduce the time of analysis have been developed. The objective of this work was to test a rapid method for the detection and enumeration of total viable bacteria using direct fluorescent labelling and detection by laser scanning. This method (referred to as TVC for Total Viable Count) was compared to the R2A culture method and the cyano-ditolyl-tetrazolium chloride (CTC) staining method for the analysis of samples before the final chlorination (after GAC filtration) and drinking water samples. For the comparison of TVC and CTC, the outcome depends on the water type: for samples after GAC filtration, TVC counts were significantly lower than CTC counts by up to 2 log10 orders of magnitude. For chlorinated water samples, TVC counts were not significantly different from CTC counts. The comparison of TVC and R2A showed that TVC counts could be lower than R2A counts or equivalent depending on the type of water. For drinking water, the TVC method proved to yield results equivalent to those of the R2A method. The TVC method requires much shorter time frame than others. It is also simple to use and allows the analysis of large volumes (100 ml) of drinking water.     

Inhibition of basal and stimulated progesterone synthesis by dichlorodiphenyldichloroethylene and methoxychlor in a stable pig granulosa cell line

The effects of the insecticide dichlorodiphenyldichloroethylene (DDE) and methoxychlor in a stable pig granulosa cell line, JC-410, were investigated. The studies of DDE and methoxychlor were conducted in combination with studies of cholera toxin, the protein kinase A activator that stimulates cAMP and progesterone synthesis and gene expression of P450 cholesterol side chain cleavage (P450scc), which converts cholesterol to pregnenolone. Administration of DDE at 3000 and 10 000 ng ml (-1) was found to decrease progesterone synthesis 0.49- and 0.25-fold, respectively, and to block the stimulatory effect of 100 ng cholera toxin ml (-1), after 24 h incubation. At 1-100 ng ml (-1), methoxychlor did not affect progesterone synthesis after 48 h incubation. However, 1000 ng methoxychlor ml (-1) decreased progesterone synthesis 0.32-fold, and both 100 and 1000 ng methoxychlor ml (-1) blocked the stimulatory effect of cholera toxin. At 3000 and 10 000 ng ml(-1), DDE decreased cAMP synthesis 0.66-and 0.36-fold, respectively. At 300, 3000 and 10 000 ng ml (-1), DDE also decreased cholera toxin-stimulated cAMP synthesis 0.84-, 0.68-, and 0.52-fold, respectively. Administration of 1-100 ng methoxychlor ml (-1) did not affect basal or cholera toxin-stimulated cAMP synthesis. Cholera toxin increased P450scc mRNA 1.4-fold after 24 h incubation, while 3000 and 10 000 ng DDE ml (-1) led to 0.39- and 0.18-fold reductions, respectively. The stimulatory effect of cholera toxin on P450scc mRNA was blocked by 3000 and 10 000 ng DDE ml(-1). Cholera toxin increased P450scc mRNA 3.48-fold after 48 h incubation, while 100 and 1000 ng methoxychlor ml (-1) increased P450scc mRNA 1.79- and 3.0-fold, respectively, and further increased the stimulatory effect of cholera toxin 6.47- and 5.44-fold, respectively. The results of the present study indicate that DDE inhibits granulosa cell steroidogenesis by affecting cAMP production and P450scc gene expression. However, methoxychlor appears to inhibit steroidogenesis by a mechanism occurring before the conversion of cholesterol into pregnenolone.