Effect of Cross-Linking Waste Protein with Diepoxides on its Biodegradation under Anaerobic Conditions

Biodegradability testing was performed in an aqueous environment under anaerobic conditions after inoculation with digested sludge from municipal wastewater treatment plant. In cross-linking with 1,2:3,4-diepoxybutane in limits 0.8–9.1% weight, biodegradability degree decreased from 76.8 to 62.2%; when 1,2:7,8 diepoxyoctane in quantities 1.1–13.2% weight was used, biodegradability degree dropped more prominently – from 72.3 to 22.8%. There is obviously a direct connection between growing cross-link degree (assessed by so-called fixation index) and decreasing readiness to biodegradation, apparently owing to build-up of a network forming an obstacle to access of micro-organisms and enzymes.     

Best Management Practices for Silvicultural Chemicals and the Science Behind Them

Silvicultural chemicals include fertilizers and pesticides applied for forest management. All states east of the Rockies have at least some form of silvicultural chemical best management practices (SCBMPs) and it is widely accepted that SCBMPs effect some protection of water quality. All SCBMPs recommend handling and application precautions and a minimum width streamside management zone (SMZ) on each side of streams for protection of water quality and aquatic ecosystems. Typically these zones increase in width as stream width increases. In areas where cold-water fish are present, additional widths are designated for their protection. Minimum SMZ widths range from 8 to 91 meters on each side of the stream bank for intermittent and perennial streams. Most SMZ recommendations do not cover ephemeral drainages, ditches or canals. SMZs are generally described as being site specific with width dependent on slope, soil type and other conditions as well as the stream's designation as perennial or intermittent. The science behind SCBMPs is often elusive. Spray drift can be controlled through proper selection and use of application technology while considering site specific conditions. SMZs greatly reduce the amount of herbicides reaching streams. Available toxicological data and research on aquatic ecosystem impacts from herbicide use suggest that additional protection from silvicultural chemicals may not be necessary. However, there is evidence to suggest that protection of ephemeral and intermittent channels can further reduce entry of silvicultural chemicals into streams and also reduce sedimentation. This may be the most fruitful area of research we can pursue in light of the knowledge gaps listed.     

Best management practices compliance monitoring approaches for forestry in the eastern United States

Many of the eastern states that have published best management practices (BMPs) or forest management guidelines have also developed compliance monitoring programs to assess the application of these BMPs or guidelines on public and private forest land. The approaches among these states to collecting on-site monitoring data (measuring compliance) and evaluating sites are variable. A survey of eastern states found that almost all southern states monitor application of BMPs, but proportionally fewer of the northern states have established compliance monitoring programs. The state forestry agencies provide the leadership for these programs in most of the eastern states. States that monitor tend to evaluate all public and private forest landowner categories located within their states. In general, northern states monitor a broader array of site resources (e.g., cultural resources, visual quality) as compared to southern states which focus on water quality and wetlands protection. However, northern states focus their monitoring on timber harvesting, forest road construction and maintenance as compared to southern states which tend to monitor a broader array of forest management activities (e.g., site preparation, reforestation). When selecting sites for monitoring, the most common approach is to select some sites from all landowner categories within the state. Many states do not specify any criteria to identify sites for monitoring so that all sites have an equal chance for selection. Some states do use specific criteria to filter sites for monitoring, most commonly size of forest management activity and proximity to water.     

Review of in situ remediation technologies for lead,zinc, and cadmium in soil

This article presents a review of in situ technologies for the remediation of soils contaminated with lead, zinc, and/or cadmium. The objective of this review is to assess the developmental status of the available in situ technologies and provide a general summary of typical applications and limitations of these technologies. The literature review identified seven in situ remediation technologies—solidification/stabilization, vitrification, electrokinetic remediation, soil flushing, phytoextraction, phytostabilization, and chemical stabilization. These technologies were considered for their ability to meet a specific set of remediation objectives under a range of conditions. Each of these technologies has both strengths and weaknesses for addressing particular remedial situations discussed in the article for each of the technologies. A general summary of which technologies are most applicable to common remedial scenarios is also provided. © 2004 Wiley Periodicals, Inc.     

Towards a model of safety climate measurement.

In this study, a survey instrument was developed to measure safety climate. A review of the scientific literature as well as consultation with an expert panel was used to determine the survey's dimensions. Next, the survey was administered, first as a pilot study (n = 15) and then as a full scale study (n = 229), to employees of the City of Cincinnati Department of Public Works. The psychometric integrity of the survey was assessed according to validity, reliability and utility criteria. Results are presented and discussed.     

Symptom patterns, and perceptual and cognitive styles in subjects with multiple chemical sensitivity (MCS)

Multiple chemical sensitivity (MCS) is defined as a syndrome with multiple medically unexplained symptoms attributed to low levels of chemically unrelated substances in the environment. The etiology of this syndrome is still unclear. As MCS may be conceptualized as an atypical type of somatoform disorder, the purpose of the study was to examine whether MCS subjects show symptom patterns, personality traits, and perceptual and cognitive styles as typically found in somatoform patients. Nonsensitive controls (n=36) were compared to subjects with moderate (n=35) and high (n=35) MCS intensity with self-report psychological questionnaires and structured interviews for depression and somatoform disorders. The high MCS group scored significantly higher than the other two groups on self-report scales for somatoform symptoms and depression. Moreover, high MCS was strongly associated with the diagnosis of somatoform disorder, and weaker but still significantly with depression. In a stepwise multiple regression analysis, cognitions about environmental threat, trait anxiety, focus on autonomic sensations, and general environmental sensitivity predicted MCS symptoms in the total sample, explaining 53% of the variance. These results support the hypothesis that trait negativity and mechanisms of symptom perception and symptom amplification contribute to the enhanced symptom reports of MCS individuals.     

Environmental assessment of supercritical water oxidation of sewage sludge

Environmental aspects of using supercritical water oxidation (SCWO) to treat sewage sludge were studied using a life cycle assessment (LCA) methodology. The system studied is the first commercial scale SCWO plant for sewage sludge in the world, treating sludge from the municipal wastewater treatment facility in Harlingen, TX, USA. The environmental impacts were evaluated using three specific environmental attributes: global warming potential (GWP), photo-oxidant creation potential (POCP) and resource depletion; as well as two single point indicators: EPS2000 and EcoIndicator99. The LCA results show that for the described process, gas-fired preheating of the sludge is the major contributor to environmental impacts, and emissions from generating electricity for pumping and for oxygen production are also important. Overall, SCWO processing of undigested sewage sludge is an environmentally attractive technology, particularly when heat is recovered from the process. Energy-conserving measures and recovery of excess oxygen from the SCWO process should be considered for improving the sustainability potential.     

TRANSIENT RESPONSE FUNCTIONS FOR CONJUNCTIVE WATER MANAGEMENT IN THE SNAKE RIVER PLAIN,IDAHO1

ABSTRACT: Increasing demands on western water are causing a mounting need for the conjunctive management of surface water and ground water resources. Under western water law, the senior water rights holder has priority over the junior water rights holder in times of water shortage. Water managers have been reluctant to conjunctively manage surface water and ground water resources because of the difficulty of quantification of the impacts to surface water resources from ground water stresses. Impacts from ground water use can take years to propagate through an aquifer system. Prediction of the degree of impact to surface water resources over time and the spatial distribution of impacts is very difficult. Response functions mathematically describe the relationship between a unit ground water stress applied at a specific location and stream depletion or aquifer water level change elsewhere in the system. Response functions can be used to help quantify the spatial and temporal impacts to surface water resources caused by ground water pumping. This paper describes the theory of response functions and presents an application of transient response functions in the Snake River Plain, Idaho. Transient response functions can be used to facilitate the conjunctive management of surface and ground water not only in the eastern Snake River Plain basin, but also in similar basins throughout the western United States.     

CHARACTERIZATION OF INORGANIC PARTICLES IN SELECTED RESERVOIRS AND TRIBUTARIES OF THE NEW YORK CITY WATER SUPPLY1

ABSTRACT: Individual particle analysis (IPA) by scanning electron microscopy interfaced with automated image and X‐ray analyses was used to characterize inorganic particles in five reservoirs and four tributaries located within the Catskill and Delaware systems of the New York City water supply. Individual particle analysis provides combined elemental and morphologic characterizations. Results are presented in terms of particle projected area per unit volume (PAV), consistent with optical impacts, and partitioned into seven generic particle types according to composition. Minerals of terrigenous origins, particularly clay minerals, dominated the inorganic particle populations of all the study systems except one downstream reservoir. Higher PAV levels were observed in the Catskill system. Particle dynamics represented by PAV were driven primarily by runoff, while the reservoirs were also greatly influenced by the timing of sediment resuspension promoted by drawdown of the surface and fall mixing. The benefit of the serial configuration of the reservoirs in decreasing inorganic particles with progression downstream towards the city is demonstrated. The patterns in PAV levels among the study systems generally tracked those of more common metrics of impacts of suspensoids, including mass concentrations of suspended solids, turbidity, and Secchi disc transparency.