Butyltins in the sediments of Kochi and Mumbai harbours, west coast of India

Surface sediment samples were collected from various locations in the Mumbai and Kochi harbours, west coast of India, to assess the presence of butyltin compounds. Tributyltin (TBT) and dibutyltin (DBT) varied from 16 to 16,816 ng/g dry wt. and from undetected to 469 ng/g dry wt., respectively, of the sediment in Kochi harbour. In Mumbai harbour, the values of TBT and DBT ranged between 4.5 and 1193 ng/g dry wt. and from undetected to 131 ng/g dry wt. of the sediments, respectively. The concentrations of both TBT and DBT showed strong seasonal variation probably due to the effect of tides and currents. Nevertheless, the levels of butyltin compounds were generally higher at sites influenced by shipping activities such as navigation, dry dock and ship-building activities. The presence of DBT indicates the abiotic or microbiological degradation of TBT. Compared to TBT, DBT was relatively less abundant, suggesting either fresh inputs of TBT and/or less degradation of TBT. The concentrations of TBT showed significant positive relationships with organic carbon and lipid, implying that both lipophilic and ionic interactions were probably involved in controlling the abundance of TBT at these sediments. The observed levels of butyltin compounds are much higher than those required to induce toxic effects on marine organisms, suggesting that these sediments were contaminated with butyltin compounds.     

Summary of 25 Years of Xylem Tracheids and Sewage/Sludge in the Sea

The Rapid Sewage/Sludge Indicator Technique (RSIT), developed during the early 1970′s, responded to critical needs within the Bureau of Water Pollution Control. It enabled quick detection of contamination in ocean water and bottom sediments during sewage-related emergencies and routine monitoring. RSIT became an invaluable tool for resource management, in determining where and to what extent marine environments are impacted, and when immediate information is necessary for public health decisions.

The RSIT utilizes microscopic examination for terrestrial plant vascular tissue, especially the xylem tracheid elements, as identifiers of sewage/sludge. Not normally found in ocean waters, this material, in toilet paper and the roughage of the human diet which passes through the digestive system intact, is an indicator of human faecal contamination. Minimal training and common laboratory materials allow gross screening in five minutes. New studies by the United States Environmental Protection Agency (USEPA), United States Geologic Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA), most recently at the 106-mile dump site off the New York Bight, revalidated the technique as a rapid, inexpensive, easy to use, semiquantitative indicator both for water column and sediment samples.     

Microbial diversity and dynamics during methane production from municipal solid waste

The objectives of this study were to characterize development of bacterial and archaeal populations during biodegradation of municipal solid waste (MSW) and to link specific methanogens to methane generation. Experiments were conducted in three 0.61-m-diameter by 0.90-m-tall laboratory reactors to simulate MSW bioreactor landfills. Pyrosequencing of 16S rRNA genes was used to characterize microbial communities in both leachate and solid waste. Microbial assemblages in effluent leachate were similar between reactors during peak methane generation. Specific groups within the Bacteroidetes and Thermatogae phyla were present in all samples and were particularly abundant during peak methane generation. Microbial communities were not similar in leachate and solid fractions assayed at the end of reactor operation; solid waste contained a more abundant bacterial community of cellulose-degrading organisms (e.g., Firmicutes). Specific methanogen populations were assessed using quantitative polymerase chain reaction. Methanomicrobiales, Methanosarcinaceae, and Methanobacteriales were the predominant methanogens in all reactors, with Methanomicrobiales consistently the most abundant. Methanogen growth phases coincided with accelerated methane production, and cumulative methane yield increased with increasing total methanogen abundance. The difference in methanogen populations and corresponding methane yield is attributed to different initial cellulose and hemicellulose contents of the MSW. Higher initial cellulose and hemicellulose contents supported growth of larger methanogen populations that resulted in higher methane yield.     

Passive sampling in combination with thermal desorption and gas chromatography as a tool for self-assessment of chemical exposure

Diffusive samplers for monitoring of air quality are user-friendly devices that can normally be operated by the user himself. Hence these samplers are suitable for self-assessment. Practical and work organisational aspects of self-assessment of chemical exposure were studied in different occupational settings. It was found that the diffusive sampler used in these studies, the Perkin-Elmer tube in combination with thermal desorption, worked well for the purpose and could be correctly handled by the individuals using it. The results from self-assessments agreed well with expert measurements carried out by an occupational hygienist. However, in order to obtain a sustainable system of self-assessment strong organizational support is needed.     

Reducing phosphorus runoff from dairy farms

Phosphorus (P) runoff from manure can lead to eutrophication of surface water and algae growth. This study evaluates the impacts of alternative P reduction practices on dairy farm net returns and on potential P runoff. The P control practices include dairy herd nutrient management, crop nutrient management, and runoff and erosion control. Four farms representative of dairies in the Virginia Shenandoah Valley are simulated including dairies with and without supplementary broiler enterprises and with average and below average land area. A mathematical programming model was developed to predict farm production and net returns and the GLEAMS model was used to predict potential P runoff. The farms are evaluated under four scenarios: Scenario 1, no constraint on P runoff with access to crop nutrient, runoff and erosion control strategies but no access to dairy herd nutrient control strategies; Scenario 2, no constraint on P runoff with access to all crop and dairy herd nutrient control strategies; Scenario 3, constraint on P runoff with access to crop nutrient, runoff and erosion control strategies but no access to dairy herd nutrient control strategies; and Scenario 4, constraint on P runoff with access to all crop and dairy herd nutrient control strategies. Under Scenario 2, the herd nutrient control strategies increase milk output per cow and net returns on both farms and reduce P content of manure and P runoff. Under Scenario 3, limiting P runoff reduces farm returns by 1 and 3% on the average and small farms, respectively. Under Scenario 4, the P runoff constraint is less costly, reducing returns by less than 1% on both farms. Animal nutrient control strategies should be an important part of pollution control policies and programs for livestock intensive watersheds.     

Phosphorus recovery methods from secondary resources,assessment of overall benefits and barriers with focus on the Nordic countries

Phosphorus (P) recovery and recycling play a crucial role in improving resource efficiency, sustainable nutrient management and moving toward circular economy. Increasing demand for fertilizers, signs of geopolitical constraints, and high discharge of P to waterbodies are the other reasons to pursue the circularity of P. Various research have been carrying out and several processes have been developed for P-recovery from different resources. However, there is still a huge unexplored potential for P-recovery specially in the regional framework from the four main P-rich waste resources: food waste, manure, mining waste, and sewage sludge. This study reviews recovery methods of P from these secondary resources comprehensively. Additionally, it analyzes the Nordic viewpoint of P-cycle by evaluating Nordic reserves, demands, and secondary resources to gain a systematic assessment of how Nordic countries could move toward circular economy of P. Results of this study show that secondary resources of P in Nordic countries have the potential of replacing mineral fertilizer in these countries to a considerable extent. However, to overcome the challenges of P-recovery from studied resources, policymakers and researchers need to take decisions and make innovation along each other to open the new possibilities for Nordic economy.