Management of hazardous waste in Thailand: present situation and future prospects

 This paper deals with the present scenario of hazardous waste management practices in Thailand, and gives some insights into future prospects. Industrialization in Thailand has systematically increased the generation of hazardous waste. The total hazardous waste generated in 2001 was 1.65 million tons. It is estimated that over 300 million kg/year of hazardous waste is generated from nonindustrial, community sources (e.g., batteries, fluorescent lamps, cleansing chemicals, pesticides). No special facilities are available for handling these wastes. There are neither well-established systems for separation, storage, collection, and transportation, nor the effective enforcement of regulations related to hazardous wastes management generated from industrial or nonindustrial sectors. Therefore, because of a lack of treatment and disposal facilities, these wastes find their way into municipal wastewaters, public landfills, nearby dump sites, or waterways, raising serious environmental concern. Furthermore, Thailand does not have an integrated regulatory framework regarding the monitoring and management of hazardous materials and wastes. In addition to the absence of a national definition of hazardous wastes, limited funding has caused significant impediments to the effective management of hazardous waste. Thus, current waste management practices in Thailand present significant potential hazards to humans and the environment. The challenging issues of hazardous waste management in Thailand are not only related to a scarcity of financial resources (required for treatment and disposal facilities), but also to the fact that there has been no development of appropriate technology following the principles of waste minimization and sustainable development. A holistic approach to achieving effective hazardous waste management that integrates the efforts of all sectors, government, private, and community, is needed for the betterment of human health and the environment. Received: February 26, 2001 / Accepted: October 11, 2002     

厌氧-准好氧型填埋的渗滤液实验研究

通过室内模拟试验，在渗滤液回灌的厌氧填埋柱基本进入稳定状态后，改用准好氧运行方式。同时监测了渗滤液中有机物浓度以压温度、pH值的变化。改变模拟垃圾柱的运行方式两个月以后。氨氯浓度由2000mg／L迅速下降至101．48mg／L，试验结果显示，准好氧运行方式可以解决生物反应器填埋场进入稳定阶段后存在的氨氮浓度高的问题，加速填埋场的稳定。     

Characteristics of large cooking oil pool fires and their extinguishment by water mist

Large cooking oil pool fires, occurring in industrial oil cookers, present a severe hazard to food processing plants due to their size and the large amount of hot oil involved. This paper reports a series of full-scale fire experiments conducted in a large industrial oil cooker mock-up. The characteristics of large cooking oil pool fires and the effect of oil depth and hood position in the oil cooker on fire growth were studied. The use of water mist for extinguishing large oil pool fires and their extinguishing performance under different discharge pressure and with different types of water mist systems were investigated. Experimental results showed that the cooking oil underwent a substantial expansion in volume during heating. The fires developed quickly once the oil auto-ignited. The fire growth rate was affected by the oil depth in the pan and the hood position in the oil cooker. The water mist fire suppression systems effectively extinguished large cooking oil fires and prevented them from re-igniting. Their extinguishing performance was determined by the type of water mist system, discharge pressure and hood position in the oil cooker.     

EFFECTIVENESS OF POLYACRYLAMIDE (PAM) IN IMPROVING RUNOFF WATER QUALITY FROM CONSTRUCTION SITES1

ABSTRACT: Erosion from construction sites significantly affects water quality in receiving streams. A rainfall simulator was used to evaluate the effectiveness of different methods for controlling erosion from construction sites. Erosion control methods investigated included dry and liquid applications of polyacrylamide (PAM), hydroseed, and straw mulch. Fertilizer was also applied to each plot to examine the effectiveness of the methods in reducing nutrient losses in runoff. Runoff samples were analyzed for total suspended solids (TSS), nitrate, total Kjeldahl nitrogen (TKN), ammonium, total phosphorus (TP), and orthophosphate. Among all treatments investigated, straw mulch was the most effective treatment for controlling TSS and nutrient losses during short term and long term simulations. The low liquid PAM (half the recommended PAM) treatment resulted in the highest reduction in runoff, TSS bound nitrogen, and total nitrogen (TN) concentrations and loadings. The study results indicate that a high application rate (twice the recommended rate) of PAM could actually increase runoff and TSS losses. At a low application rate, both liquid and dry PAM were effective in reducing TSS and nutrient losses in runoff. However, application of the liquid form of PAM to construction sites is more practical and perhaps more economical than applying the PAM in the dry form.     

Literary and economic impact of the Bhopal gas tragedy

The 1984 Bhopal disaster is widely regarded as a watershed event in the field of process-safety and has been largely responsible for a paradigm shift in the outlook of both industry and the public towards risk management within the processing industries. The Bhopal disaster has led to increased regulations and awareness for process-safety related activities across the globe. This paper reports the effect of the infamous Bhopal incident on the research community and examines the performance of manufacturing industries following the disaster.

For this paper, databases of scientific publications were used to investigate research trends in the safety area following the 1984 Bhopal disaster. Our analysis focuses on prominent safety-related research fields that have emerged following the gas tragedy as well as economic indicators of the processing industries. The study reveals that the process industry has consistently progressed over the years, in spite of added regulations and a worsened public image following the Bhopal disaster, and promises to be a stable economy in the future.     

Material flow analysis of lubricating oil use in California

Petroleum lubricating oils, used throughout the economy, are distinct among petroleum products in their capacity to be recovered and recycled at the end of their useful life. Used lubricating oil is regulated at the state and federal level because of concerns about environmental impacts arising from improper disposal, although rates of recovery are not known. We present a material flow analysis of lubricants through California's economy in the years 2007–2012. We introduce a novel technique for computing aggregate waste generation from a collection of hazardous waste manifest records, and apply it in order to determine a recovery rate for used oil and to estimate the quantity of oil managed informally in the state. The records also offer a detailed view of the fate of used oils after they are recovered. We find that around 62% of lubricants are recoverable at end of life, of which 70–80% is being recovered. This rate shows a slight downward trend. If the trend is accurate, measures should be taken to improve the performance of the used oil management system. Policy opportunities exist to reduce the quantity of oil managed informally through improving access to responsible used oil management methods. These include increasing the collection of used oil from industrial sources as well as “do it yourself” oil changes, expanding in-state reprocessing capacity, and promoting increased out-of-state reprocessing of used oil. Our methods introduce new possibilities to make use of direct observation in material flow analysis, potentially improving data availability and quality and increasing the relevance of material flow methods in policy applications.     

Investigation of multiple domino scenarios caused by fragments

A model of multiple domino scenarios and the risk of the domino effect, which is a sequential chain escalating from the primary unit to the last unit, is presented in this paper. The trajectories of fragments from all units, the ground distribution of projectiles, and the risk of the sequential chain of the domino effect were calculated using Monte Carlo simulations. The results showed that the range affected by the fragments from each tank included the other tanks, meaning that fragments from one tank could hit the other tanks and cause multiple accidents, and that the sequential chain of the domino effect could indeed happen. The distributions of ground impacts showed that tank fragments were projected over long distances, up to 1200 m from the source. The spatial distribution of the kinetic energy at ground impact for tank fragments was also obtained. Moreover, the magnitudes of the probabilities of the primary, secondary, third, and fourth accidents in the domino chain were respectively about 10⁻⁷, 10⁻¹¹, 10⁻¹⁵, and 10⁻¹⁹. These results showed that for neighboring domino effect units in the same accident chain, the risk of the most recent domino effect was 10⁴ times that of the following domino effect.     

Fine‐resolution conservation planning with limited climate‐change information

Climate‐change induced uncertainties in future spatial patterns of conservation‐related outcomes make it difficult to implement standard conservation‐planning paradigms. A recent study translates Markowitz's risk‐diversification strategy from finance to conservation settings, enabling conservation agents to use this diversification strategy for allocating conservation and restoration investments across space to minimize the risk associated with such uncertainty. However, this method is information intensive and requires a large number of forecasts of ecological outcomes associated with possible climate‐change scenarios for carrying out fine‐resolution conservation planning. We developed a technique for iterative, spatial portfolio analysis that can be used to allocate scarce conservation resources across a desired level of subregions in a planning landscape in the absence of a sufficient number of ecological forecasts. We applied our technique to the Prairie Pothole Region in central North America. A lack of sufficient future climate information prevented attainment of the most efficient risk‐return conservation outcomes in the Prairie Pothole Region. The difference in expected conservation returns between conservation planning with limited climate‐change information and full climate‐change information was as large as 30% for the Prairie Pothole Region even when the most efficient iterative approach was used. However, our iterative approach allowed finer resolution portfolio allocation with limited climate‐change forecasts such that the best possible risk‐return combinations were obtained. With our most efficient iterative approach, the expected loss in conservation outcomes owing to limited climate‐change information could be reduced by 17% relative to other iterative approaches.     

Efficacy of created and restored nesting sites for the conservation of colonial Laridae in the South of France

By rapidly modifying key habitat components, habitat restoration is at risk of producing attractive cues for animals without providing habitats of sufficient quality. As such, individual fitness components, such as reproduction, could be reduced and restored habitats could become ecological traps. This risk notably appears by using artificial constructions in restoration projects, yet few studies have evaluated their efficacy in a robust way. We investigated this by analyzing 154 islets that were created or restored to improve the conservation status of 7 colonial Laridae species in the South of France. From 2007 to 2016, we compared occupancy dynamics and breeding parameters of these species between the restored sites and 846 unmanaged nesting sites. We also explored species’ preference for different nesting site characteristics and their respective effect on breeding parameters. Restored nesting sites were 2–9 times as attractive as unmanaged sites for all species except the Black-headed Gull (Chroicocephalus ridibundus). Colonization probability was up to 100 times higher in sites already used by other species the previous year and increased with distance to the shore until >0.2 when distance was over 250 m. Abandonment probability was 29–70% lower when breeding was successful the previous year in all species except the Sandwich Tern (Thalasseus sandvicensis). Productivity and breeding success probability were 2 times higher on managed sites. Distance from the shore was an important attractive characteristic of artificial nesting sites in all species. Other nesting site characteristics had species-specific effects on colonization, abandonment, and breeding success. Our results indicate that managed nesting sites are successful conservation tools for colonial Laridae in the Mediterranean and do not act as ecological traps. Our study showed that testing the ecological trap hypothesis is a robust way to evaluate the success of restoration projects of breeding habitats.     

低碳经济背景下我国产业结构升级对策研究

为了实现我国经济的平稳发展,改变以"高消耗、高增长、高污染"的传统经济增长方式,解决资源的过度消耗和温室气体的过量排放等问题,文章从我国产业及内部结构、产业的碳排放量和产业节能率三个方面进行了分析,提出了在低碳经济背景下实现我国产业结构升级的对策。