Action strategies for strengthening industrial clusters in southern Taiwan

For the past decade, the Taiwanese government has applied the policy of “North heavy, South light” to put more emphasis on development in northern Taiwan instead of the south. This has resulted in uneven development between the northern and southern regions, especially when introducing, developing, and supporting high technology and resource allocation in education. Industry clusters have become the centerpiece of economic development policy in many parts of the world. In this study, it is assumed that there are two categories of less-advantaged regions in Taiwan: (1) older industrialized regions dominated by labor-intensive/capital-intensive industries, and (2) industrial regions that have merged with potential high-technology small firms but still lack infrastructure. This study discusses the following points: (a) How do industrial clusters work in action? (b) What barriers do less-advantaged industrial clusters face? (c) What action strategies promote less-advantaged industrial clusters?     

Water-Circulating Aerator: Optimizing Structure and Predicting Water Flow Rate and Oxygen Transfer

Thermal stratification is a common phenomenon in deep lakes and reservoirs, which often results in water-quality deterioration, including such problems as hypolimnetic anoxia, the release of pollutants from sediments, and algal blooms. Hypolimnetic oxygenation and destratification are the two commonly used methods for resolving these water-quality problems. A new water-quality improvement device, the water-circulating aerator, was designed to destratify lakes and reservoirs, by circulation and oxygenation of upper and lower layers of water. The design of the structure of the water-circulating aerator is detailed. Three mathematical models were built to optimize this structure, estimate the rate of water flow in the aerator, and calculate the rate of oxygen transfer from air bubbles to water in the aerator. These models were verified by experiments. The water-circulating aerator system has been successfully applied in a stratified reservoir to increase dissolved oxygen to reduce the releasing of ammonia-nitrogen from sediments under anoxic conditions.     

The correlation between skin-care effects and phytochemical contents in Lamiaceae plants

In this study, well-known skin-care functional parameters were used, including UV absorption, DPPH-scavenging, NO-production-inhibition, tyrosinase-inhibition activity and anti-Staphylococcus aureus activity to measure the effects of the 70% acetone-extracts form 28 species of Lamiaceae plants. Further, the phytochemical contents were explored by total phenol (TP), total flavone (TF) and total coumarin (TC). The correlation between the skin-care effects and the phytochemical contents was analysed by non-parametric correlation analysis. Amongst the 70% acetone-extracts, Origanum majorana displayed the strongest DPPH-scavenging and tyrosinase-inhibitory effects and the richest phenol content. Based on the statistics results, the phytochemical contents were related with those parameters, such as: DPPH-scavenging effects vs. TP (R = 0.542), TF vs. TP (R = 0.613), and NO-inhibitory vs. anti-bacterial activities (R = 0.767). Moreover, each genus of Lamiaceae had different properties of skin-care effects. Form our research works, the Lamiaceae is good resources to develop skin-care cosmetics.     

Nitrogen Removal Characteristics of a Newly Isolated Indigenous Aerobic Denitrifier from Oligotrophic Drinking Water Reservoir,Zoogloea sp. N299

Nitrogen is considered to be one of the most widespread pollutants leading to eutrophication of freshwater ecosystems, especially in drinking water reservoirs. In this study, an oligotrophic aerobic denitrifier was isolated from drinking water reservoir sediment. Nitrogen removal performance was explored. The strain was identified by 16S rRNA gene sequence analysis as Zoogloea sp. N299. This species exhibits a periplasmic nitrate reductase gene (napA). Its specific growth rate was 0.22 h⁻¹. Obvious denitrification and perfect nitrogen removal performances occurred when cultured in nitrate and nitrite mediums, at rates of 75.53% ± 1.69% and 58.65% ± 0.61%, respectively. The ammonia removal rate reached 44.12% ± 1.61% in ammonia medium. Zoogloea sp. N299 was inoculated into sterilized and unsterilized reservoir source waters with a dissolved oxygen level of 5–9 mg/L, pH 8–9, and C/N 1.14:1. The total nitrogen removal rate reached 46.41% ± 3.17% (sterilized) and 44.88% ± 4.31% (unsterilized). The cell optical density suggested the strain could survive in oligotrophic drinking water reservoir water conditions and perform nitrogen removal. Sodium acetate was the most favorable carbon source for nitrogen removal by strain N299 (p < 0.05). High C/N was beneficial for nitrate reduction (p < 0.05). The nitrate removal efficiencies showed no significant differences among the tested inoculums dosage (p > 0.05). Furthermore, strain N299 could efficiently remove nitrate at neutral and slightly alkaline and low temperature conditions. These results, therefore, demonstrate that Zoogloea sp. N299 has high removal characteristics, and can be used as a nitrogen removal microbial inoculum with simultaneous aerobic nitrification and denitrification in a micro-polluted reservoir water ecosystem.     

Nitrogen Removal from Micro-Polluted Reservoir Water by Indigenous Aerobic Denitrifiers

Treatment of micro-polluted source water is receiving increasing attention because of environmental awareness on a global level. We isolated and identified aerobic denitrifying bacteria Zoogloea sp. N299, Acinetobacter sp. G107, and Acinetobacter sp. 81Y and used these to remediate samples of their native source water. We first domesticated the isolated strains in the source water, and the 48-h nitrate removal rates of strains N299, G107, and 81Y reached 33.69%, 28.28%, and 22.86%, respectively, with no nitrite accumulation. We then conducted a source-water remediation experiment and cultured the domesticated strains (each at a dry cell weight concentration of 0.4 ppm) together in a sample of source water at 20–26 °C and a dissolved oxygen concentration of 3–7 mg/L for 60 days. The nitrate concentration of the system decreased from 1.57 ± 0.02 to 0.42 ± 0.01 mg/L and that of a control system decreased from 1.63 ± 0.02 to 1.30 ± 0.01 mg/L, each with no nitrite accumulation. Total nitrogen of the bacterial system changed from 2.31 ± 0.12 to 1.09 ± 0.01 mg/L, while that of the control system changed from 2.51 ± 0.13 to 1.72 ± 0.06 mg/L. The densities of aerobic denitrification bacteria in the experimental and control systems ranged from 2.8 × 10⁴ to 2 × 10⁷ cfu/mL and from 7.75 × 10³ to 5.5 × 10⁵ cfu/mL, respectively. The permanganate index in the experimental and control systems decreased from 5.94 ± 0.12 to 3.10 ± 0.08 mg/L and from 6.02 ± 0.13 to 3.61 ± 0.11 mg/L, respectively, over the course of the experiment. Next, we supplemented samples of the experimental and control systems with additional bacteria or additional source water and cultivated the systems for another 35 days. The additional bacteria did little to improve the water quality. The additional source water provided supplemental carbon and brought the nitrate removal rate in the experimental system to 16.97%, while that in the control system reached only 3.01%, with no nitrite accumulation in either system. Our results show that aerobic denitrifying bacteria remain highly active after domestication and demonstrate the applicability of such organisms in the bioremediation of oligotrophic ecosystems.     

Theoretical analysis on non-uniformity of water distribution and influence of construction parameters on settling efficiency

During the reconstruction of horizontal flow tanks into inclined settling tanks in Chinese water plants, uniformity of water distribution has not been solved theoretically. Based on the concepts of hydraulics, a model of inclined tanks, including the ratio (L/B) of tank length (L) to width (B), diameter of inclined tubes (d) and height of the water distribution area (h1) and so on, was established to simulate and analyze the effects of these parameters on Non-Uniformity of Water Distribution (NUWD). The influences of NUWD on settling efficiency were also analyzed based on Yao's formula. Simulated results show that the ratio (L/B) has the greatest impact on NUWD, and the settling efficiency decreases with it. Under the conditions of q=10 or 20 m/h and L/B>or=5 or 3, the total forces imposed on down-sliding flocs tend to be zero, which reduces the separating efficiency. Moreover, critical settling velocity (CSV) of the first inclined tube will decrease with the increase of h1, and the optimal range of h1 will be 1.2-1.6 m. The difference of CSV between the first tube and the average value of the tank u0 (shown as Delta(uF0-u0)) will increase with d and surface load (q).     

A new mixing–oxygenating technology for water quality improvement of urban water source and its implication in a reservoir

The Water-lifting Aerator, which is a retrofit of the hydraulic gun, was developed to oxygenate lower-layer water and mix the water on the upper and lower layers in stratified reservoirs where pollutants increase from sediments because of anoxic condition in the lower-layer water. The Fenhe reservoir began to supply raw water to the drinking water treatment plant of the City of Taiyuan, China in 2004. The surface of the reservoir froze in winter, and the lower-layer water above the reservoir bed became anoxic because of oxygen consumption by the sediments. Hence, ammonia–nitrogen released from the sediments and trapped in the lower-layer water. After the ice surface thawed in spring, the ammonia–nitrogen in the deepwater was brought up owing to the wind–wave mixing processes. Thus the concentration of ammonia–nitrogen in the outlet water exceeded the permitted level, and the water supply from the Fenhe reservoir had to be cut off. To solve the problem, the Water-lifting Aerator system was installed in the reservoir in the winter of 2005, the dissolved oxygen concentration in the lower-layer water has been maintained at more than 3 mg/L and the ammonia–nitrogen concentration has been reduced to less than 0.1 mg/L. The ammonia–nitrogen concentration in the outlet water is a 95% reduction compared to the same period of last year before the system installation. Since then the water supply from the Fenhe reservoir has no longer been interrupted. Compared with traditional water treatment technology to remove ammonia–nitrogen, the new technology saves energy for 77%.     

Microbial effects on phosphorus release in aquatic sediments

Microbial effects on phosphorus release were studied for the sediments of Tianjin source water by controlling DO and pH. The results show that: (1) In sterilised water, phosphorus began to release when pH = 9.1 and the stable release rate was 9.51 mg/(d.m2). It indicates that microorganisms may utilise anaerobic iron respiration to release Fe-P. (2) With unsterilised water, phosphorus release rate is 2.14 mg/(d.m2) when pH = 6.5, 8.60 mg/(d.m2) when pH is uncontrolled, and gets to 8.51 mg/(d.m2) when pH = 9.1. This indicates that microorganisms can dissolve insoluble phosphates to accelerate the ion exchange of OH(-) and PO4(3-), which are derived from iron-bound ortho-P and aluminium-bound ortho-P.     

Optimization analysis of decentralised sanitation and re-use system.

With the application of system dynamics, a dynamic nonlinear model reflecting the relationship between decentralised water use and reclaimed water supply and demand has been established. Through a system analysis, the model has been applied to a small residential district to predict and analyse the situation of future use of fresh water, demand and supply of re-used water, and treatment scale of reclaimed water. It is illustrated in this paper that wastewater decentralised treatment and re-use can decrease the consumption of fresh water without lowering the standard of living water for the district residents. On this basis, a rational scale and construction time of the decentralised sanitation and re-use system have been determined. Also, the paper predicts the influencing factors of the increasing water cost and changes in consumers' acceptability to re-use water in the decentralised sanitation and re-use system.