Yi Kuo Chang

The influence of heavy metals on the polymorphs of dicalcium silicate in the belite-rich clinkers produced from electroplating sludge.

The purpose of this study is to utilize an electroplating sludge for belite-rich clinker production and to observe the influence of heavy metals on the polymorphs of dicalcium silicate (C(2)S). Belite-rich clinkers prepared with 0.5-2% of NiO, ZnO, CuO, and Cr(2)O(3) were used to investigate the individual effects of the heavy metals in question. The Reference Intensity Ratio (RIR) method was employed to determine the weight fractions of gamma-C(2)S and beta-C(2)S in the clinkers, and their microstructures were examined by the transmission electron microscopy (TEM). The results showed that nickel, zinc, and chromium have positive effects on beta-C(2)S stabilization (Cr(3+)>Ni(2+)>Zn(2+)), whereas copper has a negative effect. The addition of up to 10% electroplating sludge did not have any negative influence on the formation of C(2)S. It was observed that gamma-C(2)S decreased while beta-C(2)S increased with a rise in the addition of the electroplating sludge. Moreover, nickel and chromium mainly contributed to stabilizing beta-C(2)S in the belite-rich clinkers produced from the electroplating sludge.

Reusing pretreated desulfurization slag to improve clinkerization and clinker grindability for energy conservation in cement manufacture

The purpose of this study was to combine the physical pretreatments of grinding, sieving, and magnetic-separation processes to reclaim iron-rich materials from the desulfurization slag, and to use the remainder for cement clinker production. The iron-rich materials can be separated out efficiently by grinding for 30 min and sieving with a 0.3 mm mesh. The non-magnetic fraction of the particles smaller than 0.3 mm was in the majority, and proved to be suitable for use as a cement raw material. The raw mixes prepared with a pretreated desulfurization slag had a relatively high reactivity, and the temperature at which alite forms was significantly reduced during the clinkerization process. The clinkers produced with 10% desulfurization slag had a high level of alite and good grindability. Generally, the improvements in clinkerization and clinker grindability are beneficial to energy conservation in cement manufacture.

Research on the Implementation and Analysis of High-Turbidity Raw Water Pre-Treatment with a Barrier Board

The purpose of this Research is to simulate the water quality of varied High-turbidity Raw Water at different depths under the water’s surface. During the experiment, a Barrier Board was used to extend the flowing route and to change the overflow level for carrying out the pre-treatment of High-turbidity Raw Water through the changes of varied flow rates in order to study the changes and the removal rate of the turbidity for the influent and effluent; with the settled bottom mud surveyed, the operating requirements of the Surface Overflow Rate (SOR). The experimental result indicated that the turbidity of High-turbidity Water can be reduced by means of an inertia restrained flow, extending the flowing route and heightening the overflow level. The results indicated that the turbidity of the effluent was mostly between 380-1,000 NTU in presenting an over 50% removal rate and even up to 93%. When the SOR of the Sedimentation Basin is set at 19.l m/d, a 54-86% turbidity removal rate can be achieved; whereas, a 50-72% removal rate can be achieved when set at 38.3 m/ d. It has indicated that a significant effect could be achieved for turbidity treatment by employing the properties of high-turbidity substances and the convenient physical theory of gravity settling. As such, a visible removal effect could be achieved to exhibit the effect of pre-treatment.

Chromium Contamination in Sediments of Anping Harbor, Taiwan

The distribution, enrichment, accumulation, and potential ecological risk of chromium (Cr) in the surface sediments of Anping Harbor, Taiwan, were investigated. Sediment samples from ten locations were collected and characterized for Cr, aluminum, water content, organic matter, and grain size. The results show that samples collected at all monitoring points contain 23.3–881.3 mg/kg of Cr with an average of 250.0±265.4 mg/kg. The spatial distribution of Cr reveals that the Cr concentration is relatively high in the Bamboo River mouth region, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Results from the enrichment factor and geo-accumulation index analyses imply that the Bamboo River mouth sediments can be characterized as severe enrichment and moderate to strong accumulation of Cr, respectively. However, results of potential ecological risk index indicate that the sediment has low ecological potential risk. The results can provide valuable information to developing future strategies for the management of river mouth and harbor.

Zinc Contamination in Sediments of Southern Kaohsiung Harbor, Taiwan

Major objectives of this study are to evaluation the enrichment, accumulation, and potential ecological risk of zinc (Zn) in the surface sediments of southern Kaohsiung Harbor, Taiwan. Twelve sampling locations were installed of southern Kaohsiung Harbor to collect sediment samples for analyzing Zn. Results showed that the Zn concentrations varied from 731–946 mg/kg with an average of 323±525 mg/kg. The spatial distribution of Zn reveals that the Zn concentration is relatively high in the river mouth region, and gradually diminishes toward the harbor entrance region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of Zn pollution. Results from the enrichment factor and geo-accumulation index analyses imply that the sediments collected from the Salt River mouth can be characterized very severe degree enrichment and strong to very strong accumulation of Zn, respectively. Results of potential ecological risk index indicate that the sediment has low ecological potential risk.

Assessment of Polycyclic Aromatic Hydrocarbons Contaminations in Sediments of Love River Mouth, Taiwan

The surface samples were collected from the Love River mouth, Taiwan and analyzed for polycyclic aromatic hydrocarbons (PAHs). Total PAHs concentrations varied from 785 to 1,893 ng/g dw. The spatial distribution of PAHs reveals that the PAHs concentration is relatively high in the river mouth region, and gradually diminishes toward the harbor region. Diagnostic ratios showed that the possible source of PAHs in the Love River mouth could be petroleum combustion. The toxic equivalent concentrations (TEQcarc) of PAHs varied from 117 to 272 ng TEQ/g dw. Higher total TEQcarc values were found in the river mouth region. As compared with the US Sediment Quality Guidelines (SQGs), the observed levels of PAHs at Love River mouth were lower than the effects range low (ERL), and would probably not exert adverse biological effects.

Distribution and Contamination of Chromium in the Surface Sediments of Salt River Estuary, Taiwan

Major objectives of this study are to evaluation the pollution and potential ecological risk of chromium (Cr) in the sediments of Salt River estuary, Taiwan. Nine monitoring stations were installed near the estuary of Salt River to collect sediment samples for analyzing Cr. Results of laboratory analyses show that contents of Cr in the sediments are between 32 and 79 mg/kg with an average of 58±17 mg/kg. The spatial distribution of Cr reveals that the Cr concentration is relatively high near the boundary of the river estuary, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Results from the enrichment factor analysis imply that the sediments can be characterized as minor to moderately severe degree of Cr enrichment. Results of geo-accumulation index analysis indicate that the sediments can be characterized as moderate degree of Cr accumulation. Results of potential ecological risk index indicate that the sediments at Salt River estuary have low ecological potential risk.

Research on the Implementation and Analysis of High-Turbidity Raw Water for Particle Pre-Treatment with a Barrier Board

In this research, the raw water presenting turbidity was sampled to simulate the change of the water quality. A barrier board was used to extend the flowing route and the level change of the overflow; carry out the pre-treatment of high-turbidity raw water. Particle detention time and the average flowing speed analyzed as well for comparing the removal effect with that in the physical field. The particle detention time is as follows: At 4-141 min, the operating time can be shortened; when this is less than 90 min, the effluent still can maintain a 50-88% turbidity removal rate and the water quality of the effluent can even drop to 530 NTU. During the test, most of the average flowing speed was within the operating scope of the rectangular Sedimentation Basin for which the removal rate was 61%-93% and the effluent turbidity was below 1,000 NTU and even up to the optimal 380 NTU. A total of 3 items meet the operating requirements of the Inclinometer Sedimentation Basin, presenting a 54%-72% removal rate and 1,000-1,650 NTU of effluent turbidity; and one item exceeds the operating requirements of the Inclinometer Sedimentation Basin, presenting a lowered 1,900 NTU of effluent turbidity from 3,800 NTU and a 50% removal rate. Large-size particles exist in the high-turbidity raw water, which tends to settle under the gravity effect during after a long-route flowing journey. For example, the turbidity of the influent is 4,300-5,300 NTU which was reduced to 920-750 NTU after the pre-treatment experiment presenting a 79-86% or higher removal rate.

Research on Utilizing Environmental Friendly Materials of Barrier Board for Turbidity Reduction of High-Turbidity Raw Water

The high-turbidity raw water was formed during the initial period of typhoons or storms, and it affected the operation of the water supply purifying system. In this research, the raw water with various turbidity levels (1,500~5,500 NTU) was used, a barrier board treatment was used to extend the flowing route and varied flow rates were also employed to carry out the treatment of high-turbidity raw water. The experiment results indicated that under a flow rate at designed 8, 17, 50 and 100ml/s, the majority of the effluent water was between 100~1,000 NTU, exhibiting an 50% to 90% removal rater. In view of this, a certain degree of the turbidity could be reduced applying barrier board treatment and suitable for consequent water supply purifying system.

Particle Removal Efficiencies of a Barrier Board that Pre-Treats High-Turbidity Raw Water

It tends to produce high-turbidity raw water during the initial period of typhoons or storms and affect the operation of the purifying system. In this research, the particles size (D98) in raw water was 100–125 μm; that in effluent water was <25 μm. When was under 8 ml/s, effluent water D98 was <10 μm. Flow ratio mitigation and the increase of overflow level can improve the particle removing ratio In aspect of particle size analysis, optimal operating conditions can be achieved setting an 8 ml/sec and 40cm overflow level and D98 grain size can be reduced to 6.25μm as well, particle size removal ratio will gradually climb with the increase of accumulated percentage so that it can reach 70 % for the respective effluent water under D50 and even becomes over 80 % under D98. When under D90, the removing ratio can even go beyond 90 % at an 8 ml/s of flow ratio. Therefore, the proposed pre-treatment reduces high turbidity due to the sudden increase of raw water to the barrier in front of the board.