[Effect of HMME-PDT on hyperplastic scar in rabbit ear model].

OBJECTIVE: To investigate the effect of HMME-PDT (Hematoporphyrin Monomethyl Ether-Photodynamic therapy) on Hyperplastic scar in the rabbit ear. METHODS: The acute model of dermal Hyperplastic scar in the rabbit ear was established. 24 scars were randomly divided into 2 groups: the experimental group (n = 12) received HMME-PDT treatment, and the controlled group (n = 12) received no special treatment. Specimens were harvested from scars on postoperative 28 day. Scar hyper plasty and collagen fibers were observed by haematoxylin-eosin staining and Van-Gieson staining respectively. The microvessel density was calculated under microscope. RESULTS: Compared with the controlled group, HMME-PDT treatment in the experimental group reduced scar formation, decreased the microvessel density and prevented excess collagen deposition at the wound site. CONCLUSIONS: HMME-PDT may play a role in inhibiting hyperplastic scar in rabbit ear.

Control of bromate and THM precursors using ozonation combined system.

OBJECTIVE: To investigate the feasibility of reducing THM precursors and controlling bromate taste and odor in drinking water taken from the Yellow River by an ozonation combined system. METHODS: The appropriate ozone dosage was determined, and then the changes of TOC, UV254 and THM formation potential (THMFP) in the combined system were evaluated. RESULTS: One mg/L ozone could effectively remove taste and odor and meet the maximum allowable bromate level in drinking water. The pre-ozonation increased THMFP, but the conventional treatment system could effectively reduce the odor. The bio-ceramic filter could partly reduce CHCl3FP, but sometimes might increase CHCl2BrFP and CHClBr2FP. The biological activated carbon (BAC) filter could effectively reduce CHCl3FP and CHCl2BrFP, but increase CHClBr2FP. Compared with other filters, the fresh activated carbon (FAC) filter performed better in reducing THMFP and even reduced CHClBr2FP. CONCLUSION: The combined system can effectively reduce taste, odor, CHCl3FP, and CHCl2BrFP and also bring bromate under control.

Reduction of precursors of chlorination by-products in drinking water using fluidized-bed biofilm reactor at low temperature.

OBJECTIVE: To investigate the reduction of chlorination by-products (CBPs) precursors using the fluidized-bed biofilm reactor (FBBR). METHODS: Reduction of total organic carbon (TOC), ultraviolet absorbance (UV254), trihalomethane (THM) formation potential (THMFP), haloacetic acid (HAA) formation potential (HAAFP), and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3 degrees C, however, it could quickly rise to over 50% above 3degrees C. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.