Advanced Materials Research Vol. 777

Abstract: Experiments were conducted to study the role of enhanced micro-electrolysis techniques (METs) in treatment of s-atrazine wastewater, regarding atrazine production wastewater as the object of this research. The intensified METs methods included O₃ and ultrasound (US). With O₃ METs technology, a better result could be achieved under weak acidity condition. The highest removal rate of TOC reached 18.7%. US before METs could gain higher removal rate of 38.7% compared to the rate of 27.8% by US in METs.

Abstract: The treatment of H₂S and NH₃ odor produced in sewage disposal process was carried out in industrial scale bio-trickling filters filled with different kinds of filler. The processing capacity per unit volume and the processing capacity per unit volume filler on odor removal performance for different bio-trickling filter were investigated. The results demonstrate that there are remarkable differences in deodorization performance between different kinds of bio-trickling filters.

Abstract: The variation of disinfection by-products (DBPs) at several stages of drinking water treatment plants was investigated in two drinking water plants. The results clearly indicate that the low molecular weight total organic carbon (TOC) which has been identified as primary precursor for chlorinated DBPs was difficult to remove by coagulation. Plant A which used conventional coagulation/sedimentation could not decrease the species of trihalomethanes (THMs) and haloacetic acids (HAAs) formation potential. Biological activated carbon (BAC) was applied in Plant B which removed the maximum amount of TOC, while more kinds of microbial products were produced in BAC unit which could be the potential precursors of DBPs. Therefore, the species of DBPs formation potential still increased in the treatment processes of Plant B. Because different components of organic precursors produced different DBPs species, the processes of Plant B could decrease TOC efficiently but the species of THMs and HAAs formation potential.

Abstract: This paper analyzed the characteristics of valve-closure water hammer rising pressure, according to the basic theory of water hammer rising pressure in the gravity flow water-delivery system. It is indicated that the end valve-closure is the main cause of water hammer, and which is an important problem of influencing the safety and stable operation of the system. Combined With an engineering example that is a gravity pressurized water delivery system with the branch line, the paper studied water hammer rising pressure when the various combinations of valve-closure duration and angle . See that off valve water hammer boost of the branch line gravity flow system is more significant, more dangerous, so we recommend that reliable and effective security measures of practical engineering must be taken.

Abstract: Chemical Oxygen Demand was split into S_A (volatile acid / fermentation products), S_F (fermentable, readily bio-degradable organic substrates), X_S (slowly biodegradable substrates), S_I (Inert soluble organic material) and X_I (Inert particulate organic material). Research of how these model components affect the oxygen transfer coefficient (K_La) was studied in this paper. The results showed that with the increase of S_A, K_La decreased, K_La first decreased when S_F was in 25-100 mgCOD/L, then it increased in 100-200 mg/L,then it decreased again. X_S has a poor regularity and slight infect on oxygen mass transfer, X_I, S_I may inhibit the oxygen transfer.

Abstract: The deep-well seawater desalination technology is using deep-well water hydrostatic pressure as reverse osmosis pressure, which uses the principle of reverse osmosis desalinate seawater. Can reduce energy consumption and more economic compared with the traditional high-pressure pump reverse osmosis desalination. In this paper, the principle and the technical feasibility of the deep-well seawater desalination technology is analyzed.

Abstract: A combination process of biological contact oxidation, membrane bioreactor (MBR) and sodium hypochlorite disinfectant was utilized to treat hospital wastewater. The amount of wastewater is about 200 m³/d. As a result, COD and NH₃-N of treated water are less than 50 mg/L and 10 mg/L, respectively. Total coliform and fecal coliform were not detected in the treated water. The main indexes could meet the requirement of Chinese Discharge Standard of Water Pollution for Medical Organization. With reasonable design and low cost of investment and running the hybrid process may be a good guide and reference for similar projects.

Abstract: The cancer risk assessment model recommended US EPA was used to access the carcinogenicity of disinfection byproducts (DBPs) in water distribution network in a Southern City of Jiangsu. The trihalomethanes (THMs) and haloacetic acids (HAAs) with carcinogenic risk was considered to be the research focus on the cancer risk assessment. The carcinogenic risk along the pipeline was explored through monitoring the changes of the THMs and HAAs .The results showed as follows: the disinfection by-products increased along the pipe network and cancer risk increased too. The maximum cancer risk within the area of water supply pipe network was calculated. The R_Tmax was 4.72×10^-5, which was between5.10^-5 and 10^-6. So the carcinogenic risk could be accepted and some measures could be considered to be taken to reduce the carcinogenic risk.

Abstract: A combination process of cellulosic ethanol wastewater treatment was described. This process includes iron-carbon micro-electrolysis-Fenton, UASB and MBR. Through the process, well get an exploration of engineering design operation parameters and pollutant removal mechanism. Test results show that if the wastewater have 5 hours micro response,36 hours to stay on the USAB and 25 hours to stay in the membrane bioreactor ,after the flocculation decollating, the COD and ammonia nitrogen indexes of the wastewater have all reached the discharge standard of the Discharge Standard of Water Pollutants for Fermentation Alcohol and Distilled Spirits Industry (GB 276312011), and the effect of the operation is stable, cost is low.

Abstract: Treatment of two-dimensional and three-dimensional electrode method was researched and compared respectively using aluminum electrodes. The influences of voltage, electrolysis time, pH and electrode distance on the result were also discussed. It was found that the degradation rate of wastewater with three-dimensional electrode method was much better than two-dimensional method. For the treatment of vehicle-washing wastewater, the best of voltage was 20V, the electrolysis time was 30 min, and the electrode distance was 2cm.