Advanced Materials Research Vols. 356-360

Abstract: The electrosorption technology for removal of chloride ion is researched by the static adsorption experiment, and various factors of the impact of the removal efficiency, combined with the removal of water quality and water treatment requirements, best adsorption conditions is identified that voltage is 5V, plate spacing is 1.0cm, adsorption time is 15min. Electrosorption technology in wastewater recycling project has certain benefits at economic, environmental and social, and have certain application value.

Abstract: High-solid anaerobic digestions of sewage sludge were investigated in completely stirred tank reactors (CSTR) at 35±1°C. The total solid (TS) concentrations of the sludge fed to the reactors were designed at 10%, 15% and 20% respectively after start-up periods. By start-up period is meant the TS concentration of the substrate in the reactor has not reached its designed level. Special attention was paid to the effect of organic loading rate (OLR), TS concentration, and ammonia inhibition on methane yield, volatile solid (VS) reduction and volatile fatty acid (VFA) concentration during the start-up periods. Experimental results showed that no evident inhibition of TS or ammonia was found as long as the concentration of TS was below 10% or the concentration of ammonia-N was below 2000 mg/l. Digestion at TS concentration of 12.5%-14.8% was slightly influenced by ammonia at concentration of 3200-3800 mg N/l. As the TS concentration was above 14.8%, the ammonia-N concentration of 3500-3800 mg/l showed evident inhibition on methanogetic activity, leading to sharp decrease of methane yield and methane content. After start-up, the methane yields at feeding TS of 10%, 15%, and 20% at OLR of 3.0 kg VS m-3d-3 were 0.221, 0.248 and 0.177 l CH4 g-1VSadded-1 d-1, and the VS reduction were 33%, 39.5% and 40%, respectively.

Abstract: Physicochemical and biological properties were studied during the forced aeration composting of digested sludge and sawdust under ambient temperature between 9 and 15°C. The temperature above 55°C in the core of composting pile kept for 5d during the whole composting process. Total organic carbon and moisture content obviously declined with the increase of composting time, and the content of NO3--N increased. pH, electrical conductivity, NH4+-N, cellulose and urease activities originally increased and then declined. The germination index was 82.82% on day 35. The research results showed that forced aeration composting of digested sludge and sawdust under low ambient temperature could meet the demand of mature on day 35.

Abstract: Lime residuals left from water softening process reused as desulferizer in the coal-fired power plants has been reported. The active composition (CaO) is 43.06 %. 98.77% of lime residuals are particles smaller than 45 µm. The dissolution rate of lime residuals is higher than that of limestone. The results show that the reuse of lime residuals shall facilitate the absorbance of SO₂ and enhance the efficiency of desulfurization. Additional corrosion of apparatus and pipes, the slurry bubble or overflow has not been observed during the experiment. The water consumption can be largely reduced, and the gypsum matches the reuse standard. Coal ashes and gypsum are concluded for many kinds of applications.

Abstract: The disposal of solid waste using landfilling method has become a critical issue in Malaysia especially when concerning their impact towards environment. Eventhough the landfilling strategy applied in Malaysia is a very much improved version; gas and leachate produced from the landfill site still gave a major health issue to the existing residents. Thus, the work performance has been questioned. This paper presents a survey study of the environmental impacts to the nearby residents emerged from the landfilling activities at Jabi town, located in Kedah state, Malaysia based on their awareness and perceptions. Using the data collected, the work performance at site can be assessed. The landfill site has been categorised as a semi aerobic sanitary landfill. A self-administered questionnaire was used as a data collection tools. The level of severity has been determined using Severity Index method. From the discussions, the environmental impacts at specific site can be categorized as light problems and in a control condition. The work performance of selected landfill can be categorised as good due to the level of severity concluded.

Abstract: Dissolved organic matter (DOM) from different biological treated wastewater in secondary effluent of different municipal wastewater treated plants are isolated and fractionated using resin adsorption into five different fractions: hydrophobic bases (HOB), hydrophobic acids (HOA), hydrophilic bases (HIB), hydrophilic acids (HIA) and hydrophilic neutrals (HIN). The characteristics of three dimensional excitation emission matrix fluorescence spectroscopy (3DEEM) and disinfection by-products formation potential (THMFP) of each fraction are investigated. The objective of this study is to investigate the influence of different biological processes on THMs generation and transformation. The results show that for each municipal wastewater treated plant, HIA and HOA fractions content more fulvic-like acid and humic-like acid, which are the important matter to result the higher THMFP. THMFP of HIA rang from 736μg/L to 359μg/L in the secondary effluent. It shows that acidic organic matters are important THMs precursors, especially fulvic-like acids and humic-like acids. The Orbal oxidation ditch process can lead to the highest THMFP, and secondly is the Convert A²/O process.

Abstract: Wastewater discharges from livestock premises could cause serious environmental problems, and it difficult to remove effectively by using a single reactor due to the following characteristics such as high organic matter and high ammonia In this experiment by using the mixed processing mode of UASB plus SBR to study the pilotscale experiment for treatment of piggery wastewater, and investigate the reactor remove pollutants from wastewater at room temperature. After stable operation, the results of removal on COD, ammonia, SS were quite obvious, with the removal rate of 92, 90 and 95% respectively, the removal rate of TP was 80%, and the pH monitoring indicates that the reactor operate normally.

Abstract: In this project, limestone dust from a limestone crushing plant was mixed with several pottery clays from the Northeasetern part of Thailand, i.e., Ban Ponsai, Ban Tha Hai, Ban Nanuan and Ban Nam Kamnoi. The limestone dust was sieved and then mixed with 4 sources of clays at 50 wt%. Samples with and without limestone dust were sintered at 700°C for 1 h. Compared to the samples without limestone dust, the samples with limestone dust showed higher flexural strength and slightly higher water absorption, but lower linear firing shrinkage. Furthermore pottery was produced using the mixture of pottery clay and limestone dust.

Abstract: Bio-demulsifier has not been applied in industrial scale due to its production cost. In order to reduce the production cost and improve the efficiency of demulsification, cheap materials such as oilfield sludge, workshop waste oil and edible waste oil were used in experiments as carbon sources to culture PRJ-1 demulsifying bacteria. As a result, cell concentrations of 5.4g/L, 3.7g/L and 4.2g/L were gotten, which were higher than the concentration of 2.6g/L cultivated by using paraffin. PRJ-1 demulsifying bacteria were used to prepare the demulsifying solution with a concentration of 10g/L, which was used in the demulsification experiment on Liaohe crude oil with a water cut of 80%. With 100 ml/L being added into the crude oil, the demulsification efficiency at 12h reached 91%, which was higher than that of 100mg/L chemical demulsifier. Demulsification efficiency of 96% can be achieved by using the combination of 60ml/L demulsifying bacteria and 40mg/L chemical demulsifier, furthermore, the demulsifying speed was higher and dehydrated water was clearer.

Abstract: 2-acrylamido-2-methylpropane sulfonic acid (AMPS) is commonly used in the synthesis of polyacrylamide which is widely used as surface-active agents, water treatment chemicals and oil-displacing agents. In the production process of AMPS, there are some byproducts. In this paper, the residue from AMPS production is analyzed. The main byproducts in the residue are ascertained by means of HPLC and ESI-MS, which are butylacrylamide (TBAA) and acrylamide. By external standard method, the residue is analyzed quantitatively. Using the residue as raw materials, a kind of polyacrylamide with low molecular weight is synthesized, which can be used as paper reinforcing agent or emulsifier. After the residue is purified, the high molecular weight polyacrylamide is synthesized, which can be used as flocculating agent or oil-displacing agent.