Statistical regression modeling for energy consumption in wastewater treatment

Wastewater treatment is one of critical issues faced by water utilities, and receives more and more attentions recently. The energy consumption modeling in biochemical wastewater treatment was investigated in the study via a general and robust approach based on Bayesian semi-parametric quantile regression. The dataset was derived from a municipal wastewater treatment plant, where the energy consumption of unit chemical oxygen demand (COD) reduction was the response variable of interest. Via the proposed approach, the comprehensive regression pictures of the energy consumption and truly influencing factors, i.e., the regression relationships at lower, median and higher energy consumption levels were characterized respectively. Meanwhile, the proposals for energy saving in different cases were also facilitated specifically. First, the lower level of energy consumption was closely associated with the temperature of influent wastewater, and the chroma-rich wastewater also showed helpful in the execution of energy saving. Second, at median energy consumption level, the COD-rich wastewater played a determinative role in the reduction of energy consumption, while the higher quality of treated water led to slightly energy intensive. Third, the higher level of energy consumption was most likely to be attributed to the relatively high temperature of wastewater and total nitrogen (TN)-rich wastewater, and both of the factors were preferably to be avoided to alleviate the burden of energy consumption. The study provided an efficient approach to controlling the energy consumption of wastewater treatment in the perspective of statistical regression modeling, and offered valuable suggestions for the future energy saving.     

Removal of cyanobacterial blooms in Taihu Lake using local soils. I. Equilibrium and kinetic screening on the flocculation of Microcystis aeruginosa using commercially available clays and minerals

Algal removal abilities of 26 clays/minerals were classified into three categories according to the 8-h equilibrium removal efficiency (Q8h) and removal rate at a clay loading of 0.7 g/L. Type I clays (sepiolite, talc, ferric oxide, and kaolinite) had a Q8h > 90%, a t50 (time needed to remove 50% of the algae) < 15 min, and a t80 < 2.5 h. Type II clays (6 clays) had a Q8h 50-90%, a t50 < 2.5 h, and a t80 > 2.5 h. Type III clays (14 clays) with Q8h < 50%, t50 > 8 h and t80 > 14 h had no practical value in removal of algal blooms. When the clay loading was reduced to 0.2 g/L, Q8h for all the 25 materials decreased to below 60%, except for sepiolite whose Q8h remained about 97%. The high efficiency for sepiolite to flocculate M. aeruginosa cells in freshwaters was due to the mechanism of netting and bridging effect.     

Fenton试剂在处理难降解有机废水中的应用

介绍了Ferton试剂的作用机理,探讨了不同外界因素对该技术处理效果的影响,对该试剂在实际中的应用进行阐述。并提出Fenton试剂的研究方向。     

某二高线通风改造实践研究

根据自然通风原理,对某二高线厂房进行了通风改造,主要从以下三方面人手：在进风窗下增设百页进风口、用通风栅栏代替封闭平台以及扩大天窗喉口。改造前后气流及温度分布的实测结果表明,改造后工作区的热环境得到了较大的改善,气流分布均匀,温度下降明显,提高了人体舒适性。     

工业锅炉环境污染控讨与控制

对工业锅炉运行中造成环境污染的因素及危害进行分析,结合实际,制定了减少危害的措施。     

[HPMo][OTAC]2/SiO2的制备及其催化柴油氧化脱硫的研究

采用溶胶-凝胶法制备不同负载量的[HPMo][OTAC]2/SiO2,通过红外光谱、比表面积和孔结构分析对[HPMo][OTAC]2/SiO2进行表征,考察负载量、催化剂用量、氧化剂用量、反应温度和反应时间对模拟柴油脱硫效果的影响。结果表明,掺杂后的催化剂保持了Keggin结构,[HPMo][OTAC]2/SiO2在最佳反应条件下,苯并噻吩的脱除率达到48.3%,二苯并噻吩的脱除率达到67.2%。     

Reaction mechanism of arsenic capture by a calcium-based sorbent during the combustion of arsenic-contaminated biomass: A pilot-scale experience

Pilot-scale combustion is required to treat arsenic-enriched biomass in China. CaO addition to arsenic-enriched biomass reduces arsenic emission. CaO captures arsenic via chemical adsorption to form Ca₃(AsO₄)₂. Large quantities of contaminated biomass due to phytoremediation were disposed through combustion in low-income rural regions of China. This process provided a solution to reduce waste volume and disposal cost. Pilot-scale combustion trials were conducted for in site disposal at phytoremediation sites. The reaction mechanism of arsenic capture during pilot-scale combustion should be determined to control the arsenic emission in flue gas. This study investigated three Pteris vittata L. biomass with a disposal capacity of 600 kg/d and different arsenic concentrations from three sites in China. The arsenic concentration in flue gas was greater than that of the national standard in the trial with no emission control, and the arsenic concentration in biomass was 486 mg/kg. CaO addition notably reduced arsenic emission in flue gas, and absorption was efficient when CaO was mixed with biomass at 10% of the total weight. For the trial with 10% CaO addition, arsenic recovery from ash reached 76%, which is an ~8-fold increase compared with the control. Synchrotron radiation analysis confirmed that calcium arsenate is the dominant reaction product.     

Personal exposure to PM2.5-bound heavy metals associated with cardiopulmonary function in general population

Environmental Science and Pollution Research - To better understand the cardiopulmonary alterations associated with personal exposed PM2.5-bound heavy meals, we conducted a cross-sectional study in...