Assessment of the Heavy Metal Pollution Effects on the Soil Respiration in the Baix Llobregat (Catalonia, NE Spain)

A main goal of investigations is to determine could a soilrespiration be an indicator of the soil pollution. In this case a measured levelof the soil oxygen consumption depends of its pollution. It alsomeans that the pollution reduces biological processes in edaphon.Investigated soil samples were taken from polluted andnon-polluted places in the Baix Llobregat near Barcelona (Catalonia, NE Spain). Soil samples were taken from the top ofsoil (0–5 cm) without a litter. Soil analysis were done, determining percentage shares of coarsefragments, coarse sand, fine sand, coarse silt, fine silt, clay,CaCO₃, organic matter as well as water pH and conductivityCE (1:5 [mS cm^-1]). Also were determined (in mg kg^-1)quantities of heavy metals, as Fe, Al, Mn, Zn, Cr, Ni, V, Cu, Cd, Pb.The soil respiration was investigated in temperatures15 and 30 °C and with controlled humidity.The respiration in 30 °C is number of times greater thenin 15 °C both for polluted and non-polluted soils.Particularly high coefficients of correlation between the soilrespiration and soil pollution in polluted soils were obtainedfor Pb: r = 0.75 in 15 °C and r = 0.98 in30 °C; for Ba: 0.90 and 0.57; for V: 0.99 and 0.81. In non-polluted soils highest correlation coefficients are for Pb: r = 0.70 in 15 °C; Fe: 0.60 and 0.72; Al: 0.68 and0.64; Mn: 0.51 and 0.66; Ba: 0.63 and 0.61; Cr: 0.94 and0.70; Ni: 0.64 and 0.65; Cu: 0.69 and 0.48; as well as V: 0.62in 15 °C; and Cd: 0.69 in 15 °C.This way the soil respiration could be a good indicator of the soil pollution.     

用呼吸仪监测取代酚类化合物对活性污泥的抑制

应用呼吸仪测定活性污泥中微生物的活性。研究了九种取代酚对微生物活性的影响,发现抑制效应与有机物的正辛醇-水分配系数、最低未占轨道能级有着相关联系,并发现取代酚对活性污泥硝化细菌比起异养细菌有着更强的抑制。生物膜比活性污泥具有更好的耐抑制能力,驯化对抗抑制有明显的效果,增大污泥浓度在一定程度上可以减轻毒害。     

Starch- polyvinyl alcohol crosslinked film— performance and biodegradation

Starch-PVOH cast films were prepared with and without crosslinking agent (hexamethoxymethylmelamine) in the absence of plasticizer. Moisture absorption in films without crosslinking agent at a low relative humidity was similar to that of PVOH and increased as the relative humidity increased. Films with crosslinking agent showed moisture absorption linearly proportional to the relative humidity. Significant improvement in resistance to water disintegration for crosslinked starch-PVOH films was observed. While the tensile strength decreased with increased relative humidity, crosslinking significantly improved the tensile strength. Increased PVOH content improved elongation of films even when the relative humidity was 80% or higher. Biodegradation studies revealed that the degradation rate was negatively correlated with the PVOH content in films and crosslinking generated more converged degradation curves. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

渗滤液生化特性在Fenton处理过程中的变化

采用电解呼吸仪分析早、晚期渗滤的生化特性在Fenton过程前后的变化。根据BOD累积曲线 ,由非线性最小二乘法求解出第一阶段生化需氧量BODu 和一级生化动力学常数K。结果表明早期渗滤液易于生化降解 ,经Fenton氧化后 ,由于产生了毒性更强的中间产物 ,渗滤液的驯化时间反面延长 ,K值也略有下降。晚期渗滤液很难生化降解 ,经Fenton处理后其生化特性得到很大的改善。     

Assessing the biodegradation potential of polymers in screening- and long-term test systems

This paper presents a test scheme for assessing the biodegradation potential of polymers, starting with aquatic screening systems (aerobic and anaerobic) and continuing to long-term systems. At the end of the scheme the material has to prove its behavior under the relevant disposal conditions. Aerobic screening was performed mainly under aquatic conditions, but also in soil, using BOD-respirometry. Carbon balances were performed to obtain a better evaluation of the biodegradation potential. Under anaerobic conditions, biodegradation in an aquatic medium was followed by measuring CH₄ and CO₂ production. Polymers not fully degraded in the screening systems were tested in aquarium systems for at least 1 year. Biodegradation was followed by monitoring the DOC released in the water, mass loss, and microbial growth on the samples and in the water as well as via FTIR spectroscopy and SEM pictures. Results are presented for the polymers PHB, PHBV, PCL, Mater-Bi AI05H and ZF03U, and Bioceta. By combining the data from the screening with the aquarium system, a good picture of the degradation behavior of the polymers is obtained.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.     

城市污水处理厂活性污泥呼吸速率的研究

利用差压仪分别测定了5个污水处理厂曝气池混合液的内源呼吸耗氧量,同时设计了密闭投加醋酸钠的差压仪测定方法,测定了投加醋酸钠后的外源呼吸耗氧量。不同污水处理厂污泥呼吸性能有较大差异,比基质内源呼吸在14～42mgO2/（g MLVSS.d）范围变化,投加有机物后比外源呼吸在120～450mgO2/（g MLVSS.d）范围变化。不同污水处理厂之间的内源呼吸耗氧速率OUR的大小和挥发性污泥浓度MLVSS的高低没有必然联系,但比内源呼吸OUR高的污泥有较强的基质去除能力,表现出较强的比外源呼吸能力。提高污泥内源呼吸能力就可以实现城市污水处理厂节能减排。     

ECOSUNIDE工艺中活性污泥生物代谢活性的测定研究

利用差压仪测定原理,设计了在差压瓶中密闭投加基质的试验方法,测定了ECOSUNIDE工艺和其它4个不同工艺的污水处理厂曝气池混合液中活性污泥的生物代谢能力,通过内源呼吸速率和投加基质后的外源呼吸速率来表达生物代谢能力,采用各自的比呼吸速率用来比较单位污泥浓度的生物代谢活性能力。研究结果表明,具有高效脱氮除磷能力的ECOSUNIDE工艺中活性污泥在1～2 d时段内的比内源呼吸速率为43 mg O2(/gVSS.d),投加醋酸钠和氨氮后比外源呼吸分别为450和283 mg O2(/gVSS.d),均高于其它不同工艺的普通进水方式污水处理厂混合液相应的呼吸速率。该工艺在提高活性污泥中异养菌和自养菌代谢能力,缩短污染物去除时间上有较明显的优势。     

ECOSUNIDE工艺活性污泥中自养菌浓度的测定与分析

设计并利用在差压仪中密闭投加基质的实验方法,根据ASM模型中自养菌和硝化过程耗氧速率的关系,对比研究了ECOSUNIDE工艺和其他4个污水处理厂曝气池混合液中自养菌的浓度。研究表明,在不考虑自养菌增长和衰减情况下,ECOSUNIDE工艺混合液自养菌生物浓度为48.15 mg COD/L,该结果显著高于其他受试污水处理厂的混合液自养菌生物浓度(17.2～37.5 mg COD/L),表明ECOSUNIDE工艺在提高活性污泥中自养菌生物浓度上有较强的优势。设计的实验方法可以简便、有效地测定用于ASM模型中的自养菌浓度。     

焦化废水中难降解有机物的共代谢降解特性

针对焦化废水中的几种主要难降解有机物吡啶、萘、氯苯、苯、二苯酚等 ,利用瓦氏呼吸仪测定微生物耗氧量的方法 ,对它们在单基质和共基质条件下的可生化性进行了实验研究 ,初步了解了共代谢降解焦化废水中难降解有机污染物的生理生化特性 ,为焦化废水深度处理作了有益的探索     

应用瓦勃氏技术研究工业污水的可生化性

本文应用瓦勃测试技术对沈阳市西部污水及其１０个重点工业污染源１８个排污口污水的可生化性进行了研究，对可生化性级别及生化毒性作出了判定．