Bioremediation by Composting of Heavy Oil Refinery Sludge in Semiarid Conditions

The present work attempts to ascertain the efficacy of low cost technology (in our case, composting) as a bioremediation technique for reducing the hydrocarbon content of oil refinery sludge with a large total hydrocarbon content (250–300 g kg⁻¹), in semiarid conditions. The oil sludge was produced in a refinery sited in SE Spain The composting system designed, which involved open air piles turned periodically over a period of 3 months, proved to be inexpensive and reliable. The influence on hydrocarbon biodegradation of adding a bulking agent (wood shavings) and inoculation of the composting piles with pig slurry (a liquid organic fertiliser which adds nutrients and microbial biomass to the pile) was also studied. The most difficult part during the composting process was maintaining a suitable level of humidity in the piles. The most effective treatment was the one in which the bulking agent was added, where the initial hydrocarbon content was reduced by 60% in 3 months, compared with the 32% reduction achieved without the bulking agent. The introduction of the organic fertiliser did not significantly improve the degree of hydrocarbon degradation (56% hydrocarbon degraded). The composting process undoubtedly led to the biodegradation of toxic compounds, as was demonstrated by ecotoxicity tests using luminescent bacteria and tests on plants in Petri dishes.     

城市污泥好氧堆肥过程中积温规律的探讨

对城市污泥好氧堆肥稳定化过程的温热条件进行了探讨 ,将物候学中的积温概念应用于堆肥稳定化 (腐熟 )过程。它同时兼顾到堆肥过程中的温度强度和持续时间两个参数。对于采用的强制通风静态垛堆肥工艺 ( CTB自动控制堆肥工艺 ) ,建议以 1 5℃作为生物学零度 ,积温指标为 1 0 0 0 0℃· h左右。堆肥原料的性质、堆肥工艺、微生物种群、生物学零度、外界环境等因素可能会对积温产生一定影响     

油橄榄加工废液对小麦和玉米种子萌发及相关酶活性的影响

用不同稀释倍数的油橄榄加工废液(OMWS)处理小麦和玉米种子,采用计数法、测量法和比色法测定了发芽率、根长和相关生化参数,以探索OMWS对种子萌发特性及相关酶活性的影响。结果表明:不同稀释倍数的OMWS对小麦和玉米种子的发芽率、发芽势和生长存在不同程度的影响;低稀释倍数(高浓度)的OMWS(原液和5倍稀释液)在抑制种子发芽的同时,对叶芽和根的生长存在延缓甚至毒害作用;随着稀释倍数的提高(浓度降低),这种抑制作用逐渐减弱,而高稀释倍数(30和50倍稀释液)处理则表现出一定程度的促生作用,这种影响存在浓度依赖性。OMWS处理同样可导致种子可溶性蛋白质含量以及过氧化氢酶(CAT)、过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活性的变化,呈现高浓度抑制和低浓度诱导增强的趋势;OMWS处理后小麦和玉米根的生长与POD和PAL活性存在明显正相关性。研究认为,OMWS对小麦和玉米种子的发芽及生长存在高浓度抑制和低浓度诱导的双重作用,并可能以多酚的影响为主;鉴于OMWS中多酚及其氧化产物可能产生的高浓度抑制、植物毒性和低浓度诱导化感作用,其在用做有机肥料或土壤改良剂时应做适当稀释处理。     

Effects of olive mill wastewater addition in composting of agroindustrial and urban wastes

In order to study the suitability of olive mill wastewater (OMW) for composting, thisliquid waste was added to two different mixtures of agroindustrial and urban wastesand the composting process was compared with two other piles of similar composition,but without OMW. These four piles were studied in a pilot plant using the Rutgers staticpile system. The addition of OMW produced a greater proportion of degradable organic matter or a higher degradation rate, higher electrical conductivity values, greater losses of total N and lower nitrification than in piles without OMW. Its addition also restricted the increase of the cation exchange capacity and provoked the appearance of phytotoxicity or a longer persistence of phytotoxicity. However, in general, all the composts showed increases in the cation exchange capacity, the percentage of humic acid-like carbon, the polymerisation ratio of these humic substances (which revealed that the organic matter had been humified during composting) and the germination index, the latter indicating the reduction of phytotoxicity during the process.