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71.
This paper compares the quantity and quality of solid waste obtained from traditional ponds and recirculating aquaculture systems (RAS) for striped catfish and evaluates methane and compost production from these wastes. Striped catfish sludge was collected from four commercial ponds along the Mekong river and from three indoor RAS. The amount of sludge dry matter produced per kilogram of fish in ponds was 6 times higher than that in RAS. However, the concentration of nutrients in solid waste from RAS was much higher, with better compost quality and higher methane yield than that of sludge from ponds. Out of the collected 381 L biogas, the methane yield of striped catfish’s solid waste in RAS systems was 201 L per kg chemical oxygen demand (COD). In ponds, the collected 267 L biogas yielded 125 L CH4 per kg COD. The higher methane production from RAS sludge concurred with higher digestibility of COD: 58% for RAS versus 38% for ponds. The quality and quantity of methane from striped catfish sludge were lower than that for other animal manures, and the resulting electricity yield was low. Considering the higher nutrient concentration in RAS-sludge, we recommend the combination RAS and composting in reusing sludge, which is presently the best option for a more sustainable and cleaner striped catfish production system. 相似文献
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73.
为了研究污泥发酵基和HM发酵基对堆肥的作用效果,以牛粪为原料,加入麦秆为调理剂,设置4个处理,接种不同剂量的发酵基进行室内堆肥。经过30 d的堆肥处理,4个堆体总磷含量变化差异不显著,有效氮和有效磷含量对照堆体中增量最大;相比于对照堆体,只加入HM发酵基的堆体在升温期的升温速率最高,只加入污泥发酵基的堆体高温期温度最高,腐殖质下降幅度最大,总氮损失较多;同时加入2种发酵基的堆体高度和有机物含量下降最多。结果表明,加入2种发酵基的堆体效果最优,且可实现污泥的资源化利用,堆肥原料中污泥、牛粪和发酵基的干质量比为10∶4∶0.002 5。 相似文献
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75.
[目的]探讨超声波和微波联用对污泥厌氧消化的促进作用。[方法]在单因素试验的基础上,通过正交试验寻找超声波和微波联用促进污泥厌氧消化的最优条件组合。[结果]超声波和微波联用能促进污泥的厌氧消化,而且超声波和微波之间表现出一定的协同效应。最优的联用条件是:500 mL污泥先用超声波(120 W)处理3.5 min,再用微波(450 W)处理4min。该联用条件能使污泥中的细胞全部破碎,经过10 d的厌氧消化后,其累积产气量比对照样增加了270%。[结论]超声波和微波联用能促进污泥的厌氧消化。 相似文献
76.
将城市污泥施加于干旱区黄土中,进行小麦盆栽试验,用Tessier连续提取法对土壤镉(Cd)的形态分布进行分析,同时研究了污泥堆肥对小麦各部位Cd含量及Cd赋存形态的影响。主要得到以下结论:随Cd胁迫水平的升高,不施加污泥的对照中小麦各部位生物量无显著变化,而施加污泥的处理下的小麦根、茎叶、颖壳及籽粒均表现出生物量先增大后减小的趋势。施加不同配比污泥的土壤中,小麦各部位Cd含量均随Cd胁迫浓度的升高而升高,各部位相较,根茎叶壳籽粒;随着Cd处理水平的增大,Cd活性增强,对作物的潜在危害增大;施加污泥后残渣态和有机结合态的分配系数显著增高,碳酸盐结合态降低,污泥的施用增加了不可利用态Cd的含量;无论施加污泥与否,Cd的总再分配系数均随着Cd胁迫水平的增加呈递增趋势,而结合强度系数呈递减趋势;施加污泥后Cd的总分配系数变小,结合强度系数变大,说明施加污泥降低了Cd的活性。施加污泥处理下,小麦各部位对Cd吸收的主要贡献形态为可交换态。 相似文献
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78.
杨国栋 《农业环境科学学报》1999,18(1):3
采样分析了污灌区铬的土壤环境背景值,计算了铬的土壤环境容量以及用含铬皮革废水污灌和施用含铬污泥后铬在土壤中的积累和残留量。 相似文献
79.
Microbiological and chemical changes in two arable soils after long-term sludge amendments 总被引:7,自引:0,他引:7
Sludge amendments increase the input of carbon and nutrients to the soil. However, the soil concentrations of heavy metals
and xenobiotica can also increase due to sludge amendments, with possible effects on soil microorganisms and soil fertility.
Therefore, we studied the effects on soil microorganisms and soil chemistry in two arable soils after 12 and 16 years of sewage
sludge amendment (0, 1 and 3 dry matter ha–1 year–1). The sludge amendments were combined with nitrogen addition at three rates according to crop requirements, and all combinations
were replicated 4 times, giving a total number of 36 parcels at each experimental site in a non-randomised block design. Univariate
data evaluation as well as principal component analysis and discriminant function analysis (DFA) were used to identify differences
between treatments in microbial and chemical parameters. The DFA showed that acid and alkaline phosphatase, potential ammonium
oxidation and total nitrogen were the most important parameters to discriminate between a priori defined groups of sludge
treatments. Among the heavy metals, copper showed the highest increase in soil concentration with sludge amendments, but this
increase was still not high enough to have a significant influence on the measured parameters. None of the xenobiotica investigated
was found in high soil concentrations. In conclusion, the present study showed that the sewage sludge affected several of
the biological and chemical parameters investigated. However, no severe negative effects on soil microorganisms were detected
at these moderate levels of sludge amendment.
Received: 3 December 1998 相似文献
80.
重庆污水处理厂污泥特性分析 总被引:6,自引:1,他引:5
[目的]为科学合理进行污泥处置奠定基础。[方法]以重庆市10个具有代表性的污水处理厂的污泥为样品,对其进行含水率、pH值、有机质和重金属含量分析。[结果]总体上所采集污泥是一种富含有机质(平均为296.84 g/kg)、高氮(平均为48.33 g/kg)、中磷(平均为18.94 g/kg)、低钾(平均为14.17 g/kg)的养分含量颇高的有机肥。pH值在5.95~7.73,处于微酸性和微碱性之间,在园林土壤中施用,不会对土壤的酸碱度造成大的影响。污泥中含水量较高(平均为77.8%),不宜直接施用。污泥中含有Pb、Cr、Cd、Cu、N i、Zn、Hg等重金属,但含量不高,只有个别区县的污泥中重金属含量稍微超标。[结论]对污泥性质的分析为污泥的资源化利用提供了参考。 相似文献