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221.
222.
高分子絮凝剂CPF的合成和用于生活污水处理研究 总被引:6,自引:0,他引:6
通过改变水溶液聚合配比、温度和时间等得出合成高分子絮凝剂CPF的最佳工艺条件.并将合成的CPF絮凝剂与5种无机絮凝剂进行复配,对生活污水进行絮凝处理,优化出CPF与无机絮凝剂的最佳复配方案.采用最佳复配方案,进行了絮体回用效果实验,为CPF絮凝剂在水处理中的应用提供了重要的科学依据. 相似文献
223.
Reduced emissions of acidifying pollutants have changed the acidification process, and as a result, forest soils and surface
waters are slowly recovering in Sweden. However, model calculations show that some areas may never recover completely unless
further measures, such as liming, are undertaken. Liming of surface waters (lakes, rivers and wetlands) has been successfully
practised in Sweden since the 1970s, but repeated treatments are necessary. A full recovery of acidified lakes and streams
without frequent liming is however not possible until soil acidification is reversed in the most strongly affected areas.
In this study, the recovery of acidified streams was examined using ‘the total catchment approach’ i.e. treatment of both
recharge and discharge areas. The aim was to compare the quantitative effect of different treatments on run off chemistry
and the recovery of brown trout. Catchments in southwest Sweden were treated with a combination of 2 tons of wood ash and
4, 6 or 12 tons of crushed limestone per hectare in 1998/1999. Treatment of both recharge and discharge areas resulted in
fast and significant changes in stream water quality, e.g. increased concentrations of calcium, higher pH and ANC and a decreased
concentration of inorganic aluminium. The initial changes were dependent on the distribution of the applied lime between discharge
and recharge areas rather than the average dose on the total catchment. Treatment of recharge areas only, resulted in smaller
but still significant effects on calcium, pH and ANC in stream water. Furthermore, there was an initial leaching of nitrate
but it was only minor compared with the elevated leaching that occurs after a clear-cut. As a result of the treatments, brown
trout is now successfully reproducing.
Olle Westling (deceased). 相似文献
224.
J. Bai K. R. Li D. Y. Liu J. Zhang H. F. Zhang G. S. Liu J. L. Li Z. Y. Li D. M. Gao 《Water, Air, & Soil Pollution: Focus》2007,7(6):673-681
The distribution patterns and factors affecting uptake rates and turnover times of dissolved inorganic nutrients by heterotrophic
bacterioplankton (HB) in Jiaozhou Bay were studied based on in situ surveys and laboratory culturing. The uptake rates of
dissolved inorganic phosphorus (DIP) and dissolved inorganic nitrogen (DIN) by HB are limited by the temperature of the water
and the concentration of dissolved organic carbon. The turnover times of DIP and DIN by HB are regulated by the concentrations
of the nutrients and the numbers of HB, which show significant spatiotemporal variability in Jiaozhou Bay. HB may aggravate
the P-limitation of phytoplankton by competing for phosphorus in summer in Jiaozhou Bay. HB play an important role in the
biogeochemical cycling of nutrients and may increase the N:P ratio and the accumulation of DIN, thereby accelerating the imbalance
of the N:P ratio in Jiaozhou Bay. 相似文献
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228.
Elisangela Heiderscheidt Jaakko Saukkoriipi Anna-Kaisa Ronkanen Bjrn Klve 《环境科学学报(英文版)》2013,25(4):659-669
The drainage of peatland areas for peat extraction,agriculture or bioenergy requires affordable,simple and reliable treatment methods that can purify waters rich in particulates and dissolved organic carbon.This work focused on the optimisation of chemical purification process for the direct dosage of solid metal salt coagulants.It investigated process requirements of solid coagulants and the influence of water quality,temperature and process parameters on their performance.This is the first attempt to provide information on specific process requirements of solid coagulants.Three solid inorganic coagulants were evaluated:aluminium sulphate,ferric sulphate and ferric aluminium sulphate.Pre-dissolved aluminium and ferric sulphate were also tested with the objective of identifying the effects of in-line coagulant dissolution on purification performance.It was determined that the pre-dissolution of the coagulants had a significant effect on coagulant performance and process requirements.Highest purification levels achieved by solid coagulants,even at 30% higher dosages,were generally lower(5%-30%) than those achieved by pre-dissolved coagulants.Furthermore,the mixing requirements of coagulants pre-dissolved prior to addition differed substantially from those of solid coagulants.The pH of the water samples being purified had a major influence on coagulant dosage and purification efficiency.Ferric sulphate(70 mg/L) was found to be the best performing solid coagulant achieving the following load removals:suspended solids(59%-88%),total organic carbon(56%-62%),total phosphorus(87%-90%),phosphate phosphorus(85%-92%) and total nitrogen(33%-44%).The results show that the use of solid coagulants is a viable option for the treatment of peatland-derived runoff water if solid coagulant-specific process requirements,such as mixing and settling time,are considered. 相似文献
229.
Kun Luo Ya Pang Dongbo Wang Xue Li Liping Wang Min Lei Qi Huang Qi Yang 《环境科学学报(英文版)》2021,33(10):201-216
Biochar as an emerging carbonaceous material has exhibited a great potential in environmental application for its perfect adsorption ability. However, there are abundant persistent free radicals (PFRs) in biochar, so the direct and indirect PFRs-mediated removal of organic and inorganic contaminants by biochar was widely reported. In order to comprehend deeply the formation of PFRs in biochar and their interactions with contaminants, this paper reviews the formation mechanisms of PFRs in biochar and the PFRs-mediated environmental applications of biochar in recent years. Finally, future challenges in this field are also proposed. This review provides a more comprehensive understanding on the emerging applications of biochar from the viewpoint of the catalytic role of PFRs. 相似文献
230.
利用从高硫煤矸石堆场浸出液中培养驯化获得的氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,A.f),通过静态实验,探讨添加不同量的碳酸盐岩对酸性硫酸盐体系中Fe2+生物氧化速率及次生铁矿物合成的影响.结果表明:添加10 g和30 g碳酸盐岩不会对体系中pH、氧化还原电位(ORP)和Fe2+生物氧化速率产生明显影响,但总铁(TFe)的去除率可从37%分别提高到55%和62%,矿物生成量也从8.17 g·L-1分别增加到12.03 g·L-1和13.69 g·L-1;同时,体系中合成的次生铁矿物相与不加碳酸盐岩时无明显变化,主要为黄铁矾和施氏矿物的混合物.随着碳酸盐岩添加量增至50、70和90 g时,体系pH快速上升,Fe2+生物氧化速率受到抑制,并产生大量结晶程度较好的硫酸钙,形成的铁矿物主要为纤铁矿或针铁矿.而适量的碳酸盐岩添加可使体系中产生Ca2+和Mg2+,从而影响次生铁矿物的合成.因此,在以碳酸盐岩为反应介质的酸性矿山废水处理工艺设计中,可通过添加A.f菌并控制碳酸盐岩投加量,强化系统中Fe2+生物氧化及次生矿物的合成,从而进一步提高反应系统对TFe的去除效果. 相似文献