硫酸酸洗废水处理与回用工艺设计

通过对吉林某汽车标准配件厂的废水进行处理及回用研究,设计了该厂酸洗废水处理及回用工艺,工程建设投资86.0万元,运行费用331 400元/a,挽回资金流失1 463 550元/a,当年即可回收投资并创造可观的经济效益.通过加酸冷冻结晶法实现了酸洗废水中废酸回用的目的,并且有效地回收了FeSO4·7H2O,以进一步用于聚合铁等其他产品的生产,达到废物利用、生产用水零排放的目的.     

Toxicity attenuation of olive mill wastewater in soil slurries

Olive mill wastewaters are toxic for plants and microbes due to their high polyphenol content. We studied the effect of agricultural soil as a natural catalyst to promote polyphenol oxidation and polymerization, and in turn detoxify olive mill wastewaters. We show that model polyphenols are fully converted in soil slurries. Their products show no toxicity to the growth of a typical soil bacterium, Bacillus cereus, and reduced phytotoxicity in germination tests with English cress seeds. Those findings are promising for the sustainable treatment of olive wastewater in aerated soil slurries.     

Polyphenols dynamics and phytotoxicity in a soil amended by olive mill wastewaters

The effects of unprocessed olive mill wastewaters (OMW) on soil characteristics were investigated. Phenolic compounds levels in the treated soil were compared to those of a control soil profile. Results showed that OMW infiltration caused a modification of soil physicochemical characteristics. Phenolic compounds were detected at a depth of 1.2m four months after the last application of OMW. A moderate phytotoxic residual phenolic fraction (F) was extracted from the superficial soil layer 1 year after the OMW application. This residual F had a phytotoxic potential comparable to that of 25-fold diluted OMW.     

Performance of a stratified sand filter in removal of chemical oxygen demand, total suspended solids and ammonia nitrogen from high-strength wastewaters

A stratified sand filter column, operated in recirculation mode and treating synthetic effluent resembling high-strength dairy wastewaters was studied over a 342-d duration. The aim of this paper was to examine the organic, total suspended solids (TSS) and nutrient removal rates of the sand filter, operated in recirculation mode, under incrementally increasing hydraulic and organic loading rates and to propose a field filter-sizing criterion. Best performance was obtained at a system hydraulic loading rate of 10 L m(-2) d(-1); a higher system hydraulic loading rate (of 13.4 L m(-2) d(-1)) caused surface ponding. The system hydraulic loading rate of 10 L m(-2) d(-1) gave a filter chemical oxygen demand (COD), TSS, and total kjeldahl nitrogen (TKN) loading rate of 14, 3.7, and 2.1 g m(-2) d(-1), respectively, and produced consistent COD and TSS removals of greater than 99%, and an effluent NO(3)-N concentration of 42 mg L(-1) (accounting for an 86% reduction in total nitrogen (Tot-N)). As the proportional surface area requirement for the sand filter described in this study is less than the recommended surface area requirement of a free-water surface (FWS) wetland treating an effluent of similar quality, it could provide an economic and sustainable alternative to conventional wetland treatment.     

Heavy Metals Removal by Biosorption and Flotation

The removal of a mixture of heavy (toxic) metal cations (copper, nickeland zinc) from liquid effluents was investigated in this study at pilotscale, using counter-current contact mode. The innovative processinvolved the abstraction of metal ions onto fungal biosorbents, followedby the application of flotation for the subsequent solid/liquid separationof biomass particles. The ability of microorganisms to remove metal ionsfrom aqueous solutions is a well-known phenomenon. Nevertheless,engineering considerations are very important in decisions, concerningthe commercial future of biosorption and practical solutions are neededfor certain problems, such as the efficient post-separation ofmetal-loaded biomass. The two processes (flotation and biosorption) caneffectively operate in combination, in what it was termed biosorptiveflotation process. The sorbents may be recycled, after appropriate elutionof metals, as well as the treated (clean) water.     

循环微电解法处理染料废水的研究

采用循环微电解法处理染料废水,测量水样的COD值、pH值、色度等指标.结果表明,色度去除率可高达95%,且脱色迅速;COD值的去除率约为60%.使用循环微电解法可以对染料废水进行预处理,很大程度上提高废水的可生化性,为染料废水的进一步生化处理创造条件.     

Multivariate Statistics of the Pyrolysis Products of High Molecular Components in Pulping Wastewaters to Explain Their Toxicity (6 pp)

Background, Aim and Scope At present, large-scale paper manufacture involves delignification and bleaching by elemental chlorine free (ECF) or totally chlorine free (TCF) processes. The wastewater is purified by secondary treatment (mechanical, chemical and biological) which removes most of the toxic substances from the discharge. However, we found residual toxicity in the high molecular (> 1000 D) matter (HMWM) of the discharge by test of the RET (reverse electronic transfer) inhibition. This fraction consists mainly of polydisperse lignin (LIG) and carbohydrate (CH) macromolecules. Structural units in these molecules are studied by pyrolysis gas chromatography / mass spectrometry (Pyr-GC/MS). In the present work, our aim was to find out those structural units which could explain the RET toxicity of LIG or CH molecules. We compared statistically RET toxicity values of the HMWM samples from treated wastewaters of pilot pulping experiments and intensity variation of the pyrolysis product gas chromatograms of these samples. This application is a novel study procedure. Methods Pyrolysis products (Py-GC/MS results) and inhibition of RET (reverse electronic transport toxicity) as TU50 and TU20 of HMWM (High Molecular Weight Material; Mw > 1000 D) were compared by multivariate statistics. The samples were from laboratory pilot stages of TCF (Totally Chlorine Free) and ECF (Elemental Chlorine Free) manufacture of softwood pulp. Py-GC/MS was done without and with addition of TMAH (Tetra Methyl Ammonium Hydroxide). The name and structure of each abundant fragment compound was identified from its retention time and mass spectrum compared to authentic reference compounds or literature. Four sets of Toxicity Units (TUs) and GC peak areas of the pyrolysis fragments were obtained. The data were normalized by division with LIG (lignin content of each sample). TU values were dependent and the fragment values independent (explanatory) variables in statistical treatments by SPSS system. Separate analyses of correlations, principal components (PCA) and stepwise multiple linear regression (SMLR) were performed from the four sample sets TCF and ECF with and without TMAH. Results and Discussion From the CH fragments, 2-furfural in TCF, and from the LIG fragments, styrene in ECF showed the highest probabilities to originate from source structures of toxicity. Other possible compounds in concern were indicated to be CH fragment 2-methyl-2-cyclopenten-1-one in ECF and LIG fragments 2-methoxy-4-methylphenol, 4,5-dimethoxy-2-methylphenol and 2-methylphenol in TCF.     

Immunotoxic potential of aeration lagoon effluents for the treatment of domestic and hospital wastewaters in the freshwater mussel Elliptio complanata

Municipal wastewaters are major sources of pollution for the aquatic biota. The purpose of this study was to determine the levels of some pharmaceutical products and the immunotoxic potential of a municipal wastewater aeration lagoon for the treatment of the domestic wastewaters of a small town with wastewater inputs from a 400-bed hospital complex. Endemic mussels were collected, caged and placed in the final aeration lagoon and at sites 1 km upstream and 1 km downstream of the effluent outfall in the receiving river for a period of 14 days. The results showed that the final aeration lagoon contained high levels of total coliforms, conductivity and low dissolved oxygen (2.9 mg/L) as well as detectable amounts of trimethoprim, carbamazepine, gemfibrozil, and norfloxacin at concentrations exceeding 50 ng/L. The lagoon effluent was indeed toxic to the mussel specimens, as evidenced by the appearance of mortality after 14 days (10% mortality), decreased mussel weight-to-shell-length ratio and loss of hemocyte viability. The number of adhering hemocytes, phagocytic activity, total nitrite levels and arachidonic cyclooxygenase activity were significantly higher in mussels placed in the final aeration lagoon. A multivariate analysis also revealed that water pH, conductivity, total coliforms and dissolved oxygen were the endpoints most closely linked with phagocytic activity, the amount of adhering hemocytes and loss of hemocyte viability. In conclusion, exposure of mussels to treated aerated lagoon wastewater is deleterious to freshwater mussels where the immune system is compromised.     

利用废水和固体废弃物中有机质发酵产氢研究进展

总结了发酵法产氢的机理、微生物种类、产氢菌的富集方法 ,综述了利用废水和固体废弃物中有机质生物发酵产氢的最新研究进展及存在的问题     

糖蜜、淀粉与乳品废水厌氧发酵法生物制氢

采用连续流厌氧发酵法研究了糖蜜废水、淀粉废水与牛奶废水生物制氢,讨论了有机物中3大类物质的厌氧发酵产氢的可行性,并对几种底物的产氢稳定性进行了探讨.结果表明,糖蜜废水与淀粉废水都是较好的厌氧发酵法生物产氢底物,在3大类有机物中碳水化合物是目前技术条件下最具有可能性的原材料.在碳水化合物中,溶解性好的糖比溶解性差的淀粉在目前的技术条件下具有生物产氢可行性,而淀粉比溶解性糖更具有产氢前景.不同底物厌氧生物制氢的生态位范围有所不同,对于溶解性好的糖,稳定运行的工程控制参数为pH 4.5±0.3,而溶解性较差的淀粉废水为pH 4.0±0.2;厌氧发酵产氢的ORP值也随底物的不同而不同,但总体必须低于-220mV,在-300mV左右时较好.牛奶废水不适用于作为CSTR反应器中发酵法生物制氢底物.