Valorization of rendering industry wastes and co-products for industrial chemicals,materials and energy: review

Over the past decades, strong global demand for industrial chemicals, raw materials and energy has been driven by rapid industrialization and population growth across the world. In this context, long-term environmental sustainability demands the development of sustainable strategies of resource utilization. The agricultural sector is a major source of underutilized or low-value streams that accompany the production of food and other biomass commodities. Animal agriculture in particular constitutes a substantial portion of the overall agricultural sector, with wastes being generated along the supply chain of slaughtering, handling, catering and rendering. The recent emergence of bovine spongiform encephalopathy (BSE) resulted in the elimination of most of the traditional uses of rendered animal meals such as blood meal, meat and bone meal (MBM) as animal feed with significant economic losses for the entire sector. The focus of this review is on the valorization progress achieved on converting protein feedstock into bio-based plastics, flocculants, surfactants and adhesives. The utilization of other rendering streams such as fat and ash rich biomass for the production of renewable fuels, solvents, drop-in chemicals, minerals and fertilizers is also critically reviewed.     

Edible mushrooms from olive oil mill wastes

The biological remediation of olive oil mill wastes has been attempted several times in the past through the use of different types of microbes. Among them, a relatively large array of fungi were studied for neutralizing the heavy pollutant effects and/or for converting these wastes into new value-added products. The present investigation was aiming at examining whether olive oil mill wastes could be exploited for the cultivation of mushrooms of the genus Pleurotus. At a preliminary stage, two Pleurotus species, i.e. P. eryngii and P. pulmonarius, were tested for their ability to colonize an olive press-cake (OPC) substrate supplemented with various dilutions of raw olive mill wastewater (OWW). Some important cultural characters related to mushroom production (earliness, yield, biological efficiencies and quality of basidiomata) were estimated. The outcome revealed different cultural responses for each Pleurotus species examined; the P. pulmonarius strain showed better earliness values and P. eryngii, although it was a slow growing fungus, produced basidiomata in high yields and of a very good quality. On the other hand, the OPC substrate supplemented with low concentrations of OWW (12.5% v/w) behaved satisfactorily as regards the fungal colonization rates and mushroom yield, but when the addition of higher rates of raw, untreated OWW (75–100% v/w) was attempted then the Pleurotus strains were completely unable to grow. The optimal concentration of OWW for Pleurotus mycelial growth was assessed through measurements of the biomass produced in liquid nutrient media and was found to lie within the 25–50% range, depending on the Pleurotus species and on the properties of the substrates examined. Furthermore, the phytotoxic effects that the spent liquid medium possessed were examined in comparison with the phytotoxicity of the raw liquid waste. The prospects of exploiting olive oil mills wastes for mushroom cultivation is discussed.     

Bioprospecting microbes for single-cell oil production from starchy wastes

Production of lipid from oleaginous yeast using starch as a carbon source is not a common practice; therefore, the purpose of this investigation was to explore the capability of starch assimilating microbes to produce oil, which was determined in terms of biomass weight, productivity, and lipid yield. Saccharomyces pastorianus, Rhodotorula mucilaginosa, Rhodotorula glutinis, and fungal isolate Ganoderma wiiroense were screened for the key parameters. The optimization was also performed by one-factor-at-a-time approach. Considering the specific yield of lipid and cell dry weight yield, R. glutinis and R. mucilaginosa showed superiority over other strains. G. wiiroense, a new isolate, would also be a promising strain for starch waste utilization in terms of extracellular and intracellular specific yield of lipids. Extracellular specific yield of lipid was highest in R. glutinis culture (0.025?g?g^?1 of biomass) followed by R. mucilaginosa (0.022?g?g^?1 of biomass) and G. wiiroense (0.020?g?g^?1 of biomass). Intracellular lipid was again highest in R. glutinis (0.048?g?g^?1 of biomass). The most prominent fatty acid methyl esters among the lipid as detected by GC-MS were saturated lipids mainly octadecanoic acid, tetradecanoate, and hexadecanoate. Extracellular lipid produced on starch substrate waste would be a cost-effective alternative for energy-intensive extraction process in biodiesel industry.     

Determining the level of total nitrogen in wastes from the microbiological industry]

Optimization of the Kjeldahl method for determination of total nitrogen in the objects of microbial synthesis was performed in regard to biomass of the benzylpenicillin-producing culture, activated sludge and certain organic compounds. Mathematical processing of the data was carried out, which showed that the difference in the mean values for the five tested conditions of mineralization was insignificant. The method is useful in assaying the final and intermediate products as well as the waste in biotechnological production.     

秦渭玫瑰精油研究

采用ISO9842和GB11538-89对在陕西渭南栽培的大马士革玫瑰“卡赞勒克”精油(工业化蒸馏法提取产品)进行了分析,结果表明,精油产品各项指标均符合ISO 9842和保加利亚БДС653标准要求。证明引种国际香型(纯甜型)玫瑰品种在陕西渭南栽培是成功的,所用精油提取工艺是合理的。     

Valorization of solid olive mill wastes by cultivation of a local strain of edible mushrooms

Olive oil industry generates huge quantities of solid olive mill wastes (SOMW), causing environmental damage. Cultivation of edible mushrooms, such as Pleurotus ostreatus is a valuable approach for SOMW valorization. A local strain mycelium (Tizi-Ouzou, Algeria) of P. ostreatus (LPO) was isolated from castor oil plants. Oyster mushroom spawn, produced on barley grains, was used to inoculate wet SOMW, steamed in a traditional steamer during 45 min. The mycelium growth rate on SOMW was first estimated in Petri dish by measuring the surface colonized by the mycelium. The fruit body yields were estimated on culture bags containing 2 kg each of SOMW inoculated at 7% (w/w). The local strain potential was compared with that of a commercial one. Both strains produced high-quality mushrooms, but with low yields. The supplementation of the SOMW with wheat straw at the rate of 10% and 2% of CaCO₃ had significantly enhanced the productivity of the two strains, multiplying it by 3.2 for LPO and by 2.6 for CPO.     

Biodegradation of petroleum-based oil wastes through composting

Composting of horse manure was used as a means of degradation of two oil wastes, oil sludge from petrol stations and petroleum residues from a refinery. Paraffin oil was chosen as a reference. Oil wastes decomposed to 78–93% during 4.5 months of composting. The degradation of the waste oils was higher than that of the reference paraffin oil and no difference was found between the two types of oil wastes concerning their decomposition. At the end of the experiment, most of the polyaromatic hydrocarbons had been degraded except pyrene, chrysene and dibenz(ah)anthracene. Gaseous losses of oil compounds through volatilisation from composts were found not to be significant.     

Effect of carbohydrates on possible utilization of wastes from antibiotic-manufacturing plants in the construction industry

Utilization of antibiotic manufacture waste containing a certain amount of carbohydrates in concrete preparation requires their control. It was shown that the content of not more than 0.5 per cent of carbohydrates in the waste had no unfavourable effect on the concrete hardening.     

Aerobic biodegradation and detoxification of wastewaters from the olive oil industry

Growth and polyphenol biodegradation by three microorganisms namely Geotrichum sp., Aspergillus sp. and Candida tropicalis were studied on olive mill wastewater (OMW). These three microorganisms were selected for their tolerance to the polyphenols. The biodegradation process of OMW was investigated in batch regime by conducting experiments where the initial concentration of chemical oxygen demand (COD) was varied. Furthermore, some tests were performed to determine the most important nutrients necessary for aerobic degradation of OMW. Average COD removals were 55.0%, 52.5% and 62.8% in wastewaters fermented with Geotrichum sp., Aspergillus sp. and C. tropicalis, respectively. The maximum removal of polyphenols was 46.6% (Geotrichum sp.), 44.3% (Aspergillus sp.) and 51.7% (C. tropicalis). In addition, significant decolorization was evident.     

Effect of ammonia content in the biodegradability of the salmon industry wastes

Lately, efforts put into solving the serious environmental problems caused by the accumulation of liquid, gaseous or solid industrial residues, have been greatly increased, being solid wastes the last ones to be considered. This work studies the anaerobic biodegradation of salmon waste produced by death in the farming process. The results obtained: 61.99% degradation (expressed in volatile solids abatement), with a methane productivity of 535.66?l?CH₄/kg_d.k. in studies done to samples with 1%?w/v of dry residue, show that the anaerobic technology is adequate to treat these wastes. Runs performed with higher solid contents (7, 13 and 20%?w/v) showed an ammonia accumulation, coming from protein degradation. They represent an upper limit of the system studied at a maximum value of ammonia nitrogen of 3.5?g/l attained, amount which hinders the further increase of solid matter in the tests. With the results obtained during this study, two inhibition models were analyzed (the Luong model and one proposed by the authors), which allow the prediction of the performance of the system studied.     

Assessing the efficiency of methods for the bioremediation of oil production wastes

The results obtained during the laboratory remediation modeling of oil-containing waste (652 g/kg) and natural radionuclides (Ra²²⁶, Th²³², and K⁴⁰) using the methods of landfarming, biostimulation, and bioaugmentation are given in the article. It is found that landfarming and biostimulation decrease the content of oil products and phytotoxicity of the waste. Landfarming is the most rapid process.     

Anticonflict effects of rose oil and identification of its active constituents

The present study investigates the pharmacologically active constituents of rose oil, which possesses anti-conflict effects. Analysis using GC/MS revealed that rose oil contains 9 substances that were identified as myrcene, benzyl alcohol, 2-phenethyl alcohol, citronellol, geraniol, citronellyl acetate, eugenol, geranyl acetate and methyl eugenol. We examined the effects of each of these substances using the Geller and Vogel conflict tests in ICR mice. Myrcene, benzyl alcohol and citronellyl acetate did not produce any effects in either tests. Geranyl acetate and methyl eugenol produced no effect in the Geller conflict test. Geraniol and eugenol decreased the response rate during the safe period of the Geller conflict test, but did not affect the response rate during the alarm period. In contrast, 2-phenethyl alcohol and citronellol, like rose oil, produced an increasing effect on the response rate during the alarm period in the Geller conflict test. In addition, both chemicals increased the number of electric shocks mice received in the Vogel conflict test in a manner similar to that of rose oil. Given that 2-phenethyl alcohol and citronellol produced the same anti-conflict effects in both tests as rose oil, we concluded that they are the pharmacologically active constituents of anti-anxiety-like effect of rose oil.     

Biodegradation of slop oil from a petrochemical industry and bioreclamation of slop oil contaminated soil

Slop oil, i.e. waste oil from a petrochemical complex, contains at least 240 hydrocarbon components, of which 54% are from C₅ to C₁₁ and the rest from C₁₂ to C₂₃. Of 22 isolated bacterial cultures that were able to degrade slop oil, seven could each degrade about 40% of the slop oil, and a mixture of all seven could degrade 50% in liquid medium. Bioaugmentation of soil contaminated with slop oil with the mixed bacterial culture gave up to 70% degradation of slop oil after 30 days. This compares with 40% degradation without bioaugmentation. Bioaugmentation led to a significant increase in counts of bacteria able to degrade slop oil. Wheat sown on bioaugmented soil germinated and grew better than on non-augmented soil and led to increased degradation of slop oil (up to 80%). This indicates the potential of mixed culture for bioremediation.     

Abnormalities in the tracheal gills of aquatic insects collected from streams receiving chlorinated or crude oil wastes

SUMMARY. Altered tracheal gills were found on some specimens of Phasganophora capitata (Plecoptera: Perlidae) and net-spinning caddisflies (Trichoptera: Hydropsychidae) collected from streams in New York State. At one location only the basal portion remained of the normally highly-branched structures. At another location the gills were impregnated with a tar-like substance. Chlorine and crude oil are the suspected causal agents.     

3种不同香型玫瑰精油特性的研究

依照ISO9842和保加利亚玫瑰精油标准(БДС653),对来自陕西渭南玫瑰产区栽培的3种不同类型玫瑰精油进行了分析研究。渭玫1号精油来自保加利亚的大马士革玫瑰品科“kazanlik”,渭玫2号、3号分别是来自摩洛哥的百叶玫瑰和中国苦水玫瑰。就得油率而言,1996～2000年连续5年的平均得油率以渭玫l号最高达0．42‰,不低于在保加利亚栽培的得油率。3种精油在外观、色泽上无差异,而香气差别明显。三者分别为纯甜型、清甜型和浓甜型。GC-MS对3种精油分析表明,前二种均分析出115种成分,渭玫3号精油仅得到105种组分,三者主成分类型一致。主成分香茅醇均符合ISO9842和БДС653标准。中国传统玫瑰油渭玫3号蜡质含量相对极低,仅为渭玫1号的8％。     

Sulphate-reducing bacteria and the offshore oil industry

Sulphate-reducing bacteria cause a variety of serious and costly problems in the offshore oil and gas industries. To minimize their harmful effects it is essential to understand the physiology and ecology of this group of organisms.