Theoretical Analysis of Biogas Production from Septic Tanks: The Case of the City of Kinshasa

As many think that respect for the environment, is not only a question intended for industrialists but has all the sectors of life, in particular sanitary also. In this regard, our article brings alternative management of human waste (excrement) to solve the problems that plague our dear beautiful capital, namely: 1) Lack of latrines that meet the standards;2) Emptying of septic tanks directly into the gutters and;3) Water pollution by sewage csompanies. In order to carry out the cartographic analysis of the study area, we used Shapefile data from the OpenStreetMap, Diva-Gis. These different data allowed us, analyzed, to categorize with the software ArArcGIS 0.8.1 to produce different zones according to the cases incurred in the city of Kinshasa. To do this, the analytical method uses the Buswell equation to determine the amount of gas contained in human excrement. Focusing on the analysis of the excrements produced by the population of age superior to 10 years, for 2023, we obtained: 138355.7283 m3/day of CH4 (885476.66 kWh/day or 885.476 MWh/day), which, energy can light: 138,355 lamps of 60 to 100 W for six hours or nearly 70,000 lamps of 60 to 100 W for 12 hours. Considering the last one which offers the lowest access rate, i.e. 3% of the district population to these latrines, we have: a) In Tshangu, we produce: 1618.762 3>/day (10360.07 kWh/day or 10.36 MWh/day) which can light nearly 1600 lamps from 60 to 100 W for six hours or nearly 800 lamps from 60 to 100 W for twelve hours. b) Mont-Amba, we produce 1402.927 3>/day (8978.73 kWh/day or 8.97 MWh/day) which can light nearly 1400 lamps from 60 to 100 W for six hours or nearly 700 lamps from 60 to 100 W for twelve hours;c) In Lukunga, we produce: 946.35 3>/day (6056.66 kWh/day or 6.056 MWh/day) which can light nearly 900 lamps from 60 to 100 W for six hours or nearly 450 lamps from 60 to 100 W for twelve hours. d) Funa, we produce: 182.629 3>/day (1168.83 kWh/day or 1.17 MWh/day) which can light almost 180 lamps from 60 to 100 W for six hours or almost 90 lamps from 60 to 100 W for twelve hours.

MnO_(2)/carbon nanocomposite based on silkworm excrement for high-performance supercapacitors

MnO_(2)/biomass carbon nanocomposite was synthesized by a facile hydrothermal reaction.Silkworm excrement acted as a carbon precursor,which was activated by ZnCl_(2) and FeCl_(3) combining chemical agents under Ar atmosphere.Thin and flower-like MnO_(2) nanowires were in-situ anchored on the surface of the biomass carbon.The biomass carbon not only offered high conductivity and good structural stability but also relieved the large volume expansion during the charge/discharge process.The obtained MnO_(2)/biomass carbon nanocomposite electrode exhibited a high specific capacitance(238 F·g^(-1) at 0.5 A·g^(-1))and a superior cycling stability with only 7% degradation after 2000 cycles.The observed good electrochemical performance is accredited to the materials’high specific surface area,multilevel hierarchical structure,and good conductivity.This study proposes a promising method that utilizes biological waste and broadens MnO_(2)-based electrode material application for next-generation energy storage and conversion devices.

南极无冰区生态与环境变化在粪土层中的记录

The accumulative profiles of seabird and sea animal excrement together with the depositional sequences influenced by the excrement have been utilized to reconstruct the historical populations of Antarctic penguins and seals, also to study the eco-geology in the ice-free areas of Antarctica and Arctic. The historical populations of Antarctic penguins show dramatic fluctuations, the period of sharp decrease coincides well with Neoglaciation, and extremely cold or warm climate conditions are unfavorable for the survival of Antarctic penguin. The historical change of seal population seems to be related to climatic variations, sea-ice coverage and its forage behavior. The fluctuations of Hg (mercury) in the seal hairs and the sediments influenced by seal excrement were found to be closely associated with ancient gold and silver mining activities and the ancient civilization over the past several thousand years.

Analysis and Countermeasure on Present Conditions of Animal Excrement Pollution in Heilongjiang Province

Attaching more importance to the problem of animal excrement pollution is the premise of realizing the sustainable development of animal husbandry in Heilongjiang Province. With the constant expansion of the scale of breeding industry, the amount of animal excrement will increase greatly, corresponding to the increasing pressure on water and land. Therefore, for the sake of promoting the coordinated development of animal husbandry and the environment, this paper analyzed the status of animal excrement pollution in Heilongjiang Province. On this base, the paper suggested that we must control animal excrement pollution proceeding from reality by using administrative means, legal means, economic means and technical means.

Elemental and Isotopic Signatures in the Sediments Influenced by Seal Excrement on Antarctic Fildes Peninsula and Their Potential Paleoecological Applications

The elemental and isotopic signatures in the sediments influenced by seal excrement on Antarctic Fildes Peninsula are examined for their potential palaeoecologlcal applications. The seal hair abundance in sediments exhibits remarkable fluctuation versus depth, indicating similar changes in historical populations of the seals visiting the marine terrace. The combination of δ^13 C, total organic carbon concentration （TOC）, total nitrogen concentration （TN） and atomic C/N ratio shows that the organic matters in sediments with numerous seal hairs have a marine origin and are predominantly derived from seal excrements. The large δ15 N values in sediments are attributed to trophic enrichment and NH3 vollatilization processes. The large variations in the δ^15 N values and the negative correlation between the δ15 N values and the seal hair abundances seem to be the results of changes in the paleoclimates and the volatilization rates of the ammonia produced in the seal excrements. The 87 Sr/86 Sr ratios in the acid-soluble fraction of sediments are interpreted as a mixture of the ones from the seal excrements （30%-50%） and the chemically weathered local bedrocks （70%-50%）. The calculated proportion of seal-derived Sr based on the ^87 Sr/^86 Sr ratios has a significant correlation with seal hair abundances in sediments. These results suggest that δ15 N values and the ^87 Sr/^86 Sr ratios in the acid-soluble fraction of sediments were influenced by seal excrements, similar to seal halt numbers, and thus can potentially be used to estimate the historical seal population in the Antarctic region.

Experimental Method for Measuring Non-toilet Mountaineer＇s Excrement

The increasing number of mountain climbers made them a significant source of anthropopression. The paper is focused on the devastating impact of non-toilet human waste on high-mountain environment and discusses the scale of this phenomenon. Four male members, of mean age 31.5 （±0.5） years, volunteered for this study. The study was conducted above 12,286 feet （3,745 m）, and consisted of 12 days of measuring human excrement output, as well as calorie and liquid consumption. The average results showed the amount of human excrement remains left by climbers in high-mountain environment on a daily scale; i.e., feces of approximately 128 g （32 g without water） and approximately 1.8 L of urine. During this study, the average daily diet consisted of 4,000 （± 500） calories and average 3.6 （± 1.1） quarts （3.8 ± 1 L） of water. Based on these data, an example calculation of quantitative values of human feces and urine left by climbers in 2013 on Denali （Mount McKinley） was conducted. Results show that the 1,151 people that climbed Denali within 18 days （the mean residence time in the massif） left behind over 660 kg of feces and more than 37 thousand liters of urine in the massif in 2013 alone.

Research Progress on Production of Chlorophyll and Other Products with Silkworm Excrement and Industrial Development over the Past 50 Years

The development of sericultural industry in the Pearl River Delta has contributed greatly to good ecological environment and economic prosperity of the people’s livelihood.Comprehensive utilization of sericulture resources can turn waste into valuable resources and expand the development approaches of sericultural industry.For example,using abundant silkworm excrement to produce chlorophyll is one of the good practices in comprehensive utilization of sericulture resources,which has leading technologies and good economic benefits.In addition to chlorophyll,the products produced from silkworm excrement can be used as the main raw materials of medicine,food,plant growth regulator and cosmetics.For instances,phytol,the important raw material for synthesis of vitamin E and vitamin K,was extracted from silkworm excrement,enabling China to become an important production base of vitamin E and vitamin K.Triacontanol extracted from silkworm excrement is a new crop growth regulator,which can increase the yield of rice and vegetable.Pectin,dietary fiber and carotenoid extracted from silkworm excrement as well can be used as natural raw material in many fields.China is the biggest manufacturer and supplier of silkworm excrement products in the world,which has a development history of about 50 years and generated high export revenue.It is believed that close combination of academic research and industry development is the only way to promote the industrial development of silkworm excrement resources.

Utilization of human excrement in pre-modern China,its theoretical interpretations and ecological significance

The use of human excrement as fertilizer is a characteristic of traditional Chinese agriculture..The application of excrement from urban residents in agriculture since the Song Dynasty has ensured the cleanliness and hygiene of ancientChinesecities.As early as the Ming Dynasty,the Chinese people defined the principle of fertilizing fields with human excrement from the perspective of materialcirculation.The concept Peri-URban ecosystems(PURE)provides inspiration forurban-rural symbiosis regarding circulareconomy.The use of human excrement in fertilization is a major attribute differentiating the Chinese traditional agriculture from the agriculture in other regions around the world.Despite the fact that the exact record showing that human excrement was used as fertilizer in China emerged in the Western Han Dynasty(B.C.202-A.D.8),such records did not become prevalent until the Southern Song Dynasty(A.D.1127-1279).In the Ming and Qing eras(A.D.1368-1912),human excrement was even considered"top-class fertilizerand servedas themost essential fertilizerin farmland fertilization.The importance of human excrement in the Ming and Qing was mainly reflected by farmers'purchase of human excrement from urban areas.As fertilization practices became increasingly popular during the period,men of letters built a localized theoretical system centering on human excrement.Although the use of human excrement had both positive and negative impacts on public health and the ecological environment,the positive overshadowed the negativeas a whole.Today,it is worth pondering on how the utilization of human excrement as an agricultural resource can be improved so that a material cycle system can be rebuilt to re-connect the urban and rural areas.

Microbiome analysis reveals soil microbial community alteration with the effect of animal excretion contamination and altitude in Tibetan Plateau of China

The fertile forages in the Tibetan Plateau provide natural conditions for animal husbandry,whereas it is still unclear that whether animal excretion can result in the alteration of soil microbial community.Therefore,this study was performed to investigate the impact of animal excretion contamination and land altitude on the soil microbial community in different grazing areas of Tibetan Plateau.A total of 1160,190 high-quality valid sequences and 25,478 operational taxonomic units were achieved from 18 samples at three different altitude sites(Linzhi,Rikaze and Shannan).Here,we found excremental contamination did not alter the richness and diversity of soil microbial community,but it resulted in a significant alteration in the proportion of some bacteria.Specifically,the proportion of Proteobacteria in the LZa was obviously increased,whereas Gemmatimonadetes was significantly decreased as compared to LZe.Moreover,significant difference can also be observed in Verrucomicrobia between RKZe and RKZa.Remarkably,we also found that excremental contamination significantly decreased the abundance of some bacterial genera,such as Sphingopyxis,Polycyclovorans,Singulisphaera Cohnella,Polycyclovorans,Defluviicoccus,and Arthrobacter,which were closely related to soil health,pollutant degradation,and nutrient metabolism.Importantly,excremental contamination increased the proportion of harmful and beneficial bacteria in soil,such as the percentage of Acidibacter,Gemmatimonadaceae and Pajaroellobacter increased,while the ratio of Pontibacter,Flavisolibacter,Parasegetibacter,and Niastella decreased.Remarkably,soil samples collected from different altitude sites also displayed different soil microbial community structures.Our results demonstrated that excremental contamination could alter the soil microbial community structure and affect the normal function of the soil by affecting the proportion of harmful bacteria to beneficial bacteria.Moreover,this study can also provide a theoretical basis for the establishment of a supervision system for soil quality in Tibet.

Design and synthesis of novel water-soluble amino acid derivatives of chlorin p6 ethers as photosensitizer

Eight new water-soluble amino acid conjugates 6 a-h of chlorin p6 ethers(5 a-d) were synthesized and preliminarily investigated for their in vitro PDT antitumor activity and structure-activity relationship(SAR). The results showed that all compounds exhibited much higher phototoxicity against tumor cells than talaporfin. SAR analysis indicated that PDT antitumor effect enhanced with the increase of carbon chain length of alkoxyl ether bonds at 3~1-position, and L-aspartic acid was superior to L-glutamic acid. In particular, the IC_50 values of most phototoxic compound 6 d were 0.20 mmol/L against A549 cell and0.41υmmol/L against B16-F10 cell, which individually represented 31-and 24-fold increase of antitumor potency compared to talaporfin, suggesting that it was a promising candidate photosensitizer(PS) for PDT applications due to its strong absorption at long wavelength, high phototoxicity, low dark cytotoxicity and good water-solubility.