Effect of carbon to nitrogen ratio of food waste on biogas methane production in a batch mesophilic anaerobic digester

Food waste mixture at carbon to nitrogen (C/N) ratio 17 was combined with meat, fruits and vegetable wastes to increase its C/N ratio to 26 and 30 before anaerobic digestion. Results showed that biogas methane yield obtained during the digestion increased from 0.352L/gVS, 0.447L/gVS and finally to a maximum yield of 0.679 L/gVS at C/N ratio of 17, 26 and 30, respectively. A maximum food waste treatment efficiency of 85% was obtained at C/N ratio 30. Generally, increase in C/N ratio through co-digestion resulted in a more stable pH and better methanogenic activity due to enhanced buffering effect of the digestion medium

Effect of feed loading on biogas methane production in batch mesophilic anaerobic digesters treating food waste

Food waste mixture upgraded to a carbon to nitrogen ratio of 30 was co-digested at different feed loadings of 0.5, 1.5, 3.5 and 5.5gVS/L in batch and mesophilic conditions (37oC). Results showed that the production of biogas methane increased with an increase of the feed loading to the digester. A maximum cumulative biogas methane yield of 0.535L/gVS was attained at feed loading of 3.5gVS/L. Generally, it was observed that higher feed loading to the digester led to pH reduction and a decrease in treatment efficiency from 96% to 75%

Effect of feedstock carbon to nitrogen ratio and organic loading on foaming potential in mesophilic food waste anaerobic digestion

Foaming problem which occurred occasionally during food waste (FW) anaerobic digestion (AD) was investigated with the Malaysian FW by stepwise increase in organic loading (OL) from 0.5 to 7.5 g VS/L. The FW feedstock with carbon to nitrogen (C/N) ratio of 17 was upgraded to C/N ratio of 26 and 30 by mixing with other wastes. The digestion which was carried out at 37 °C in 1-L batch reactors showed that foam formation initiated at OL of 1.5 g VS/L and was further enhanced as OL of feedstock was increased. The digestion foaming reached its maximum at OL of 5.5 g VS/L and did not increase further even when OL was increased to 7.5 g VS/Ld. Increase in the C/N ratio of feedstock significantly enhanced the microbial degradation activity, leading to better removal of foam causing intermediates and reduced foaming in the reactor by up to 60 %

Economic Impact of Galma Irrigation Scheme on the Farming Community in Dakaci, Zaria Area of Nigeria

Irrigation scheme is introduced for socioeconomic development of the community where it is based. One of such is the Galma Irrigation Fadama Project III around River Galma in Zaria Local Government Area of Kaduna State, Nigeria. The project provides water to surrounding communities for farming. This study was carried out with a view to determine the socioeconomic impact of the irrigation scheme on farming community in Dakaci, Zaria Area of Kaduna State. The study used data acquired from questionnaire survey, interviews and other secondary sources. Relevant data which include method of land acquisition, sources of capital, size of farmland, source of labor, major crops grown, average annual crop yield and average annual income were collected. The data were analyzed using simple descriptive statistics. The study revealed that the irrigation scheme to a large extent boosted crop yields and agricultural production in the area thereby improving the socioeconomic status of the farmers in the area. It is therefore recommended that more of such projects should be introduced to improve agricultural productivity. Moreover, there is the need for timely evaluation and assessment of such projects to maintain their proper functioning. In addition, government should refurbish the canals distributing the water to the farmlands, and also provide credit facilities to the farmers in order to improve their agricultural productivity which would help in ensuring food security for the nation at large

Economic Impact of Galma Irrigation Scheme on the Farming Community in Dakaci, Zaria Area of Nigeria

Irrigation scheme is introduced for socioeconomic development of the community where it is based. One of such is the Galma Irrigation Fadama Project III around River Galma in Zaria Local Government Area of Kaduna State, Nigeria. The project provides water to surrounding communities for farming. This study was carried out with a view to determine the socioeconomic impact of the irrigation scheme on farming community in Dakaci, Zaria Area of Kaduna State. The study used data acquired from questionnaire survey, interviews and other secondary sources. Relevant data which include method of land acquisition, sources of capital, size of farmland, source of labor, major crops grown, average annual crop yield and average annual income were collected. The data were analyzed using simple descriptive statistics. The study revealed that the irrigation scheme to a large extent boosted crop yields and agricultural production in the area thereby improving the socioeconomic status of the farmers in the area. It is therefore recommended that more of such projects should be introduced to improve agricultural productivity. Moreover, there is the need for timely evaluation and assessment of such projects to maintain their proper functioning. In addition, government should refurbish the canals distributing the water to the farmlands, and also provide credit facilities to the farmers in order to improve their agricultural productivity which would help in ensuring food security for the nation at large

Effects of carbon to nitrogen ratio and organic loading rate on biogas methane production from anaerobic digestion of food waste

This study has been concerned with an investigation of biogas methane generation from the abundant food waste (FW) available in Malaysia by anaerobic digestion (AD) process at mesophilic (35oC) conditions. Methane recovered from FW digestion is a source of renewable energy for heat and electricity generation. The biogas generation was carried out in batch digesters and then in 2 semi-continuous mode digesters. The semi-continuous mode digesters consists of a 1000L pilot scale (PS) digester up-scaled from a 10L laboratory scale (LS) anaerobic digester. The key parameters investigated were the effect of carbon to nitrogen (C/N) ratio and the organic loading rate (OLR) of the FW on the biogas methane production. The FW was fed to the digesters at different OLR of 0.5-5.5 g VS /L d in the semicontinuously fed LS and PS digesters and at OL of 0.5-7.5 g VS /Ld in the batch digester. Using a constant hydraulic retention time (HRT) of 12.5 days, each OLR was investigated during the semi-continuous process. Three C/N ratio values of 17, 26 and 30 were studied at batch scale while two C/N ratio values of 17 and 30 were studied during the semi-continuous AD in the LS and PS. The available FW gathered from restaurants around Taman Sri Serdang was at C/N ratio 17. The C/N ratio 26 and 30 fed were formulated by mixing the available FW with calculated proportions of Fruits, vegetables and meat wastes to increase its C/N ratio value. Performance evaluation parameters for AD process such as the COD removal, VS destruction, volatile fatty acids, alkalinity, ammonia-nitrogen and the biogas methane yield were studied during the 30 days batch and 168 days semi-continuous AD process. The highest methane yield obtained from the batch digestion was 0.557 L/g VS fed at an OLR of 5.5 g VS /Ld during the digestion of FW of C/N=30. This compares with the maximum methane yield of 0.510 L/g VS fed obtained at OLR of 5.5 g VS /Ld in the LS digester during the semi-continuous digestion of FW at C/N=30. The maximum methane yield obtained in the PS digester was 0.392 L/gVS at OLR of 4.5gVS/Ld during the digestion of FW at C/N=30. The methane yield attained in the up-scaled PS digester was about 80% of that obtained in the LS. Results showed that process stability and digester treatment performance during semi-continuous digestion was higher during the digestion of FW at C/N=30 than at C/N=17. Foaming potential tests revealed that foaming was initiated during digestion at OLR of 1.5 g VS/Ld in all the feedstock digested. However, the highest foaming volume of 26% recorded was during the digestion of FW of C/N=17 at OLR of 7.5 g VS/Ld. The feedstock with C/N=30 had the least foaming tendency with foaming volume of 10% at OLR of 7.5 g VS/Ld